Significantly skewed memory CD8+ T cell subsets in HIV-1 infected infants during the first year of life

HIV-1 infection causes a severe T cell compromise; however, little is known about changes in naive, memory, effector and senescent T cell subsets during the first year of life.T cell subsets were studied over the first year of life in blood from 3 infant cohorts: untreated HIV-infected, HIV-exposed but uninfected, and HIV-unexposed. In HIV-infected infants, the frequency of CCR7⁺CD45RA⁺ naive CD8⁺ T cells was significantly decreased, while the frequency of CCR7⁻CD45RA⁻ effector memory CD8⁺ T cells was increased, compared with the control cohorts. A larger population of CD8⁺ T cells in HIV-infected infants displayed a phenotype consistent with senescence. Differences in CD4⁺ T cell subset frequencies were less pronounced, and no significant differences were observed between exposed and unexposed HIV-uninfected infants. We concluded that the proportion of naive, memory, effector and senescent CD8⁺ T cells during the first year of life is significantly altered by HIV-1 infection.