Development of Recombinant Antigen of Human T-lymphotropic Virus and Double-antigen Sandwich ELISA
For development of a sensitive and specific diagnostic kit of the human T-lymphotropic virus (HTLV), a chimeric envelope gene of the HTLV-Ⅰ and HTLV-Ⅱ was expressed in E. coli. The recombinant antigen, ENV168 (reacted good with anti-HTLV and was used as peroxidase conjugated antigen), together with another recombinant antigen was developed as a double-antigen sandwich ELISA(dsELISA). The dsELISA could detect out all the 31 HTLV-Ⅰ positive sera and 19 HTLV-Ⅱ positive sera, and the sensitivity of the assay on 5,065 negative sera was 99.94%. A parallel detection of 18 HTLV-Ⅰ positive sera, 17 HTLV-Ⅱ positive sera and 1,024 donors′ sera using dsELISA and a commercial kit (GeneLabs kit) was performed. The results showed that both the sensitivity and specificity of the dsELISA were 100%, and the reactivity (mean s/co value) to HTLV-Ⅰ samples was similar as to HTLV-Ⅱ samples, both were significantly higher than those of GeneLabs kit. For GeneLabs kit, the reactivity with HTLV-Ⅰ samples was significantly higher than that with HTLV-Ⅱ samples. The specificity of dsELISA was significantly higher than GeneLabs kit. These results suggest that the dsELISA kit is useful on the diagnosis of the HTLV-Ⅰ infection as well as HTLV-Ⅱ infection.