Genetic And Biological Characterization Of HIV-1 In Blood And Semen In Hiv-infected Patients After Six Months Of ART

Objective We conducted an observational study on HIV-infected patients after six months of ART. HIV levels were assessed in paired semen and blood samples. The C2-V5 region of the HIV envelope(env) genes was cloned and sequenced. The genotype and co-receptor usage were predicated based on the sequence. We expect to study the biological and genetic features of HIV-1 virus in HIV-infected patients after six months of ART to find out the reason of why there is a higher risk of HIV transmission for MSM in our country, the mechanism of transmission and pathogenesis of HIV-1 infection.Methods We choosed Nineteen HIV-infected patients who had received ART for six months, and collected their four kinds of samples including PBMC, blood plasma, seminal cells, and seminal plasma. C2V5 sequences are amplified by nest-PCR. Then through a series of experimental operation, we obtain ten C2V5 sequences for each sample of all patients. For our C2V5 results, Contig Express and Bio Edit are used to align. Finally, on the one hand, Mega6 can bulid the phylogenetic tree; on the other hand, Geno2 pheno and PSSM systems can predict the usage of co-receptor.Results(1)After six months of ART, the blood HIV RNA remained positive only in 2 patients,but seminal HIV RNA remained positive in 16 patients. Total, 2LTR circular and integrated HIV DNA in PBMC and seminal cells remained positive, although HIV RNA in blood was negative after six month of ART(2)38 cases were successful amplification C2V5 area ultimately, 2 cases in blood plasma, 16 cases in seminal plasma, 11 cases in PBMC, 9 cases in seminal cells, we got 380 monoclonal.(3)The subtypes of 13 patients were B,and 3 patients were C. The virus variation in semen is greater than that in blood.(4) The co-receptor(R5/X4) usage between blood and semen was very different. The CCR5 and CXCR4 in the blood plasma are all 50%, But in the semen plasma they are 54.4% and 45.6%. In the PBMC they are 22.7% and 77.3%, and in the seminal cells they are 14.4% and 85.6%.(5)The major central motif of V3 loop in the blood plasma, PBMC, seminal cells were GPGO. But in the semen plasma was GPGR. Some other motifs were observed in semen but not blood.(6)The charge numbers of V3 loop amino acids were higher in semen than in the blood significantly.Conclusions HIV RNA and proviral HIV DNA could be detected in semen of most patient although HIV RNA was undetectable in blood after 6 months of antiretroviral therapy.The virus evolution situations in different kind of samples are obvious different. The same situations occurred in the usage of co-receptor and V3 loop central motifs and charges.