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关键词： Animal models   Autoimmunity   CD8 T cells   MHC   Transgenic models  

摘要： Type 1 diabetes (T1D) is characterized by T-cell responses to islet antigens. Investigations in humans and the nonobese diabetic (NOD) mouse model of T1D have revealed that T-cell reactivity to insulin plays a central role in the autoimmune response. As there is no convenient NOD-based model to study human insulin (hIns) or its T-cell epitopes in the context of spontaneous T1D, we developed a NOD mouse strain transgenically expressing hIns in islets under the control of the human regulatory region. Female *** mice developed T1D at approximately the same rate and overall incidence as NOD mice. Islet-infiltrating T cells from *** mice recognized hIns peptides;both CD8 and CD4 T-cell epitopes were identified. We also demonstrate that islet-infiltrating T cells from HLA-transgenic *** mice can be used to identify potentially patient-relevant hIns T-cell epitopes. Besides serving as an antigen, hIns was expressed in the thymus of *** mice and could serve as a protector against T1D under certain circumstances, as previously suggested by genetic studies in humans. *** mice and related strains facilitate human-relevant epitope discovery efforts and the investigation of fundamental questions that cannot be readily addressed in humans. We developed a NOD-based model that transgenically expresses human insulin (hIns) in beta cells and in the thymus. Using islet-infiltrating T cells, we identified hIns CD8 T-cell epitopes. Besides serving as an antigen, thymic hIns could also protect against type 1 diabetes under certain circumstances. image

关键词： NGPV   IFN   cGAS-STING   IRF-7   immune evasion  

摘要： Outbreaks of short beak and dwarfism syndrome (SBDS), caused by a novel goose parvovirus (NGPV), have occurred in China since 2015. The NGPV, a single-stranded DNA virus, is thought to be vertically transmitted. However, the mechanism of NGPV immune evasion remains unclear. In this study, we investigated the impact of NGPV infection on the Cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway in duck embryonic fibroblast (DEF) cells. Our findings demonstrate that NGPV infection stimulates the mRNA expression of cGAS but results in weak IFN-/3 induction. NGPV impedes the expression of IFN-/3 and downstream interferon-stimulated genes, thereby reducing the secretion of IFN-/3 induced by interferon-stimulating DNA (ISD) and poly (I: C). RNA-seq results show that NGPV infection downregulates interferon mRNA expression while enhancing the mRNA expression of inflammatory factors. Additionally, the results of viral protein over-expression indicate that VP1 exhibits a remarkable ability to inhibit IFN-/3 expression compared to other viral proteins. Results indicated that only the intact VP1 protein could inhibit the expression of IFN/3, while the truncated proteins VP1U and VP2 do not possess such characteristics. The immunoprecipitation experiment showed that both VP1 and VP2 could interact with IRF7 protein, while VP1U does not. In summary, our findings indicate that NGPV infection impairs the host's innate immune response by potentially modulating the expression and secretion of interferons and interferon-stimulating factors via IRF7 molecules, which are regulated by the VP1 protein.

关键词： gliosis   reactive astrocytes   inflammation   cell passage number   alpha(V)beta(3) Integrin   DITNC1 cells   in vitro aging   extensive passaging   Thy-1   TNF  

摘要： Astrogliosis is a process by which astrocytes, when exposed to inflammation, exhibit hypertrophy, motility, and elevated expression of reactivity markers such as Glial Fibrillar Acidic Protein, Vimentin, and Connexin43. Since 1999, our laboratory in Chile has been studying molecular signaling pathways associated with "gliosis" and has reported that reactive astrocytes upregulate Syndecan 4 and alpha(V)beta(3) Integrin, which are receptors for the neuronal glycoprotein Thy-1. Thy-1 engagement stimulates adhesion and migration of reactive astrocytes and induces neurons to retract neurites, thus hindering neuronal network repair. Reportedly, we have used DITNC1 astrocytes and neuron-like CAD cells to study signaling mechanisms activated by the Syndecan 4-alpha(V)beta(3) Integrin/Thy-1 interaction. Importantly, the sole overexpression of beta(3) Integrin in non-reactive astrocytes turns them into reactive cells. In vitro, extensive passaging is a simile for "aging", and aged fibroblasts have shown beta(3) Integrin upregulation. However, it is not known if astrocytes upregulate beta(3) Integrin after successive cell passages. Here, we hypothesized that astrocytes undergoing long-term passaging increase beta(3) Integrin expression levels and behave as reactive astrocytes without needing pro-inflammatory stimuli. We used DITNC1 cells with different passage numbers to study reactivity markers using immunoblots, immunofluorescence, and astrocyte adhesion/migration assays. We also evaluated beta(3) Integrin levels by immunoblot and flow cytometry, as well as the neurotoxic effects of reactive astrocytes. Serial cell passaging mimicked the effects of inflammatory stimuli, inducing astrocyte reactivity. Indeed, in response to Thy-1, beta(3) Integrin levels, as well as cell adhesion and migration, gradually increased with multiple passages. Importantly, these long-lived astrocytes expressed and secreted factors that inhibited neurite outgrowth and caused neuronal death, just lik

关键词： MHC   Microbiome   Metabolism   Graft-versus-host disease  

摘要： Allogeneic hematologic stem cell transplantation is a cornerstone in modern hematological treatment, yet its efficacy is compromised by acute Graft-versus-Host Disease. In acute Graftversus-Host Disease, conditioning regimen induced epithelial damage leads to release of damage and pathogen associated molecular patters which in turns triggers activation of alloreactive donor T cells, ultimately resulting in destruction of healthy tissue. Advances in major histocompatibility complex typing and preclinical studies using tissue specific major histocompatibility complex deletion have illuminated the contributions of both, hematopoietic and nonhematopoietic cells to acute Graft-versus-Host Disease pathophysiology. Concurrently, highthroughput sequencing techniques have enabled researchers to recognize the significant impact of the intestinal microbiome and newly discovered metabolites in the pathophysiology of acute Graft-versus-Host Disease. In this review, we discuss the implications of major histocompatibility complex expression on hematopoietic and non-hematopoietic cells, the effect on the intestinal microbiome and the metabolic alterations that contribute to acute Graft-versus-Host Disease. By combining these findings, we hope to untangle the complexity of acute Graft-versus-Host Disease, ultimately paving the way for the development of novel and more effective treatmen options in patients.

关键词： human leukocyte antigen   HLA-DQ   class II HLA   disulfide bond   Fc fusion protein   antibody-mediated rejection   immunotherapy  

摘要： HLA-DQ molecules drive unwanted alloimmune responses after solid-organ transplants and several autoimmune diseases, including type 1 diabetes and celiac disease. Biologics with HLA molecules as part of the design are emerging therapeutic options for these allo- and autoimmune conditions. However, the soluble alpha and beta chains of class II HLA molecules do not dimerize efficiently without their transmembrane domains, which hinders their production. In this study, we examined the feasibility of interchain disulfide engineering by introducing paired cysteines to juxtaposed positions in the alpha and beta chains of HLA-DQ7, encoded by HLA-DQA1 & lowast;05:01 and HLA-DQB1 & lowast;03:01 respectively. We identified three variant peptide-HLA-DQ7-Fc fusion proteins (DQ7Fc) with increased expression and production yield, namely Y19C-D6C (YCDC), A83C-E5C (ACEC), and A84C-N33C (ACNC). The mutated residues were conserved across all HLA-DQ proteins and had limited solvent exposure. Further characterizations of the YCDC variant showed that the expression of the fusion protein is peptide-dependent;inclusion of a higher-affinity peptide correlated with increased protein expression. However, high-affinity peptide alone was insufficient for stabilizing the DQ7 complex without the engineered disulfide bond. Multiple DQ7Fc variants demonstrated expected binding characteristics with commercial anti-DQ antibodies in two immunoassays and by a cell-based assay. Lastly, DQ7Fc variants demonstrated dose-dependent killing of DQ7-specific B cell hybridomas in a flow cytometric, complement-dependent cytotoxicity assay. These data support inter-chain disulfide engineering as a novel approach to efficiently producing functional HLA-DQ molecules and potentially other class II HLA molecules as candidate therapeutic agents.

关键词： Inflammatory bowel diseases   Treatment discontinuation   Relapse   Tumor necrosis factor   Anti- TNF  

摘要： Background: Inflammatory bowel disease (IBD) patients who cease anti-tumor necrosis factor (TNF) therapy are at risk of relapse, which is a matter of concern for the medical community. This study aimed to determine the relapse rate of IBD in patients who cease anti- TNF therapy. Methods: A systematic search of international databases (Medline, Web of Sciences, Scopus, and EMBASE) was conducted until Mar 9th, 2022. The random effects model was used to calculate the IBD relapse rate, accompanied by a 95% confidence interval. Results: The IBD relapse rate in patients who discontinued anti-TNF therapy was 44%. The pooled IBD-UC and IBD-CD relapse rate in patients who stopped anti-TNF therapy were 43% and 46%, respectively. The studies using infliximab (IFX) showed a pooled IBD relapse rate of 45%, and the IBD relapse rate in the IFX/ADA (Adalimumab) group was 42%. The IBD relapse rate for papers with treatment durations of less than or equal to 12 months was 51%, while for articles with treatment durations of more than 12 months, it was 30%. Conclusion: This study emphasizes the need for careful evaluation and monitoring of IBD patients who cease anti-TNF therapy, as well as further investigation of alternative treatments for those who exhibit intolerance or inadequate response to anti-TNF therapy.

关键词： GBM   LLT-1   NLRC4   NK cell   TNF  

摘要： PurposeLLT-1 is a well-known ligand for the natural killer (NK) cell inhibitory receptor NKRP1A. Here, we examined NLRC4 inflammasome components and LLT-1 expression in glioblastoma (GBM) tissues to elucidate potential associations and interactions between these *** tissues were collected for RNA sequencing (RNA-seq) and Immunofluorescent experiments. Colocalization of LLT-1 and other proteins was assessed by immunofluorescence. Computational analyses utilized RNA-seq data from 296 to 52 patients from the Chinese Glioma Genome Atlas and CHA medical records, respectively. These data were subjected to survival, non-negative matrix factorization clustering, Gene Ontology enrichment, and protein-protein interaction analyses. Receptor-ligand interactions between tumor and immune cells were confirmed by single-cell RNA-seq *** GBM tissues, LLT-1 was predominantly colocalized with glial fibrillary acidic protein (GFAP)-expressing astrocytes, but not with microglial markers like Iba-1. Additionally, LLT-1 and activated NLRC4 inflammasomes were mainly co-expressed in intratumoral astrocytes, suggesting an association between LLT-1, NLRC4, and glioma malignancy. High LLT-1 expression correlates with poor prognosis, particularly in the mesenchymal subtype, and is associated with TNF and NOD-like receptor signaling pathway enrichment, indicating a potential role in tumor inflammation and progression. At the single-cell level, mesenchymal-like malignant cells showed high NF, NLR, and IL-1 signaling pathway enrichment compared to other malignant cell *** revealed an association between NLRC4 inflammasome activity and LLT-1 expression, suggesting a novel regulatory pathway involving TNF, inflammasomes, and IL-1, potentially offering new NK-cell-mediated anti-glioma approaches.

关键词： MDA-7/IL-24   Allergy   Inflammation   Autoimmune diseases  

摘要： Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24) is a pleiotropic member of the IL-10 family of cytokines, and is involved in multiple biological processes, including cell proliferation, cell differentiation, tissue fibrosis, the inflammatory response, and antitumor activity. MDA-7/IL-24 can regulate epithelial integrity, homeostasis, mucosal immunity and host resistance to various pathogens by enhancing immune and inflammatory responses. Our recent study revealed the mechanism of MDA-7/IL-24 in promoting airway inflammation and airway remodeling through activating the JAK/STAT3 and ERK signaling pathways in bronchial epithelial cells. Herein, we summarize the cellular sources, inducers, target cells, signaling pathways, and biological effects of MDA-7/IL-24 in several allergic and autoimmune diseases. This review also synopsizes recent advances in clinical research targeting MDA-7/IL-24 or its receptors. Based on these advancements, we emphasize its potential as a target for immunotherapy and discuss the challenges of developing immunotherapeutic drugs targeting MDA-7/IL-24 or its receptors in autoimmune and inflammatory disorders.

关键词： HLA-A*03:01   Immunotherapy   KRAS-G12V   Neoantigen   T cell receptor  

摘要： Mutations in KRAS are some of the most common across multiple cancer types and are thus attractive targets for therapy. Recent studies demonstrated that mutant KRAS generates immunogenic neoantigens that are targetable by adoptive T-cell therapy in metastatic diseases. To expand mutant KRAS-specific immunotherapies, it is critical to identify additional HLA-I allotypes that can present KRAS neoantigens and their cognate T-cell receptors (TCR). Here, we identified a murine TCR specific to a KRAS-G12V neoantigen ((7)VVVGAVGVGK(16)) using a vaccination approach with transgenic mice expressing HLA-A*03:01 (HLA-A3). This TCR demonstrated exquisite specificity for mutant G12V and not WT KRAS peptides. To investigate the molecular basis for neoantigen recognition by this TCR, we determined its structure in complex with HLA-A3(G12V). G12V-TCR CDR3 beta and CDR1 beta formed a hydrophobic pocket to interact with p6 Val of the G12V but not the WT KRAS peptide. To improve the tumor sensitivity of this TCR, we designed rational substitutions to improve TCR:HLA-A3 contacts. Two substitutions exhibited modest improvements in TCR binding avidity to HLA-A3 (G12V) but did not sufficiently improve T-cell sensitivity for further clinical development. Our study provides mechanistic insight into how TCRs detect neoantigens and reveals the challenges in targeting KRAS-G12V mutations.

关键词： Brain   Neuroimmunology  

摘要： Previous studies of brain structure in anorexia nervosa (AN) have reported reduced gray matter in underweight patients, which largely normalizes upon weight gain. One underlying biological mechanism may be glial cell alterations related to low-grade inflammation. Here, we investigated relationships between brain structure as measured by magnetic resonance imaging and serum concentrations of two pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) cross-sectionally in 82 underweight adolescent and young adult female patients (mean age 16.8 years;59 of whom were observed longitudinally after short-term weight restoration;mean duration 2.8 months), 20 individuals long-term weight-recovered from AN (mean age 22.7 years) and 105 healthy control (HC) participants (mean age 17.2 years). We measured cortical thickness, subcortical volumes and local gyrification index, a measure of cortical folding. In contrast to most previous studies of cytokine concentrations in AN, we found no cross-sectional group differences (interleukin-6: p = 0.193, tumor necrosis factor alpha: p = 0.057) or longitudinal changes following weight restoration (interleukin-6: p = 0.201, tumor necrosis factor alpha: p = 0.772). As expected, widespread gray matter reductions (cortical thickness, subcortical volumes, cortical folding) were observed in underweight patients with AN compared to HC. However, we found no evidence of associations between cytokine concentrations and structural brain measures in any participant group. Furthermore, longitudinal changes in cytokine concentrations were unrelated to changes in gray matter. In conclusion, we did not identify any association between (sub-)inflammatory processes and structural brain changes in AN. Future studies are needed to elucidate which other factors besides nutritional status may contribute to brain morphological alterations.