Epidemiologic dominance of HIV-1 subtype CRF02_AG in Ghana: preliminary virological evidence of increasing association with new infections

In Ghana, HIV-1 subtype prevalence has varied appreciably over the past two and half decades. Recombinant forms have also increasingly emerged over the past decade. The dynamic nature of HIV-1 species profile in Ghana deserves exploration. This preliminary study investigates virological properties of epidemiologically prevalent HIV-1 subtypes in Ghana. Viruses were isolated from PBMCs obtained from Ghanaian HIV-1-infected individuals. Viral supernatants were prepared by transfection with subtyped HIV-1 full length DNA clones derived from viral isolates. Levels of virion production were quantitated by HIV-1 p24 antigen ELISA. MAGIC5A cells were infected by normalized virus and viral infectivity was determined by MAGI assay. Virion productivities and viral infectivities were compared by the nonparametric Kuskal-wallis one way ANOVA test. Findings show successful transfection of HIV DNA clones into cells. Virion productivity was found to be comparable (p=0.405) among eight strains tested. MAGI assay showed the infectivity of HIV-1 circulating recombinant form, CRF02_AG to be significantly higher (p=0.044) as compared to pure subtype A and subtype G viruses. The apparently high infectivity of the recombinant form observed in this study may suggest that recombination events might have the advantage in acquiring higher infectivity and pathogenesis during viral evolution. This may explain the increasing association of the CRF02_AG subtype with new infections and also highlight the evolutionary potential of HIV-1 in Ghana. The study sheds light on the virological basis of the epidemiologic dominance of prevalent HIV-1 subtypes and the role of in vitro HIV-1 infectivity in the in vivo situation.