技术资料

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

BackgroundInterleukin-17 (IL-17) family cytokines promote protective inflammation for pathogen resistance,but also facilitate autoimmunity and tumor development. A direct signal of IL-17 to regulatory T cells (Tregs) has not been reported and may help explain these dichotomous responses.MethodsWe generated a conditional knockout of Il17ra in Tregs by crossing Foxp3-YFP-Cre mice to Il17ra-flox mice (Il17ra ΔTreg mice). Subsequently,we adoptively transferred bone marrow cells from Il17ra ΔTreg mice to a mouse model of sporadic colorectal cancer (Cdx2-Cre +/Apc F/+),to selectively ablate IL-17 direct signaling on Tregs in colorectal cancer. Single cell RNA sequencing and bulk RNA sequencing were performed on purified Tregs from mouse colorectal tumors,and compared to those of human tumor infiltrating Treg cells.ResultsIL-17 Receptor A (IL-17RA) is expressed in Tregs that reside in mouse mesenteric lymph nodes and colon tumors. Ablation of IL-17RA,specifically in Tregs,resulted in increased Th17 cells,and exacerbated tumor development. Mechanistically,tumor-infiltrating Tregs exhibit a unique gene signature that is linked to their activation,maturation,and suppression function,and this signature is in part supported by the direct signaling of IL-17 to Tregs. To study pathways of Treg programming,we found that loss of IL-17RA in tumor Tregs resulted in reduced RNA splicing,and downregulation of several RNA binding proteins that are known to regulate alternative splicing and promote Treg function.ConclusionIL-17 directly signals to Tregs and promotes their maturation and function. This signaling pathway constitutes a negative feedback loop that controls cancer-promoting inflammation in CRC. View Publication

SummaryEnvironmental lipids are essential for fueling tumor energetics,but whether these exogenous lipids transported into cancer cells facilitate immune escape remains unclear. Here,we find that CD36,a transporter for exogenous lipids,promotes acute myeloid leukemia (AML) immune evasion. We show that,separately from its established role in lipid oxidation,CD36 on AML cells senses oxidized low-density lipoprotein (OxLDL) to prime the TLR4-LYN-MYD88-nuclear factor κB (NF-κB) pathway,and exogenous palmitate transfer via CD36 further potentiates this innate immune pathway by supporting ZDHHC6-mediated MYD88 palmitoylation. Subsequently,NF-κB drives the expression of immunosuppressive genes that inhibit anti-tumor T cell responses. Notably,high-fat-diet or hypomethylating agent decitabine treatment boosts the immunosuppressive potential of AML cells by hijacking CD36-dependent innate immune signaling,leading to a dampened therapeutic effect. This work is of translational interest because lipid restriction by US Food and Drug Administration (FDA)-approved lipid-lowering statin drugs improves the efficacy of decitabine therapy by weakening leukemic CD36-mediated immunosuppression. Graphical abstract Highlights•CD36 on AML cells suppresses T cell proliferation independently of lipid oxidation•OxLDL and palmitate synergize to inhibit T cell activity via CD36 signaling in AML cells•Targeting CD36 signaling with statins improves the efficacy of decitabine therapy in AML Guo et al. find that OxLDL and palmitate uptake by AML cells synergistically upregulates CD36-mediated innate immune signaling to suppress T cell activity. High-fat-diet or decitabine treatment dampened the therapeutic effect by hijacking CD36 signaling. Targeting the CD36 immunosuppressive pathway with statins improves the efficacy of decitabine therapy in AML. View Publication

The progressive decline of CD8 T cell effector function—also known as terminal exhaustion—is a major contributor to immune evasion in cancer. Yet,the molecular mechanisms that drive CD8 T cell dysfunction remain poorly understood. Here,we report that the Kelch-like ECH-associated protein 1 (KEAP1)-Nuclear factor erythroid 2-related factor 2 (NRF2) signaling axis,which mediates cellular adaptations to oxidative stress,directly regulates CD8 T cell exhaustion. Transcriptional profiling of dysfunctional CD8 T cells from chronic infection and cancer reveals enrichment of NRF2 activity in terminally exhausted (Texterm) CD8 T cells. Increasing NRF2 activity in CD8 T cells (via conditional deletion of KEAP1) promotes increased glutathione production and antioxidant defense yet accelerates the development of terminally exhausted (PD-1+TIM-3+) CD8 T cells in response to chronic infection or tumor challenge. Mechanistically,we identify PTGIR,a receptor for the circulating eicosanoid prostacyclin,as an NRF2-regulated protein that promotes CD8 T cell dysfunction. Silencing PTGIR expression restores the anti-tumor function of KEAP1-deficient T cells. Moreover,lowering PTGIR expression in CD8 T cells both reduces terminal exhaustion and enhances T cell effector responses (i.e. IFN-γ and granzyme production) to chronic infection and cancer. Together,these results establish the KEAP1-NRF2 axis as a metabolic sensor linking oxidative stress to CD8 T cell dysfunction and identify the prostacyclin receptor PTGIR as an NRF2-regulated immune checkpoint that regulates CD8 T cell fate decisions between effector and exhausted states. One Sentence Summary:The KEAP1-NRF2 pathway is hyperactivated in terminally exhausted CD8 T cells and drives T cell dysfunction via transcriptional regulation of the prostacyclin receptor,Ptgir. View Publication

Activating interferon responses with STING agonists (STINGa) is a current cancer immunotherapy strategy,and therapeutic modalities that enable tumor-targeted delivery via systemic administration could be beneficial. Here we demonstrate that tumor cell-directed STING agonist antibody-drug-conjugates (STINGa ADCs) activate STING in tumor cells and myeloid cells and induce anti-tumor innate immune responses in in vitro,in vivo (in female mice),and ex vivo tumor models. We show that the tumor cell-directed STINGa ADCs are internalized into myeloid cells by Fcγ-receptor-I in a tumor antigen-dependent manner. Systemic administration of STINGa ADCs in mice leads to STING activation in tumors,with increased anti-tumor activity and reduced serum cytokine elevations compared to a free STING agonist. Furthermore,STINGa ADCs induce type III interferons,which contribute to the anti-tumor activity by upregulating type I interferon and other key chemokines/cytokines. These findings reveal an important role for type III interferons in the anti-tumor activity elicited by STING agonism and provide rationale for the clinical development of tumor cell-directed STINGa ADCs. Activation of the STING pathway can promote anti-tumor immunity. Here the authors generate tumor cell-directed STING agonist antibody-drug conjugates that activate STING in tumor and myeloid cells,promoting anti-tumor innate immune responses in preclinical cancer models. View Publication

Migrasomes are organelles that are generated by migrating cells. Here we report the key role of neutrophil-derived migrasomes in haemostasis. We found that a large number of neutrophil-derived migrasomes exist in the blood of mice and humans. Compared with neutrophil cell bodies and platelets,these migrasomes adsorb and enrich coagulation factors on the surface. Moreover,they are highly enriched with adhesion molecules,which enable them to preferentially accumulate at sites of injury,where they trigger platelet activation and clot formation. Depletion of neutrophils,or genetic reduction of the number of these migrasomes,significantly decreases platelet plug formation and impairs coagulation. These defects can be rescued by intravenous injection of purified neutrophil-derived migrasomes. Our study reveals neutrophil-derived migrasomes as a previously unrecognized essential component of the haemostasis system,which may shed light on the cause of various coagulation disorders and open therapeutic possibilities. Jiang et al. document an abundance of neutrophil-derived migrasomes in the blood of mice and humans and show that migrasomes are enriched in coagulation factors,accumulate at sites of injury and trigger platelet activation and clot formation. View Publication

IntroductionInnate lymphoid cells (ILCs) are enriched at mucosal surfaces where they respond rapidly to environmental stimuli and contribute to both tissue inflammation and healing. MethodsTo gain insight into the role of ILCs in the pathology and recovery from COVID-19 infection,we employed a multi-omics approach consisting of Abseq and targeted mRNA sequencing to respectively probe the surface marker expression,transcriptional profile and heterogeneity of ILCs in peripheral blood of patients with COVID-19 compared with healthy controls. ResultsWe found that the frequency of ILC1 and ILC2 cells was significantly increased in COVID-19 patients. Moreover,all ILC subsets displayed a significantly higher frequency of CD69-expressing cells,indicating a heightened state of activation. ILC2s from COVID-19 patients had the highest number of significantly differentially expressed (DE) genes. The most notable genes DE in COVID-19 vs healthy participants included a) genes associated with responses to virus infections and b) genes that support ILC self-proliferation,activation and homeostasis. In addition,differential gene regulatory network analysis revealed ILC-specific regulons and their interactions driving the differential gene expression in each ILC. DiscussionOverall,this study provides mechanistic insights into the characteristics of ILC subsets activated during COVID-19 infection. View Publication