Briz, V. | Search bioRxiv

bioRxiv2024

Changes in the senescence profile and immune checkpoints in HIV-infected individuals after COVID-19

BackgroundBoth SARS-CoV-2 and HIV infection exhibit alterations in the senescence profile and immune checkpoint (IC) molecules. However, the midterm impact of SARS-CoV-2 on these profiles in people with HIV (PWH) remains unclear. This study aimed to evaluate differences in plasma biomarker levels related to ICs, the senescence-associated secretory phenotype (SASP), and pro- and anti-inflammatory cytokines in PWH following recovery from SARS-CoV-2 infection. MethodsWe conducted a cross-sectional study of 95 PWH receiving antiretroviral therapy, stratified by SARS-CoV-2 infection status: a) 48 previously infected (HIV/SARS) and b) 47 controls without previous infection (HIV). Plasma biomarkers (n=44) were assessed using Procartaplex Multiplex Immunoassays. Differences were analyzed using a generalized linear model adjusted for sex and ethnicity and corrected for the false discovery rate. Significant values were defined as an adjusted arithmetic mean ratio [≥]1.2 or [≤]0.8 and a qvalue<0.1. Spearman correlation evaluated relationships between plasma biomarkers (significant correlations, rho[≥]0.3 and q value<0.1). ResultsThe median age of the PWH was 45 years, and 80% were men. All SARS-CoV-2-infected PWH experienced symptomatic infection; 83.3% had mild symptomatic infection, and sample collection occurred at a median of 12 weeks postdiagnosis. The HIV/SARS group showed higher levels of ICs (CD80, PDCD1LG2, CD276, PDCD1, CD47, HAVCR2, TIMD4, TNFRSF9, TNFRSF18, and TNFRSF14), SASP (LTA, CXCL8, and IL13), and inflammatory plasma biomarkers (IL4, IL12B, IL17A, CCL3, CCL4, and INF1A) than did the HIV group. ConclusionsSARS-CoV-2 infection in PWH causes significant midterm disruptions in plasma ICs and inflammatory cytokine levels, highlighting SASP-related factors, which could be risk factors for the emergence of complications in PWH.

microbiology↗

bioRxiv2021

Control of protein synthesis and memory by GluN3A-NMDA receptors through inhibition of GIT1/mTORC1 assembly

De novo protein synthesis is required for synapse modifications underlying stable memory encoding. Yet neurons are highly compartmentalized cells and how protein synthesis can be regulated at the synapse level is unknown. Here we characterize neuronal signaling complexes formed by the postsynaptic scaffold GIT1, the mTOR kinase and Raptor that couple synaptic stimuli to mTOR-dependent protein synthesis; and identify NMDA receptors containing GluN3A subunits as key negative regulators of GIT1 binding to mTOR. Disruption of GIT1/mTOR complexes by enhancing GluN3A expression or silencing GIT1 inhibits synaptic mTOR activation and restricts the mTOR-dependent translation of specific activity-regulated mRNAs. Conversely, GluN3A removal enables complex formation, potentiates mTOR-dependent protein synthesis, and facilitates the consolidation of associative and spatial memories in mice. The memory enhancement becomes evident with light or spaced training, can be achieved by selectively deleting GluN3A from excitatory neurons during adulthood, and does not compromise other aspects of cognition such as memory flexibility or extinction. Our findings provide mechanistic insight into synaptic translational control and reveal a potentially selective target for cognitive enhancement.

neuroscience↗