Background: Human cyclophilin A (CypA) encoded by peptidyl prolyl isomerase A gene (PPIA), enhances HIV-1 replication by aiding capsid uncoating. The association of genetic variation in the PPIA regulatory region with susceptibility to HIV-1 infection, disease progression, and gene expression among black South Africans at risk for infection or infected with HIV-1 is unknown.
Methods: We genotyped 539 participants from 2 longitudinal study cohorts of black South Africans at high risk for infection or infected with HIV-1 for PPIA regulatory single nucleotide polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.
Results: Minor allele (G) of SNP rs6850 (rs6850 G) significantly associated with higher viral loads (mean 4.85 versus 4.46 log copies/mL, P = 0.0006) and lower CD4 T-cell counts (mean 506 versus 557 cells/μL, P = 0.0256) during the acute phase of infection in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 002 cohort. Consistently, rs6850 G significantly associated with higher viral loads (mean 4.49 versus 4.01 log copies/mL, P < 0.0001) and lower CD4 T-cell counts (mean 442 versus 494 cells/μL, P = 0.0002) during the early chronic phase of infection in the CAPRISA 002 cohort; rs6850 G further associated significantly with rapid CD4 T-cell decline in the CAPRISA 002 cohort (P = 0.0481) and Sinikithemba chronic infection cohort (P = 0.0156). Interestingly, rs6850 G significantly associated with elevated CypA mRNA levels in HIV-1-positive individuals (P = 0.0061).
Conclusions: These data suggest that rs6850 G enhances HIV-1 replication through upregulation of CypA expression following HIV-1 infection. The data support ongoing efforts to develop anti-HIV-1 drugs that block interaction of HIV-1 and cellular proteins.