ABSTRACT SIGNIFICANCE: HIV has been shown to seed in the central nervous system (CNS) during primary viremia and serve as a reservoir of HIV (PMCID: PMC10266791, PMC32332225). In addition to latent reservoirs, replication- competent reservoirs are believed to persist in the CNS during cART (PMID: PMC31790378, PMC5831193, PMC5044815, PMC5559639, PMC7896558). This is particularly concerning for infants as their brains grow and develop, leading to numerous neurodevelopment consequences (PMID: 24125015) and neurologic diseases (PMID: 24806816). Compared to peripheral infection and reservoirs, current understandings of CNS infection and associated neuroinflammation during early infection and under early treatment are limited. Advances in molecular biology, nucleotide sequencing, and bioinformatic approaches have allowed our team to develop a strategy to track infected cell clones with viral integration sites to show the impact of therapy on virus infected clonally expanded cells (PMID: 32766447, PMID: 25289675, PMID: 24702996, PMID: 20844053, PMID: 28654067). Moreover, we explore the utility of a library of barcoded viruses to achieve a population level analysis of infection in latent reservoirs and after HIV rebound (PMID: 33377133, PMID: 35013215). Here, these technologies will be adapted to assess the impact of bNAbs on SHIV CNS infection. AIMS: In this project, we propose to examine in detail the early dynamics and neuroinflammation of CNS infection in the SHIV infant macaque model established at the ONPRC. We have established unique molecular approaches to delineate CNS infection and reservoirs and their changes responding to treatment. Our team uses a library of barcoded viruses to quantify the frequency of tagged viruses which are integrated, and the relative level of each tagged virus produced in the periphery and the CNS. We have also developed high throughput sequence analysis of viral integration sites, which enables quantitation of clonal expansion of infected cells. Both assays together provide sensitive and quantitative means to assess the impact of therapy upon the contribution of infected cells to the SHIV reservoir in the CNS. In Aim 2, we will further test a novel therapeutic strategy aimed towards CNS infection suppression and clearance through effective delivery of nanocapsuled bNAb in the CNS. Importantly, our CNS-delivered nanocapsules can be extended to various bNAbs and other therapeutics (e.g., other immunotherapeutics, gene-editing agents, anti-viral drugs), opening a new avenue for the development of novel HIV therapeutics. IMPACT: The success of this study will begin to dissect the mechanisms underlying CNS infection in infants and demonstrate the effectiveness of bNAbs with improved CNS delivery to suppress CNS and deep tissue infection and reservoirs. The successful completion of this project and acquired knowledge may lead to interventions that could be initiated within the first few weeks of infection, the window of opp...