AIDS research and human retroviruses 2017 12 14() doi 10.1089/AID.2017.0169
Despite optimization of preventative measures for vertical HIV-1 transmission, daily roughly 400 infants become HIV infected, most of them via breastfeeding. Viral entry has been presumed to occur in the gastrointestinal tract; however, the exact entry site(s) have not been defined. Therefore, we quantified viral RNA and DNA in oral, intestinal and systemic tissues of 15 infant macaques within 48-96 hours after oral SIVmac251 exposure. SIV DNA was detected as early as 48 hours, whereas SIV RNA was typically detected at later time points (72-96 hours). Transmitted founder viruses were identical or very similar to a single genotype in the SIVmac251 challenge stock. SIV RNA and DNA were most frequently found in lymph nodes draining the oral cavity and in the ileum. Using in situ hybridization, SIV-infected cells in LNs were exclusively represented by CD3+ T cells. SIV RNA and DNA were also detected in the lungs of 20% of the animals, and 60% of the animals had detectable SIV DNA in the cerebrum. The early detection of viral RNA or DNA in lung and brain tissues emphasizes the need for early treatment of pediatric HIV infection to prevent damage not only to the immune system, but also to the respiratory tract and central nervous system.