The effects of AiiA protein expressed in eukaryotic cells on the virulence factors producted by Pseudomonas aeruginosa
Objective To construct the eukaryotic expression vector harboring the fragment of Alia gene, and to investigate the effects of it on the signal of quorum sensing and virulence factors producted by Pseudomonas aeruginosa(Pa). Methods The plasmid pET-AiiA was cutted by Nhe Ⅰ and Xho Ⅰ , then the AiiA fragment was cloned into eukaryotic expression vector pEGFP-N2. After the plasmid was transfected into A549 cells, the protein was extracted and AiiA protein was found in it by Western blot. After the extrac- tion was admixed into the LB broth, from culture supernatant extracts of Pa, the N-acylhomoserine lactone (AHL) was detected by bioassay, and the expression of pyocyanin and elastase were assayed by RT-PCR and optical density. Results The fragment of AiiA gene was cutted and then cloned into pEGFP-N2. AiiA protein was found in the transfected cells. After admixed with the extract harboring AiiA protein, in Pa medium, the AHL was hydrolyzed, and the expression of pyocyanin and elastase were reduced. Conclusion The virulence factors synthesized by Pa were reduced by the AiiA protein expressed in eukaryotic cell. 
 
Key words: 
Pseudomonas aeruginosa;  Quorum sensing;  Virulence factor;  AiiA protein