Relationship between CCR5(WT/Δ32) heterozygosity and HIV-1 reservoir size in adolescents and young adults with perinatally acquired HIV-1 infection

Abstract

[Background] Several host factors contribute to human immunodeficiency virus (HIV) disease progression in the absence of combination antiretroviral therapy (cART). Among them, the CC-chemokine receptor 5 (CCR5) is known to be the main co-receptor used by HIV-1 to enter target cells during the early stages of an HIV-1 infection.

[Objective] We evaluated the association of CCR5(WT/Δ32) heterozygosity with HIV-1 reservoir size, lymphocyte differentiation, activation and immunosenescence in adolescents and young adults with perinatally acquired HIV infection receiving cART. [Methods] CCR5 genotype was analysed in 242 patients with vertically transmitted HIV-1 infection from Paediatric Spanish AIDS Research Network Cohort (coRISpe). Proviral HIV-1 DNA was quantified by digital-droplet PCR, and T-cell phenotype was evaluated by flow cytometry in a subset of 24 patients (ten with CCR5(Δ32/WT) genotype and 14 with CCR5(WT/WT) genotype). [Results] Twenty-three patients were heterozygous for the Δ32 genotype but none was homozygous for the mutated CCR5 allele. We observed no difference in the HIV-1 reservoir size (455 and 578 copies of HIV-1 DNA per million CD4+ T cells in individuals with CCR5(WT/WT) and CCR5(Δ32/WT) genotypes, respectively; p 0.75) or in the immune activation markers between both genotype groups. However, we found that total HIV-1 DNA in CD4+ T cells correlated with the percentage of memory CD4+ T cells: a direct correlation in CCR5(WT/Δ32) patients but an inverse correlation in those with the CCR5(WT/WT) genotype. [Conclusions] This finding suggests a differential distribution of the viral reservoir compartment in CCR5(WT/Δ32) patients with perinatal HIV infection, which is a characteristic that may affect the design of strategies for reservoir elimination.