Project description:We performed single cell sequencing analysis of exhausted monocytes generated in vitro through prolonged incubation with high dose LPS. We demonstated that 5-day prolonged stimulation of WT but not TRAM KO monocytes with high dose LPS drastically induced monocyte exhaustion, as reflected in higher levels of inflammatory marker genes such as CD38 and immuno-suppressor genes including PD-L1.
Project description:Monocyte exhaustion characterized by sustained pathogenic inflammatory and immune-suppressive features underlies the pathogenesis of sepsis induced by systemic polymicrobial infections. However, effective strategies in blocking monocyte exhaustion and restoring innate homeostasis are currently not available. In this study, we found that Methoxy-Mycolic Acid (M-MA), a branched mycolic acid derived from Mycobacterium Bovis Bacillus Calmette–Guérin (BCG), to be a potent agent in alleviating monocyte exhaustion and restoring immune homeostasis. Co-treatment of monocytes with M-MA can effectively block the expansion of exhausted Ly6Chi /CD38hi/PD-L1hi monocytes induced by repetitive LPS challenges, and restore the expression of immune-enhancing CD86 on co-treated monocytes. Functionally, M-MA treatment restored mitochondrial functions of exhausted monocytes and alleviated their suppressive activities on co-cultured T cells. Mechanistically, M-MA exerts its protective effects independent of cellular receptor TREM2, and relieves cellular stress signaling through blocking Src-STAT1 mediated pathogenic inflammatory polarization as well as reducing the production of compensatory immune suppressors TAX1BP1 and PLAC8. Our whole genome methylation analyses further revealed that M-MA can effectively erase methylation memory of exhausted monocytes, with validated restoration of plac8 methylation by M-MA. Together, our data reveal M-MA as a potent agent in restoring monocyte homeostasis with future therapeutic potential for the treatment of sepsis.
Project description:Pregnancy appears to accelerate mortality associated with infectious diseases; however, the underlying mechanism of the crosstalk between pregnancy and sepsis remains poorly understood. Integrated multiomics analysis of gut microbiome revealed that the abundances of Parabacteroides merdae and its-derived formononetin (FMN) were decreased during pregnancy. Here, we verified that gut microbiota dysbiosis during pregnancy exacerbated immune exhaustion caused by sepsis through accelerating macrophage pyroptosis. Mechanistically, FMN suppressed nucleus-accumulation of hnRNPUL2 to prevent it from binding to Nlrp3 promoter region, thus to inhibit priming of NLRP3 inflammasome. Genetic knockdown of murine hnRNPUL2 by an adeno-associated virus protected against sepsis. Intriguingly, the abundances of Parabacteroides merdae and FMN in feces were negatively correlated with the progression of septic patients. Our data highlighted the significance of FMN/hnRNPUL2/NLRP3 axis mediated by dysbiosis of Parabacteroides merdae in immune exhaustion of pregnant septic hosts, shedding light on promising therapeutic strategies for the treatment of sepsis.
Project description:STING gain-of-function (GOF) mutations lead to T cell lymphopenia, in the context of severe combined immunodeficiency (SCID) for STING GOF V154M mice. This T cell lymphopenia, which is of central origin, has been described as type I IFN independent and associated with dysfunctions of the rare mature T cells found in the periphery. To better describe the biological mechanisms of these dysfunctions, we performed a transcriptomic analysis by RNA-seq on sorted splenic CD4+ and CD8+ mature T cells from STING GOF mice. We highlighted an unexpected T cell exhaustion phenotype that could partly explain their dysfunctions. Acquired very early in life, but only once the peripheral environment is reached, the phenotype appeared to depend neither on type I IFNs, nor on the intrinsic activation of STING in T or stromal cells. Mechanistically, the few mature T cells reaching the periphery seem to be rapidly impacted by the lymphopenic environment through increased antigenic and IL-7 stimulations that could lead to their exhaustion. By using STING GOF long term-hematopoietic stem cells (LT-HSC) transplantations with supportive wild-type bone marrow (BM) cells, we prevented the T cell exhaustion of STING GOF T cells in the resulting non lymphopenic context. With the support of lymphopenic RAG1 hypomorphic mice developing the phenotype, our data uncover a lymphopenia-mediated T cell exhaustion mechanism in STING GOF mice, for which a synergistic effect of the mutation is also envisaged.
Project description:During persistent antigen stimulation, CD8+ cytolytic T cells (CTL) show a gradual decrease in effector function, or “exhaustion”, which impairs the immune response to tumors and infections. Here we show that NFAT, a transcription factor with an established role in T cell activation, in parallel controls a second transcriptional program conferring the characteristic features of CD8+ T cell exhaustion, including upregulation of genes encoding inhibitory cell surface receptors and diminished TCR signaling. Expression of an engineered NFAT1, which induces this negative regulatory program in the absence of the effector program, interferes with the ability of CD8+ T cells to protect against Listeria infection or attenuate tumor growth in vivo. NFAT elicits this second program of gene expression in large part by binding to a subset of the sites occupied by NFAT during a typical effector response, suggesting that a balance between the two pathways determines the outcome of TCR signaling. Determination of NFAT1 binding sites in CD8 T cells in vitro
Project description:Interventions: monocyte/neutrophil apheresis
non monocyte/neutrophil apheresis
Primary outcome(s): Evaluation neutrophil function of patients at high risk for postoperative infection treated with monocyte/neutrophil apheresis
Study Design: Parallel Non-randomized
Project description:Interventions: multiple monocyte/neutrophil apheresis
non monocyte/neutrophil apheresis
Primary outcome(s): Evaluation neutrophil function of patients at high risk for postoperative infection treated with monocyte/neutrophil apheresis
Study Design: Parallel Non-randomized
Project description:CD8+ T cells isolated from HCC tissue were divided into three groups: PD1-TIM3- CD8+ TILs, exhibiting full effector function; PD1-intTIM3+ CD8+ TILs, exhibiting partial exhaustion; and PD1-hiTIM3+ CD8+ TILs, exhibiting severe exhaustion, as reflected by the differences in their ability to produce effector cytokines respectively. Transcriptome sequence analysis was performed to investigate the gene expression profile was performed.
Project description:The alteration in extracellular matrix (ECM) architecture and stiffness becomes one of the hallmarks of cancer. Whether the mechanical property of ECM contributes to the functionality of CD8+ T cells, a key component of anti-tumor response, remains largely unknown. Here we report that mechanical stress drives T cell exhaustion program via Osr2, a transcription factor that had been poorly investigated in T cells. Osr2 is highly and selectively induced in CD8+ T cells when encountering stiff matrix or mechanical force signaling (MFS). Integrated genetic and multi-omics analyses reveals that Osr2 is enriched in the terminal exhausted tumor infiltrating lymphocytes and its expression is modulated by the combined TCR and MFS mediated by Piezo1/Calcium/CREB axis. Importantly, depletion of Piezo1 or Osr2 alleviates T cell exhaustion, which is associated with enhanced anti-tumor immunity mediated by antigen specific T cells or CAR-T cells in solid tumor models. On the contrary, forced Osr2 expression in CD8+ T cells augment their exhaustion and dampens tumor control. In agreement with these observations, high Osr2 expression is correlated with poor prognosis in multiple human malignancies. Mechanistically, Osr2 recruits HDAC3, which in turn establishes epigenetic reprogramming to suppress cytotoxic genes expression and to promote CD8+T cell exhaustion. Thus, our results unravel a mechanical signaling cascade centered by Osr2 that serves as a key driver for CD8+ T cell exhaustion and suggest that mechanical checkpoints could be promising targets for cancer immunotherapy.