Co-receptor usage and prediction of v3 genotyping algorithms in hiv-1 subtype b' from paid blood donors experienced anti-retroviral therapy in chinese central province

HIV-1 strains were isolated in treatment HIV-1 infections and treatment-na？ve HIV-1 infections, then co-receptor usage of HIV-1 strains was identified based on Ghost cell lines using flow cytometry. HIV-1 V3 region was amplified and submitted into web-server (WebPSSM and geno2pheno) to predict HIV-1 co-receptor usage. The feasibility of prediction HIV-1 usage with Web-server assay was analyzed by comparing prediction of V3 genotyping algorithms with HIV phenotype assay based on Ghost cell line.45 HIV-1 strains and 114 HIV-1 strains were isolated from HIV-1 infections exposed anti-retroviral therapy and treatment-na？ve, respectively. 41% clinical viruses from ART patients and 18% from treatment-na？ve patients used CXCR4 as co-receptor. The net charge in the V3 loop was significantly difference in both groups. The sensitivity and specificity for predicting co-receptor capacity is 54.6% and 90.0% on 11/25 rule, 50.0% and 90% on Web-PSSMx4r5, 68.2% and 40.0% on Geno2pheno[co-receptor].Dual/mixed/X4 co-receptor utilization was higher in ART patients than treatment-na？ve patients. It is should paid attention to predicting HIV-1 co-receptor usage based on V3 genotyping algorithms in HIV-1 subtype B' from paid blood donors experienced anti-retroviral therapy in Chinese central province.HIV-1 enters a host cell using the CD4 receptor and co-receptors including the CXCR4 and/or CCR5. In general, R5-tropic strains using CCR5 as co-receptor are responsible for the early stage of infection, while mixed or dual-tropic R5/X4 strains using both CXCR4 and CCR5 as co-receptor, and X4 using CXCR4 co-receptor are detected in more advanced disease stages, and are believed to be associated with more rapid CD4 + T cell decline and accelerate disease progression to AIDS[1]. However the X4 viruses usually coexist with R5 viruses in the viral swarm[2]. There are still 50% patients with late stage HIV-1 B infection having only R5 viruses detectable in treatment-na？ve HIV-1 patients[3] but not