The proportion of CD57+ cells among effector CD8+ T cells is lower in HIV controllers compared with antiretroviral therapy-treated patients

Background: HIV infection has often been linked to faster immune ageing. We sought to determine whether or not treatment-naive spontaneous HIV-1 controllers (HICs) and ART-exposed patients differ with regard to the expression of cell senescence markers. Methods: Eighty-eight chronically infected HICs and ART-exposed patients (median time since infection: 15 years) with an undetectable plasma HIV RNA load (at least for the previous 2 years) were included. We used flow cytometry to measure immunosenescence markers (KLRG-1 and CD57) expression in fresh blood samples collected from patients and healthy donors. Results: For the CD8(+) T-cell population as a whole, the ART-exposed but not the HIC patients exhibited a much higher proportion of KLRG-1(+) and CD57(+) CD8(+) T cells than healthy blood donors. For the CD8(+) T-cell subsets, HICs had a lower proportion of CD57(+) effector CD8(+) T cells than ART patients or healthy blood donors, whereas the proportions of KLRG-1(+) effector were similar. A similar trend was observed for terminal effectors. No impact of age, sex or standard parameters of infection (CD4(+) percentage, protective HLA allele, viral blips) was observed. The difference in the proportion of CD57(+) cells between HICs and ART was observed more specifically in long-term infected patients (>20 years). However, whenever considering the CD57(-) effector memory and effector subsets, the cytotoxic granule content was greater in HICs than in ART. Conclusion: The proportion of CD57(+) effector CD8(+) T cells is lower in HICs than in ART-exposed patients. This profile may be beneficial by ensuring limited senescence associated with consistent cytotoxic potential. Copyright (C) 2019 Wolters Kluwer Health, Inc. All rights reserved.