Remission of HIV-1 where antiretroviral therapy may be discontinued without viremic rebound remains elusive for the 33 million infected persons living with HIV-1/AIDS, 2.5 million of whom are children younger than 13 years. A single case of HIV-1 remission in a perinatally infected child has provided optimism that prompt antiretroviral therapy of an infected neonate may be sufficient to achieve HIV-1 remission in perinatal HIV-1 infection. Work outlined in this proposal will provide insights into whether distinctive features of the neonatal immune system, combined with prompt initiation of combination antiretroviral therapy (cART) in perinatally-infected infants, can sufficiently alter proviral reservoirs to facilitate vial remission, allowing discontinuation of cART without viral rebound.
The overall goal of this application is to understand whether distinctive features of the neonatal immune system, combined with prompt initiation of combination antiretroviral therapy (cART) in perinatally-infected infants, can sufficiently alter te size and distribution of proviral reservoirs to facilitate viral remission, where cART can be stopped without viremic rebound. A major barrier to HIV-1 remission is the early establishment of latent cellular reservoirs that permit lifelong persistence of replication-competent virus. The opportunity to start cART promptly in infants may severely restrict or abort the formation of these long-lived HIV-1 reservoirs. This concept is exemplified in the recent case of the Mississippi Child in whom cART started by 31 hours of age led to HIV-1 remission. We specifically hypothesize that early or very early cART in the context of HIV-1 infection of a predominantly fetal immune system restricts the size, distribution, and replication-competence of the HIV-1 reservoirs in long-lived central memory CD4+ T cells, eventually permitting HIV-1 remission. In three different cohorts of perinatally-infected children spanning the neonatal period through adolescents, including in a planned clinical trial sponsored by the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) Network, we will use ultrasensitive molecular, immunology and virus culture assays to: 1) Confirm ongoing decay of and identify where HIV-1 proviral reservoirs reside under long-term effective cART in perinatal HIV-1 infection, 2) identify a virologic and immunologic profile of HIV-1 near-remission that indicates the appropriate timing of cART cessation after very early or early cART initiation, 3) determine if infection of neonatal CD4+ T cells is associated with diminished HIV-1 integration events and replication-deficient genomes that permit clearance of HIV-1 in neonates initiating very early cART and 4) determine whether a predominance of fetal T and/or myeloid cells at birth is associated with and predictive of rapid decay of a restricted viral reservoir. The proposed project will improve scientific knowledge on the long-term virologic and immunologic effects of early/very early HAART for infants who are now likely to survive to young adulthood. It will also provide insights into the early infection events leading up to HIV-1 reservoir formation and whether prompt antiretroviral therapy will lead to HIV-1 remission or cure, thus sparing HIV- 1 infected children a lifetime of therapy. The studies have direct relevance to the research mission of the National Institutes of Health where finding ways to achieve viral remission or cure is a top research priority area.