技术资料

During the humoral immune response,B cells undergo rapid metabolic reprogramming with a high demand for nutrients,which are vital to sustain the formation of the germinal centers (GCs). Rag-GTPases sense amino acid availability to modulate the mechanistic target of rapamycin complex 1 (mTORC1) pathway and suppress transcription factor EB (TFEB) and transcription factor enhancer 3 (TFE3),members of the microphthalmia (MiT/TFE) family of HLH-leucine zipper transcription factors. However,how Rag-GTPases coordinate amino acid sensing,mTORC1 activation,and TFEB/TFE3 activity in humoral immunity remains undefined. Here,we show that B cell-intrinsic Rag-GTPases are critical for the development and activation of B cells. RagA/RagB deficient B cells fail to form GCs,produce antibodies,and generate plasmablasts in both T-dependent (TD) and T-independent (TI) humoral immune responses. Deletion of RagA/RagB in GC B cells leads to abnormal dark zone (DZ) to light zone (LZ) ratio and reduced affinity maturation. Mechanistically,the Rag-GTPase complex constrains TFEB/TFE3 activity to prevent mitophagy dysregulation and maintain mitochondrial fitness in B cells,which are independent of canonical mTORC1 activation. TFEB/TFE3 deletion restores B cell development,GC formation in Peyer’s patches and TI humoral immunity,but not TD humoral immunity in the absence of Rag-GTPases. Collectively,our data establish Rag-GTPase-TFEB/TFE3 axis as an mTORC1 independent mechanism to coordinating nutrient sensing and mitochondrial metabolism in B cells. View Publication

AbstractIntestinal chronic inflammation is associated with microbial dysbiosis and accumulation of various immune cells including myeloid-derived suppressor cells (MDSC),which profoundly impact the immune microenvironment,perturb homeostasis and increase the risk to develop colitis-associated colorectal cancer (CAC). However,the specific MDSCs–dysbiotic microbiota interactions and their collective impact on CAC development remain poorly understood. In this study,using a murine model of CAC,we demonstrate that CAC-bearing mice exhibit significantly elevated levels of highly immunosuppressive MDSCs,accompanied by microbiota alterations. Both MDSCs and bacteria that infiltrate the colon tissue and developing tumors can be found in close proximity,suggesting intricate MDSC-microbiota cross-talk within the tumor microenvironment. To investigate this phenomenon,we employed antibiotic treatment to disrupt MDSC–microbiota interactions. This intervention yielded a remarkable reduction in intestinal inflammation,decreased MDSC levels,and alleviated immunosuppression,all of which were associated with a significant reduction in tumor burden. Furthermore,we underscore the causative role of dysbiotic microbiota in the predisposition toward tumor development,highlighting their potential as biomarkers for predicting tumor load. We shed light on the intimate MDSCs-microbiota cross-talk,revealing how bacteria enhance MDSC suppressive features and activities,inhibit their differentiation into mature beneficial myeloid cells,and redirect some toward M2 macrophage phenotype. Collectively,this study uncovers the role of MDSC-bacteria cross-talk in impairing immune responses and promoting tumor growth,providing new insights into potential therapeutic strategies for CAC.Significance:MDSCs–dysbiotic bacteria interactions in the intestine play a crucial role in intensifying immunosuppression within the CAC microenvironment,ultimately facilitating tumor growth,highlighting potential therapeutic targets for improving the treatment outcomes of CAC. View Publication

SummaryHispanic/Latino children have the highest risk of acute lymphoblastic leukemia (ALL) in the US compared to other racial/ethnic groups,yet the basis of this remains incompletely understood. Through genetic fine-mapping analyses,we identified a new independent childhood ALL risk signal near IKZF1 in self-reported Hispanic/Latino individuals,but not in non-Hispanic White individuals,with an effect size of ∼1.44 (95% confidence interval = 1.33–1.55) and a risk allele frequency of ∼18% in Hispanic/Latino populations and <0.5% in European populations. This risk allele was positively associated with Indigenous American ancestry,showed evidence of selection in human history,and was associated with reduced IKZF1 expression. We identified a putative causal variant in a downstream enhancer that is most active in pro-B cells and interacts with the IKZF1 promoter. This variant disrupts IKZF1 autoregulation at this enhancer and results in reduced enhancer activity in B cell progenitors. Our study reveals a genetic basis for the increased ALL risk in Hispanic/Latino children. Graphical abstract Highlights•IKZF1 variants contribute to the increased risk of ALL in Hispanic/Latino children•Risk allele is associated with Indigenous American ancestry and underwent selection•Risk variant impacts IKZF1 enhancer that is selectively active in B cell development•Risk allele reduces enhancer activity,chromatin accessibility,and IKZF1 expression Genetic fine-mapping across the IKZF1 gene revealed a variant associated with childhood ALL that contributes to the increased risk of this disease in Hispanic/Latino individuals. The ALL risk allele reduces enhancer activity and IKZF1 expression specifically in B cell progenitors,likely resulting in stalled B cell development and an increased risk of ALL. View Publication

SummaryThe viral vector-based COVID-19 vaccine Ad26.COV2.S has been recommended by the WHO since 2021 and has been administered to over 200 million people. Prior studies have shown that Ad26.COV2.S induces durable neutralizing antibodies (NAbs) that increase in coverage of variants over time,even in the absence of boosting or infection. Here,we studied humoral responses following Ad26.COV2.S vaccination in individuals enrolled in the initial Phase 1/2a trial of Ad26.COV2.S in 2020. Through 8 months post vaccination,serum NAb responses increased to variants,including B.1.351 (Beta) and B.1.617.2 (Delta),without additional boosting or infection. The level of somatic hypermutation,measured by nucleotide changes in the VDJ region of the heavy and light antibody chains,increased in Spike-specific B cells. Highly mutated mAbs from these sequences neutralized more SARS-CoV-2 variants than less mutated comparators. These findings suggest that the increase in NAb breadth over time following Ad26.COV2.S vaccination is mediated by affinity maturation. Graphical abstract Highlights•Ad26.COV2.S induced neutralizing antibodies increase in breadth over 8 months•Somatic hypermutation in spike specific B cells also increases over 8 months•Highly mutated monoclonal antibodies neutralize more variants than less mutated•Ad26.COV2.S induces long term affinity maturation Health sciences; Immunity; Immune response; Virology View Publication

SummaryDrug resistance threatens the effective control of infections,including parasitic diseases such as leishmaniases. Neutrophils are essential players in antimicrobial control,but their role in drug-resistant infections is poorly understood. Here,we evaluated human neutrophil response to clinical parasite strains having distinct natural drug susceptibility. We found that Leishmania antimony drug resistance significantly altered the expression of neutrophil genes,some of them transcribed by specific neutrophil subsets. Infection with drug-resistant parasites increased the expression of detoxification pathways and reduced the production of cytokines. Among these,the chemokine CCL3 was predominantly impacted,which resulted in an impaired ability of neutrophils to attract myeloid cells. Moreover,decreased myeloid recruitment when CCL3 levels are reduced was confirmed by blocking CCL3 in a mouse model. Collectively,these findings reveal that the interplay between naturally drug-resistant parasites and neutrophils modulates the infected skin immune microenvironment,revealing a key role of neutrophils in drug resistance. Graphical abstract Highlights•Drug-resistant parasites induce distinct neutrophil transcriptional programs•Meglumine-antimoniate-resistant (MAR) Leishmania limits neutrophil chemokine release•Infection with MAR parasites impairs CCL3-driven early myeloid cell recruitment Immunology; Parasitology View Publication

BackgroundNatural killer (NK) cells are key effector cells of antitumor immunity. However,tumors can acquire resistance programs to escape NK cell-mediated immunosurveillance. Identifying mechanisms that mediate this resistance enables us to define approaches to improve immune-mediate antitumor activity. In previous studies from our group,a genome-wide CRISPR-Cas9 screen identified Charged Multivesicular Body Protein 2A (CHMP2A) as a novel mechanism that mediates tumor intrinsic resistance to NK cell activity.MethodsHere,we use an immunocompetent mouse model to demonstrate that CHMP2A serves as a targetable regulator of not only NK cell-mediated immunity but also other immune cell populations. Using the recently characterized murine 4MOSC model system,a syngeneic,tobacco-signature murine head and neck squamous cell carcinoma model,we deleted mCHMP2A using CRISPR/Cas9-mediated knock-out (KO),following orthotopic transplantation into immunocompetent hosts.ResultsWe found that mCHMP2A KO in 4MOSC1 cells leads to more potent NK-mediated tumor cell killing in vitro in these tumor cells. Moreover,following orthotopic transplantation,KO of mCHMP2A in 4MOSC1 cells,but not the more immune-resistant 4MOSC2 cells enables both T cells and NK cells to better mediate antitumor activity compared with wild type (WT) tumors. However,there was no difference in tumor development between WT and mCHMP2A KO 4MOSC1 or 4MOSC2 tumors when implanted in immunodeficient mice. Mechanistically,we find that mCHMP2A KO 4MOSC1 tumors transplanted into the immunocompetent mice had significantly increased CD4+T cells,CD8+T cells. NK cell,as well as fewer myeloid-derived suppressor cells (MDSC).ConclusionsTogether,these studies demonstrate that CHMP2A is a targetable inhibitor of cellular antitumor immunity. View Publication

SummarySeptic patients with worst clinical prognosis have increased circulating immature granulocytes (IG),displaying limited phagocytosis and reactive oxygen species (ROS) production. Here,we developed an ex vivo model of incubation of human granulocytes,from septic patients or healthy donors,with Escherichia coli. We showed that the ROS production in Sepsis-IG is lower due to decreased activation and protein expression of the NADPH oxidase complex. We also demonstrated that the low level of ROS production and lower phagocytosis of IG in sepsis induce the bacterial SOS response,leading to the expression of the SOS-regulated quinolone resistance gene qnrB2. Without antimicrobial pressure,the sepsis immune response alone may promote antibiotic resistance expression. Graphical abstract Highlights•Immature granulocytes in sepsis have decreased phagocytosis and ROS production•SOS response is induced in granulocyte-phagocyted bacteria and is ROS dependent•The level of bacterial SOS induction depends on granulocyte maturation and priming•Phagocyted bacteria induce SOS-dependent quinolone resistance qnrB2 expression Immunology; Microbiology; Bacteriology View Publication

Stimulator of interferon genes (STING) is a central component of the cytosolic nucleic acids sensing pathway and as such master regulator of the type I interferon response. Due to its critical role in physiology and its’ involvement in a variety of diseases,STING has been a focus for drug discovery. Targeted protein degradation (TPD) has emerged as a promising pharmacology for targeting previously considered undruggable proteins by hijacking the cellular ubiquitin proteasome system (UPS) with small molecules. Here,we identify AK59 as a STING degrader leveraging HERC4,a HECT-domain E3 ligase. Additionally,our data reveals that AK59 is effective on the common pathological STING mutations,suggesting a potential clinical application of this mechanism. Thus,these findings introduce HERC4 to the fields of TPD and of compound-induced degradation of STING,suggesting potential therapeutic applications. In this paper,Mutlu et al. identifies a STING degrader,AK59,which inhibits downstream cGAS/STING activity through STING degradation employing a HECT-domain E3 ligase HERC4 and proteasomal ubiquitination pathway. View Publication

SummaryMonocytes (Mos) are crucial in the evolution of metabolic dysfunction-associated steatotic liver disease (MASLD) to metabolic dysfunction-associated steatohepatitis (MASH),and immunometabolism studies have recently suggested targeting leukocyte bioenergetics in inflammatory diseases. Here,we reveal a peculiar bioenergetic phenotype in circulating Mos of patients with MASH,characterized by high levels of glycolysis and mitochondrial (mt) respiration. The enhancement of mt respiratory chain activity,especially complex II (succinate dehydrogenase [SDH]),is unbalanced toward the production of reactive oxygen species (ROS) and is sustained at the transcriptional level with the involvement of the AMPK-mTOR-PGC-1α axis. The modulation of mt activity with dimethyl malonate (DMM),an SDH inhibitor,restores the metabolic profile and almost abrogates cytokine production. Analysis of a public single-cell RNA sequencing (scRNA-seq) dataset confirms that in murine models of MASH,liver Mo-derived macrophages exhibit an upregulation of mt and glycolytic energy pathways. Accordingly,the DMM injection in MASH mice contrasts Mo infiltration and macrophagic enrichment,suggesting immunometabolism as a potential target in MASH. Graphical abstract Highlights•Circulating monocytes (Mos) in patients with MASH show a bioenergetic reprogramming•SDH inhibition in vitro restores MASH Mo bioenergetics,abolishing cytokine production•In mice,energy pathways are upregulated in liver Mo-derived macrophages during MASH•SDH inhibition in vivo reduces Mo infiltration and differentiation in MASH Sangineto et al. investigate the bioenergetics and mitochondrial activity of circulating monocytes in patients with MASH,revealing a hypermetabolic state also identified in liver monocyte-derived macrophages through transcriptomic analysis. Immunometabolic modulation via SDH inhibition attenuates inflammation both in vitro and in vivo,ameliorating MASH. View Publication

T lymphocyte activation plays a pivotal role in adaptive immune response and alters the spatial organization of nuclear architecture that subsequently impacts transcription activities. Here,using stochastic optical reconstruction microscopy (STORM),we observe dramatic de-condensation of chromatin and the disruption of nuclear envelope at a nanoscale resolution upon T lymphocyte activation. Super-resolution imaging reveals that such alterations in nuclear architecture are accompanied by the release of nuclear DNA into the cytoplasm,correlating with the degree of chromatin decompaction within the nucleus. The authors show that under the influence of metabolism,T lymphocyte activation de-condenses chromatin,disrupts the nuclear envelope,and releases DNA into the cytoplasm. Taken together,this result provides a direct,molecular-scale insight into the alteration in nuclear architecture. It suggests the release of nuclear DNA into the cytoplasm as a general consequence of chromatin decompaction after lymphocyte activation. The authors show that under the influence of metabolism,T lymphocyte activation de-condenses chromatin,disrupts the nuclear envelope,and releases DNA into the cytoplasm. View Publication

Acute and chronic coronary syndromes (ACS and CCS) are leading causes of mortality. Inflammation is considered a key pathogenic driver of these diseases,but the underlying immune states and their clinical implications remain poorly understood. Multiomic factor analysis (MOFA) allows unsupervised data exploration across multiple data types,identifying major axes of variation and associating these with underlying molecular processes. We hypothesized that applying MOFA to multiomic data obtained from blood might uncover hidden sources of variance and provide pathophysiological insights linked to clinical needs. Here we compile a longitudinal multiomic dataset of the systemic immune landscape in both ACS and CCS (n = 62 patients in total,n = 15 women and n = 47 men) and validate this in an external cohort (n = 55 patients in total,n = 11 women and n = 44 men). MOFA reveals multicellular immune signatures characterized by distinct monocyte,natural killer and T cell substates and immune-communication pathways that explain a large proportion of inter-patient variance. We also identify specific factors that reflect disease state or associate with treatment outcome in ACS as measured using left ventricular ejection fraction. Hence,this study provides proof-of-concept evidence for the ability of MOFA to uncover multicellular immune programs in cardiovascular disease,opening new directions for mechanistic,biomarker and therapeutic studies. Multiomic factor analysis of blood multiomic data,including single-cell transcriptomics,for individuals with either acute or chronic coronary syndrome identifies immune cell signatures that correlate with treatment outcomes. View Publication

AbstractDespite the success of antiretroviral therapy,human immunodeficiency virus (HIV) cannot be cured because of a reservoir of latently infected cells that evades therapy. To understand the mechanisms of HIV latency,we employed an integrated single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin with sequencing (scATAC-seq) approach to simultaneously profile the transcriptomic and epigenomic characteristics of ∼ 125,000 latently infected primary CD4+ T cells after reactivation using three different latency reversing agents. Differentially expressed genes and differentially accessible motifs were used to examine transcriptional pathways and transcription factor (TF) activities across the cell population. We identified cellular transcripts and TFs whose expression/activity was correlated with viral reactivation and demonstrated that a machine learning model trained on these data was 75%–79% accurate at predicting viral reactivation. Finally,we validated the role of two candidate HIV-regulating factors,FOXP1 and GATA3,in viral transcription. These data demonstrate the power of integrated multimodal single-cell analysis to uncover novel relationships between host cell factors and HIV latency. View Publication