The role of CSF Memory B cells in neuropathogenesis in PWH on ART

PROJECT SUMMARY/ABSTRACT Despite the success of antiretroviral therapy (ART) in achieving viral suppression, people with HIV (PWH) experience persistent immune activation in the central nervous system (CNS), contributing to cognitive impairment. While prior studies have focused on T cell and microglial contributions to CNS pathology, the role of B cells remains unexplored. B cells are critical regulators of immune responses, and evidence from other neuroinflammatory diseases suggests they can drive CNS pathology through antigen-specific and autoreactive mechanisms. Understanding B cell activity and antigen specificity in the CNS of PWH could uncover novel drivers of neuronal injury and cognitive decline. Our preliminary studies from cerebrospinal fluid (CSF) and blood in virally suppressed PWH compared to controls revealed markedly aberrant memory B cell gene expression and altered somatic hypermutation patterns in the CSF, suggesting persistent antigen-driven stimulation in the CNS despite ART. These abnormalities suggest that CNS-resident memory B cells play a unique and potentially pathogenic role in HIV-related neuroinflammation. To address this crucial knowledge gap, this study proposes to generate monoclonal antibodies (mAbs) from CSF-derived memory B cells in PWH and uninfected controls, and to test these mAbs for antigen reactivity. We will test for reactivity against HIV and opportunistic pathogens using massively high-throughput phage display assays that include over >500,000 pathogen derived peptides, including >7500 HIV peptides. To understand the role of autoimmunity in HIV-associated CNS dysfunction, we will next test CSF memory B cell derived mAbs for autoimmune reactivity using two parallel approaches. This multidisciplinary research will leverage advanced single-cell transcriptomics, high-throughput antigen screening, and cutting-edge antibody profiling techniques. The findings will provide crucial insights into the CNS-specific humoral immune response in PWH, with implications for vaccine design and the development of targeted therapies to mitigate CNS immune dysregulation.