Institution: University of Port Harcourt

Project Affiliation: CEBioGen

Abstract

With the introduction of HIV-1 coreceptor inhibitors as components of antiretroviral therapy, it is critical to screen HIV positive persons prior to starting coreceptor inhibitor medication with Maraviroc. There is very little information about HIV coreceptor use in Nigeria, particularly in Rivers State. A cross-sectional study was adopted to characterize the coreceptor usage in HIV-1 infected individuals in Port Harcourt, Nigeria. Viral RNA extracted from blood samples of consenting HIV-1 infected individuals attending the antiretroviral therapy (ART) clinic of the University of Port Harcourt Teaching Hospital, was used to synthesize cDNA. The env C2-V3 region of the HIV-1 cDNA was amplified by nested RT-PCR, sequenced and evolutionary relationships determined using MEGA 5.2.2. HIV-1 coreceptor usage was predicted using the geno2pheno tool. Data obtained was analysed using SPSSV22.0. R5 tropic virus phenotypes slightly prevailed (53.8%) in the study over X4 (46.2%, n=18) virus phenotypes. The type of coreceptor usage by HIV was found to be significantly associated with the HIV Subtype, the V3 Loop Tip Motif, CD4 cell count and the number of X4 associated mutations (p<0.05). Most of the X4 variants had the basic amino acid, Arginine, at Position 11 of the V3 loop sequence, Majority (90.5%) of the R5 variants had the NNT sequon as potential glycosylation sites. A larger part (88.9%) of the X4 variants had more (4) mutation sites associated with X4 coreceptor usage than 71.4% of the R5 variants that had less (0 to 2) mutation sites. Many of the X4 variants (88.9%) harboured V3 loop X4 associated mutations with maraviroc-resistant phenotype while only 9.5% of the R5 variants harboured the mutation. This study gives baseline data for HIV tropism diversity in Rivers State, Nigeria. Documented data on mapping out cellular tropism based on viral tropism are important as maraviroc and the other CCR5 antagonist could be introduced as part of HIV treatment regimen in Nigeria.

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