Intersection of Neuro-Immune-Vascular Dynamics in Preclinical NeuroHIV Model - SUMMARY Following systemic infection, HIV-1 enters the CNS by a “Trojan horse” mechanism, using infected monocytes or T-cells from the periphery to cross the blood-brain barrier (BBB) and infect CNS cells. Within the CNS, microglia (MG), resident macrophages (MΦ), serve as reservoirs for HIV-1. Although neurons are not directly infected, they appear highly susceptible to dysfunction due to the presence of the virus in the CNS. HIV-1 infection leads to BBB dysfunction, exacerbating viral replication within the CNS. Inflammatory factors released by infected MG/MΦ contribute to selective synaptic damage in neurons, gradually resulting in CNS pathology. This neuronal dysfunction manifests as impaired cognitive function, known as HAND, affecting 30- 50% of HIV-1 individuals regardless of antiretroviral treatment. The goal of this proposal is to develop new insights into how HIV-1 affects the brain, recapitulate aspects of BBB and CNS pathology in a highly controllable manner and define the pathogenic state of CNS HIV-1 infection. We will develop a next generation preclinical model of NeuroHIV, that better recapitulate neuro-immune-vascular system interactions in the context of ART-mediated HIV suppression. We will incorporate peripheral immune cells that support a natural route of HIV entry across the BBB into the CNS, glial cells relevant to the neuropathogenesis of HIV infection, neurons, brain endothelial cells and BBB supporting cell types. We propose the following aims to achieve the goals. Aim 1 (R61), Generate, characterize and validate iPSC-derived CNS cells and immune cells. Aim 2 (R61), Establish a perfused HIV-1 blood-BBB/CNS model. Milestones of the R61 phase will be to validate iPSC types, optimize protocols and demonstrate reliable HIV-1 infection of MG/MΦ, establishment of at a HIV-CNS 3D model with flow, test MΦ’s BBB transmigration and finally to optimize protocols to track the spread of HIV-1GFP infection within the CNS compartment. Finally Aim 3 (R33), we will create a 3D blood- BBB/CNS model with flow, which dynamically examines neuro-immune-vascular “circuit responses” in the context of ART-suppressed HIV-1 infection. By creating the first 3D human HIV-1 blood-BBB/CNS model that allows for single-cell imaging and transcriptomic analysis, we have a unique opportunity to recapitulate the clinical picture of NeuroHIV, including neurological endpoint measures. This model will enable us to study how HIV expression drive pathogenic neuro-immune-vascular “circuit responses” in the context of an ART- suppressed infection and to examine the potential neurotoxic effects of ART therapies themselves. The proposal addresses significant knowledge gaps related to the disease etiology of NeuroHIV in clinical populations on ART, with a high potential for overall impact.
