Longitudinal analysis of innate immune system in infants with perinatal HIV infection until 18 months of age.

Vertical transmission of HIV has been reduced globally in recent years, however in utero exposure and acquisition of HIV continues to occur, especially in sub-Saharan Africa. Immediate ART initiation is recommended in infants diagnosed with HIV, but adherence is often suboptimal due to behavioral and sociological challenges. The impacts of perinatal HIV infection and ART on the developing immune system in infants are still unclear. Here, we evaluated a cohort of HIV exposed infected infants, and age-matched HIV exposed uninfected infants from Mozambique at pre-ART (age 1-2m) and post-ART longitudinally (up to 18m) specifically to compare the innate immune cellular components. We found that circulating innate immune cells including Natural Killer (NK) cells, monocytes, and Dendritic Cells (DC) exhibited altered distributions and more activated (inflammatory) phenotypes at pre-ART in infants with HIV suggesting the presence of a virus specific immune response. Despite suboptimal ART adherence in the cohort, differences in innate immune subsets between infected (suppressed and unsuppressed) and uninfected were not observed longitudinally pointing to normalized immune development despite HIV infection. Our study provides new insights into the early innate immune response during perinatal HIV.