Biology subjects

Ancuta, P.

Publications and source records attributed to Ancuta, P..

11 recordsLinked to original sources

bioRxiv2026

ALDH Activity in Monocytes is Associated with Subclinical Coronary Atherosclerosis in Treated People with HIV-1

People living with HIV-1 (PWH) receiving antiretroviral therapy (ART) exhibit an increased cardiovascular disease (CVD) risk. Coronary atherosclerotic plaque formation is linked to chronic immune activation, a process fueled in PWH by additional mechanisms likely including residual HIV-1 production and microbial translocation from the gut during ART. Our previous studies demonstrated that aldehyde dehydrogenase (ALDH), an enzyme converting vitamin A into retinoic acid (RA), is upregulated in myeloid cells upon exposure to viral/bacterial/fungal products and that RA promotes HIV-1 production. To explore the link between ALDH/RA pathway and CVD risk, we used PBMC/plasma from ART-treated PWH (PWH+ART; n=51) and people without HIV-1 (Pw/oH; n=63) from the Canadian HIV/Aging Cohort Study, with/without subclinical coronary atherosclerosis, measured by coronary computed tomography angiography. ALDH expression was analyzed by flow cytometry on monocyte subsets, dendritic cells, and CD4+ T-cells. Unsupervised t-SNE-guided FlowSOM analysis associated top ALDH activity with a monocyte phenotype. The frequency of ALDH+ monocytes and plasma levels of RA and retinol binding protein 4 were increased in PWH+ART versus Pw/oH, with the highest RA levels coinciding with detectable plasma levels of soluble HIV-1 gp120. Multivariate regression models linked ALDH activity in monocytes to subclinical coronary atherosclerosis (i.e., total plaque volume, low attenuated plaque volume, coronary artery calcification score) presence/burden in PWH+ART, independently of Framingham risk score. Finally, ALDH+ monocyte frequency and RA levels positively correlated with pericoronary fat attenuation index, an emerging CVD predictor. Thus, ALDH/RA pathway may represent a new marker of metabolic/immune dysfunction contributing to CVD risk in ART-treated PWH.

immunology↗

bioRxiv2026

REV-ERBα/β Targeting Transcriptionally Reprograms HIV-Infected CD4+ T-Cells for Increased Viral Reactivation but Limited Virion Spread

The circadian clock repressors REV-ERB/{beta} control rhythmic gene expression and inhibit HIV-1 transcription. Whether REV-ERB/{beta} modulate the HIV-1 replication cycle beyond transcription remains unknown. Here, we demonstrate that memory CD4+ T-cells predominantly express the REV-ERB{beta} isoform ex vivo and that T-cell receptor (TCR) triggering downregulates both REV-ERB/{beta} expression, with levels of REV-ERB/{beta} mRNA being lower in ART-treated people with HIV (PWH) receiving antiretroviral therapy (ART) compared to people without HIV (PWoH) before/after TCR triggering. In single-round infection, the REV-ERB/{beta} antagonist SR8278 facilitated HIV-1 reverse transcription, integration, and intracellular HIV-p24 expression, but limited virion release. Moreover, SR8278 downregulated CCR5 mRNA expression, inhibited R5-tropic HIV-1 replication in vitro, and limited viral outgrowth in CD4+ T-cells from ART-treated PWH. Finally, genome-wide RNA-sequencing and functional validations revealed HIV-1 restriction/dependency factors that represent novel putative REV-ERB/{beta} targets. Thus, pharmacological inhibition of REV-ERB/{beta} uniquely combines a latency reversal activity with the inhibition of progeny virion spread.

immunology↗

bioRxiv2026

Identification of the cellular transcription factor KLF16 as a novel repressive epigenetic repressor of HIV-1 transcription

Despite antiretroviral therapy, human immunodeficiency virus type 1 (HIV-1) persists in latently-infected cells through epigenetic and transcriptional mechanisms. Latency-reversing agents have failed clinically, partly due to incomplete understanding of HIV-1 latency reversal. Here, using DNA-affinity capture and mass spectrometry on the HIV-1 5 long terminal repeat (5LTR) enhancer-core promoter, we identify KLF16 (Kruppel-like Factor 16) as a novel regulator of HIV-1 gene expression. KLF16 binds to the HIV-1 5LTR in vivo at Sp1 binding sites, and KLF16 depletion reactivates latent HIV-1 in T-lymphoid and monocytic cell models. Mechanistically, KLF16 represses HIV-1 transcription by competing with Sp1 for promoter binding and by recruiting the Sin3A/HDAC1 and HP1/Suv39H1 repressive epigenetic complexes. KLF16 is also upregulated in CD4+ T cells from ART-treated people with HIV-1 upon T-cell activation. Additionally, All-Trans retinoic acid (ATRA) reactivates latent HIV-1 in myeloid cells, partly by downregulating KLF16. These findings establish KLF16 as a novel transcriptional repressor of HIV-1, identifying it as a potential promising therapeutic target for cure strategies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=136 SRC="FIGDIR/small/722432v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1611026org.highwire.dtl.DTLVardef@16b5eaforg.highwire.dtl.DTLVardef@153b11org.highwire.dtl.DTLVardef@1d90330_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Humanized Bone Marrow-Liver-Thymus Mice for Studying HIV-1 Persistence in Liver and Lung CD4+ T and Myeloid Cell Subsets during Antiretroviral Therapy

BackgroundWhile the role of CD4+ T-cells in HIV-1 reservoir persistence during antiretroviral therapy (ART) is well-established, studies on tissue-resident macrophages (M{Phi}) in people with HIV-1 (PWH) are restricted by difficulties in accessing deep tissue samples. Investigations in myeloid-only humanized mouse models demonstrated the contribution of M{Phi} to viral rebound upon ART interruption. Two distinct M{Phi} subsets exist in mice and humans: one of embryonic origin and self-renewal capacity generating long-lived tissue-resident M{Phi} (LL-TRM), and another one of short-lived M{Phi} (SL-M{Phi}), constantly replenished by bone marrow monocytes. The relative contribution of LL-TRM versus SL-M{Phi} to tissue HIV-1 reservoir persistence during ART remains understudied. Here, we used a humanized BM-liver-thymus (hu-BLT) mouse model to quantify integrative HIV-1 infection in liver/lung M{Phi} versus CD4+ T-cells before/after ART and document their expression of LL-TRM/SL-M{Phi} markers. ResultsLung/liver immune cells were extracted from ART-naive (ART-) and ART-treated (ART+) HIV-infected (HIV+) hu-BLT mice, as well as HIV-uninfected mice (HIV-). M{Phi} were identified as cells expressing the myeloid markers CD33/HLA-DR and/or CD68 and flow-cytometry sorted based on their differential expression of CD14 and/or CCR2. Matched CD3+CD4+ T-cells were sorted in parallel and used as controls. HIV-DNA integration was measured by nested real-time PCR. In contrast to CD4+ T-cells that carried the highest levels of proviral HIV-DNA before and after ART, integrative infection in liver/lung M{Phi} was detected before ART, but was drastically reduced in HIV+ART+ hu-BLT mice, regardless of CD14 or CCR2 expression on M{Phi}. Markers of LL-TRM (CD163/CX3CR1/Ki67/c-Kit) were expressed on a small fraction of liver but not lung M{Phi}, indicative of a deficient LL-TRM development in this hu-BLT model. ConclusionsTogether our results demonstrate that lung/liver M{Phi} in hu-BLT mice support integrative HIV-1 infection in vivo, but their contribution to viral reservoir persistence during ART is minor when compared to CD4+ T-cells. This is consistent with the deficient development of LL-TRM we observed in hu-BLT mice. However, HIV-1 permissive M{Phi} present in this model likely contribute to viral rebound upon ART interruption. Therefore, HIV-1 cure interventions that are tested in such preclinical models should consider targeting HIV-1 replication in both M{Phi} and CD4+ T-cells.

immunology↗

bioRxiv2024

Novel Immunological Markers of Intestinal Impairment Indicative of HIV-1 Status and/or Subclinical Atherosclerosis

Antiretroviral therapy (ART) controls HIV-1 replication in people with HIV-1 (PWH), but immunological restauration is not achieved at mucosal barriers. Intestinal integrity impairment fuels microbial translocation and chronic immune activation, thus heightening the cardiovascular disease (CVD) risk. Here, we sought to identify novel immunological predictors of the HIV and CVD status in the peripheral blood of ART-treated PWH (HIV+; n=42) and uninfected participants (HIV-; n=40) of the Canadian HIV and Aging Cohort Study (CHACS), with/without subclinical coronary atherosclerotic plaques, measured by Coronary Computed Tomography Angiography as total plaque volume (TPV, mm3). PBMCs were analyzed by flow cytometry for the expression of T-cell lineage (CD45, CD3, CD4, CD8, CD8{beta}, TCR{beta}, TCR{gamma}{delta}), epithelial cell (EpCAM/CD326), activation (HLA-DR), and gut-homing/residency markers (CD69, CD196/CCR6, CD199/CCR9, CD49d/Itg4, CD103/ItgE, Itg{beta}7). CellEngine supervised clustering of the flow cytometry data revealed profound alterations in the CD3+ T-cell pool in relationship with the HIV status, with the accumulation of peculiar CD8+TCR{beta}+ and TCR{gamma}{delta}+ cells, to the detriment of CD4+TCR{beta}+ subsets. FlowJo manual gating further identified CD4+ T-cell subsets with peculiar CD326+CD69+CCR6+ItgE+ and CCR6+Itg{beta}7- phenotypes that were increased in frequency in HIV+ versus HIV- participants, together with a decreased frequency of CD8+ T-cells with an intraepithelial lymphocyte (IEL)-like CD3+CD4- TCR{beta}+TCR{gamma}{delta}-CD8+CD8{beta}- phenotype. Finally, multivariate logistic regression revealed the predictive capacity of specific T-cell subsets regarding the HIV/CVD status, and TPV values. Of particular relevance, we identified ItgE+CD8+, ItgE-CD8+, CCR6+CD4+, and CCR6+Itg{beta}7- CD4+ T-cell subsets as strong positive predictors of atherosclerotic plaque volume in crude models or upon adjustment for HIV/CVD confounding factors.

immunology↗

bioRxiv2024

Unveiling Humoral and Cellular Immune Responses to SARS-CoV-2 in Head and Neck Cancer: A Comparative Study of Vaccination and Natural Infection in Romania

BackgroundTo fill the knowledge gap regarding the antiviral immunity in oncologic patients, we performed a comparative study on natural/vaccine-induced SARS-CoV-2 immunity in head and neck cancer (HNC) in Romania. MethodsBlood was collected from HNC (n=49) and controls (n=14), stratified as vaccinated (RNA/adenovirus-based vaccines), convalescent, and hybrid immunity. Plasma IgG/IgA antibodies (Abs) against Spike (S1/S2), receptor binding domain (RBD), and nucleocapsid (NC), and cytokines were quantified using the MILLIPLEX(R) technology. The frequency/phenotype/isotype of RBD-specific B-cells were studied by flow cytometry using tetramers (Tet++). Cell proliferation in response to Spike/NC peptides was monitored by carboxyfluorescein succinimidyl ester (CFSE) assay. A longitudinal follow-up was performed on n=25 HNC. FindingsLevels of S1/S2/RBD-specific IgG/IgA Abs were similarly high in HNC and controls, but significantly increased in convalescent/hybrid versus vaccinated HNC. NC-specific IgG/IgA Abs were only detected in convalescent/hybrid immunity groups. The frequency of Tet++ B-cells in HNC was similar to controls, irrespective of the immunization status, and correlated positively with RBD IgG/IgA Abs and negatively with the time since immunization (TSI). Compared to total B-cells, Tet++ were enriched in CD27+ memory phenotype and IgG/IgA isotype. A linear regression model identified Spike S2 IgG and NC IgA Abs as strong positive predictors of Tet++ frequencies, while IL-6 was a marginally significant negative predictor. Tet++ frequency remained stable at median TSI of 341 versus 117 days, despite a decline in memory phenotype. InterpretationHNC participants mount efficient and durable SARS-CoV-2 humoral immunity, with RBD-specific IgG/IgA Abs and Tet++ B-cells representing the major immunization outcomes.

immunology↗

bioRxiv2024

Metformin Enhances Antibody-Mediated Recognition of HIV-Infected CD4+ T-Cells by Decreasing Viral Release

The mechanistic target of rapamycin (mTOR) positively regulates multiple steps of the HIV-1 replication cycle. We previously reported that a 12-weeks supplementation of antiretroviral therapy (ART) with metformin, an indirect mTOR inhibitor used in type-2 diabetes treatment, reduced mTOR activation and HIV transcription in colon-infiltrating CD4+ T-cells, together with systemic inflammation in nondiabetic people with HIV-1 (PWH). Herein, we investigated the antiviral mechanisms of metformin. In a viral outgrowth assay performed with CD4+ T-cells from ART-treated PWH, and upon infection in vitro with replication-competent and VSV-G-pseudotyped HIV-1, metformin decreased virion release, but increased the frequency of productively infected CD4lowHIV-p24+ T-cells. These observations coincided with increased BST2/Tetherin (HIV release inhibitor) and Bcl-2 (pro-survival factor) expression, and improved recognition of productively infected T-cells by HIV-1 Envelope antibodies. Thus, metformin exerts pleiotropic effects on post-transcription/translation steps of the HIV-1 replication cycle and may be used to accelerate viral reservoir decay in ART-treated PWH. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=106 SRC="FIGDIR/small/580166v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@a17eeborg.highwire.dtl.DTLVardef@939d9aorg.highwire.dtl.DTLVardef@1502a62org.highwire.dtl.DTLVardef@e8ec2_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO C_FIG

immunology↗

bioRxiv2023

A Blood Immunological Signature of Subclinical Coronary Artery Atherosclerosis in People Living with HIV-1 Receiving Antiretroviral Therapy

Cardiovascular disease (CVD) remains an important co-morbidity in people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Our previous studies performed on the Canadian HIV/Aging Cohort Study (CHACS) (>40 years-old; Framingham Risk Score (FRS) >5%), revealed a 2-3-fold increase in non-calcified coronary artery atherosclerosis (CAA) plaque burden, measured by Computed tomography angiography scan (CTAScan) as total (TPV) and low attenuated plaque volume (LAPV) in ART-treated PLWH (HIV+) versus uninfected controls (HIV-). In an effort to identify novel correlates of subclinical CAA, markers of intestinal damage (sCD14, LBP, FABP2); cell trafficking/inflammation (CCL20, CX3CL1, MIF, CCL25); subsets of Th17-polarized and regulatory (Tregs) CD4+ T-cells, classical/intermediate/non-classical monocytes, and myeloid/plasmacytoid dendritic cells, were studied in relationship with HIV and TPV/LAPV status. The TPV detection/values coincided with higher plasma sCD14, FABP2, CCL20, MIF, CX3CL1 and triglyceride levels, lower Th17/Treg ratios, and classical monocyte expansion. Among HIV+, TPV+ versus TPV- exhibited lower Th17 frequencies, reduced Th17/Treg ratios, higher frequencies of non-classical CCR9lowHLADRhigh monocyte, and increased plasma fibrinogen levels. Finally, Th17/Treg ratios and non-classical CCR9lowHLADRhigh monocyte frequencies remained associated with TPV/LAPV after adjusting for FRS and HIV/ART duration in a logistic regression model. These findings point to Th17 paucity and non-classical monocyte abundance as novel immunological correlates of subclinical CAA that may fuel the CVD risk in ART-treated PLWH.

immunology↗

bioRxiv2023

Retinoic Acid Boosts HIV-1 Replication in Macrophages via CCR5/SAMHD1-Dependent and mTOR-Modulated Mechanisms

The intestinal environment facilitates HIV-1 infection via mechanisms involving the gut-homing elixir retinoic acid (RA), which transcriptionally reprograms CD4+ T-cells for increased HIV-1 permissiveness. Consistently, colon-infiltrating CD4+ T-cells carry replication-competent viral reservoirs in people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Intriguingly, integrative infection in colon macrophages, a pool replenished by circulating monocytes, represents a rare event in ART-treated PLWH, thus questioning on HIV-1 permissiveness in gut-resident macrophages. Here, we demonstrate that RA significantly boosts R5 but not X4 HIV-1 replication in monocyte-derived macrophages (MDMs). RNA-Sequencing, Gene Set Variation Analysis, and HIV interactor NCBI database interrogation, revealed RA- mediated transcriptional reprogramming associated with metabolic/inflammatory processes and HIV-1 resistance/dependency factors. Functional validations pointed to mechanisms of RA action, including CCR5 upregulation and SAMHD1 phosphorylation under the control of mTOR. These results support a model in which intestinal MDM contribute to viral replication/dissemination before ART and upon treatment interruption in mTOR-sensitive manner. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/561142v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@f966a0org.highwire.dtl.DTLVardef@1c0b4baorg.highwire.dtl.DTLVardef@992142org.highwire.dtl.DTLVardef@156a599_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1:C_FLOATNO C_FIG

immunology↗

bioRxiv2022

Identification of Aryl Hydrocarbon Receptor as a Barrier to HIV-1 Infection and Outgrowth in CD4+ T-Cells

The Aryl hydrocarbon receptor (AhR) identifies "non-pathogenic" Th17-polarized CD4+ T-cells in autoimmune models. Thus, we explored whether AhR restricts HIV-1 in Th17-cells, consistent with its antiviral role in macrophages. AhR-specific CRISPR/Cas9-mediated knockout and pharmacological blockade decreased AhR target gene expression (CYP1A1/IL-22/IL-17A/IL-10/ ITGB7), while increasing HIV-1 replication in CD4+ T-cells. Pharmacological AhR activation caused opposite effects. AhR agonism/antagonism modulated HIV-1 replication mainly in Th17/Th22-polarized CCR6+CD4+ T-cells. Single-round VSV-G-pseudotyped HIV-1 infection demonstrated that AhR acts at post-entry levels, with AhR blockade increasing the efficacy of early/late reverse transcription steps and subsequently integration/translation. In viral outgrowth assay, the AhR blockade boosted the detection of replication-competent viral reservoirs in CD4+ T-cells of people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Finally, RNA-Sequencing revealed genes/pathways modulated by AhR blockade in CD4+ T-cells of ART-treated PLWH, with known HIV-1 interactor activities (NCBI HIV Interactor Database) and AhR responsive elements in their promoters (ENCODE). Among them, HIC1, a repressor of Tat-mediated HIV-1 transcription and a tissue-residency inducer, represents a putative AhR mechanism of action. These results demonstrate that AhR governs an antiviral transcriptional program in CD4+ T-cells and point to the use of AhR inhibitors to boost viral outgrowth in "shock and kill" HIV-1 remission/cure strategies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/512596v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@ddd99org.highwire.dtl.DTLVardef@4fa24eorg.highwire.dtl.DTLVardef@28e66forg.highwire.dtl.DTLVardef@130b2bb_HPS_FORMAT_FIGEXP M_FIG Model of AhR-mediated transcriptional reprogramming with implications for "silent" HIV-1 reservoir persistence and gut homing/residency.RNA-Sequencing revealed genes sets modulated by AhR blockade in CD4+ T-cells of ART-treated PLWH, with known HIV-1 interactor activities (NCBI HIV Interactor Database) and AhR responsive elements in their promoters (ENCODE). Among them, HIC1, a repressor of Tat-mediated HIV-1 transcription and a tissue-residency regulator, represents a putative AhR mechanism of action. These results support a model in which AhR activation favors the gut homing and residency via the induction of ITGB7 and CXCR6 expression, respectively, and fuels the persistence of silent" HIV-1 reservoirs in CD4+ T-cells of ART-treated PLWH. At the opposite, pharmacological AhR blockade facilitates viral outgrowth, and by interfering with tissue residency, likely promotes the mobilization of << reactivated >> reservoir cells from deep tissues into the circulations. C_FIG BRIEF SUMMARYWe identified the aryl hydrocarbon receptor as a barrier to HIV-1 infection/outgrowth in Th17-polarized CD4+ T-cells and a novel therapeutic target in HIV-1 cure/remission interventions.

immunology↗

bioRxiv2021

Th17 cell master transcription factor RORC2 regulates HIV-1 gene expression and viral outgrowth

Among CD4+ T-cells, T helper 17 (Th17) cells are particularly susceptible to HIV-1 infection and are depleted from mucosal sites, which causes damage to the gut barrier resulting in microbial translocation-induced systemic inflammation, a hallmark of disease progression. Furthermore, a proportion of latently infected Th17 cells persist long-term in the gastro-intestinal lymphatic tract, where low-level HIV-1 transcription is observed. This residual viremia contributes to chronic immune activation. Thus, Th17 cells are key players in HIV pathogenesis and viral persistence, however it is unclear why these cells are highly susceptible to HIV-1 infection. Th17 cell differentiation depends on expression of the master transcriptional regulator RORC2, a retinoic acid-related nuclear hormone receptor that regulates specific transcriptional programs by binding to promoter/enhancer DNA. Here, we report that RORC2 is a key host-cofactor for HIV replication in Th17 cells. We found that specific inhibitors that bind to the RORC2 ligand-binding domain reduced HIV replication in CD4+ T-cells. Depletion of RORC2 inhibited HIV-1 infection, whereas RORC2 overexpression enhanced it. RORC2 was found to promote HIV-1 gene expression. Chromatin immune precipitation revealed that RORC2 binds to the nuclear receptor responsive element (NRRE) in the HIV-1 LTR. In treated HIV-1 patients, RORC2+ CD4 T cells contained more proviral DNA than RORC2- cells. Pharmacological inhibition of RORC2 potently reduced HIV-1 outgrowth in CD4+ T-cells from antiretroviral-treated patients. Altogether, these results provide a new explanation as to why Th17 cells are highly susceptible to HIV-1 infection and point to RORC2 as a cell-specific target for HIV-1 therapy. Significance statementHIV-1 infects CD4 T cells and among these, Th17 cells are known to be particularly permissive for virus replication. Infection of Th17 cells is critical for AIDS pathogenesis and viral persistence, however it is not clear why these cells are highly permissive to HIV-1. We found that Th17 cell permissiveness depends on expression of the hormone receptor RORC2, which is the master transcriptional regulator of Th17 cell differentiation. We identify RORC2 as a new, cell-specific host-dependency factor that can be targeted by small molecules. Our results point to RORC2 as a cell-specific target for HIV-1 therapy, an entirely new concept in the field, and suggest HIV-1 might have evolved to exploit RORC2 to promote its own persistence.

microbiology↗