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Biology subjects

Spudich, S.

Publications and source records attributed to Spudich, S..

7 recordsLinked to original sources

Multi-omic Characterization of HIV Effects at Single Cell Level across Human Brain Regions

HIV infection exerts profound and long-lasting neurodegenerative effects on the central nervous system (CNS) that can persist despite antiretroviral therapy (ART). Here, we used single-nucleus multiome sequencing to map the transcriptomic and epigenetic landscapes of postmortem human brains from 13 healthy individuals and 20 individuals with HIV who have a history of treatment with ART. Our study spanned three distinct regions--the prefrontal cortex, insular cortex, and ventral striatum--enabling a comprehensive exploration of region-specific and cross-regional perturbations. We found widespread and persistent HIV-associated transcriptional and epigenetic alterations across multiple cell types. Detailed analyses of microglia revealed state changes marked by immune activation and metabolic dysregulation, while integrative multiomic profiling of astrocytes identified multiple subpopulations, including a reactive subpopulation unique to HIV-infected brains. These findings suggest that cells from people with HIV exhibit molecular shifts that may underlie ongoing neuroinflammation and CNS dysfunction. Furthermore, cell-cell communication analyses uncovered dysregulated and pro-inflammatory interactions among glial populations, underscoring the multifaceted and enduring impact of HIV on the brain milieu. Collectively, our comprehensive atlas of HIV-associated brain changes reveals distinct glial cell states with signatures of pro-inflammatory signaling and metabolic dysregulation, providing a framework for developing targeted therapies for HIV-associated neurological dysfunction.

bioinformatics↗

Changes in Cerebrospinal Fluid Proteins across the Spectrum of Untreated and Treated Chronic HIV-1 Infection

Using the Olink Explore 1536 platform, we measured 1,463 unique proteins in 303 cerebrospinal fluid (CSF) specimens from four clinical centers that included uninfected controls and 12 groups of people living with HIV-1 infection representing the spectrum of progressive untreated and treated chronic infection. We present three initial analyses of these measurements: an overview of the CSF protein features of the sample; correlations of the CSF proteins with CSF HIV-1 RNA and neurofilament light chain protein (NfL) concentrations; and comparison of the CSF proteins in HIV-associated dementia (HAD) and neurosymptomatic CSF escape (NSE). These reveal a complex but coherent picture of CSF protein changes that includes highest concentrations of many proteins during CNS injury in the HAD and NSE groups and variable protein changes across the course of neuroasymptomatic systemic HIV-1 progression, including two common patterns, designated as lymphoid and myeloid patterns, related to the principal involvement of their underlying inflammatory cell lineages. Antiretroviral therapy reduced CSF protein perturbations, though not always to control levels. The dataset of these CSF protein measurements, along with background clinical information, is posted online. Extended studies of this unique dataset will provide more detailed characterization of the dynamic impact of HIV-1 infection on the CSF proteome across the spectrum of HIV-1 infection, and further the mechanistic understanding of HIV-1-related CNS pathobiology.

microbiology↗

Single-cell immune profiling reveals the impact of antiretroviral therapy on HIV-1-induced immune dysfunction, T cell clonal expansion, and HIV-1 persistence in vivo

Despite antiretroviral therapy (ART), HIV-1 persists in proliferating T cell clones that increase over time. To understand whether early ART affects HIV-1 persistence in vivo, we performed single-cell ECCITE-seq and profiled 89,279 CD4+ T cells in paired samples during viremia and after immediate versus delayed ART in six people in the randomized interventional Sabes study. We found that immediate ART partially reverted TNF responses while delayed ART did not. Antigen and TNF responses persisted despite immediate ART and shaped the transcriptional landscape of CD4+ T cells, HIV-1 RNA+ cells, and T cell clones harboring them (cloneHIV-1). Some HIV-1 RNA+ cells reside in the most clonally expanded cytotoxic T cell populations (GZMB and GZMK Th1 cells). CloneHIV-1+ were larger in clone size, persisted despite ART, and exhibited transcriptional signatures of antigen, cytotoxic effector, and cytokine responses. Using machine-learning algorithms, we identified markers for HIV-1 RNA+ cells and cloneHIV-1+ as potential therapeutic targets. Overall, by combining single-cell immune profiling and T cell expansion dynamics tracking, we identified drivers of HIV-1 persistence in vivo.

immunology↗

Immunologically distinct responses occur in the CNS of COVID-19 patients

One third of COVID-19 patients develop significant neurological symptoms, yet SARS-CoV-2 is rarely detected in central nervous system (CNS) tissue, suggesting a potential role for parainfectious processes, including neuroimmune responses. We therefore examined immune parameters in cerebrospinal fluid (CSF) and blood samples from a cohort of patients with COVID-19 and significant neurological complications. We found divergent immunological responses in the CNS compartment, including increased levels of IL-12 and IL-12-associated innate and adaptive immune cell activation. Moreover, we found increased proportions of B cells in the CSF relative to the periphery and evidence of clonal expansion of CSF B cells, suggesting a divergent intrathecal humoral response to SARS-CoV-2. Indeed, all COVID-19 cases examined had anti-SARS-CoV-2 IgG antibodies in the CSF whose target epitopes diverged from serum antibodies. We directly examined whether CSF resident antibodies target self-antigens and found a significant burden of CNS autoimmunity, with the CSF from most patients recognizing neural self-antigens. Finally, we produced a panel of monoclonal antibodies from patients CSF and show that these target both anti-viral and anti-neural antigens--including one mAb specific for the spike protein that also recognizes neural tissue. This exploratory immune survey reveals evidence of a compartmentalized and self-reactive immune response in the CNS meriting a more systematic evaluation of neurologically impaired COVID-19 patients. One Sentence SummaryA subset of COVID-19 patients with neurologic impairment show cerebrospinal fluid-specific immune alterations that point to both neuroinvasion and anti-neural autoimmunity as potential causes of impairment.

immunology↗

Group Based Trajectory Analysis of Cognitive Outcomes in Children with Perinatal HIV

BackgroundCognitive impairment is common in children with perinatally-acquired HIV (pHIV). It is not known whether exposure to HIV-related neuropathogenic mechanisms during vulnerable periods of neurodevelopment may produce distinct long-term cognitive phenotypes as children age. We used group based trajectory modeling to identify clusters of children with pHIV following a unique developmental trajectory across age and predictors of belonging to select cognitive trajectory groups.\n\nMethodsParticipants included children aged 1 to 17 enrolled in the PREDICT resilience study, a cohort study of children with pHIV in Thailand and Cambodia. Cognitive testing was conducted semi-annually over three years. Group based trajectory analyses determined subgroups of children with differing cognitive trajectories using maximum likelihood estimates and Bayesian statistics. Multiple logistic regression identified baseline factors associated with belonging to the lowest scoring trajectory group.\n\nResultsThree distinct cognitive phenotypes were identified for each neurocognitive test categorized as high, medium and low scoring groups. A subgroup of children demonstrated normal developmental patterns for Color Trails Test 1 and 2. Children in the low trajectory group were more likely to present at an older age (>8 years, OR: 2.72; p 0.01) and report lower household income level (OR: 0.33-0.42; p<0.005). Neither CD4 nadir nor treatment arm was associated with cognitive trajectory status.\n\nConclusionOur study reflects the benefit of using group based trajectory modeling to classify the heterogeneity in cognitive outcomes of children with pHIV. Children were described as belonging to three distinct subgroups determined at study onset alluding to the fact that cognitive outcomes are likely to be determined at an early age with little variability over time in children with pHIV. Demographic variables, including older age at presentation and household income, were associated with low scoring cognitive trajectories, whereas HIV related variables were not. These findings mirror other studies and demonstrate the impact of socioeconomic factors on cognitive development in children with pHIV.

neuroscience↗

Systems analysis by mass cytometry identifies susceptibility of latent HIV-infected T cells to targeting of p38 and mTOR pathways

Efforts to cure HIV are hindered by viral persistence in latently infected memory CD4+ T cells. Targeting T cell death pathways dysregulated by HIV infection offers a novel approach for eradication of the latent reservoir. To identify potential therapeutic targets, we compared signaling and apoptosis in uninfected and latently infected primary cultured CD4+ central memory T cells by mass cytometry following T cell receptor stimulation. We found that HIV-infected cells were sensitized to activation of pro-apoptotic p38 kinase signaling via p53, and to inhibition of anti-apoptotic mTOR kinase signaling, even without HIV protein expression. Simultaneous targeting of p38 and mTOR kinases in resting CD4+ T cells from virally-suppressed HIV+ patients ex vivo reduced cell-associated HIV RNA and DNA. Our results demonstrate how systems biology approaches are useful for identifying novel therapeutic approaches to treat HIV latency, and further suggest that it may be possible to deplete latent HIV-infected T cells without viral reactivation.

systems biology↗

Single cell RNA sequencing reveals a novel, microglia-like cell type in cerebrospinal fluid during virologically suppressed HIV

Central nervous system (CNS) immune activation in an important driver of neuronal injury during several neurodegenerative and neuroinflammatory diseases. During HIV infection, CNS immune activation is associated with high rates of neurocognitive impairment, even with sustained long-term suppressive antiretroviral therapy (ART). However, the cellular subsets that drive immune activation and neuronal damage in the CNS during HIV infection and neurological conditions remain unknown, in part because CNS cells are difficult to access in living humans. Using single cell RNA sequencing (scRNA-seq) on cerebrospinal fluid (CSF) and blood from adults with HIV, we identified a rare (<5% of cells) subset of myeloid cells in CSF presenting a gene expression signature consistent with neurodegenerative disease associated microglia. This highlights the power of scRNA-seq of CSF to identify rare CNS immune cell subsets that may perpetuate neuronal injury during HIV infection and other conditions.

immunology↗