技术资料

The persistence of HIV-1 in long-lived latent reservoirs during suppressive antiretroviral therapy (ART) remains one of the principal barriers to a functional cure. Blocks to transcriptional elongation play a central role in maintaining the latent state,and several latency reversal strategies focus on the release of positive transcription elongation factor b (P-TEFb) from sequestration by negative regulatory complexes,such as the 7SK complex and BRD4. Another major cellular reservoir of P-TEFb is in Super Elongation Complexes (SECs),which play broad regulatory roles in host gene expression. Still,it is unknown if the release of P-TEFb from SECs is a viable latency reversal strategy. Here,we demonstrate that the SEC is not required for HIV-1 replication in primary CD4+ T cells and that a small molecular inhibitor of the P-TEFb/SEC interaction (termed KL-2) increases viral transcription. KL-2 acts synergistically with other latency reversing agents (LRAs) to reactivate viral transcription in several cell line models of latency in a manner that is,at least in part,dependent on the viral Tat protein. Finally,we demonstrate that KL-2 enhances viral reactivation in peripheral blood mononuclear cells (PBMCs) from people living with HIV (PLWH) on suppressive ART,most notably in combination with inhibitor of apoptosis protein antagonists (IAPi). Taken together,these results suggest that the release of P-TEFb from cellular SECs may be a novel route for HIV-1 latency reactivation. Author summarySince the start of the HIV pandemic,it is estimated that nearly 86 million people have been infected with the virus,and about 40 million people have died. Modern antiretroviral therapies potently restrict viral replication and prevent the onset of AIDS,saving millions of lives. However,these therapies are not curative due to the persistence of the virus in a silenced or ‘latent’ state in long-lived cells of the body. One proposed strategy to clear this latent reservoir,termed “shock and kill”,is to activate these silenced viruses such that the infected cells can be cleared from the body by the immune system. While several drugs have been developed that can activate latent viruses,none have proven effective at reducing the size of the latent reservoir in patients in clinical trials. Here,we describe a new method for latency reactivation using a small molecule inhibitor of a human protein complex called the Super Elongation Complex (SEC). Inhibiting the SEC enhances viral transcription during active infection and triggers the reactivation of latent viruses,especially when in combination with other latency reversing agents. These results pave the way for developing more effective strategies to reactivate latent viruses towards a functional cure. View Publication

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of mortality worldwide. Laminar shear stress from blood flow,sensed by vascular endothelial cells,protects from ASCVD by upregulating the transcription factors KLF2 and KLF4,which induces an anti-inflammatory program that promotes vascular resilience. Here we identify clustered γ-protocadherins as therapeutically targetable,potent KLF2 and KLF4 suppressors whose upregulation contributes to ASCVD. Mechanistic studies show that γ-protocadherin cleavage results in translocation of the conserved intracellular domain to the nucleus where it physically associates with and suppresses signaling by the Notch intracellular domain. γ-Protocadherins are elevated in human ASCVD endothelium; their genetic deletion or antibody blockade protects from ASCVD in mice without detectably compromising host defense against bacterial or viral infection. These results elucidate a fundamental mechanism of vascular inflammation and reveal a method to target the endothelium rather than the immune system as a protective strategy in ASCVD. Joshi et al. show that γ-protocadherins suppress the anti-inflammatory KLF2 and KLF4 pathway and that targeting them is a viable therapeutic strategy to protect against atherosclerosis. View Publication

BackgroundPlasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) proteins are expressed on the surface of infected erythrocytes,mediating parasite sequestration in the vasculature. PfEMP1 is a major target of protective antibodies,but the features of the antibody response are poorly defined.MethodsIn Malawian children with cerebral or uncomplicated malaria,we characterized the antibody response to 39 recombinant PfEMP1 Duffy binding like (DBL) domains or cysteine-rich interdomain regions (CIDRs) in detail,including measures of antibody classes,subclasses,and engagement with Fcγ receptors and complement. Using elastic net regularized logistic regression,we identified a combination of seven antibody targets and Fc features that best distinguished between children with cerebral and uncomplicated malaria. To confirm the role of the selected targets and Fc features,we measured antibody-dependent neutrophil and THP-1 cell phagocytosis of intercellular adhesion molecule-1 (ICAM-1) and endothelial protein C (EPCR) co-binding infected erythrocytes.ResultsThe selected features distinguished between children with cerebral and uncomplicated malaria with 87% accuracy (median,80–96% interquartile range) and included antibody to well-characterized DBLβ3 domains and a less well-characterized CIDRγ12 domain. The abilities of antibodies to engage C1q and FcγRIIIb,rather than levels of IgG,correlated with protection. In line with a role of FcγRIIIb binding antibodies to DBLβ3 domains,antibody-dependent neutrophil phagocytosis of ICAM-1 and EPCR co-binding IE was higher in uncomplicated malaria (15% median,8–38% interquartile range) compared to cerebral malaria (7%,30–15%,p < 0.001).ConclusionsAntibodies associated with protection from cerebral malaria target a subset of PfEMP1 domains. The Fc features of protective antibody response include engagement of FcγRIIIb and C1q,and ability to induce antibody-dependent neutrophil phagocytosis of infected erythrocytes. Identifying the targets and Fc features of protective immunity could facilitate the development of PfEMP1-based therapeutics for cerebral malaria.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12916-024-03604-8. View Publication

Durable response to chimeric antigen receptor T (CART) cell therapy remains limited in part due to CART cell exhaustion. Here,we investigate the regulation of CART cell exhaustion with three independent approaches including: a genome-wide CRISPR knockout screen using an in vitro model for exhaustion,RNA and ATAC sequencing on baseline and exhausted CART cells,and RNA and ATAC sequencing on pre-infusion CART cell products from responders and non-responders in the ZUMA-1 clinical trial. Each of these approaches identify interleukin (IL)-4 as a regulator of CART cell dysfunction. Further,IL-4-treated CD8+ CART cells develop signs of exhaustion independently of the presence of CD4+ CART cells. Conversely,IL-4 pathway editing or the combination of CART cells with an IL-4 monoclonal antibody improves antitumor efficacy and reduces signs of CART cell exhaustion in mantle cell lymphoma xenograft mouse models. Therefore,we identify both a role for IL-4 in inducing CART exhaustion and translatable approaches to improve CART cell therapy. The application and therapeutic success of CAR-T cell approaches are limited by the development of T cell exhaustion. Here,Stewart et al discover a role for IL-4 in driving CD8+ CAR-T cell exhaustion and demonstrate the improvement of CAR-T cell effectivity with interruption of IL-4 signalling. View Publication

Seminal plasma (SP) is the main vector of C. trachomatis (CT) during heterosexual transmission from male to female. It has immunomodulatory properties and impacts the susceptibility to HIV-1 infection,but its role has not been explored during CT infection. In the female reproductive tract (FRT),CT infection induces cytokine production and neutrophil recruitment. The role of neutrophils during CT infection is partially described,they could be at the origin of the pathology observed during CT infection. During this study,we developed an experimental in vitro model to characterize the impact of CT infection and SP on endocervical epithelial cell immune response in the FRT. We also studied the impact of the epithelial cell response on neutrophil phenotype and functions. We showed that the production by epithelial cells of pro-inflammatory cytokines increased during CT infection. Moreover,the pool of SP as well as individuals SP inhibited CT infection in a dose-dependent manner. The pool of SP inhibited cytokine production in a dose-dependent manner. The pool of SP altered gene expression profiles of infected cells. The culture supernatants of cells infected or not with CT,in presence or not of the pool of SP,had an impact on neutrophil phenotype and functions: they affected markers of neutrophil maturation,activation and adhesion capacity,as well as the survival,ROS production and phagocytosis ability. This study proposes a novel approach to study the impact of the environment on the phenotype and functions of neutrophils in the FRT. It highlights the impact of the factors of the FRT environment,in particular SP and CT infection,on the mucosal inflammation and the need to take into account the SP component while studying sexually transmitted infections during heterosexual transmission from male to female. View Publication

A diverse antibody repertoire is essential for humoral immunity. Antibody diversification requires the introduction of deoxyuridine (dU) mutations within immunoglobulin genes to initiate somatic hypermutation (SHM) and class switch recombination (CSR). dUs are normally recognized and excised by the base excision repair (BER) protein uracil-DNA glycosylase 2 (UNG2). However,FAM72A downregulates UNG2 permitting dUs to persist and trigger SHM and CSR. How FAM72A promotes UNG2 degradation is unknown. Here,we show that FAM72A recruits a C-terminal to LisH (CTLH) E3 ligase complex to target UNG2 for proteasomal degradation. Deficiency in CTLH complex components result in elevated UNG2 and reduced SHM and CSR. Cryo-EM structural analysis reveals FAM72A directly binds to MKLN1 within the CTLH complex to recruit and ubiquitinate UNG2. Our study further suggests that FAM72A hijacks the CTLH complex to promote mutagenesis in cancer. These findings show that FAM72A is an E3 ligase substrate adaptor critical for humoral immunity and cancer development. Antibody diversification relies on the intentional mutagenesis of immunoglobulin genes for adaptive immune responses. Here,the authors identified a CTLH E3 ubiquitin ligase complex that co-opts FAM72A to recruit and degrade the UNG2 base excision repair factor to permit mutagenesis. View Publication

Dendritic cells (DCs) are pivotal in regulating allergic asthma. Our research has shown that the absence of Sema3E worsens asthma symptoms in acute and chronic asthma models. However,the specific role of PlexinD1 in these processes,particularly in DCs,remains unclear. This study investigates the role of PlexinD1 in CD11c+ DCs using a house dust mite (HDM) model of asthma. We generated CD11c+ DC-specific PlexinD1 knockout (CD11cPLXND1 KO) mice and subjected them,alongside wild-type controls (PLXND1fl/fl),to an HDM allergen protocol. Airway hyperresponsiveness (AHR) was measured using FlexiVent,and immune cell populations were analyzed via flow cytometry. Cytokine levels and immunoglobulin concentrations were assessed using mesoscale and ELISA,while collagen deposition and mucus production were examined through Sirius-red and periodic acid Schiff (PAS) staining respectively. Our results indicate that CD11cPLXND1 KO mice exhibit significantly exacerbated AHR,characterized by increased airway resistance and tissue elastance. Enhanced mucus production and collagen gene expression were observed in these mice compared to wild-type counterparts. Flow cytometry revealed higher CD11c+ MHCIIhigh CD11b+ cell recruitment into the lungs,and elevated total and HDM-specific serum IgE levels in CD11cPLXND1 KO mice. Mechanistically,co-cultures of B cells with DCs from CD11cPLXND1 KO mice showed significantly increased IgE production compared to wild-type mice.These findings highlight the critical regulatory role of the plexinD1 signaling pathway in CD11c+ DCs in modulating asthma features. View Publication

A portion of the genetic basis for many common autoimmune disorders has been uncovered by genome-wide association studies (GWAS),but GWAS do not reveal causal variants,effector genes,or the cell types impacted by disease-associated variation. We have generated 3D genomic datasets consisting of promoter-focused Capture-C,Hi-C,ATAC-seq,and RNA-seq and integrated these data with GWAS of 16 autoimmune traits to physically map disease-associated variants to the effector genes they likely regulate in 57 human cell types. These 3D maps of gene cis-regulatory architecture are highly powered to identify the cell types most likely impacted by disease-associated genetic variation compared to 1D genomic features,and tend to implicate different effector genes than eQTL approaches in the same cell types. Most of the variants implicated by these cis-regulatory architectures are highly trait-specific,but nearly half of the target genes connected to these variants are shared across multiple autoimmune disorders in multiple cell types,suggesting a high level of genetic diversity and complexity among autoimmune diseases that nonetheless converge at the level of target gene and cell type. Substantial effector gene sharing led to the common enrichment of similar biological networks across disease and cell types. However,trait-specific pathways representing potential areas for disease-specific intervention were identified. To test this,we pharmacologically validated squalene synthase,a cholesterol biosynthetic enzyme encoded by the FDFT1 gene implicated by our approach in MS and SLE,as a novel immunomodulatory drug target controlling inflammatory cytokine production by human T cells. These data represent a comprehensive resource for basic discovery of gene cis-regulatory mechanisms,and the analyses reported reveal mechanisms by which autoimmune-associated variants act to regulate gene expression,function,and pathology across multiple,distinct tissues and cell types. View Publication

Clinical studies have shown that Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is associated with aggressive periodontitis and can potentially trigger or exacerbate rheumatoid arthritis (RA). However,the mechanism is poorly understood. Here,we show that systemic infection with A. actinomycetemcomitans triggers the progression of arthritis in mice anti-collagen antibody-induced arthritis (CAIA) model following IL-1β secretion and cell infiltration in paws in a manner that is dependent on caspase-11-mediated inflammasome activation in macrophages. The administration of polymyxin B (PMB),chloroquine,and anti-CD11b antibody suppressed inflammasome activation in macrophages and arthritis in mice,suggesting that the recognition of lipopolysaccharide (LPS) in the cytosol after bacterial degradation by lysosomes and invasion via CD11b are needed to trigger arthritis following inflammasome activation in macrophages. These data reveal that the inhibition of caspase-11-mediated inflammasome activation potentiates aggravation of RA induced by infection with A. actinomycetemcomitans. This work highlights how RA can be progressed by inflammasome activation as a result of periodontitis-associated bacterial infection and discusses the mechanism of inflammasome activation in response to infection with A. actinomycetemcomitans. View Publication

IntroductionThe early transcription unit 3 (E3) of human adenoviruses (HAdVs) encodes several immunoevasins,including the E3/49K protein,which is unique for species D of HAdVs. It is expressed as surface transmembrane protein and shed. E3/49K of HAdV-D64 binds to the protein tyrosine phosphatase surface receptor CD45,thereby modulating activation of T and NK cells.MethodsConsidering that E3/49K represents the most polymorphic viral protein among species D HAdVs,we demonstrate here that all tested E3/49K orthologs bind to the immunologically important regulator CD45. Thus,this feature is conserved regardless of the pathological associations of the respective HAdV types.ResultsIt appeared that modulation of CD45 is a unique property restricted to HAdVs of species D. Moreover,E3/49K treatment inhibited B cell receptor (BCR) signaling and impaired BCR signal phenotypes. The latter were highly comparable to B cells having defects in the expression of CD45,suggesting E3/49K as a potential tool to investigate CD45 specific functions.ConclusionWe identified B cells as new direct target of E3/49K-mediated immune modulation,representing a novel viral immunosubversive mechanism. View Publication