The capacity of a polypeptide chain to engage in an amyloid formation process and cause a conformational disease is contained in its sequence. Some of the sequences undergoing fibrillation contain critical methionine (Met) residues which in vivo can be synthetically substituted by selenomethionine (SeM) and alter their properties.35]Aβ40, [SeM129]HuPrP(106–140) and [SeM134]HuPrP(106–140)), retarded assembly, modulation of polymer shape and retention of toxicity ([SeM112]HuPrP(106–140) to absence of effects ([SeM109]HuPrP(106–140)).Using peptide synthesis, biophysical techniques and cell viability determinations we have studied the effect of the substitution of methionine (Met) by selenomethionine (SeM) on the fibrillogenesis and toxic properties of Aβ40 and HuPrP(106–140). We have found that the effects display site-specificity and vary from inhibition of fibrillation and decreased toxicity ([SeMThis work provides direct evidence that the substitution of Met by SeM in proamyloid sequences has a major impact on their self-assembly and toxic properties, suggesting that the SeM pool can play a major role in dictating the allowance and efficiency of a polypeptide chain to undergo toxic polymerization. Protein conformational diseases share the occurrence of a basic misfolding event that leads to the accumulation of proteins or fragments thereof as distinct oligomeric self-assemblies with gained toxic functions Among the different strategies for modifying protein sequences, the replacement of Met residues by SeM is unique in that it occurs in the absence of changes at the nucleic acid level 35, through the oxidation of its side chain, modulates the oligomerization kinetics, the shape of the final polymer (oligomer vs amyloid fibril) and the neurotoxic function C) form the specific amyloid deposits 109, Met112, Met129, Met134) flanking either side of the palindromic AGAAAAGA region essential for assembly 109 and Met112 are not conserved in mammalian PrP sequences and their mutation to Val does not impede fibrillation while it regulates the processing at the α-cleavage site 129 and Met132 are polymorphic positions in human and deer, respectively, and their substitution by Val or Leu regulates the disease phenotype and the ability to recognize and amplify exogenous prions Of the various amyloid-forming sequences, the amyloid β peptides (Aβ40 and Aβ42) and the PrP(106–140) region are essential components of protein deposits in degenerative dementias and share the presence of regulatory Met residues 35 substitution in Aβ40, the presence of four methionines in HuPrP(106–140) allows to investigate the role of the replacement site on fibril formation. Herein we show that the substitution of Met by SeM in Aβ40 and HuPrP(106–140) regulates both amyloid formation and toxicity. For HuPrP(106–140), the inhibitory effect displays site-specificity, with the activity varying from inhibition of fibrillation and decrease in toxicity ([SeM35]Aβ40 and [SeM129]HuPrP(106–140)) to accelerated fibrillation and modulation of the polymer shape with retention of toxicity ([SeM109]HuPrP(106–140) and [SeM112]HuPrP(106–140)).To establish the role of Se intake as related to its specific incorporation as SeM into amyloid forming sequences, we have synthesized Aβ40 and HuPrP(106–140) sequences containing SeM as a replacement for Met. In contrast to the single Met35) in Aβ40 allowed an unambiguous SeM replacement, while the four  in HuPrP(106–140) required a more extensive investigation of the site-specificity of SeM replacement. Hence, the wt HuPrP(106–140) sequence with four SeM residues , a non-oxidizable variant sequence  with all four Met residues mutated to Val, plus four analogs with single SeM replacements at either position 109, 112, 129 or 134, and Val at the other positions, were prepared. While all seven peptide sequences are of a size generally regarded as viable for solid phase synthesis methodologies, their well-known tendency to aggregate clearly placed them in the “synthetically difficult” category 35]Aβ40, the O-acyl isopeptide approach 35]Aβ(1–40), was prepared and purified to near-homogeneity, then incubated at pH 7.4 to give the target peptide in precipitate form. For its part, HuPrP(106–140) , its all-Val counterpart and the four site-specifically SeM-substituted analogs were efficiently assembled by microwave-assisted solid phase synthesis on ChemMatrix®, a resin proven successful in preventing aggregation during the synthesis of large, complex peptides 35) or [SeM35]Aβ40 were incubated at 20–40 µM concentration in PBS in the presence of 15 µM ThT and the increase in fluorescence emission as consequence of its binding to cross β-sheets was monitored . 35, or can take place also in other sequences, we analyzed the effect of this substitution on the fibrillation properties of HuPrP(106–140). In this case, given the presence of four Met residues and the possible interference of undesired oxidations in long time incubations, we investigated a non-oxidizable version , as well as single SeM replacements with Val at the other positions [To ascertain whether the previous findings are uniquely related to the Aβ40 sequence and the essential role played by Metositions Figure 1129]PrP compared to [Met129]PrP and the higher propensity of [Met129]PrP(109–135) over its Val129 variant to form β-sheet stabilized fibers 109 behaves as an all-Val variant. On the contrary, placing SeM at position 112 significantly increases the lag time to 19.7±1.2 h with no effects in the maximum ThT intensity. Surprisingly, the introduction of SeM at position 129 drastically impairs the fibrillation process. Prolonged incubations (up to 1 week) yielded ThT intensity increases below 2.5 with averaged lag phases of >72 h. Along similar lines but to a lesser extent, placing SeM at position 134 allowed a slight fibrillation process featured by a final ThT intensity of 8 and a lag time of 31.5±2.0 h.109 and SeM112 versions of HuPrP(106–140) yielded fibrillar structures, of which those formed by SeM112 differed notably from the others by appearing as regular straight rods with a high homogeneity in length. On the contrary, the reaction product of the SeM129 analog yielded mainly amorphous aggregates with rarely the presence of fibrillar aggregates. The SeM134 peptide displayed an intermediate behaviour, showing few but detectable fibrillar assemblies. The aggregation profile was also studied by SDS-PAGE. 109 and SeM112 versions of PrP(106–140) yielded bands of SDS-resistant aggregated species, whereas SeM129 and SeM134 ran mainly as monomers.To confirm these findings we analyzed by AFM the products of the aggregation reactions HuPrP(106–140) forms fibrillar aggregates that differ notably from those obtained from all-M, all-V and SeM109 peptides. To gain an insight on the basis of this polymorphism, the fibrils were isolated from the aggregation reactions by centrifugation and, after resuspension, were characterized for their ThT binding on fibril molar basis and by far-UV CD for comparison with previous reports 129 and SeM134 peptides were not considered in this study given their failure to form fibrils with minimal efficiency.As noted above, . Importantly, no peaks at +16/+32 Da expected for the oxidized variants were detected Aβ40 with Aβ40 and with its longer and more fibrillogenic form Aβ42 impaired their fibrillation process [35]Aβ40 and at equal concentration, both Aβ40 and Aβ42 undergo fibrillation. Rather, the results agreed with an inhibition process and suggested that [SeM35]Aβ40 interacts with Met35-bearing peptides, and halts their productive aggregation through the formation of growth-impaired oligomers.Co-incubation of HuPrP(106–140), acting like a quencher, interacts with either all-M or all-V HuPrP(106–140), giving rise to oligoheteromeric species that do not sustain growth. This data agreed with previous findings indicating the essential role of identity in position 129 for the allowance of formation of a stable steric zipper Similarly, in the HuPrP(106–140) case, co-incubation of 10 µM SeM134]HuPrP(106–140), of very low efficiency in fibrillogenesis, when mixed with either all-M or all-V does not alter significantly the ThT binding pattern of the previous peptides Aβ40 and the SeM129 and SeM134-analogs of HuPrP(106–140) and their mixtures have completed their fibrillation process as judged by parallel ThT reading, and the untreated cells yielded cell viability values that amounted to 97.5±1%.To investigate the structure–activity relationship of the SeM substitutions we analyzed the effect of the aggregation reaction products on the viability of rodent primary cortical neurons Figure 735]Aβ40 reduced cell death to 3±1.5%, thereby excluding any relationship between its assemblies and the highly neurotoxic nonfibrillar oligomers formed by Aβ peptides 35]Aβ40 dilution as judged from the concentration control.Aβ40 was found to cause 11±1% cell death, in agreement with previous reports 109 and SeM112 analogs caused cell death to a similar extent, in agreement with their similar amyloid forming ability at long incubation times [129 and to a lesser extent SeM134 caused minor effects on cell viability . As in the case of [SeM35]Aβ40, these statistically significant reductions in the extent of cell death compared to that caused by the amyloid-assembled sequences discards active oligomeric species. Moreover, the aggregation products of the all-M and all-V peptides mixed with SeM129 and SeM134 reproduced the profiles observed in kinetic experiments Aβ40 and [SeM129]PrP(106–140)), polymerization kinetics perturbation to polymer shape determination ([SeM112]PrP(106–140)) [Unveiling the ways proamyloid sequences can be modulated to impede their productive engagement into self-assembly processes yielding toxic events is essential for designing preventing strategies for conformational diseases. The pioneer study of Goldschmidt et al 06–140)) Figure 835]Aβ40 and [SeM129]PrP(106–140) peptides, for which the crystal structure of shorter fragments have shown Met35 and Met129 actively participating in the inter-sheet packing 109 and SeM112 analogs of PrP(106–140) 134]PrP(106–140), which retains the ability to engage in the process but does it with a very low efficiency.Despite the consideration of Met and SeM as structurally equivalent, the change of a sulfur by a selenium atom involves major steric and reactivity differences. Se is slightly larger than S (atomic radius of 1.17 vs 1.04 Å) and has also a larger van der Waals radius (1.90 vs 1.80 Å).Since the spines of amyloid fibrils consist in steric zippers formed by the interdigitation of β-sheets through their side chains, any steric perturbation may lead to clashes which may reduce the stability of this unit or even preclude its formation SeM also differs from Met in its side chain oxidation process. SeM can undergo oxidation by peroxynitrites to selenoxide but, unlike the sulfoxide, the selenoxide is easily reduced by organic thiols as glutathione and does not required enzymatic assistance 129]HuPrP(106–140) analog, which in addition to its impaired fibrillation and lack of toxic activity, prevents the fibrillation and toxicity of all-V and all-M. For these two cases, the incorporation of SeM into an essential position functions as a physiological anti-amyloid metabolic defense. However, the effect of SeM incorporation is not homogeneous. For instance, the SeM109 and SeM112 analogs of HuPrP(106–140) displayed differences in kinetics and in fibril shape, and such morphological differences can have important functional implications 112 –shape are expected to be more toxic that fibrils with shapes of the SeM109-analog, whereas if fragmented the toxicity profile inverts −1 and 1.0×10−2 s−1 for Aβ40 and Aβ42, respectively) For Aβ40 the Met35SeM non-coded or metabolic mutation impairs amyloid formation but stabilizes oligomeric assemblies as shown by AFM. Based on shape considerations, the oligomers might be suspected to act as the actual neurotoxins. However, both PAGE-SDS analysis and toxicity evaluation discard such assemblies being deleterious and support the importance of the amyloid pathway as a source of toxic species. This rationale can be extended to the [SeMAs summarized in 2 for storage at −80°C. Samples were reconstituted in 5 mM NH4OH pH 8.0 at about 2 mg/ml concentration and filtered through 0.2 µm membranes before use. Peptide concentrations were determined by UV spectroscopy and by amino acid analysis. Peptide stock solutions were diluted with PBS at 100–200 µM concentrations and kept at 4°C for less than 30 min. The aggregation reactions were performed both in eppendorf tubes and in wells of a 96-well plate by incubating 20–200 µM peptide monomers in PBS at 30°C with orbital shaking (100 rpm).The SeM-substituted versions of Aβ40 and HuPrP(106–140)  were synThe kinetics of thioflavin T (ThT) binding was monitored by bottom reading of fluorescence intensity in a POLARstar microplate reader (BMG Labtech) as described Peptide samples before and after 80 h of aggregation were removed and diluted 1∶1 in β-mercaptoethanol-free Laemmli buffer and, omotting the thermal denaturation step, loaded in BioRad precastTGX-gels. After silver staining, gel images were captured and analyzed using the Molecular Imager ChemiDoc™ XRS+ Imaging system and ImageLab 3.0.1 (beta2) software (BioRad).−9 Torr and with OMEGA software.Aliquots of the peptide solutions before and after aggregation were removed, treated with HFIP for aggregate disruption and analyzed using α-hydroxy-cinnamic acid matrix and a MALDI FT-ICR 930-MS (Varian) instrument operating at 7 T and 102O and applied onto freshly cleaved mica surfaces to adhere for 15 min. After washing with ddH2O, samples were dried with N2. AFM imaging was then performed using a PicoSPM™ , operating the AFM scanner in acoustic alternating current mode with Si,N-ACT type cantilevers (ScienTec) with a tip radius <10 nm and a spring constant of 25–75 N/m Ten µl-samples of peptide solution after 70 h incubation were diluted to 2 µM with ddHCD spectra were recorded in the far-UV region with a Jasco J-810 spectropolarimeter in continuous scan mode (250−190 nm) and a 0.1 cm path length quartz cuvette (Hellma) as described previously Mice were obtained from the Centro de Biología Molecular and treated following the guidelines of Council of Europe Convention ETS123, recently revised as indicated in the Directive 86/609/EEC. Animal experiments were performed under protocols (P22/P23) approved by the Centro de Biología Molecular Severo Ochoa Institutional Animal Care and Utilization Committee . Primary cortical neurons were obtained from the cerebral cortex of C57B16 E18 rat embryos, by enzymatic dissociation with papain  in EBSS for 45 min at 37°C. Cells were resuspended in Neurobasal medium with 2% B27, 0.25% 200 mM Gln, 1% Glutamax and 1% penicillin/streptomycin and seeded on cover slips pre-coated with poly-D-Lys (10 µg/ml). Two days later, 5 µM Ara-C was added to the medium. Seven days later, peptides preincubated in PBS were added at a final concentration of 25 µM. After 48 h incubation at 37°C, neuronal cell death was determined using the LIVE/DEAD kit (Invitrogen) for mammalian cells. Live cells  and dead cells (stained with red-fluorescent ethidium homodimer-1) were counted and the percentage of dead cells calculated.Supporting Information S1(DOCX)Click here for additional data file.


P=0.01), and between HTLV-I carriers and healthy controls (P=0.02). The frequency of the low IL-10 producer haplotype  was significantly associated with HTLV-I carriage or HAM/TSP compared with healthy controls . Our results suggest that IL-10 -819*T and -592*A alleles are significant risk factors for developing HTLLV-I infection but do not appear to convey additional risk for developing HAM/TSP.The underlying mechanisms leading to the development of human T-cell lymphotropic virus type I (HTLV-I) associated myelopathy/tropical spastic paraparesis (HAM/TSP) in HTLV-I infected individuals are not fully understood. Host genetic factors appear to be involved as risk factors for developing HAM/TSP. We investigated the possible contribution of interleukin-10 (IL-10) as a risk factor to HAM/TSP by comparing frequencies of promoter region single nucleotide polymorphisms in HTLV-I infected Iranian patients who either remained asymptomatic or developed HAM/TSP and asymptomatic HTLV-I carriers. Healthy, uninfected individuals from the same region served as healthy controls. Significant differences were observed in the distribution of IL-10 promoter alleles and genotypes at position -819 and -592 between HAM/TSP patients and healthy controls ( Human T cell lymphotropic virus type I (HTLV-I) infection is a causative factor of two diseases; namely HAM/TSP and adult T cell leukaemia (ATL) , 2. EndeThe mechanisms underlying the etiopathogenesis of (HTLV-I) associated myelopathy/tropical spastic paraparesis (HAM/TSP) in HTLV-I infected individuals are poorly understood. Viral factors and host genetic background both may influence the outcome of HAM/TSP in HTLV-I infection. The type of HTLV-I virus in Mashhad is the same as that found in Japan . HoweverIt is possible that infection with HTLV-I alone is not sufficient to cause HAM/TSP and that differences in the genetic background of individuals may be crucial for determining the progression of HTLV-I pathogenesis. A number of possible candidate genes have been implicated in HTLV-I infection. Human leukocyte antigen (HLA) class I and II genes have been carefully investigated in Japanese cases -17. in vitro production of cytokines have been proposed as candidates for many infectious and non-infectious diseases. IL- 10 shows a variety of immunoregulatory properties, suggesting it is an important factor for maintaining immune and inflammatory responses. It inhibits the production of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-α 2SO4, 2.0 mM MgCl2, 0.01% Tween 20, and 0.2 mM of each of dATP, dCTP, dGTP, and DTT . Growth hormone primers were used as an internal control (10μl of each). A volume of 5.5 μl of DNA plus master mix reaction was aliquoted into microtiter plate wells containing 5 μl of one or the other specific primer mixes (10 μM each). The protocol for the PTC-100 PCR machine (MJ Research) was as follows: 1 minute at 96°C followed by 10 cycles of 15 secs at 95°C, 50 secs at 65°C, 40 secs at 72°C followed by 20 cycles of 20 secs at 95°C, 50 secs at 59°C and 50 secs at 72°C. The amplified products were visualized on a 2% agarose gel against 200 bp DNA ladders and stained with 5 μl (0.5 μg/ml) of ethidium bromide.1.5 μ of DNA (100-250 ng/ μl) was amplified in a 10 μl master mix solution containing 1.25 U Thermoprime Plus DNA polymerase, 75 mM Tris-HCl, 20 mM . The significance of differences in allele and haplotype frequencies between HAM/TSP patients and HTLV-I carriers, HAM/TSP patients and healthy controls and HTLV-I carriers and healthy controls were established using the Fisher exact test and by calculation of odds ratios (OR) with 95% confidence intervals (95% CI). The significance of genotype frequency differences between any of the three groups was determined by the Chi-squared test.The IL-10 -819*T allele is associated with HTLV-I carriage and HAM/TSPP=0.01; OR=1.67 (1.08-2.55) and in carriers compared with healthy controls . There was no significant difference between carriers and HAM/TSP patients . Furthermore, the frequency of the homozygous lower producer -819*T/T genotype was greater in the HAM/TSP patients  and carriers  than in controls (7.3%). The distribution of IL-10 -819*C/T allele and genotype frequencies in HAM/TSP patients, HTLV-I carriers and healthy controls were also examined. The frequency of the low IL-10 producer -819*T allele was higher in HAM/TSP patients (38%) and carriers (36.9%) compared with healthy controls (26.8%) . A signiThe IL-10 -592*A allele is associated with HTLV-I carriage and HAM/TSPBecause the IL-10 -819*C/T and the -592*C/A polymorphisms are very strongly linked, the result from the analysis of the -592 polymorphisms is identical to that described above. per se, and the IL-10 -819*C/T and -592*C/A polymorphisms, the genotypes of the HAM/TSP patients and HTLV-I carriers were combined. A highly significant association was identified in the genotype and allele frequencies compared with controls .To determine whether an association exists between HTLV-I infection, The IL-10 -1082 alleles are not associated with HTLV-I infection or HAM/TSP Allele and genotype frequencies of IL-10 gene polymorphisms  were determined in patients with HAM/TSP, healthy controls and HTLV-I carriers. The frequency of the high IL-10 producer -1082*G allele was the same in all three groups and no significant differences were observed between HAM/TSP and healthy controls, carriers and controls or between HAM/TSP and HTLV-I carriers .The IL-10 haplotype ‘ATA’ is associated with HTLV-I carriage and HAM/TSPP=0.02; OR= 1.59 (1.04-2.41) and in patients with HAM/TSP  compared with controls (26.8%). For HTLV-I infected individuals (HAM/TSP and HTLV-I carriers combined) a significant difference in ATA haplotype frequencies was observed compared with controls   . The possible influence of IL-10 genotype on HTLV-I infectionIL-10 may influence HTLV-I infection in several ways (a) because it has a variety of immunoregulatory functions and (b) because it is a differentiation factor for virus-specific cytotoxic T cells. For example, IL-10 inhibits CD80/CD86 expression by antigen presenting cells (APC), reducing the capacity of these cells to provide the co-stimulatory signals essential for T cell activation and cytokine production . Thus, tIn contrast, IL-10 acts as a T- cell differentiation factor, promoting the number of IL-2-activated cytotoxic T lymphocytes (CTL) . In the Our hypothesis was that, because polymorphisms in the IL-10 promoter region are related to IL-10 production, the IL-10 genotype of HTLV-I infected individuals might influence the pathogenesis of HTLV-I infection. Our study group was restricted to patients from an area in North Eastern Iran.IL-10 genotype is associated with HTLV-I infection, but not with HAM/TSP developmentIn this study we demonstrated that IL-10 -819*T and -592*A alleles were more frequent in HAM/TSP patients and HTLV-I carriers compared with healthy controls. Only the three anticipated IL-10 haplotypes, GCC, ACC and ATA were identified in the population from North East Iran. per se and not the development of HAM/TSP in a subset of infected patients. HTLV-I carriers and HAM/TSP patients were not significantly different for IL-10 allele or genotype frequency, although these HTLV-I infected groups, separately and collectively, were different from healthy, uninfected controls. These data therefore, suggest that low IL-10 production does not per se contribute to the development of HAM/TSP after HTLV-I infection. In a recent study  and Herpes Zoster (HZ) and human immunodeficiency virus (HIV) , 35, 36.. Genotype-phenotype interpretationin vitro evidence. It is a major assumption that the same association holds in vivo in HTLV-I infected patients. The serum levels of IL-10 in healthy controls, HAM/TSP patients and HTLV-I carriers are not known. This would have been informative in relation to IL-10 genotype and the role of IL-10 in HAM/TSP patients or HTLV-I carriers.The identification of low IL-10 producer genotypes is based on Another concern is that the -592*A/ -819*T alleles are associated with HTLV-I infection while the -1082 alleles are not. The -1082 polymorphism coincides with a binding site for ETS-1, a lymphocyte transcription factor, while the -592 polymorphism coincides with a PU-1 transcription factor expressed in cells of the monocyte lineage. Consequently, based on our findings, it may be that lymphocyte-derived IL-10 is not an important regulator of HTLV-I immunity, but macrophage or APC-derived IL-10 does influence responses to HTLV-I.Although we do not have information about the viral load of these patients, low production of IL-10 in HAM/TSP patients and HTLV-I carriers could be responsible for insufficient induction of a CTL response and perforin production, which is necessary for elimination of HTLV-I infected target cells. However, it is necessary to take into account that low IL-10 production induced a T helper response and may contribute to the HTLV-I elimination. Although this mechanism has been suggested in other viral infections such HIV , the resWe conclude that the IL-10 -819*C/T and -592*C/A polymorphisms may contribute to susceptibility to HTLV-I infection in an Iranian population, although it would not appear to be related to any additional risk ad protection for developing HAM/TSP.


In spite of these apparent similarities, HTLV-1 and HTLV-2 exhibit a significantly different pathogenic potential. HTLV-1 is recognized as the causative agent of adult T-cell leukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). In contrast, HTLV-2 has not been causally linked to human malignancy, although it may increase the risk of developing inflammatory neuropathies and infectious diseases. The present paper is focused on the studies aimed at defining the viral genetic determinants of the pathobiology of HTLV-1 and HTLV-2 through a comparison of the expression strategies and functional properties of the different gene products of the two viruses.Human T cell leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) are genetically related complex retroviruses that are capable of immortalizing human T-cells  Human T-cell leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) are related deltaretroviruses . The twoin vivo, they exhibit a significantly different pathogenic potential. HTLV-1 is recognized as the causative agent of adult T-cell leukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). In contrast, HTLV-2 has not been causally linked to human malignancy. However, large cohort studies revealed that HTLV-2 infection may be associated with lymphocytosis, increased risk of developing inflammatory neuropathies, infectious diseases, and with increased all-cause mortality .–93.91–93 Studies based on heterologous reporter plasmids mapped a CRS in the U5 region of HTLV-1 , 94. Due A further layer of complexity is added by a study that analyzed the postsplicing steps of HTLV-1 regulation by testing the expression of individual full length viral mRNAs in their intronless form. Results of this study showed that mRNA 1–3 (encoding p21rex), mRNA 1-2-3 (encoding Tax and Rex), and mRNA 1-2-B (encoding p30/tof) were inefficiently expressed when transcribed in their intronless form. The defective expression of these mRNAs was due to the inhibitory activity of the RXRE and the lack of a 5′ intronic region that counteracted the inhibitory effect of the RXRE. This cis acting stimulatory element (CSE) was mapped to the major splice donor and sequences overlapping with, but functionally distinct from, a previously described transcriptional enhancer . In addition to the CRS, other cis acting inhibitory elements (CIEs) were mapped within the gag-pol and env regions of the HTLV-1 genome . The inhBoth HTLV-1 and HTLV-2 produce truncated isoforms of Rex which lack the N-terminal arginine-rich RBD/NLS and are therefore predicted to be incapable of binding the RXRE and accumulate in the nuclear compartment. HTLV-1 produces a single truncated x-III ORF product termed p21rex, which also lacks the oligomerization domains of full-length Rex  100, 1001. It wa HTLV-2 produces a family of truncated isoforms ranging from 22 to 17 kDa which differ in the initiation codon usage and phosphorylation status . These tin vitro but important for viral spread and persistence in animal models [p30tof and p28 are products of the x-II ORF of HTLV-1 and HTLV-2, respectively. p30tof is coded by a doubly spliced mRNA containing exons 1, 2, and B; p28 is coded by 2 singly spliced mRNAs containing exons 1 and 3 or exons 1 and B . The twol models –104. p30l models , 106. Byl models , 108, p3l models , 110. Ful models , 112. Byl models , suggest+ and activates the electron transport chain, resulting in increased mitochondrial reactive oxygen species (ROS) production [ p13, a short isoform coded by the x-II ORF of HTLV-1 from a singly spliced mRNA containing exons 1 and C , correspoduction . These coduction , 118–121β and γc chains of the interleukin-2 receptor (IL-2R), reducing their surface expression [2+ release from the ER [β chain or the 16-kDa subunit of the vacuolar H+ ATPase [ HTLV-1 p12 and p8 are coded by the x-I ORF from a singly spliced mRNA containing exons 1 and A or exons 1 and B . p12 locpression . p12 exppression . p12 alspression . p12 alspression  resultinm the ER  and actim the ER –129. Witm the ER , 131. In+ ATPase . No funcTranscription from a promoter in the 3′ LTR generates transcripts from the complementary strand which encode the HBZ (HTLV-1) and APH-2 (HTLV-2) genes , 13. Thein vitro transformation but increases infectivity and viral persistence in in vivo animal model [β signalling [HBZ is not necessary for al model ; furtheral model . HBZ intal model . HBZ intal model . In addignalling  resultingnalling .κB pathway by two different mechanisms: by inhibiting the DNA binding of the NF-κB subunit p65 and by increasing the expression of PDLIM2, the E3 ubiquitin ligase of p65, leading to enhanced ubiquitination and degradation of p65 [κB pathway was proposed to counteract the onset of Tax-induced cellular senescence, which results from hyperactivation of the NF-κB pathway [in vivo and in vitro [ HBZ's bZIP domain also mediates formation of heterodimers with c-Jun, JunB, and JunD , 146. Bin of p65 . The dow pathway . HBZ expin vitro , 152. Muin vitro  possiblyin vitro . Furtherin vitro . Moreovein vitro . Following the discovery of HBZ, an antisense transcript was identified in HTLV-2 . Its proHTLV-1 and HTLV-2 are complex retroviruses with similar genetic structures but significantly different pathogenic potential. Many studies were aimed at defining the viral genetic determinants of these viruses by comparing the expression strategies and functional properties of the different gene products of the two viruses. Although these studies added considerable knowledge to the understanding of the HTLV-1 and HTLV-2 gene expression, important questions still remain open. The Tax proteins of the two viruses, although showing many similarities, exhibit some differences, especially regarding their capability to activate the NF-kB pathway and to induce genetic instability. The mechanism of function of HBZ and APH-2 as noncoding RNAs, which was underscored by their predominant nuclear localization , also de


Giardia duodenalis is a widespread intestinal protozoan of both humans and mammals. To date, few epidemiological studies have assessed the potential and importance of zoonotic transmission; and the human giardiasis burden attributable to G. duodenalis of animal origin is unclear. No information about occurrence and genotyping data of sheep and goat giardiasis is available in China. The aim of the present study was to determine prevalence and distribution of G. duodenalis in sheep and goats in Heilongjiang Province, China, and to characterize G. duodenalis isolates and assess the possibility of zoonotic transmission.G. duodenalis infection was 5.0% (34/678) by microscopy after Lugol's iodine staining, with 5.6% (30/539) for the sheep versus 2.9% (4/139) for the goats. Molecular analysis was conducted on 34 G. duodenalis isolates based on the triosephosphate isomerase (tpi) gene. 29 tpi gene sequences were successfully obtained and identified as assemblages A (n = 4), B (n = 2) and E (n = 23). High heterogeneity was observed within assemblage E at the tpi locus, with five novel subtypes found out of seven subtypes. Two subtypes of assemblage A were detected, including subtype AI (n = 3) and a novel subtype (designated as subtype AIV) (n = 1). Two assemblage B isolates were identical to each other in the tpi gene sequences.A total of 678 fecal specimens were collected from sheep and goats on six farms ranging in age from one month to four years in Heilongjiang Province, China. The average prevalence of G. duodenalis infections in sheep and goats in China. The present data revealed the unique endemicity on prevalence, distribution and genetic characterization of G. duodenalis in sheep and goats in Heilongjiang Province. The findings of assemblages A and B in sheep and goats implied the potential of zoonotic transmission.This is the first report of  G. duodenalis isolates in Heilongjiang Province, China. The average infection rate was 5.0% (34/678), with 5.6% (30/539) for the sheep versus 2.9% (4/139) for the goats. G. duodenalis assemblages and subtypes were genetically diagnosed by sequence analysis. Three assemblages were successfully identified out of 29 tpi gene sequences, with the percentages 13.8% (4/29), 6.9% (2/29), 79.3% (23/29) for assemblages A, B and E, respectively. Five novel subtypes were found out of seven subtypes of assemblage E. Two subtypes of assemblage A were detected, with one belonging to a novel subtype and the other belonging to assemblage AI. Two assemblage B isolates were identical to each other at the tpi locus. Prevalence, distribution and genetic characteristics of subtypes of G. duodenalis in sheep and goats appear to be unique in the areas examined. The sheep and goats infected with assemblages A and B have important public heath significance.Giardiasis is a kind of zoonotic disease with global distribution. Due to the great number of asymptomatic giardiasis cases, human giardiasis is often underreported. The sources of infection of giardiasis are feces of humans and mammals with the pathogen being transmitted by the fecal-oral route. In this study, we described the occurrence of sheep and goat giardiasis and genetic charaterizations of  Giardia duodenalis  is one of the most common protozoa in humans and animals. Giardiasis of humans and animals has a wide spectrum of clinical signs, including the onset of diarrhea, abdominal pain, bloating, vomiting, nausea and/or weight loss. The parasite can lead to growth and development retardation of children, even in asymptomatic cases G. duodenalis based on genetic analysis and host specificity. In a recent study, assemblage H has been described in marine vertebrates To date, molecular data revealed the presence of seven assemblages (A to G) within G. duodenalis is one of the most common pathogens in water-associated outbreaks of parasitic protozoan diseases, accounting for 40.6% (132/325) out of total outbreaks G. duodenalis in case control studies Outbreaks of human giardiasis are most frequently waterborne and caused by contamination of drinking water, although other routes have also been described G. duodenalis infection in sheep and goats, indicating a wide range in prevalence from 1.5% to 55.6% in sheep and from 12.3% to 42.2% in goats G. duodenalis in sheep and goats. Assemblage E was the major genotype in sheep/goats in most countries, with assemblage A being occasionally detected in Australia, Sweden, the USA, Belgium, and Spain and with assemblage B being occasionally detected in Norway and Spain G. duodenalis assemblages A and B have been reported in sheep in Italy, with an absence of assemblage E Years of epidemiological data have documented the occurrence of genotyping data of sheep and goat giardiasis so far. China has one of the largest populations of sheep and goat flocks G. duodenalis in sheep and goats in China, a survey of G. duodenalis was conducted in sheep and goats in Heilongjiang Province, and the tpi gene sequences of G. duodenalis isolates were analyzed for genetic characterization and assessment of the potential of zoonotic transmission at both genotyping and subtyping levels.In China, there are no reports about the investigations and Before beginning work on the study, we contacted the farm owners and obtained their permission to have their animals involved. During specimen collection, all animal work followed guidelines in accordance with the Regulations for the Administration of Affairs Concerning Experimental Animals, and approved by the Animal Ethical Committee of Harbin Medical University.G. duodenalis cysts by light field microscopy at 400× magnification. All G. duodenalis-positive specimens were stored in 2.5% potassium dichromate solution at 4°C before DNA extraction.A total of 678 fecal specimens (539 from sheep and 139 from goats) were randomly collected on six farms within Heilongjiang Province, China in a two-year survey from October 2009 to November 2011 . The speG. duodenalis-positive fecal specimens were washed four times with distilled water to remove potassium dichromate from the solution. Genomic DNA was directly extracted from approximately 200 mg of the fecal pellet using a QIAamp DNA Stool Mini Kit  according to manufacturer's instruction. DNA was eluted in 200 µL of AE elution buffer and DNA preparation was stored at −20°C prior to use in PCR analysis.G. duodenalis isolates were genotyped and subtyped at the tpi locus using a nested PCR which amplifies an approximately 530-bp fragment as previously described G. duodenalis isolates were identified by analyzing and comparing the tpi gene sequences obtained in the present study with those published in GenBank.All secondary PCR products were sequenced with secondary PCR primers on an ABI PRISM™ 3730 DNA Analyzer , using a BigDye Terminator v3.1 Cycle Sequencing kit . Accuracy of the sequencing data was confirmed by sequencing in both directions and a new PCR product once more if necessary for some isolates. Nucleotide sequences obtained in the present study were aligned with each other and reference sequences downloaded from GenBank and analyzed using Clustal X 1.83.G. duodenalis cysts. The average prevalence of G. duodenalis infection was 5.0% (34/678), with 5.6% (30/539) for the sheep versus 2.9% (4/139) for the goats. With the exception of Farm 5 where G. duodenalis infection was absent, the parasite was detected on the other five farms  for assemblage A, 6.9% (2/29) for assemblage B and 79.3% (23/29) for assemblage E. Assemblage E was not only the most prevalent but also the most widespread in the investigated areas, accounting for assemblage E on four farms, assemblage A on two farms and assemblage B on only one farm , which had 100% similarity with the human-derived subtype AI sequences from Malaysia (HQ836660), France (FJ560569), the USA (EF688031 to EF688043), Peru , Australia , Israel (EF688040), Egypt (EF688036) and Henan of China (GU564274 to GU564276). It was also identical to subtype AI sequences from animals, including sheep in Australia (GQ444447), cattle  in the USA, and cats (AB569393) in Japan. The remaining one was a novel subtype of assemblage A (JQ928710), having four, four and five base differences compared to AI, AII and AIII, respectively (tpi locus (JQ928712) and had 100% homology with those from dairy cattle (JN162353), rabbits (HQ397719) and wastewater (HQ603781) in the investigated areas.Sequence analysis of the ectively . The genG. duodenalis assemblage E was observed in the present study. Seven representative sequences  were obtained out of 23 tpi gene sequences. They were respectively named as subtypes E-I to E-VII for convenient description, with one to four base variations noted at nine different nucleotide sites  G. duodenalis were noticed to be inversely associated with the age of animals, with the highest infection rate (17.0%) in lambs and (10.5%) in goat kids. There were an apparent declining infection rates with the increasing age of the animals -month-old lambs in Spain G. duodenalis infected animals, and infection rates ranged from 2.9% to 8.1% , tpi gene was frequently used to differentiate G. duodenalis at genotype and subtype levels because of the highest genetic heterogeneity at the locus tpi gene sequences were obtained, with 13.8% (4/29),6.9%(2/29) and 79.3% (23/29) for assemblages A, B and E, respectively. Assemblage E was detected on four farms, whereas assemblages A and B were detected on two farms and one farm, respectively  G. duodenalis infections have an effect on growth and performance of animals, and most of relationship studies are only at the species level of G. duodenalisG. duodenalis could lead to decreased hot carcase weights and dressing percentage of sheep Currently, PCR-based molecular analysis techniques (DNA sequencing of PCR products and PCR-RFLP) have been developed and used to identify ectively . Assembltpi gene of G. duodenalis revealed the presence of seven subtypes out of 23 assemblage E isolates. The most common subtype E-I  showed 100% similarity with the cattle-derived assemblage E sequences in our investigated areas (JN162347) and the USA . Subtype E-II  had the same nucleotide sequence as the isolate of G. duodenalis from an Australian sheep (GQ444447). Subtypes E-I and E-II appeared to have no differences in geographical distribution. The remaining five novel subtypes (E-III to E-VII) have never been reported before and might represent endemic genetic characterizations of assemblage E in the investigated areas. In addition to high polymorphism observed within assemblage E in sheep and goats at the tpi locus in the present and previous studies bg locus tpi gene Sequence analysis of the It is generally considered that assemblages A and B are infrequently detected in sheep and goats. However, there are exceptions appearing in a few studies of sheep and goat giardiasis, with assemblage A being found to be a common genotype besides assemblage E G. duodenalis-positive specimens. Three of them were identified as subtype AI, showing 100% homology with each other as well as the subtype AI tpi gene sequences from humans , representing two subtypes, were detected from the m humans  and somem humans . The samm humans , and cattpi, gdh, bg and SSU rRNA genes. Among 14 representative sequences of assemblage A obtained from 49 isolates, six sequences show 100% homology with those derived from humans. Even in Australia and China, the same sequences of assemblage AI have been seen in both humans and sheep  and environmental specimen (wastewater) in the investigated areas may reflect characteristic geographical distribution. The transmission dynamic of assemblages A and B, and the burden of human giardiasis caused by animals need to be assessed by systematic molecular epidemiological investigations of humans and animals in the future.In conclusion, the findings above provide the first report on sheep and goat giardiasis in China. Percentages and genetic characteristics of


The combinatorial complexity of signaling networks has led to an opposing perspective, namely that signaling proceeds via heterogeneous pleiomorphic ensembles of transient complexes. Since many hypotheses regarding network function rely on how we conceptualize signaling complexes, resolving this issue is a central problem in systems biology. Unfortunately, direct experimental characterization of these complexes has proven technologically difficult, while combinatorial complexity has prevented traditional modeling methods from approaching this question. Here we employ rule-based modeling, a technique that overcomes these limitations, to construct a model of the yeast pheromone signaling network. We found that this model exhibits significant ensemble character while generating reliable responses that match experimental observations. To contrast the ensemble behavior, we constructed a model that employs hierarchical assembly pathways to produce scaffold-based signaling machines. We found that this machine model could not replicate the experimentally observed combinatorial inhibition that arises when the scaffold is overexpressed. This finding provides evidence against the hierarchical assembly of machines in the pheromone signaling network and suggests that machines and ensembles may serve distinct purposes in vivo. In some cases, e.g. core enzymatic activities like protein synthesis and degradation, machines assembled via hierarchical energy landscapes may provide functional stability for the cell. In other cases, such as signaling, ensembles may represent a form of weak linkage, facilitating variation and plasticity in network evolution. The capacity of ensembles to signal effectively will ultimately shape how we conceptualize the function, evolution and engineering of signaling networks.Despite the importance of intracellular signaling networks, there is currently no consensus regarding the fundamental nature of the protein complexes such networks employ. One prominent view involves stable  pleiomorphic ensemble hypothesis, which posits that diverse and rapidly changing sets of transient protein complexes can transmit and process information. Our goal was to use computational approaches, specifically rule-based modeling, to test these hypotheses. We constructed a model of the prototypical yeast mating pathway and found significant ensemble-like behavior. Our results thus demonstrated that ensembles can in fact transmit extracellular signals with minimal noise. Additionally, a comparison of this model with one tailored to generate machine-like complexes displayed notable phenotypic differences, revealing potential advantages for ensemble-like signaling. Our demonstration that ensembles can function effectively will have a significant impact on how we conceptualize signaling and other processes inside cells.Intracellular signaling networks are central to a cell's ability to adapt to its environment. Developing the capacity to effectively manipulate such networks would have a wide range of applications, from cancer therapy to synthetic biology. This requires a thorough understanding of the mechanisms of signal transduction, particularly the kinds of protein complexes that are formed during transmission of extracellular information to the nucleus. Traditionally, signaling complexes have been largely perceived  as machine-like structures. However, the number of molecular complexes that could theoretically be formed by complex signaling networks is astronomically large. This has led to the  Much of our reasoning about the function of biological systems relies on the formation of multi-subunit protein complexes combinatorial complexity; that is, they can  generate anywhere from millions to 1020 or more unique molecular species 5 possible phosphorylation states, many of which could be (stably) occupied by any given molecule a priori difficult to understand how a protein folds quickly and stably into a single native structure One issue that complicates this machine-based picture is the fact that the protein interaction networks that underlie cellular signaling exhibit considerable et al. have speculated, however, that signaling networks might not need to assemble machine-like structures at all in order to function Mayer a priori reduction in the set of possible species that can be formed in silico. We focused on the pheromone response network  that have been explicitly characterized experimentally. We found that this model is able to fit available data on the response of the network to pheromone, despite exhibiting significant ensemble character. We also constructed an alternative set of rules that could assemble a scaffold-based signaling machine, similar to those typically drawn to graphically summarize the cascade A summary of the molecular interactions underlying the yeast pheromone response network may be found in http://yeastpheromonemodel.org) 3 billion unique molecular structures . The rules themselves, which follow mass-action kinetics, were primarily derived from two sources: an online model  for each of the 18 protein agents and stochastic rate constants for each of the 232 rules. We obtained the initial conditions directly from experimental measurements of copy number in yeast cells We found that only 25 of these parameters had a strong impact on the dynamics of important observables in the model, and so we only modified those values during our fitting procedure. Of these 25, 22 had original estimates obtained from related proteins. In those cases, we restricted variation of the parameters to an increase or decrease of about one order of magnitude, to maintain similarity between the fitted value and the original estimate. Two of the remaining parameters had no available estimate, and so we restricted variations in those parameters to a biologically realistic range  equivalent fits to this data; we thus cannot make any claims regarding the identifiability of the parameters or even the rule set itself i and j, using the Jaccard distance, which we refer to as “compositional drift” iC represents the set of unique complexes in simulated cell i, Δ and X| is the cardinality of set X. Given the complexes present in two simulated cells, drift is the number of complexes unique to either one cell or the other, divided by the total number of complexes in the union of the two cells. Drift can thus be interpreted as the probability that a complex found in one cell is not found in the other at a particular point in time. For example, d = 0 indicates identical sets of complexes, whereas d = 1 means the sets are pairwise disjoint. We only performed this comparison between multiple simulation replicates that started from exactly the same steady-state initial condition; thus d = 0 at t = 0 for all of our simulations , around 80% of all unique complexes were exclusive to one simulation or the other  as opposed to those without pheromone . At peakhe other . Such smhe other . In Fig.While the results in i maintains a specific set of complexes, or if the set changes over time. To answer this question, we used an alternative drift calculation, termed autodrift: id instead of d. We found that simulated cells employ rapidly changing sets of complexes during peak signaling times in this model  signaling species that form around a large “core” signaling complex. We thus examined in detail the structures of the scaffold-based species at various time points in our simulations. If a core complex were present, we would expect to see substantial conservation of protein binding patterns (ignoring phosphorylation state) in the set of unique complexes. Though Ste5 dimers are present in ∼70% of species during peak signal throughput, conservation significantly declines as the binding pattern is expanded to include more proteins . In factgraph edit distance metric, which is simply the number of changes (or edits) that would be required to form one complex starting from another. This distance accounts for differences in the members of a complex  as well as differences in phosphorylation state, etc.  in order to generate stable signaling machines. The simplest possible approach would be to create rules and rates that render the desired machine complex incredibly stable. The decamer, however, is essentially never generated in our original model's simulations  index designed to extrapolate binary TAP/MS interaction data in order to discover novel “eukaryotic cellular machines” via clustering analysis in vivo signaling complexes, we characterized the signaling species generated in both the ensemble and the machine models using the SA index Since these two models can both reproduce general pheromone-dependent trends, one might ask if it is possible to differentiate machine- and ensemble-like signaling processes directly using available experimental techniques. The most natural approach would be tandem affinity purification in conjunction with mass spectrometry (TAP/MS), which is widely employed as a high-throughput assay for the discovery and analysis of protein complexes same scaffold dimer This leads to the question of whether one could ever detect any functional differences between ensembles and machines in a signaling context. Previous work has established the presence of “combinatorial inhibition” positive ΔFus3pp (12× – WT), corresponding to an increase in Fus3 activation  could be used to provide direct evidence for (or against) the hierarchical assembly of a signaling machine. For instance, in the machine model, Ste7 only binds Ste5 after Ste11 is already bound. Observation of Ste7-Ste5 association in the absence of Ste11 binding to Ste5 would thus provide evidence against the type of signaling machine considered here  spectrum of structural specificity in the formation of complexes during signal transduction Since machines do indeed form in some signaling networks (e.g. the apoptosome), there is likely a N untreated “cells.” We treated the cells with pheromone, and generated a set of N′ independent hour-long simulations from each steady-state starting cell. All of the complexes present in the simulation were recorded at logarithmically spaced time intervals. Compositional drift calculations were performed using these “snapshots;” we only performed this calculation between simulations that started from exactly the same initial conditions  may be simulated using the freely available KaSim simulator (https://github.com/jkrivine/KaSim/). The BNGL models (“*.bngl”) must first be converted to XML format using BioNetGen prior to simulation with NFSim .(ZIP)Click here for additional data file.Text S1Supporting information. This file contains the additional figures, tables, methods and explanations referenced in the main text.(PDF)Click here for additional data file.


The HTLV-1 integrase enzyme shares important structural similarities with the HIV-1 integrase. Experimental studies have demonstrated that styrylquinolines and diketo acids can inhibit both HIV-1 and HTLV-1 integrases. Raltegravir is the only approved integrase inhibitor for the treatment of HIV infection. No data exist about its potential benefit in HTLV-1 carriers.A series of HTLV-1 individuals on regular follow-up at two Spanish clinics were invited to participate in a pilot trial in which raltegravir 40 mg bid was administered for 12 months. Proviral DNA was measured using a validated real-time PCR assay that targets the HTLV-1 pol region on PBMCs at baseline and periodically during follow-up. Demographics and clinical signs/symptoms were closely monitored in all patients.A total of 5 HTLV-1 individuals entered the study. Their country of origin was Peru (2), Ecuador (1), Dominican Republic (1) and Colombia (1). Their median age was 52-years old. Three were women. All were infected with HTLV-1 subtype a subgroup a transcontinental. Route of contagion was heterosexual contact in 3, Transfusion in 1 and homosexual relationships in 1. The latest was coinfected with HIV-1. Two patients had TSP/HAM whereas the other 3 were asymptomatic.Median proviral load was 1,658 HTLV-1 DNA copies per 10,000 PBMC in symptomatic patients compared to 758 copies in asymptomatic individuals. Following initiation of raltegravir therapy and up to 6 months, TSP patients experienced a transient decline in HTLV-1 proviral load . However, a return to baseline levels was seen in subsequent determinations, being proviral load at 12 months of 2,219 and 1,175, respectively. No improvement in clinical manifestations could be recognised. No significant changes in HTLV-1 proviral load were noticed in the 3 asymptomatic individuals with median proviral load values over time fluctuating around 755 copies /10,000 PBMCs.Treatment with raltegravir may produce a transient decline in HTLV-1 proviral load in TSP/HAM patients, which is not seen in asymptomatic carriers. However, there is no improvement in TSP/HAM clinical manifestations nor sustained virological benefit beyond six months of therapy.


HTLV-1 and HTLV-2 are retroviruses linked etiologically to various human diseases, and both of them can be transmitted by vertical route, sexual intercourse, blood transfusion and intravenous drug use. Recently, some HTLV-infected cases have been reported and this virus is mainly present in the Southeast coastal areas in China, but has not been studied for the people in Central China.To know the epidemiologic patterns among different population samples in Central China and further identify risk factor for HTLV-1 and HTLV-2 infection.From January 2008 to December 2011, 5480 blood samples were screened for HTLV-1/2 antibodies by using enzyme immunoassay, followed by Western Blot.The prevalence of HTLV-1 and HTLV-2 was found with infection rates 0.13% and 0.05% among all population samples for HTLV-1 and HTLV-2, respectively. The highest percentages of infection, 0.39% and 0.20%, were found in the high risk group, while only 0.06% and 0.03% in the blood donor group. There was only one case of HTLV-1 infection (0.11%) among patients with malignant hematological diseases. Of seven HTLV-1 positive cases, six were co-infected with HBV, two with HCV and one with HIV. Among three HTLV-2 positive individuals all were co-infected with HBV, one with HCV.HTLV-1 and HTLV-2 have been detected in the Central China at low prevalence, with the higher infection rate among high risk group. It was also found that co-infection of HTLV-1/2 with HIV and HBV occurred, presumably due to their similar transmission routes. HTLV-1/2 antibody screen among certain population would be important to prevent the spread of the viruses. Human T-cell lymphotropic virus (HTLV) was the first retrovirus discovered in humans HTLV-1/2 are present in different high-risk populations and spread globally. HTLV-1 is endemic in regions of the Caribbean, Central and Western Africa, Southwestern Japan, South and Central America, Melanesia and Australia. HTLV-2 has a more restricted distribution than HTLV-1, more prevalent among some native Americans and some Central African tribes, but is relatively common among intravenous drug users (IDUs) and their sex partners in Europe, North America, and other regions of the world China is considered to be a non-endemic region for HTLV as few positive individuals found in China. Since 1985, several investigations of the prevalence of HTLV have been carried out in China Henan and Hubei province, located in central areas of China, with large and great migrant population, are high endemic areas for blood transmitted diseases. The prevalence of HIV and HBV ranks the first position in the country The study design was approved by the Committee on Human Research of Zhengzhou University located in Zhengzhou, China. All adult participants and the parents/legal guardians on behalf of their children (5–18 years) signed a written informed consent sheet, and were informed about the purpose and procedures of the study. All participants were free to withdraw from the study at any time without further obligation.T. pallidum (Syphilis ELISA IgG + IgM).From Jan 2008 to Dec 2011, a cross-sectional study was performed to assess the seroprevalence of HTLV-1/2 infection among different population in Henan and Hubei, China. A total number of 5480 blood samples were collected and divided into three groups. The random samples of 3548 voluntary blood donors were recruited from 2 blood banks (Henan Red Cross Blood Center and Wuhan blood center of Guangzhou military). All these donors fulfilled the criteria for blood donation. The 908 cases were patients with malignant hematological diseases (MHDs) attending the First Affiliated Hospital of Zhengzhou University and Wuhan General Hospital of Guangzhou Military, which were diagnosed by the Hematology Unit, including acute lymphocytic leukemia , acute myeloid leukemia , chronic lymphocytic leukemia , chronic myelogenous leukemia , non-Hodgkins lymphoma , and Hodgkins lymphoma . The remaining 1024 cases were high risk group (HRs), including injecting drug users , female sex workers , men who have sex with men , former paid blood donors  and patients attending clinics for sexually transmitted infections  in Zhengzhou and Wuhan, China. All samples went through a standard screening for antibodies to HIV (anti-HIV), HBV (HBsAg), HCV (anti-HCV), and E. coli. The purified recombinant polypeptide was labeled with horse radish peroxidase (HRP) and coated onto microtitre plate. The assays were performed according to the manufacturers' instruction, which indicates that serum samples that yielded an OD/cut-off ≥1.0 are considered positive for HTLV-1/2 antibodies. Reactive samples were retested in duplicate with the same kit.Participants were screened for the presence of HTLV-specific antibodies using an enzyme-linked immunosorbent assay . Briefly, 212 amino acids from the envelope region (aa 185–396) of HTLV type 1 fused to 26 amino acids from the envelope region (aa 185–210) of HTLV type 2 were expressed in All repeatedly reactive samples were further confirmed by Western blot assay  in accordance with the manufacturer's criteria. Seroreactivity was interpreted according to the stringent criteria indicated by the manufacturer. A Western blot test was scored as HTLV-1 positive only if bands for the Gag (p19 with or without p24) and two Env (GD21 and rpg46-1) bands were detected; it was scored as HTLV-2 positive if bands for the Gag (p24 with or without p19) and two Env (GD21 and rpg46-2) were found. The presence of p24, p19, and GD21 was considered as HTLV positive but nontyped. Samples that demonstrated reactivity to Gag (p19 and p24) and Env  were defined as HTLV-1- and HTLV-2-positive. Any other pattern of bands was considered indeterminate.For sequencing of full proviral genomes, proviral DNA was prepared form peripheral blood lymphocytes of the HTLV-1 positive individual with non-Hodgkin's lymphoma. Each major coding regions and the long terminal repeat (LTR) were amplified with Primes STAR HS DNA Polymerase  Chi-square test and Fisher's exact test were used to compare proportions. Logistic regression was applied to estimate the magnitude of associations to risk factors for HTLV infection, expressed as odds ratios with 95% confidence intervals. All statistical analyses were performed by using SPSS software version 17.0 .The complete genome sequence of HTLV-1 strain newly reported here has been deposited in GenBank database under accession number KF807984.All 18 publicly available full-length HTLV-1 proviral genome sequences were downloaded from GenBank and aligned with the new proviral sequence. The geographic locations of recovery and accession numbers of the GenBank sequences are as follows: Germany: AF042071; Caribbean: M86840, D13784; USA: AF139170, NC_001436, AF033817; France: L36905; Brazil: AY563953, AY563954; Canada: HQ606137, HQ606138; Japan: L03561, U19949, J02029, AB513134; China: AF259264; Central Africa: JX507077; Solomon Islands: L02534. All of these sequences have been shown previously to belong to the so-called “Cosmopolitan” HTLV-1 subtype A We also performed the phylogenetic analysis on gp46 sequence (683 nt). These isolates were representative of subtype A: D13784 and AY604934 (French Guiana) for the West African subtype; AF 438763 (Japan), M37301 (Japan) and J02029 (Japan) for Japanese subtype; AF165067 and AF165068 , AY604935 (Iran), U32556 (British Columbia), M69044 (African), AY604894 (Franch Guiana) and L76061 (Caribbean) for the Transcontinental subtype. The representative isolates of genotype B are L26586, AY604933 (Gabon), AF091494 (Gabon); and the representative isolates of genotype C are L02434 (Melanesia), L02533 (Melanesia), and M92818 .The sequence alignment were made using Clustal W program; gaps were removed, and distance-based trees were generated by using the Kimura two-parameter model in conjunction with the neighbor-joining method in the MEGA program (version 5.2). The reliability of the final topology of the trees was tested with 1000 bootstrap replicates.T. pallidum was detected in 12 (0.22%), 272 (4.96%), 357 (6.51%), and 149 (2.72%) of study participants, respectively. Demographic characteristics and co-infection with HIV, HBV, HCV and T. pallidum are shown in A total of 5480 subjects were enrolled in this study: 3296 (60.1%) were males and 2184 (39.9%) were females. The average age ±SD of the study population was 29.21 years ±12.03 (range  = 3–72 years). Infection with HIV, HBV, HCV, and In total, 17 of 5480 samples in this study were positive for anti-HTLV antibody using the ELISA assays. Seven of 17 samples were confirmed positive for anti-HTLV-1 antibody and three of 17 samples positive for anti-HTLV-2 antibody using the immunoblot (data not shown). p = 0.21). Of the 7 HTLV-1 positive cases, 2 were blood donors (0.06%), 1 was lymphoma/leukemia patient (0.11%), and 4 were high risk population (0.39%). The prevalence of HTLV-1 in high risk group was significantly higher than in blood donors (p = 0.03). HTLV-2 prevalence was 0.03% (1/3548) among blood donors and 0.2% (2/1024) among high risk group. None of 908 lymphoma/leukemia patients had HTLV-2 antibodies. No significant difference was found in HTLV-2 seroprevalence between blood donors and high risk group (p = 0.10).p = 0.82, p = 0.72). In addition, majority of HTLV-1 infection were found among >40 years age group,yielding a prevalence of 0.23%, followed by <20 years age group and 20–40 years age group with prevalence of 0.16% and 0.08%, respectively (p = 0.45). There was no HTLV-2 positive individuals in <20 years age group, although the prevalence among 20–40 years and >40 years age group were 0.06% and 0.08% (p = 0.68).Gender groups and age groups show no significant association with the infection of HTLV-1/2. The prevalence of HTLV-1 and HTLV-2 among male population (0.15% and 0.06%) tended to be higher than that among female population (0.09% and 0.05%) . On the other hand, it shows statistically significant difference between various pathogens co-infection among HTLV-1 positive cases (p = 0.03).Co-infection of HTLV-1 and 2 with sexually and parenterally transmitted agents is shown in p = 0.006) and HBV . No independent risk factors were found to be associated with HTLV-2.In the univariant analysis gender, age showed no significant association with the risk of HTLV-1 infection. HTLV-1 prevalence rate appeared to be higher among high risk group, and HTLV tended to be found in individuals positive for HIV, HBV or HCV antibodies, with variable tendency. To further identify independent risk factors, all variables from the univariate analysis were entered into multiple logistic regression models . In thisThe length of the complete genome sequence reported here was 9034 bp. In the phylogenetic tree, this new proviral sequence KC807984 can be recognized in the Genotype A. This new strains formed a tight clade with other genome form China (AF259264) and clustered with genomes from Japan (L03561) and Canada (HQ606137 and HQ606138) .In This is the first large-scale cross-sectional study to evaluate the prevalence and epidemiological characteristics of HTLV-1/2 infections and co-infections with other pathogens among different population in Central China. Our findings indicate that the final HTLV-1/2 seroprevalence rate was 0.18% (10/5480), yielding a prevalence of 0.13% for HTLV-1 and 0.05% for HTLV-2. The lowest prevalence of HTLV-1/2 infection is found in blood donors (0.06% and 0.03%). However, population of high risk group shows the high level of HTLV-1 and HTLV-2 infection . Moreover,these findings suggest that HTLV-1/2 seroprevalence is associated with HIV, HBV and HCV infections. Among 10 HTLV-1/2 positive cases, 9 were co-infected with HBV, 3 with HCV and 1 with HIV.Due to inadequate treatment options for TPS/HAM or ATL and lack of an effective vaccination, prevention of new HTLV infections is currently only possible by restricting transmission, either blood transfusion or sexually intercourse. In this regard, knowing the HTLV prevalence status seems to be the most effective way to reduce the transmission of HTLV. China is non-endemic area for these viruses. In 1980s, Zeng et al. ATL is one of the major HTLV-1 associated diseases. 2–6% HTLV-1 carriers could develop ATL if infection occurs in early childhood T. pallidum were associated with HTLV-1 infection; IDUs play an important role in HTLV-2 transmission; and the significant high rate of HTLV-1/2 infection has been found in HCV/HIV/HBV antibody positive individuals. In Argentina, Berini et al. T. pallidum in different high risk groups, the prevalence for HTLV-1/2 was 2.4%. The highest prevalence of HTLV-1/2 was found among IDUs (19.1%) and the lowest was MSM (0.4%). High rate (63%) of co-infection between HTLV-1 and HBV was observed. In this study, the participants of high risk group including IDUs, FSW, STIs, MSM, and PBDs. 2 HTLV-1 positive cases were found in FSW and 2 were from STIs. The prevalence rate was the highest in high risk population compared to those two groups of the blood donors and MHDs. The result was in agreement with Wang et al. Like other sexual transmitted diseases, some high risk behaviors cause the spread of the virus, including sexual contact without protection with multiple partners, sharing injecting equipment, unsafe blood product transfusion, etc. Therefore, high risk behavior population could be the source of HTLV-1/2 spread in non-endemic regions, and cause co-infection with other sexually transmitted pathogens due to the same modes of transmission This study suffered from some limitations. First, due to the nature of cross-sectional study, the associations reported herein between the infections and the relate risk factors may not be related to a cause-effect manner. Second, the limitation of the low prevalence of the HTLV cases in Central China and the inadequate size of the study samples may have caused the lack of statistical significance of some associations, although in the presence of high ORs. Third, the convenience sampling may have led to bias and therefore either underrepresentation or overrepresentation of true prevalence. Last, this study was conducted only in provincial capital cities of Henan and Hubei. Thus, we were unable to evaluate any geographical region characters among any high risk factors across the country. However, we still believe that we could evaluate actual prevalence and associated risk factors in a reliable manner.In summary, our study reveals the seroprevalence of HTLV-1/2 among different population samples in Central China, which shows a high prevalence rate among high risk group, and low rate among blood donors and MHDs. The infection of HTLV-1/2 has not been found in malignant hematological diseases. HIV, HBV, and HCV were the common risk factors associated with HTLV-1/2 infection, suggested that further study should be carried out in specific population, aiming to prevent the virus spreading. Our results can also provide theoretical basis for revise standard of voluntary blood donation in this area.


Degenerate codes—codes in which multiple code words have the same meaning or interpretation—arise in a wide range of biological processes, from the many-to-one mapping of codons to amino acids to the numerous instances of degenerate coding in the nervous system, both in the periphery and in the cortex. There are a number of reasons why neural systems might seek some degree of degeneracy; by enabling a number of inputs (stimuli) to be mapped to the same output code, the system is endowed with a certain level of robustness to noise and to cell death. Furthermore, degenerate codes provide invariance to certain types of variability in the raw sensory input. This is particularly useful in object recognition for instance, where despite photometric variability, the representation of an object under different illumination conditions should be equivalent at some level of processing even if the neural representations for these states are slightly different.Degeneracy is a ubiquitous feature of computation and coding in biological systems. sparsity also appears to also play an important role in neural coding; a sparse code is one that requires a small number of active neurons relative to the size of the population. Sparse codes are also associated with a high degree of specificity: each cell in the population only responds to a limited number of inputs. Sparse coding has been observed in the visual cortex of macaque, mushroom body in locusts, and auditory cortex in grasshoppers.In tandem with nature's desire to produce degeneracy and invariance in the brain’s representation of sensory inputs, Experimental studies suggest that neural systems might seek to strike an appropriate balance between the degeneracy and the sparsity of the neural code. Here, we describe a framework in which one can tradeoff between these two objectives in a natural way. In contrast to models for global sparse coding such as the locally competitive architectures in LCA  which fiAfter motivating the utility of group sparse coding in neural systems, we show how one can implement these sparse coding networks by coupling a collection of winner-take-all (WTAs) networks that were first introduced for state-dependent computation in . WTAs ar


With the increasing scale of the melody database, the query-by-humming system faces the trade-offs between response speed and retrieval accuracy. Melody accurate matching is the key factor to restrict the response speed. In this paper, we present a GPU acceleration method for melody accurate matching, in order to improve the response speed without reducing retrieval accuracy. The method develops two parallel strategies  to obtain accelerated effects. The efficiency of our method is validated through extensive experiments. Evaluation results show that our single GPU implementation achieves 20x to 40x speedup ratio, when compared to a typical general purpose CPU's execution time. With the development of information technology, music retrieval technology has been widely applied. Query-by-humming (QBH) is an important application for music retrieval, where users can hum a melody to retrieve the song –3. DiffeTypical QBH systems consist of three modules, including feature extraction, melody database, and melody matching . The feaThe core of QBH is the melody matching between the humming melody and the melody database. From the view of practical application, melody matching algorithms can be divided into fast match and accurate match , 9. FastThere has to be a trade-off between response speed and accuracy, if the QBH system wants to improve the retrieval accuracy within acceptable times. However, with the increasing scale of the melody database, the size of candidate melodies is also growing, which results in an extended response time and poor user experience. The usual method for improving the response speed is to reduce the size of the candidate melodies, but this may cause low retrieval accuracy .Therefore, many efforts are made to develop methods and techniques that execute the melody matching in high performance platforms, allowing the production of accurate results in a shorter time. Graphic Processing Unit (GPU) is one of the recent trends in high performance platforms, which has demonstrated significant speedups for many scientific applications , 12. ResIn this paper, by analyzing the existing accurate matching algorithms, we propose a GPU-based parallelization for the accurate matching algorithm. Our proposed method develops two parallel strategies . By taking full advantage of multicomputing units of GPU, our method can greatly decrease the computation time of the accurate match algorithm and improve the system's response speed without reducing the retrieval accuracy.The rest of this paper is organized as follows. In a QBH system, the humming input is firstly put into a pitch tracker frame by frame and then the output pitch sequence is converted to a semitone scale according to . The MIDm is denoted by Q = , where qi represents the pitch corresponding to the ith frame of humming.The humming pitch sequence at semitone scale of length Q is denoted by P = {, , …, }, where pi and di represent the pitch and duration of the ith note, respectively.The MIDI note sequence matched with qi, pj), where qi and pj represent the pitch of humming sequence and MIDI melody.The distance function between the humming sequence and the MIDI note sequence is denoted by dist , recursiLinear scaling (LS) is a simple, intuitive, and effective melody matching algorithm. LS chooses different scaling factors to stretch or compress the pitch contour of the humming melody to more accurately match the MIDI melody. The deficiency of LS is also quite obvious: local mismatch may deteriorate the global matching; the selection of suitable stretching coefficient or pitch offset is difficult; the length of humming melody may affect the retrieval accuracy.Recursive alignment (RA) uses recursive linear scaling match to explore the optimal matching results. Although it is derived from the LS, this method overcomes the disadvantage of using single stretch factor or pitch offset throughout the entire melody matching. Hence, RA is capable of capturing long distance information in human singing. The drawbacks of this approach are matching the finer, higher time complexity; the segmentation fragments based on midpoint, and the MIDI melodies do not necessarily satisfy the linear relationship.Dynamic time warping (DTW) is one of the most effective approaches to melody accurate matching, which is a frame-based dynamic programming algorithm. In DTW, the candidate note sequences should be expanded to frame sequences. Compared to LS and RA, DTW has higher accuracy but higher complexity. The details of DTW-based melody accuracy matching are described in following section.Over the past few years, GPU has gained significant popularity as a powerful tool for high performance computing. With the development of general programming toolkits, such as Compute Unified Device Architecture (CUDA), GPU becomes a general-purpose shared-memory many-core computing platform and plays important roles in applications such as computer vision, search, and sorting , 18.CUDA is an extension of C/C++ which enables users to write scalable multithreaded programs for CUDA-enabled GPUs . In the Thread creation, scheduling, and management are performed entirely in hardware. In order to manage large number of threads, the GPU employs the SIMT (Single Instruction Multiple Thread) architecture  in whichO(mt). This is the motivation for our research, hoping that we can accelerate DTW computation using GPU without reducing the accuracy.As described in Q = , and the note sequence is denoted by P = {, , …, }. Then we can construct a m × t DTW matrix D according to  is the minimum distance starting from the left-most side (i = 1) of the matrix to the current position . ConsiderThe melody accurate matching based on DTW is outlined in = q1, q, …, qm,The corresponding boundary conditions for the above recursion can be expressed asThe cost of the optimal DTW path is defined asj, the optimal DTW path can be obtained by back tracking.After finding the optimizing As previously described, tempo variation and pitch transposition should be considered before the accurate matching.For most users, tempo variation is attributed to linear variation. Researchers apply the LS algorithm to the humming pitch sequence before comparing it to the candidate melody. The recurrent relation shows that the optimal path exists only when the humming input is within half to twice the size of the candidate melody. Hence, the humming sequence can be scaled several times, ranging from 0.5 to 2 times the original length and compared to the candidate melody in order to achieve the best scaling factor.For pitch transposition, a heuristic method can be applied that shifts the entire humming pitch sequence to a suitable position in order to generate the minimum DTW distance.In this section, our proposed parallelization strategies for melody accurate matching based on DTW are explained. We investigate two approaches for parallelizing the melody accurate matching using CUDA: intra-task parallelization and inter-task parallelization. Intra-task parallelization indicates that each task is assigned to one thread block and all threads in the thread block cooperate to perform the task in parallel. Inter-task parallelization indicates that each task is assigned to exactly one thread and all threads in a thread block perform the tasks in parallel.D, which can be easily implemented as a simple two nested loops. According to  can be computed only if D,  D, and D have already been computed. For instance, as shown in D (red cell locates) depends on D, D, and D (green cells locate). This indicates that all elements in column two are computable simultaneously if the elements in column zero and column one have already been computed. Thus, every entry of the same column is computable and elements within the column can be computed in parallel.As described in the above section, the DTW algorithm has quadratic time complexity that limits its usefulness. The purpose of computation during the DTW algorithm is to fill the matrix rding to , a givenD, as shown in D. Lines 3–5 are the core of our parallel algorithm, which calculates each element of a column in parallel. After calculating all elements of each column, synchronization operation is performed to ensure that all processors have finished current computation (line 6).Based on this idea, we present an efficient parallel implementation for calculating matrix p processors for computing simultaneously. Based on We can easily determine the time complexity of N pieces of melodies, we can launch N threads executing As described in above the section, inter-task parallelization indicates that we compute in parallel all the scores of a humming query with every piece of melody in the candidate melody set. For instance, if the candidate set contains N entries correspond to the first note of each sequence; the next N entries correspond to the second note of each sequence, and so forth.We store the humming pitch sequence in texture memory, which is the cached, fast memory and shared among all threads. Because of the increasing scale of the melody database, the candidate melody set usually contains too many pieces of melodies to be stored in any of the cached memories . Therefore, we store the candidate melody set in the global memory. To gain maximum bandwidth and best performance, all threads in a half-warp should access the note sequences in global memory in a coalesced pattern. In order to adopt the coalesced pattern, every note sequence is stored in an array of double-float, a CUDA structure containing two 32-bit floats storing the pitch and duration of each note. Then we organize all note sequences in memory as a one-dimensional array, such that its first D. In order to minimize the amount of required memory, we only store the current column and forward two columns of each matrix in shared memory. Finally, in order to allow simultaneous read/write operations by the active threads, we store the matrices using the same strategy as the note sequences.Each thread performs the computations on its own matrix Based on the above parallelization strategies, we present an acceleration method for melody accurate matching, as shown in In order to evaluate the performance of our GPU-parallel melody accurate matching algorithm, several experiments were carried out. We first introduce the singing corpus used in this study. Then, we compare the performance and accuracy between our parallel implementation and the existing sequential implementation.Evaluation environment is shown in To evaluate our proposed acceleration method, we used the publicly available MIREX  QBSH corpus , which hi means the rank of the correct song for the ith query.We introduce the speedup ratio to evaluate the performance of GPU-parallel melody accurate matching algorithm. Top-M hit rate and mean reciprocal rank (MRR) are used to evaluate the accuracy of our proposed algorithm. MRR is a standard metrics in MIREX, which can be denoted asAs shown in To verify whether the accelerated strategy affects the retrieval accuracy, we evaluate the accuracy of our proposed parallel algorithm simultaneously. We selected 829 singing clips from the corpus to test the performance. As shown in This paper presents a GPU-parallel melody accurate matching method for query-by-humming. The method uses two parallelization strategies  to accelerate melody matching. The experimental results show that our proposed method can obtain 20x to 40x speedups without reducing retrieval accuracy.For future work, we will further optimize the parallel program to improve the performance. Second, we will perform exhaustive comparison with other QBH acceleration methods.


Recently, it has become increasingly clear that some committed effecter and regulatory T (Treg) cells are not stable, and the plasticity of committed T-cells may be related to autoimmunity and inflammatory disease. However, the environmental (extrinsic) molecules that allow for plasticity have not yet been clearly understood.In Human T-lymphotropic virus type 1 (HTLV-1) associated myelopathy /tropical spastic paraparesis (HAM/TSP), the pathogenesis is known as HTLV-1 infected CD4+ T-cells triggered hyper immune response, which leads to chronic inflammation of the central nervous system. In our previous study, we demonstrated that the majority of CD4+CD25+CCR4+ T-cells were infected with HTLV-1 and that this T-cell subset was increased in HAM/TSP. Although CD4+CD25+CCR4+ T-cells of healthy condition include suppressive T cell subsets such as Treg and Th2, this T-cell subset becomes Th1-like cells with overproduction of IFN-γ in HAM/TSP patients (PLoS ONE 2009). Since HTLV-1 tax is known to up-regulate the expression of several proinflammatory cytokines, and importantly, the level of HTLV-1 tax mRNA expression is reported to correlate with disease severity in HAM/TSP patients, we hypothesize that HTLV-1 tax may convert HTLV-1 infected T-cells into abnormal IFN-γ producing Th1-like T-cells in HAM/TSP. In this study, we present the molecular mechanisms underlying the plasticity of HTLV-1 infected CD4+CD25+CCR4+ T-cells through HTLV-1 tax.


A type-I interferon (IFN) response can be induced by HTLV-1-infected cells and suppresses HTLV-1 expression in vitro, suggesting a role of type-I IFN response in viral suppression and pathogenesis in vivo. Both acquired and innate immune responses control the status of HTLV-1-infected cells and could be the important determinants in the development of HTLV-1-mediated malignant and inflammatory diseases.Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis in small subsets of HTLV-1 carriers. HTLV-1-specific T-cell responses play critical roles in anti-viral and anti-tumor host defense during HTLV-1 infections. Some HTLV-1 carriers exhibit selective loss or anergy of HTLV-1-specific T-cells at an asymptomatic stage. This is also observed in ATL patients and may therefore be an underlying risk factor of ATL in combination with elevated proviral loads. HTLV-1-specific T-cells often recognize the viral oncoprotein Tax, indicating expression of Tax protein  Human T-lymphotropic virus type I (HTLV-1) causes adult T-cell leukemia (ATL)  and HTLVOne of the factors that are known to differ between ATL and HAM/TSP patients is the strength of HTLV-1-specific T-cell responses. T-cell responses are activated in HAM/TSP patients, but are weak in ATL patients, and are thus considered to be one of the most important determinants of the disease manifestation. Many investigators, including us, have been investigating HTLV-1-specific cytotoxic T lymphocyte (CTL) responses, and demonstrated the importance of these CTLs on anti-viral and anti-tumor surveillance in HTLV-1-infected hosts . Based oin vivo, they are slightly higher in HAM/TSP patients compared with asymptomatic HTLV-1 carriers , indicating that innate immune responses can be another host determinant for HTLV-1-induced diseases  encoded by the minus-strand HTLV-1 genome is also an important factor for viral pathogenesis as HBZ elicits indirect effects on tumor development and inflammation  HTLV-1 proteins are not detectable in infected cells in the peripheral blood of HTLV-1 carriers; (b) two types of ATL cases exist, and while HTLV-1 expression in ATL cells is conserved in some cases, this expression is lost in other cases .The understanding of HTLV-1 expression in vivo at least at a transcriptional level. Furthermore, based on the findings that HTLV-1-infected individuals maintain serum antibodies directed to the HTLV-1 structural Env and Core proteins as well as Tax-specific T-cells, HTLV-1 expression must be occurring also at a protein level in vivo. This notion is further supported by the emergence of Tax-specific CTL responses in ATL patients who received hematopoietic stem cells from HTLV-1-negative donors  of HTLV-1-infected individuals including ATL patients . The pree donors , 2005. Iin vitro cultivation , RNA expression of the transgene is detectable only in selected organs, including the central nervous system, eyes, salivary glands, and joints . Transge+ HTLV-1-specific CTL responses are activated in HAM/TSP patients but not in ATL patients  patients tested -specific CTLs remain functional  induced a type-I IFN response through Toll-like receptor 7 TLR7; . pDCs arAt cell–cell contacts between HTLV-1-infected T-cells and stromal cells, we found that HTLV-1 induced a type-I IFN response in the stromal cells, suggesting an involvement of pattern recognition molecules other than TLR7. However, the precise mechanisms of HTLV-1-induced type-I IFN responses remain to be clarified.Figure 3; HTLV-1 mRNA and protein expression in HTLV-1-infected T-cells are markedly decreased when co-cultured with stromal cells such as epithelial cells and fibroblasts. This suppression of HTLV-1 expression is inhibited by blocking the IFN-α/β receptor, and is therefore thought to be mediated through type-I IFN responses . This phenomenon resembles the induction of HTLV-1 expression in freshly isolated ATL cells after culture in vitro. Type-I IFNs might therefore explain the long-puzzling observation that HTLV-1 expression is suppressed in vivo. In support of this notion, viral expression in HTLV-1-infected cells was significantly suppressed when injected into wild-type mice but not into IFN regulatory factor-7-knockout mice, which are deficient in most type-I IFN responses  response element-like repeats by the Tax protein , limitatAddition of IFNs alone also elicits suppressive effects in HTLV-1 expression. However, the levels of suppressive effects differ among studies. In HTLV-1-infected cell lines, it has been reported that IFN-α2a decreased HTLV-1 assembly and viral release but not viral protein synthesis .in vivo, and it is unclear to what extent the evading mechanisms observed in vitro are effective in vivo.As is the case with many other viruses, HTLV-1 has developed strategies to evade IFN responses. It has been reported that HTLV-1 infection reduces the phosphorylation of tyrosine kinase 2 (TYK2) and signal transducer and transcriptional activator 2 STAT2; , and thain vivo. Intriguingly, this combination of AZT/IFN-α does not affect HTLV-1-infected cells in vitro .Supposing that the suppression of viral expression is the first barrier and T-cell surveillance of infected cells is the second barrier in the host defense, the balance of these barriers would influence the status of HTLV-1-infected cells If viral expression is well controlled, the viral pathogenesis may not be apparent until malignant cell clones appear through the process of clonal evolution in the infected cell reservoir. This might explain the long incubation time for ATL development. In the absence of effective T-cell responses, the emergence of such clones may occur earlier, as clonal survival may be more likely.In contrast, if the suppression of viral expression is insufficient, either by insufficient IFN response or increased inflammatory cytokines, viral pathogenesis will become apparent and symptoms will be exhibited, especially in the tissues where viral proteins reach functional levels. In this case, however, the elevated levels of viral expression would also activate HTLV-1-specific T-cells, which potentially limit further growth of infected cells.The status of HTLV-1-specific T-cell response has been shown to be a determinant of HTLV-1-mediated diseases because of its anti-tumor and anti-viral effects. The selective impairment of HTLV-1-specific T-cell responses in early stages of ATL patients implies the presence of HTLV-1-specific suppressive mechanisms. The combination of insufficient HTLV-1-specific T-cell response and elevated proviral load may allow the identification of a group with a high risk for the development of ATL. In addition, vaccines that augment HTLV-1-specific T-cell responses may prove beneficial in reducing the risk in such a subpopu-lation.The status of HTLV-1 expression can be another determinant of HTLV-1-mediated diseases. Suppression of viral expression contributes to reduced viral pathogenesis, although it may, at the same time, partially interfere with T-cell surveillance. Host innate immunity, especially type-I IFN, is a candidate for the regulation of viral expression.Thus, both acquired and innate immunity can be host determinants that modulate HTLV-1-associated diseases. The involvement of the two control systems and their partially conflicting effects on one another may explain why the same virus can cause different diseases after a long incubation time. Further studies will elucidate the precise mechanisms for the regulation of host immunity and viral expression, and thereby provide insights for the prediction of disease risks, as well as new targets for the prevention of HTLV-1-mediated diseases.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Sugars do not only act as source of energy, but they also act as signals in plants. This mini review summarizes the emerging links between sucrose-mediated signaling and the cellular networks involved in flowering time control and defense. Cross-talks with gibberellin and jasmonate signaling pathways are highlighted. The circadian clock fulfills a crucial role at the heart of cellular networks and the bilateral relation between sugar signaling and the clock is discussed. It is proposed that important factors controlling plant growth  might fulfill central roles in the transition to flowering as well. The emerging concept of “sweet immunity,” modulated by the clock, might at least partly rely on a sucrose-specific signaling pathway that needs further exploration. In addition to their role as providers of carbon and energy, sugars fulfill a signaling role in coordination with hormonal signaling pathways  controllNext to growth and stress responses, it can be expected that sugar signaling is of great importance in flowering time control. This major developmental transition directly affects yield and its exact timing is essential for plant fitness . In manyIn this mini review, focus is on the possible contributions of sugar signaling to flowering and immunity responses, under control of the circadian clock.Arabidopsis, flowering can be autonomous or induced by gibberellins (GAs), as internal signals, or by the photoperiod and vernalization as external signals. FLOWERING LOCUS T (FT), SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) and LEAFY (LFY) transcription factors are among the best characterized floral pathway integrators, next to others  to the apex is well-documented . It is kFigure 1). GA inhibits DELLA protein levels, which are inhibitors of PHYTOCHROME INTERACTING FACTORS (PIFs), acting as growth enhancers . Recently, miR156 and miR172 were found as important factors controlling plant developmental transitions . miR172 is also under control of the clock by GI . The missing mechanistic link between GA signaling and flowering was recently established, by defining a role for DELLA as a general flowering inhibitor. DELLA inhibits SPL gene expression and miR172 production . Therefore, DELLA proteins are now considered both as growth and flowering inhibitors. Accordingly, transgenic plants overexpressing DELLA proteins or plants expressing mutant DELLA repressors show dwarfism and delayed flowering . It can be concluded that DELLAs occupy a central and crucial position in plant growth, development and flowering as well as in stress responses .DELLA proteins are crucial players in GA signaling pathways involved in plant growth control . Although the molecular mechanism for the control of transition to flowering by sugars remains to be further investigated, a possible scenario is that T6P rather than sucrose acts as a signal in such processes . Indeed, transgenic plants with altered T6P levels are also affected in their flowering time . Indeed, it was reported that PIF5 overexpression leads to early flowering, both under long day and short day conditions . Also, it would be interesting to investigate the mechanisms involved in the sucrose-mediated upregulation of the LFY gene . Another emerging link between flowering and sucrose metabolism/transport was reported by The relation between sugar metabolism/signaling and floral transition received extensive attention lately . The woring time . It can ing time . Althougnditions , stronglnditions . TherefoFigure 1) and crucial role coordinating carbon dioxide uptake, photosynthesis, and plant growth through GA- and sugar-mediated signaling pathways, with a clear connection to the flowering time control network , as explained above. Intriguingly, expression of FT in guard cells also promoted stomatal opening .These and other observations strongly suggest that there is an intimate interplay and reciprocal relationship between sugar metabolism/signaling and the plant circadian clock. So, besides light as the most important stimulus influencing the clock’s components through phytochromes and cryptochromes, endogenous sugar signals, hormones, and stresses also entrain the clock . Vice-ve2+ seems to be involved as well, probably by stimulating sucrose uptake into the cell . Strikingly, transgenic plants expressing a mammalian NO synthase become disease resistant to a broad array of plant pathogens  also have such sucrose-specific MAPKs.Sugars as signaling molecules are well-known activators of various pattern-recognition receptor genes ,b. Therethe cell . Both lithe cell . Nitric athogens  highlighathogens . The effchsianum , but it Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) was discovered in Arabidopsis .Arabidopsis. However, the putative sucrose sensor acting in this pathway remains to be identified, as well as the (transcription) factors involved in the upper part of the pathway, and this remains a challenging task.It is also proposed that efficient defense responses might not only rely on hormones and on cell wall or pathogen-derived saccharides, but perhaps also on sucrose, through a sucrose-specific signaling pathway, perhaps (partly) resembling (or overlapping) with the sucrose-mediated pathway controlling anthocyanin biosynthesis in The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.