Cis-regulatory genetic variants in the CCR5 gene and natural HIV-1 control in black South Africans

Abstract

Studies have investigated CCR5 haplotypes (HHA, HHB, HHC, HHD, HHE, HHF*1, HHF*2, HHG*1, HHG*2), defined by seven 5'UTR single nucleotide polymorphisms (SNPs), CCR2-V64I and CCR5Δ32, in HIV-1 disease. CCR5 cis-regulatory regions were sequenced, CCR2-V64I and CCR5Δ32 genotyped, and compared in HIV-1-infected black South Africans: 71 HIV-1 controllers (23 elite controllers, 37 viraemic controllers (VCs), 11 high viral load long-term non-progressors) and 74 progressors. The HHE haplotype and 3'UTR +2919 T > G SNP heterozygosity were underrepresented in total controllers and VCs vs. progressors (p = .004; p = .007 and p = .002, p_bonferroni = 0.032; p = .004, respectively). Possession of the +2919 T > G SNP (dominant mode) was associated with HIV-1 progression (controllers vs. progressors: p = .001, p_bonferroni = 0.016). The +2919 T > G SNP is in linkage disequilibrium (LD; r² = 0.73) with two 5'UTR SNPs (-2459G > A and -2135 T > C; r² = 1: 5'UTR-2SNP-hap). The 5'UTR-2SNP-hap was lower in total controllers and VCs vs. progressors (p = .003, p_bonferroni = 0.048; p = .01, respectively). Results suggest -2459G > A, -2135 T > C, and + 2919 T > G as key CCR5 variants in HIV-1 control.

Keywords: CCR5; Cis-regulatory regions; Genetic variants; HIV-1; Natural control; South Africa.