技术资料

The molecular basis of the earliest neuronal changes that lead to Alzheimer's disease (AD) is unclear. Here,we analyze neural cells derived from sporadic AD (SAD),APOE4 gene-edited and control induced pluripotent stem cells (iPSCs). We observe major differences in iPSC-derived neural progenitor (NP) cells and neurons in gene networks related to neuronal differentiation,neurogenesis,and synaptic transmission. The iPSC-derived neural cells from SAD patients exhibit accelerated neural differentiation and reduced progenitor cell renewal. Moreover,a similar phenotype appears in NP cells and cerebral organoids derived from APOE4 iPSCs. Impaired function of the transcriptional repressor REST is strongly implicated in the altered transcriptome and differentiation state. SAD and APOE4 expression result in reduced REST nuclear translocation and chromatin binding,and disruption of the nuclear lamina. Thus,dysregulation of neural gene networks may set in motion the pathologic cascade that leads to AD. View Publication

Upon immunogenic challenge,lymph nodes become mechanically stiff as immune cells activate and proliferate within their encapsulated environments,and with resolution,they reestablish a soft baseline state. Here we show that sensing these mechanical changes in the microenvironment requires the mechanosensor YAP. YAP is induced upon activation and suppresses metabolic reprogramming of effector T cells. Unlike in other cell types in which YAP promotes proliferation,YAP in T cells suppresses proliferation in a stiffness-dependent manner by directly restricting the translocation of NFAT1 into the nucleus. YAP slows T cell responses in systemic viral infections and retards effector T cells in autoimmune diabetes. Our work reveals a paradigm whereby tissue mechanics fine-tune adaptive immune responses in health and disease. View Publication

COVID-19 is currently a global pandemic,but human immune responses to the virus remain poorly understood. We analyzed 125 COVID-19 patients,and compared recovered to healthy individuals using high dimensional cytometry. Integrated analysis of {\~{}}200 immune and {\~{}}50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching {\textgreater}30{\%} of circulating B cells. However,another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three immunotypes" associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19." View Publication

Coinfection with hepatitis C virus (HCV) influences HIV reservoir size. However,it is unknown whether this coinfection also induces a higher provirus transcription. Viral transcription is promoted by synergy between cellular factors such as NF-$\kappa$B and the viral regulator Tat. The impact of HCV coinfection on HIV provirus transcription was analyzed in resting (r)CD4 T+ cells (CD3+CD4+CD25-CD69-HLADR-) and rCD4 T cells-depleted PBMCs (rCD4 T- PBMCs) from a multicenter cross-sectional study of 115 cART-treated HIV patients: 42 HIV+/HCV+ coinfected individuals (HIV+/HCV+),34 HIV+ patients with HCV spontaneous clearance (HIV+/HCV-) and 39 HIV patients (HIV+). Viral transcription was assessed in total RNA through the quantification of unspliced,single spliced,and multiple spliced viral mRNAs by qPCR. Linear correlations between viral reservoir size and viral splicing were determined. A 3-fold increase of multiple spliced transcripts in rCD4 T+ cells of HIV+/HCV+ patients was found compared to HIV+ individuals (p {\textless} 0.05). As Tat is synthesized by multiple splicing,the levels of Tat were also quantified in these patients. Significant differences in single and multiple spliced transcripts were also observed in rCD4 T- PBMCs. Levels of multiple spliced mRNAs were increased in rCD4 T+ cells isolated from HIV+/HCV+ subjects,which could indicate a higher Tat activity in these cells despite their resting state. View Publication

Inhibitory receptors (IRs) function as critical regulators of immune responses by tempering T cell activity. In humans,several persisting viruses as well as cancers exploit IR signaling by upregulating IR ligands,resulting in suppression of T cell function (i.e.,exhaustion). This allows escape from immune surveillance and continuation of disease. Here,we report the design,implementation,and results of a phenotypic high-throughput screen for molecules that modulate CD8+ T cell activity. We identify 19 compounds from the ReFRAME drug-repurposing collection that restore cytokine production and enhance the proliferation of exhausted T cells. Analysis of our top hit,ingenol mebutate,a protein kinase C (PKC) inducing diterpene ester,reveals a role for this molecule in overriding the suppressive signaling cascade mediated by IR signaling on T cells. Collectively,these results demonstrate a disease-relevant methodology for identifying modulators of T cell function and reveal new targets for immunotherapy. View Publication

Checkpoint-inhibitor (CPI) immunotherapy has achieved remarkable clinical success,yet its efficacy in 'immunologically cold' tumours has been modest. Interleukin-12 (IL-12) is a powerful cytokine that activates the innate and adaptive arms of the immune system; however,the administration of IL-12 has been associated with immune-related adverse events. Here we show that,after intravenous administration of a collagen-binding domain fused to IL-12 (CBD-IL-12) in mice bearing aggressive mouse tumours,CBD-IL-12 accumulates in the tumour stroma due to exposed collagen in the disordered tumour vasculature. In comparison with the administration of unmodified IL-12,CBD-IL-12 induced sustained intratumoural levels of interferon-$\gamma$,substantially reduced its systemic levels as well as organ damage and provided superior anticancer efficacy,eliciting complete regression of CPI-unresponsive breast tumours. Furthermore,CBD-IL-12 potently synergized with CPI to eradicate large established melanomas,induced antigen-specific immunological memory and controlled tumour growth in a genetically engineered mouse model of melanoma. CBD-IL-12 may potentiate CPI immunotherapy for immunologically cold tumours. View Publication

Drug resistance and relapse remain key challenges in pancreatic cancer. Here,we have used RNA sequencing (RNA-seq),chromatin immunoprecipitation (ChIP)-seq,and genome-wide CRISPR analysis to map the molecular dependencies of pancreatic cancer stem cells,highly therapy-resistant cells that preferentially drive tumorigenesis and progression. This integrated genomic approach revealed an unexpected utilization of immuno-regulatory signals by pancreatic cancer epithelial cells. In particular,the nuclear hormone receptor retinoic-acid-receptor-related orphan receptor gamma (ROR$\gamma$),known to drive inflammation and T cell differentiation,was upregulated during pancreatic cancer progression,and its genetic or pharmacologic inhibition led to a striking defect in pancreatic cancer growth and a marked improvement in survival. Further,a large-scale retrospective analysis in patients revealed that ROR$\gamma$ expression may predict pancreatic cancer aggressiveness,as it positively correlated with advanced disease and metastasis. Collectively,these data identify an orthogonal co-option of immuno-regulatory signals by pancreatic cancer stem cells,suggesting that autoimmune drugs should be evaluated as novel treatment strategies for pancreatic cancer patients. View Publication

Quiescence is a fundamental property that maintains hematopoietic stem cell (HSC) potency throughout life. Quiescent HSCs are thought to rely on glycolysis for their energy,but the overall metabolic properties of HSCs remain elusive. Using combined approaches,including single-cell RNA sequencing (RNA-seq),we show that mitochondrial membrane potential (MMP) distinguishes quiescent from cycling-primed HSCs. We found that primed,but not quiescent,HSCs relied readily on glycolysis. Notably,in vivo inhibition of glycolysis enhanced the competitive repopulation ability of primed HSCs. We further show that HSC quiescence is maintained by an abundance of large lysosomes. Repression of lysosomal activation in HSCs led to further enlargement of lysosomes while suppressing glucose uptake. This also induced increased lysosomal sequestration of mitochondria and enhanced the competitive repopulation ability of primed HSCs by over 90-fold in vivo. These findings show that restraining lysosomal activity preserves HSC quiescence and potency and may be therapeutically relevant. View Publication

Generating robust CD4+ T-helper cell type 1 (Th1) responses is essential for protective vaccine-induced type 1 immunity. Here,we examine whether immunization formulation associated with enhanced vaccine efficacy promotes antigen targeting and cell recruitment into lymph node (LN) niches associated with optimal type 1 responses. Immunization with antigen and Toll-like receptor agonist emulsified in oil leads to an increased differentiation of IFN$\gamma$/TNF-$\alpha$+ polyfunctional Th1 cells compared to an identical immunization in saline. Oil immunization results in a rapid delivery and persistence of antigen in interfollicular regions (IFRs) of the LN,whereas without oil,antigen is distributed in the medullary region. Following oil immunization,CXCL10-producing inflammatory monocytes accumulate in the IFR,which mobilizes antigen-specific CD4+ T cells into this niche. In this microenvironment,CD4+ T cells are advantageously positioned to encounter arriving IL-12-producing inflammatory dendritic cells (DCs). These data suggest that formulations delivering antigen to the LN IFR create an inflammatory niche that can improve vaccine efficacy. View Publication

Background Premature ovarian insufficiency (POI) represents the hypergonadotropic hypoestrogenic symptoms that result in the loss of ovarian follicles. 5-30{\%} POI cases are suggested to be involved in autoimmune etiology. MicroRNA-21 (miR-21) plays a vital role in ovarian folliculogenesis via regulating and interacting with multiple target genes. Here,we conduct the target prediction of miR-21,identify the expression and correlation of miR-21 and its putative target Pellino-1 (Peli1),and confirm their relationship with clinical characteristics in autoimmune POI. Methods Bioinformatic analysis was conducted to screen the miR-21 putative target gene. Autoimmune POI mouse models were established by ZP3 immunization. Serum miR-21,Peli1 mRNA of peripheral blood mononuclear cells (PBMCs) and regulatory T cells (Tregs),general status,spleen Tregs ratio,inflammatory factors,ovarian endocrine function,and ovarian structure were evaluated. For autoimmune POI patients,serum miR-21,PBMCs Peli1 mRNA levels,general data,immune parameters,hormone levels,and ultrasound examinations were obtained. The correlations of miR-21 with Peli1 and clinical characteristics in patients were analyzed. Results Peli1 was selected based on four microRNA prediction databases and literature retrieval. In mouse models,serum miR-21 level,PBMCs and Tregs Peli1 mRNA,and spleen Tregs ratio were 0.61 ± 0.09,0.12 ± 0.12,0.27±0.23 and 4.82 ± 0.58,respectively,lower than those in the control group. In patients,miR-21 level (0.60 ± 0.14) and Peli1 mRNA (0.30 ± 0.14) were lower than those in the control group (1.01 ± 0.07 and 1.63 ± 0.54); miR-21 was positively related with Peli1,AMH,E2,the size of the uterus,and ovarian volume and negatively related with FSH,LH,and the number of positive immune parameters (AOAb,EMAb,ACL,ANA,ds-DNA,ACA,IgG,IgA,IgM,IgE,C3,and C4). Conclusions Low expressions of miR-21 and Peli1 were detected in autoimmune POI mice and patients. Positive correlation between miR-21 and Peli1 was observed in autoimmune POI patients,suggesting that miR-21 and Peli1 might be associated with the pathogenesis of autoimmune POI. View Publication

Understanding the root causes of autoimmune diseases is hampered by the inability to access relevant human tissues and identify the time of disease onset. To examine the interaction of immune cells and their cellular targets in type 1 diabetes,we differentiated human induced pluripotent stem cells into pancreatic endocrine cells,including $\beta$ cells. Here,we describe an in vitro platform that models features of human type 1 diabetes using stress-induced patient-derived endocrine cells and autologous immune cells. We demonstrate a cell-type-specific response by autologous immune cells against induced pluripotent stem cell-derived $\beta$ cells,along with a reduced effect on $\alpha$ cells. This approach represents a path to developing disease models that use patient-derived cells to predict the outcome of an autoimmune response. View Publication

Several phase 1/2 clinical trials showed that low-dose interleukin-2 (IL-2) treatment is a safe and effective strategy for the treatment of chronic graft-versus-host disease,hepatitis C virus-induced vasculitis,and type 1 diabetes. Ulcerative colitis (UC) is a chronic inflammatory condition of the colon that lacks satisfactory treatment. In this study,we aimed to determine the effects of low-dose IL-2 as a therapeutic for UC on dextran sulfate sodium (DSS)-induced colitis. Methods: Mice with DSS-induced colitis were intraperitoneally injected with low-dose IL-2. Survival,body weight,disease activity index,colon length,histopathological score,myeloperoxidase activity and inflammatory cytokine levels as well as intestinal barrier integrity were examined. Differential gene expression after low-dose IL-2 treatment was analyzed by RNA-sequencing. Results: Low-dose IL-2 significantly improved the symptoms of DSS-induced colitis in mice and attenuated pro-inflammatory cytokine production and immune cell infiltration. The most effective dose range of IL-2 was 16K-32K IU/day. Importantly,low-dose IL-2 was effective in ameliorating the disruption of epithelial barrier integrity in DSS-induced colitis tissues by restoring tight junction proteins and mucin production and suppressing apoptosis. The colon tissue of DSS-induced mice exposed to low-dose IL-2 mimic gene expression patterns in the colons of control mice. Furthermore,we identified the crucial role of the PI3K-AKT pathway in exerting the therapeutic effect of low-dose IL-2. Conclusions: The results of our study suggest that low-dose IL-2 has therapeutic effects on DSS-induced colitis and potential clinical value in treating UC. View Publication