Exposure to HIV alters the composition of maternal microchimeric T cells in infants.

Infants exposed to HIV but uninfected (iHEU) display altered cellular immunity and are at increased risk of infection through poorly understood mechanisms. We previously reported that iHEU have lower levels of maternal microchimerism (MMc), maternal cells transferred to the offspring in utero/during breastfeeding. We evaluated MMc levels in T cell subsets in iHEU and HIV unexposed infants (iHU) to determine whether a selective deficiency in MMc may contribute to altered cellular immunity. Across all infants, MMc levels were highest in CD8+ T cells; however, the level of MMc in the CD8 T cell subset was significantly lower in iHEU compared to iHU.