Abstract Liver inflammation is a key driver of nonalcoholic fatty liver disease (NAFLD) and its progressive subtype, nonalcoholic steatohepatitis (NASH). Macrophages, as central players in the innate immune response, are crucial to disease pathogenesis; however, the upstream events that initiate their activation remain poorly defined. Here, we employed a cell-based chimeric receptor screening system and identified CD1d as a surface ligand for PIRA2. We subsequently demonstrated that CD1d stimulation activated macrophages both in vitro and in vivo. Co-immunoprecipitation assays further confirmed a direct interaction between CD1d and PIRA2. Using Pira2-deficient (Pira2 −/− ) mice, we observed significantly reduced hepatic inflammation and lipid accumulation compared to wild-type controls. Importantly, macrophage-specific Pira2 conditional knockout mice similarly exhibited reduced macrophage activation and inflammatory cytokine production in vivo, confirming a macrophage-intrinsic role of PIRA2. Mechanistically, CD1d-PIRA2 interaction involves the α1 and α2 domains of CD1d and the D1 and D2 domains of PIRA2, leading to FcRγ ITAM tyrosine phosphorylation and downstream inflammatory signaling-events that are impaired in Pira2 −/− macrophages. Additionally, CD1d and LILRA2 protein levels were elevated in NAFLD patients, and CD1d stimulation induced proinflammatory cytokine expression in human macrophages, which was attenuated by LILRA2 blockade. A recombinant LILRA2/Fc fusion protein effectively blocked CD1d-induced inflammatory gene expression in human macrophages, highlighting its potential as a therapeutic strategy for NAFLD. Collectively, our findings identify CD1d as a functional ligand of PIRA2 that promotes macrophage activation and inflammation, contributing to inflammatory progression in NAFLD.

This review summarizes how LCFA metabolic enzymes and transporters orchestrate antitumor immunity, underscoring their cell-type-specific dualities and druggability. AlphaFold3-predicted structures of CPT1A, ACSL4, ACSL5, FABP4, FABP5, and CD36 reveal deep hydrophobic pockets (Fpocket scores 0.67-0.81), and molecular docking maps inhibitor interactions: etomoxir (CPT1A His473 covalent), PRGL493 (ACSL4 AMP pocket), triacsin C (ACSL5 substrate tunnel), SBFI-26 (FABP5 β-barrel), and sulfo-N-succinimidyl oleate (CD36 SMAC pocket). Certain dietary LCFAs potently enhance antitumor responses: elaidic acid promotes MHC-I antigen presentation via the ACSL5-SIRT6-NLRC5 axis, sensitizing tumors to CD8+ T-cell-mediated killing and immune checkpoint blockade; docosahexaenoic acid (DHA) incorporates into phospholipids via ACSL4/6 to drive immunogenic ferroptosis, amplified by CD8+ T-cell-derived IFN-γ. In contrast, chronic LCFA accumulation fosters an immunosuppressive landscape: CPT1A-dependent FAO sustains Tregs, yet its succinyltransferase activity promotes PD-L1 degradation; myeloid FABP5 drives immunosuppressive macrophage differentiation; and CD36-mediated uptake of lipids or oxidized lipoproteins induces CD8+ T-cell dysfunction via the p38-CEBPB-TfR1 cascade and iron-dependent lipid peroxidation. Moreover, tumor-intrinsic ACSL4 can alternatively promote neoplastic proliferation and therapeutic resistance, revealing an oncogenic facet. Accordingly, we assess translational strategies that target these metabolic nodes in a context-aware manner: context-dependent CPT1A inhibition or non-enzymatic activation; selective blockade of CD36 or FABP5; inhibition of oncogenic ACSL4; and complementary approaches harnessing ACSL4/5-mediated antitumor pathways (e.g., ferroptosis induction and antigen presentation enhancement) through tailored dietary interventions and combination therapies. This integrated structural, biochemical, and pharmacological framework highlights the necessity of uncoupling the opposing immunomodulatory roles of LCFAs using cell-type-resolved and context-aware strategies in cancer therapy.

Background: Hepatitis B virus (HBV)-specific CD8+ T cells play a crucial role in viral clearance. However, in patients with chronic hepatitis B infections, sustained immune activation leads to functional impairment of these HBV-specific CD8+ T cells. The goal of this study was to clarify whether these virus-specific CD8+ T cells are exhausted or reflect an incomplete response derived from the initial T cell repertoire. Methods: In this study, HBV core 18–27 epitope-specific CD8+ T cells were identified by proliferation through in vitro antigen stimulation. Peptide-specific CD8+ T cells recognizing the cytomegalovirus (CMV) pp65 495–503 epitope were used as a positive control, as they exhibit a robust immune response. Single-cell sequencing was employed to characterize the TCR repertoire of expanded clones. Correlations between T cell subsets and clinical outcomes were analyzed and compared. Results: Both HBV core 18–27-specific and CMV pp65-specific CD8+ T cells were successfully classified into three functionally distinct subsets: IFNγ+, mTGFβ+, and IFNγ–/mTGFβ–. Those patients with resolved acute HBV infections and HBV core 18–27 specific CD8+ T cells exhibited the highest IFNγ+/mTGFβ+ ratio, reaching levels comparable to those of CMV pp65-specific CD8+ T cells. Inactive HBV carriers exhibited the second-highest IFNγ+/mTGFβ+ ratio, while this ratio was lowest among patients exhibiting viral immune tolerance. HBV core 18–27 tetramer staining and ERGO-Ⅱ Model prediction demonstrated that IFNγ+ subset CD8+ T cells exhibited the highest affinity for this epitope, followed by the mTGFβ+ subset, with IFNγ–/mTGFβ– cells exhibiting the lowest affinity. Conclusions: These results suggest that individuals with a high IFNγ+/mTGFβ+ ratio exhibit a lower HBV viral load. The IFNγ+/mTGFβ+ CD8+ T cell ratio, in particular, appears to be associated with HBV clearance, and this may be attributable to T cell receptor affinity for HBV epitopes.

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IntroductionSepsis associated acute respiratory distress syndrome (ARDS), is a life-threatening condition characterized by severe pulmonary inflammation. Previous research has suggested that allergic immune diseases are associated with a lower risk of sepsis. Therefore, we hypothesized that certain molecules involved in type 2 inflammation are beneficial for the outcome of sepsis associated ARDS. Thymic stromal lymphopoietin (TSLP) is known to promote Th2 responses in allergic disease, however, its role in sepsis associated ARDS remains limited.MethodsTo investigate the role of TSLP in sepsis associated lung injury, we administered exogenous recombinant TSLP to wild-type mice, followed by lipopolysaccharide (LPS) challenge. At 24 hours post-treatment, bronchoalveolar lavage fluid (BALF) and lung tissues were collected for analysis. The ratio, number, phenotype, and function of immune cells and cytokine levels were measured. Additionally, murine bone marrow-derived macrophages (BMDMs) were prepared and stimulated with LPS and TSLP to further verify our findings experimentally. To explore the molecular mechanisms of TSLP’s effect, analysis of transcriptome sequencing and single-cell transcriptome sequencing and subsequent experiments were performed.ResultsIn LPS-induced acute lung injury models, pretreatment with TSLP significantly alleviated lung injury, suppressed inflammatory cytokines secretion, and reduced macrophages and neutrophils infiltration. In addition, TSLP treatment significantly inhibited M1 macrophage polarization and promoted M2 macrophage differentiation. Transcriptome sequencing suggested IFN-γ as a potential target of TSLP, and single-cell transcriptome sequencing showed that innate like T cells are important source of IFN-γ. Consistently, flow cytometry showed that proportion of IFN-γ-producing iNKT cells was decreased by TSLP administration in the acute lung injury model. Intriguingly, Jα18−/− mice, which are completely deficient in invariant natural killer T (iNKT) cells, exhibited not only significantly less severe lung inflammation but also a notably higher degree of anti-inflammatory Arg1+ M2 macrophages infiltration when compared with their LPS-sensitized wild-type counterparts.ConclusionsThese findings not only underscore the crucial role of TSLP in the regulation of sepsis-associated ARDS but also demonstrate its potential clinical value as both a predictive biomarker for early detection and a molecular target for therapeutic intervention.

Mucosal-associated invariant T cells (MAIT) are emerging as important regulators at mucosal surfaces. While these cells have been linked to a Th1-biased immune response and support for B cells, their roles in allergic diseases characterised by type 2 inflammation remain elusive. The study seeks to characterise MAIT cells in house dust mite (HDM)-induced allergic rhinitis (AR) and subsequent allergen immunotherapy (AIT), aiming to elucidate their clinical significance in AR and potential to enhance AIT effectiveness. MAIT cells were assessed in patients with AR and individuals undergoing AIT. The ratio and cytokine-producing capacity of these cells were analysed to explore their correlations with AR progression and their responsiveness to HDM extracts and MAIT cell-specific agonists. In AR patients, there was an increase in the ratios of circulating MAIT cells and tonsil follicular T helper-like MAIT cells, alongside a decrease in the IFN-γ-producing MAIT cells. AIT restored their IFN-γ producing capacity, which was further boosted by T cell receptor (TCR) activation using MAIT cell-specific agonist-loaded artificial antigen-presenting cells (aAPCs). Synergistic effects of aAPCs and HDM enhance MAIT cell activation and IFN-γ production while reducing HDM-induced IgE levels in PBMC cocultures. Moreover, higher ratios of MAIT cells and IFN-γ-producing MAIT cells correlated with decreased IgE and increased IgG4 and improved clinical outcomes during AIT. These findings underscore the compromised IFN-γ-producing MAIT cells in AR and their restoration following AIT and TCR stimulation, highlighting the cell's therapeutic potential and predictive value for clinical outcomes in AR and AIT.

Mucosal-associated invariant T (MAIT) cells exert multifaceted effects such as anti-microbial activity, tissue repair, and pro-fibrotic effects across various disease settings. Nonetheless, their role in liver injury and hemostasis remains debated. Here, we report a significant depletion and functional dysregulation of MAIT cells, which is associated with disease severity and accumulated bile acids in HBV-infected patients with varying degree of liver injury. Liver transplantation facilitates a gradual recovery of recipient-originated MAIT cells. Transcriptome analysis reveals enhanced MAIT cell activation, while TCR mining demonstrates clonotype overlap between circulating and hepatic MAIT cells during significant liver injury. TCR-activated MAIT cells from transplant recipients display higher protective capacity but reduced pathological potential than those from liver failure patients. Compromised recovery of MAIT cells is linked to post-transplantation complications, whereas prompt recovery predicates favorable clinical outcome. These findings underscore the intricate interplay between MAIT cells and the hepatic environment, highlighting MAIT cells as potential therapeutic targets and sensitive predictors for clinical outcome in individuals experiencing liver failure and post liver transplantation.

While mismatch repair-deficient (dMMR) colorectal cancers (CRCs) exhibit strong immunogenicity and better response to immune checkpoint inhibitors, the more prevalent mismatch repair-proficient (pMMR) CRCs typically show poor T- cell infiltration and inferior outcomes. Profiling the limited tumor-infiltrating CD8+ T cells helps identify responders and guides new strategies to enhance their infiltration and function in pMMR CRC tumors. Our study reveals that the proportion and number of CD103−CD8+ T (CD103N) cells are significantly increased in pMMR CRC tissue compared to adjacent non-tumor tissue. Distinguish from CD103+CD8+ T (CD103P) cells with elevated TEX markers, these CD103N cells display a precursor exhausted T cells (TPEX) phenotype with elevated stemness properties, reduced exhaustion markers, and retained functional capacity to secrete anti-tumor mediators. Moreover, CD103N cells in pMMR CRC shared a substantial number of identical TCR clonotypes with both CD103P cells in tumor and CD103N cell in peripheral blood. In dMMR CRC patients, enrichment of TPEX-like CD103N cells is associated with a favorable prognosis following anti-PD-1 therapy, suggesting their association with clinical outcome. Our findings identify an expanded population of CD103N cells exhibiting a TPEX phenotype with anti-tumor potential in pMMR CRC, highlighting their promise as therapeutic targets for recruitment into the tumor microenvironment to enhance the efficacy of immunotherapy.

Liver inflammation is a key driver of nonalcoholic fatty liver disease (NAFLD) and its progressive subtype, nonalcoholic steatohepatitis (NASH). Macrophages, as central players in the innate immune response, are crucial to disease pathogenesis; however, the upstream events that initiate their activation remain poorly defined. Here, we employed a cell-based chimeric receptor screening system and identified CD1d as a surface ligand for PIRA2. We subsequently demonstrated that CD1d stimulation activated macrophages both in vitro and in vivo. Using Pira2-deficient (Pira2⁻/⁻) mice, we observed significantly reduced hepatic inflammation and lipid accumulation compared to wild-type controls. Mechanistically, CD1d–PIRA2 interaction involves the α1 and α2 domains of CD1d and the D1 and D2 domains of PIRA2, leading to FcRγ ITAM tyrosine phosphorylation and downstream inflammatory signaling—events that are impaired in Pira2⁻/⁻ macrophages. Additionally, CD1d and LILRA2 protein levels were elevated in NAFLD patients, and CD1d stimulation induced proinflammatory cytokine expression in human macrophages, which was attenuated by LILRA2 blockade. A recombinant LILRA2/Fc fusion protein effectively blocked CD1d-induced inflammatory gene expression in human macrophages, highlighting its potential as a therapeutic strategy for NAFLD. Collectively, our findings identify CD1d as a functional ligand of PIRA2 that promotes macrophage activation and inflammation, contributing to NAFLD progression.

BackgroundPulmonary fibrosis arises from various etiologies, often associated with elevated levels of reactive oxygen species (ROS) stress and activation of pro-fibrotic signaling pathways. The chemotherapeutic drug bleomycin has been shown to exacerbate pulmonary fibrosis during anti-tumor treatment. Further research is needed to combat bleomycin-induced fibrosis.AimThis investigation aims to identify critical mediators of bleomycin-induced pulmonary fibrosis and evaluate the therapeutic potential of mitochondria-targeted ubiquinone (MitoQ) in attenuating fibrotic pathogenesis.MethodsA bleomycin-induced pulmonary injury mouse model and fibroblast cell culture were established, followed by histopathology evaluation, molecule interaction analysis, cytokine quantification, intervention assay, and flow cytometry.ResultsWe analyzed RNA-seq data from a bleomycin-induced pulmonary fibrosis mouse model and identified a network of oxidative stress-related fibrosis genes centered on Tgfb1. In fibroblast cell lines, bleomycin exposure elevated mitochondrial and cellular ROS, increased mitochondrial mass and the MDRlow/MTGhigh cell ratio, downregulated genes linked to ROS scavenging and mitochondrial function, and upregulated transcription of pro-fibrotic molecules. MitoQ effectively reduced mitochondrial ROS, alleviated mitochondrial swelling, and restored transcription of genes involved in mitochondrial redox balance and function. Compared to conventional ubiquinone, MitoQ exhibited significantly greater antifibrotic efficacy, effectively attenuating bleomycin- and TGF-β1-induced fibroblast activation in vitro. In bleomycin-treated mice, MitoQ treatment with markedly suppressed pro-fibrotic molecule transcription and inhibited pulmonary fibrosis progression.ConclusionThese findings not only advance our understanding of the interplay between oxidative stress and pro-fibrotic signaling in bleomycin-induced pulmonary fibrosis but also provide experimental data supporting the use of mitochondria-targeted antioxidant in the treatment of this condition.

Mucosal-associated invariant T (MAIT) cells exert multifaceted effects such as anti-microbial activity, tissue repair, and pro-fibrotic effects across various disease settings. Nonetheless, their role in liver injury and hemostasis is a current topic of debate. Here, we presented a MAIT cell-centered profiling in chronic HBV-infected patients with varying degree of liver injury and those who underwent liver transplantation. Liver transplantation facilitated a gradual recovery of recipient-originated MAIT cells from dysregulation associated with disease severity and accumulated bile acids in liver failure. Transcriptome analysis and T cell receptor (TCR) mining indicated an upregulation in MAIT cell migration during liver injury and post liver transplantation, characterized by elevated liver egress in the former and rescued liver homing receptors in the latter. TCR activation exacerbated the pathological potency of MAIT cells from liver failure patients, but conferred a protective potential in those from transplant recipients. Compromised recovery of MAIT cells was linked to post-transplantation complications, whereas prompt recovery predicated a more favorable clinical outcome. These findings underscore the intricate interplay between MAIT cells and the hepatic environment, highlighting MAIT cells as potential therapeutic targets and sensitive predictors for clinical outcome in individuals experiencing liver failure and post liver transplantation.

Preterm birth (PTB) is a major problem affecting perinatal health, directly increasing the mortality risk of mother and infant that often results from the breakdown of the maternal-fetal immune balance. Increasing evidence shows the essential role of mucosal-associated invariant T (MAIT) cells to balance antibacterial function and immune tolerance function during pregnancy. However, the phenotype and function of placental MAIT cells and their specific mechanisms in PTB remain unclear. Here, we report that MAIT cells in placentas from PTBs show increased activation levels and decreased IFN-γ secretion capacity compared with those from normal pregnancies. Moreover, our data indicate gravidity is a factor affecting placental MAIT cells during pregnancies. Multi-omics analysis indicated aberrant immune activation and abnormal increase of lipids and lipid-like metabolites in the PTB placental microenvironment. Moreover, the proportion and activation of MAIT cells were positively correlated with the abnormal increase of lipids and lipid-like metabolites. Together, our work revealed that abnormal activation and impaired function of MAIT cells may be related to abnormal elevation of lipids and lipid-like metabolites in PTB.

BackgroundMutations commonly occur in cancer cells, arising neoantigen as potential targets for personalized immunotherapy of lung adenocarcinoma (LUAD). However, the substantial heterogeneity observed among individuals and distinct foci within the same patient presents significant challenges in formulating immunotherapy strategies. The aim of the work is to characterize the mutation pattern and identify neopeptides across different patients and diverse foci within the same patients with LUAD.MethodsSeven lung adenocarcinoma samples and matched tissues/blood are collected from 4 patients with LUAD for whole exome sequencing, mutation signature analysis, HLA binding prediction and neoantigen screening. Dimeric HLA-A2 molecules were prepared by Bac-to-Bac baculovirus expression system to establish a T cell stimulation system based on HLA-A2-coated artificial antigen-presenting cells for the validation of immunogenic neopeptides.ResultsSimilar mutation pattern with predominant missense mutation and high tumor mutation burden was observed across individuals with lung adenocarcinomas and between non-invasive and invasive foci. We screened and identified 3 consistent mutated genes among 100 top genes with highest mutation scores contributed across 4 patients, and 3 mutated peptides among 30 with highest HLA-A2 binding affinity distributed in at least 2 out of 4 foci in the same patient. Notably, LUAD-7-MT peptide encoded by NANOGNB demonstrated higher immunogenicity in promoting CD8+ T cells proliferation and IFN-γ secretion than the corresponding wildtype peptide.ConclusionsThis study provides an in-depth analysis of mutation characteristics of LUAD and establishes a neoantigen screening and validation system for identifying immunogenicity neopeptide across individual patients and diverse foci in the same patient with multifocal LUAD.

Autoimmune liver diseases (AILD) encompass a group of conditions in which the immune system mistakenly attacks the liver tissue. Mucosal-associated invariant T (MAIT) cells are enriched in the liver, where they play crucial roles in antibacterial defense and inflammation regulation. Compared to other autoimmune conditions affecting the synovium of the joints, MAIT cells from AILD exhibited a greater deficiency in ratio, elevated activation markers, increased apoptosis, and higher pro-inflammatory cytokines production. However, the frequency of MAIT cells in AILD was negatively correlated with anti-bacterial indexes, and their impaired responsiveness and weakened anti-bacterial potential were evidenced by reduced expansion ability, lower maximal IFN-γ production, and diminished E. coli-induced cytotoxic mediators release. Similar shifts in MAIT cell ratios and phenotypes were observed in both primary biliary cirrhosis and autoimmune hepatitis, linked to upregulation of bile acid components in the affected tissue. Specifically, ursodeoxycholic acid, a metabolic intermediate and traditional anti-primary biliary cirrhosis drug, inhibited TCR-mediated expansion and downregulated pro-inflammatory cytokines and anti-bacterial-related mediators in MAIT cells. These findings underscore the intricate interplay between hepatic pathology and MAIT cells, and highlight the importance of antibacterial monitoring during ursodeoxycholic acid treatment in AILD.

BACKGROUND:The development of pulmonary fibrosis involves a cascade of events, in which inflammation mediated by immune cells plays a pivotal role. Chemotherapeutic drugs have been shown to have dual effects on fibrosis, with bleomycin exacerbating pulmonary fibrosis and bortezomib alleviating tissue fibrotic processes. Understanding the intricate interplay between chemotherapeutic drugs, immune responses, and pulmonary fibrosis is likely to serve as the foundation for crafting tailored therapeutic strategies. METHODS:A model of bleomycin-induced pulmonary fibrosis was established, followed by treatment with bortezomib. Tissue samples were collected for analysis of immune cell subsets and functional assessment by flow cytometry and in vitro cell experiments. Additionally, multi-omics analysis was conducted to further elucidate the expression of chemokines and chemokine receptors, as well as the characteristics of cell populations. RESULTS:Here, we observed that the expression of CXCL16 and CXCR6 was elevated in the lung tissue of a pulmonary fibrosis model. In the context of pulmonary fibrosis or TGF-β1 stimulation in vitro, macrophages exhibited an M2-polarized phenotype and secreted more CXCL16 than those of the control group. Moreover, flow cytometry revealed increased expression levels of CD69 and CXCR6 in pulmonary CD4 T cells during fibrosis progression. The administration of bortezomib alleviated bleomycin-induced pulmonary fibrosis, accompanied by reduced ratio of M2-polarized macrophages and decreased accumulation of CD4 T cells expressing CXCR6. CONCLUSIONS:Our findings provide insights into the key immune players involved in bleomycin-induced pulmonary fibrosis and offer preclinical evidence supporting the repurposing strategy and combination approaches to reduce lung fibrosis.

Background and aimsT cells are master effectors of anti-tumor immunity in cancer. Recent studies suggest that altered lipid metabolism imposed by the tumor microenvironment constrains anti-tumor immunity. However, the tumor-associated lipid species changes that dampen T cell ability to control tumor progression are not fully understood. Here, we plan to clarify the influences of distinctly altered lipid components in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) on T-cell function, aiming to seek lipid metabolic targets for improving T cell anti-tumor effects. MethodsTumor tissues and non-tumor liver from HCC patients were collected for RNA-sequencing, lipid profiling and T cell characterizing, followed by correlation analysis. Additionally, the effects of significantly changed lipid components on anti-tumor potential of T cells were tested by in vitro cell experiments and/or in vivo tumor inoculated model. ResultsAltered lipid metabolism coincides with impaired T cell response in HBV-related HCC. Characteristic lipid composition, significantly marked by accumulation of long-chain acylcarnitines (LCACs) and reduction of lysophosphatidylcholines (LPCs), are found in the tumor tissue. Notably, LCACs accumulated are associated with T cells exhaustion and deficient functionality, while LPCs correlate to anti-tumor effects of T cells. In particular, supplement of LPCs, including LPC (20:0) and LPC (22:0), directly promote the activation and IFN-gamma secretion of T cells in vitro, and suppress tumor growth in vivo. ConclusionsOur study highlights the distinctly changed lipid components closely related to T cell dysregulation in HCC, and suggests a promising strategy by decreasing LCACs and increasing LPCs for anti-tumor immunotherapy.

目的 构建MR1/IgG1 Fc融合蛋白杆状病毒表达载体并使其在昆虫细胞内表达获得MR1/IgG1 Fc二聚体,制备人工抗原提呈细胞用于黏膜相关恒定T细胞(MAIT)反应性代谢物及MAIT细胞功能调控研究.方法 从人外周血单个核细胞中扩增β2m编码基因.商业化合成MR1胞外段和IgG1 Fc融合基因的全序列基因MR1/IgG1 Fc,与β2m基因重组构建pFastBac™ Dual+[β2m+MR1/IgG1 Fc]表达载体;利用Bac-to-Bac昆虫表达系统表达MR1/IgG1 Fc二聚体融合蛋白,并通过双抗体夹心ELISA、Western blot及流式细胞术进行检测.建立MR1/IgG1 Fc二聚体加载的人工抗原提呈细胞(artificial antigen presenting cells,aAPCs),即MR1 aAPCs,提呈大肠埃希菌(DH5α)来源的代谢物,与人外周血单个核细胞共培养,检测MAIT细胞的活化和增殖水平.结果 经PCR及测序鉴定证实pFastBac™ Dual+[β2m+MR1/IgG1 Fc]载体中MR1/IgG1 Fc与β2m具有正确序列.ELISA、Western blot及流式细胞术检测结果表明MR1/IgG1 Fc二聚体在重组杆粒感染的Sf9细胞培养上清富集,具有正确构象.加载DH5α来源代谢物的MR1 aAPCs能够促进MAIT细胞活化和增殖.结论 成功构建pFastBac™ Dual+[β2m+MR1/IgG1 Fc]重组质粒,并在Sf9细胞中表达MR1/IgG1 Fc二聚体,制备获得MR1 aAPCs,为研究MAIT细胞反应性代谢物及MAIT细胞功能提供了新的工具.

在2020春新冠疫情大环境下,教育部"停课不停学"的政策触发网络教学的大规模开展,以华中科技大学医学免疫学9个网络教学课堂为调查对象,结果显示疫情期间网络教学方式推进师生对教学软件、平台以及资源的充分利用,有效网络教学设计让学生深刻体会到参与式教学的优点,为后期进一步开展与完善"以学生为中心"的教学改革奠定了良好的基础.

BACKGROUND & AIMS: CD161-expressing CD8+ T cells consist of mucosal-associated invariant T cells with semi -invariant T-cell receptor (TCR) use and non-mucosal-asso-ciated invariant T CD161+CD8+ T cells with polyclonal TCR repertoire. Although CD161+CD8+ T cells are enriched in liver and embrace hepatitis B virus (HBV)-specific T cells in chronic hepatitis B (CHB) patients, their roles in disease progression remain poorly understood. This study aimed to decipher their profiling and dynamic changes during chronic HBV infection. METHODS: Blood samples from 257 CHB patients and non -tumor liver specimens from 73 HBV-positive patients were analyzed for CD161(+)CD8(+) T-cell characterization by flow cytometry, TCR repertoire determination, transcriptomic ana-lyses, and cell experiments. RESULTS: CD161+CD8+ T cells were increased and hyper-activated in patients, while positive correlation between the CD161(+)CD8(+) T-cell ratio and HBV-DNA level suggested this was insufficient to control HBV replication. The overlap of complementarity determining region 3 sequences supported the switch between CD161-CD8(+) and CD161(+)CD8(+) pop-ulations. Although CD161(+)CD8(+) T cells were endowed with innateness phenotype and enhanced antiviral capacity, the population from patients had impaired type I cytokine pro-duction, and increased interleukin 17 and granzyme B secre-tion. The increased CD161+CD8+ T cells and their increased granzyme B secretion correlated positively with inflammation-associated liver injury. Hepatic CD161(+)CD8(+) T cells showed neutrophil-related pathogenic potential because they had increased transcript signatures and proinflammatory cytokine production in neutrophil recruitment-and response-related pathways that changed consistently in the injured liver. CONCLUSIONS: Our results highlight the reduced antiviral potency but increased pathogenic potential of CD161(+)CD8(+) T cells in CHB patients, supporting CD161 expression as a marker of pathogenic CD8(+) T subset and the intervention target for liver injury. (Cell Mol Gastroenterol Hepatol 2023;15:1181-1198; https://doi.org/10.1016/j.jcmgh.2023.02.001)

Abstract CD1d-restricted invariant natural killer T (iNKT) cells actively patrol the liver and possess valuable antitumor potential. However, clinical trials evaluating administration of iNKT cell–specific agonist α-galactosylceramide (α-GalCer) have failed to achieve obvious tumor regression. Improving the efficacy of iNKT cell–based immunotherapy requires a better understanding of the factors restraining the clinical benefits. In the context of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), we found circulating and hepatic iNKT cells were hyperactivated but demonstrated imbalances in ratio and defective α-GalCer responsiveness. Exogenous IL2 helped to expand residual α-GalCer–responsive clones with reduced T-cell receptor diversity. However, transcriptome-wide analysis revealed activation of the senescence-associated secretory phenotype and dampened cytotoxicity in iNKT cells, weakening their immune surveillance capacity. The senescent status of iNKT cells from the patients was further illustrated by cell-cycle arrest, impaired telomere maintenance, perturbed calcium transport-related biological processes, and altered metabolism. Lipidomic profiling revealed the accumulation of long-chain acylcarnitines (LCAC) and aberrant lipid metabolism in HCC tissue. Exogenous LCACs, especially palmitoyl-carnitine and stearoyl-carnitine, inhibited iNKT cell expansion and promoted senescence. Collectively, our results provide deeper insights into iNKT cell dysregulation and identify a cell senescence–associated challenge for iNKT cell–based immunotherapy in HBV-related HCC. The mechanistic links between iNKT cell senescence and accumulated LCACs suggest new targets for anti-HCC immunotherapies. Significance: Patients with HBV-related HCC exhibit a cell senescence–associated dysregulation of invariant natural killer cells that is related to altered lipid metabolism and accumulated LCACs in tumor tissue.