{"title":"Senescence-Associated T cells in Immunosenescence and Diseases.","authors":"Yuji Fukushima, Ryuji Ueno, Nagahiro Minato, Masakazu Hattori","doi":"10.1093/intimm/dxae056","DOIUrl":"https://doi.org/10.1093/intimm/dxae056","url":null,"abstract":"<p><p>Age-related changes in the immune system, referred to as immunosenescence, appear to evolve with rather paradoxical manifestations, a diminished adaptive immune capacity, and an increased propensity for chronic inflammation often with autoimmunity, which may underlie the development of diverse disorders with age. Immunosenescent phenotypes are associated with the emergence of unique lymphocyte subpopulations of both T and B lineages. We report that a CD153+ PD-1+ CD4+ T-cell subpopulation with severely attenuated T-cell receptor (TCR)-responsiveness, termed senescence-associated T (SAT) cells, co-evolve with potentially autoreactive CD30+ B cells, such as spontaneous germinal center B cells and age-associated B cells, in aging mice. SAT cells and CD30+ B cells are reciprocally activated with the aid of the interaction of CD153 with CD30 in trans and with the TCR complex in cis, resulting in the restoration of TCR-mediated proliferation and secretion of abundant proinflammatory cytokines in SAT cells and the activation and production of autoantibodies by CD30+ B cells. Besides normal aging, the development of SAT cells coupled with counterpart B cells may be robustly accelerated and accumulated in the relevant tissues of lymphoid or extra-lymphoid organs under chronic inflammatory conditions including autoimmunity and may contribute to the pathogenesis and aggravation of the disorders. This review summarizes and discusses recent advances in the understanding of SAT cells in the contexts of immunosenescent phenotypes, autoimmune and chronic inflammatory diseases and provides a novel therapeutic clue.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142346132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The role of the skin in the atopic march.","authors":"Xin Tang,Mei Li","doi":"10.1093/intimm/dxae053","DOIUrl":"https://doi.org/10.1093/intimm/dxae053","url":null,"abstract":"Atopic diseases, including atopic dermatitis (AD), food allergy (FA), asthma, and allergic rhinitis (AR) are closely related to inflammatory diseases involving different body sites (i.e. the skin, airway, and digestive tract) with characteristic features including specific IgE to allergens (so-called 'atopy') and Th2 cell-mediated inflammation. It has been recognized that AD often precedes the development of other atopic diseases. The progression from AD during infancy to FA or asthma/AR in later childhood is referred as the 'atopic march' (AM). Clinical, genetic and experimental studies have provided evidence that allergen sensitization occurring through AD skin could be the origin of the AM. Here, we provide an updated review focusing on the role of the skin in the AM, from genetic mutations and environmental factors associated with epidermal barrier dysfunction in AD and the AM, to immunological mechanisms for skin sensitization, particularly recent progress on the function of key cytokines produced by epidermal keratinocytes or by immune cells infiltrating the skin during AD. We also highlight the importance of developing strategies that target AD skin to prevent and attenuate the AM.","PeriodicalId":13743,"journal":{"name":"International immunology","volume":"16 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regnase-1 D141N mutation induces CD4+ T cell-mediated lung granuloma formation via upregulation of Pim2.","authors":"Thin Sandi Htun, Hiroki Tanaka, Shailendra Kumar Singh, Diego Diez, Shizuo Akira","doi":"10.1093/intimm/dxae026","DOIUrl":"10.1093/intimm/dxae026","url":null,"abstract":"<p><p>Regnase-1 is an RNase that plays a critical role in negatively regulating immune responses by destabilizing inflammatory messenger RNAs (mRNAs). Dysfunction of Regnase-1 can be a major cause of various inflammatory diseases with tissue injury and immune cell infiltration into organs. This study focuses on the role of the RNase activity of Regnase-1 in developing inflammatory diseases. We have constructed mice with a single point mutation at the catalytic center of the Regnase-1 RNase domain, which lacks endonuclease activity. D141N mutant mice demonstrated systemic inflammation, immune cell infiltration into various organs, and progressive development of lung granuloma. CD4+ T cells, mainly affected by this mutation, upregulated the mTORC1 pathway and facilitated the autoimmune trait in the D141N mutation. Moreover, serine/threonine kinase Pim2 contributed to lung inflammation in this mutation. Inhibition of Pim2 kinase activity ameliorated granulomatous inflammation, immune cell infiltration, and proliferation in the lungs. Additionally, Pim2 inhibition reduced the expression of adhesion molecules on CD4+ T cells, suggesting a role for Pim2 in facilitating leukocyte adhesion and migration to inflamed tissues. Our findings provide new insights into the role of Regnase-1 RNase activity in controlling immune functions and underscore the therapeutic relevance of targeting Pim2 to modulate abnormal immune responses.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":"497-516"},"PeriodicalIF":4.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140862153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chisato Ono, Yuta Kochi, Yoshihiro Baba, Shinya Tanaka
{"title":"Humoral responses are enhanced by facilitating B cell viability by Fcrl5 overexpression in B cells.","authors":"Chisato Ono, Yuta Kochi, Yoshihiro Baba, Shinya Tanaka","doi":"10.1093/intimm/dxae028","DOIUrl":"10.1093/intimm/dxae028","url":null,"abstract":"<p><p>B cell initial activity is regulated through a balance of activation and suppression mediated by regulatory molecules expressed in B cells; however, the molecular mechanisms underlying this process remain incompletely understood. In this study, we investigated the function of the Fc receptor-like (Fcrl) family molecule Fcrl5, which is constitutively expressed in naive B cells, in humoral immune responses. Our study demonstrated that B cell-specific overexpression of Fcrl5 enhanced antibody (Ab) production in both T cell-independent type 1 (TI1) and T cell-dependent (TD) responses. Additionally, it promoted effector B cell formation under competitive conditions in TD responses. Mechanistically, in vitro ligation of Fcrl5 by agonistic Abs reduced cell death and enhanced proliferation in lipopolysaccharide-stimulated B cells. In the presence of anti-CD40 Abs and IL-5, the Fcrl5 ligation not only suppressed cell death but also enhanced differentiation into plasma cells. These findings reveal a novel role of Fcrl5 in promoting humoral immune responses by enhancing B cell viability and plasma cell differentiation.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":"529-540"},"PeriodicalIF":4.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140912210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lipid metabolism: a central modulator of RORγt-mediated Th17 cell differentiation.","authors":"Toshio Kanno, Keisuke Miyako, Yusuke Endo","doi":"10.1093/intimm/dxae031","DOIUrl":"10.1093/intimm/dxae031","url":null,"abstract":"<p><p>Among the T helper cell subsets, Th17 cells contribute to the development of various inflammatory and autoimmune diseases, including psoriasis, rheumatoid arthritis, inflammatory bowel disease, steroid-resistant asthma, and multiple sclerosis. Retinoid-related orphan receptor gamma t (RORγt), a nuclear hormone receptor, serves as a master transcription factor for Th17 cell differentiation. Recent findings have shown that modulating the metabolic pathway is critical for Th17 cell differentiation, particularly through the engagement of de novo lipid biosynthesis. Suppression of lipid biosynthesis, either through the pharmacological inhibition or gene deletion of related enzymes in CD4+ T cells, results in significant impairment of Th17 cell differentiation. Mechanistic studies indicate that metabolic fluxes through both the fatty acid and cholesterol biosynthetic pathways have a pivotal role in the regulation of RORγt activity through the generation of endogenous RORγt lipid ligands. This review discusses recent discoveries highlighting the importance of lipid metabolism in Th17 cell differentiation and function, as well as exploring specific molecular pathways involved in RORγt activation through cellular lipid metabolism. We further elaborate on a pioneering therapeutic approach to improve inflammatory and autoimmune disorders via the inhibition of RORγt.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":"487-496"},"PeriodicalIF":4.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141186301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Altering the competitive environment of B cell epitopes significantly extends the duration of antibody production.","authors":"Hongke Xu, Yanfei Chen, Jingzhi Li, Mengyu Li, Miao Sun, Jian Chen, Ling Li, Qinghong Xue, Hongwei Ma","doi":"10.1093/intimm/dxae027","DOIUrl":"10.1093/intimm/dxae027","url":null,"abstract":"<p><p>Persistent immunoglobulin G (IgG) production (PIP) provides long-term vaccine protection. While variations in the duration of protection have been observed with vaccines prepared from different pathogens, little is known about the factors that determine PIP. Here, we investigated the impact of three parameters on the duration of anti-peptide IgG production, namely amino acid sequences, protein carriers, and immunization programs. We show that anti-peptide IgG production can be transformed from transient IgG production (TIP) to PIP, by placing short peptides (Pi) containing linear B cell epitopes in different competitive environments using bovine serum albumin (BSA) conjugates instead of the original viral particles. When goats were immunized with the peste des petits ruminants (PPR) live-attenuated vaccine (containing Pi as the constitutive component) and BSA-Pi conjugate, anti-Pi IgG production exhibited TIP (duration < 60 days) and PIP (duration > 368 days), respectively. Further, this PIP was unaffected by subsequent immunization with the PPR live-attenuated vaccine in the same goat. When goats were coimmunized with PPR live-attenuated vaccine and BSA-Pi, the induced anti-Pi IgG production showed a slightly extended TIP (from ~60 days to ~100 days). This discovery provides new perspectives for studying the fate of plasma cells in humoral immune responses and developing peptide vaccines related to linear neutralizing epitopes from various viruses.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":"517-528"},"PeriodicalIF":4.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140857033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bo Tang, Chenchen Qin, Huihui Liu, Shengchao Miao, Chao Xue, Zhenhua Wang, Yang Zhang, Yujun Dong, Wei Liu, Hanyun Ren
{"title":"Blockade of CCR5 and CXCR3 attenuates murine acute graft-versus-host disease through modulating donor-derived T-cell distribution and function.","authors":"Bo Tang, Chenchen Qin, Huihui Liu, Shengchao Miao, Chao Xue, Zhenhua Wang, Yang Zhang, Yujun Dong, Wei Liu, Hanyun Ren","doi":"10.1093/intimm/dxae033","DOIUrl":"10.1093/intimm/dxae033","url":null,"abstract":"<p><p>Lymphocyte trafficking via chemokine receptors such as C-C chemokine receptor 5 (CCR5) and CXCR3 plays a critical role in the pathogenesis of acute graft-versus-host disease (aGVHD). Our previous studies showed that the addition of CCR5 or CXCR3 antagonists could only slightly alleviate the development of aGVHD. Given the specificity of T lymphocytes bearing CXCR3 and CCR5, we investigated whether combined CCR5 and CXCR3 blockade could further attenuate murine aGVHD. A mouse model of aGVHD was established to assess the efficacy of CCR5 and/or CXCR3 blockade on the development of aGVHD. The distribution of lymphocytes was calculated by quantification of immunostaining cells. The immunomodulatory effect on T cells was assessed by evaluating T-cell proliferation, viability, and differentiation. Using the murine allogeneic hematopoietic stem cell transplantation model, we demonstrated that blockade of both CCR5 and CXCR3 could efficiently alleviate the development of aGVHD. Further investigation on the immune mechanisms for this prophylactic effect showed that more T cells were detained into secondary lymphoid organs (SLOs), which may lead to reduced infiltration of T cells into GVHD target organs. Our study also showed that T cells detained in SLOs dampened the activation, suppressed the polarization toward T helper type 1 (Th1) and T cytotoxic type 1 (Tc1) cells, and induced the production of Treg cells. These data suggest that concurrent blockade of CCR5 and CXCR3 attenuates murine aGVHD through modulating donor-derived T-cell distribution and function, and this might be applicable for aGVHD prophylaxis in clinical settings.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":"541-552"},"PeriodicalIF":4.8,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11385202/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141081220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mechanisms and Effects of Activation of Innate Immunity by Mitochondrial Nucleic Acids.","authors":"Prashant Rai, Michael B Fessler","doi":"10.1093/intimm/dxae052","DOIUrl":"https://doi.org/10.1093/intimm/dxae052","url":null,"abstract":"<p><p>In recent years, a growing number of roles have been identified for mitochondria in innate immunity. One principal mechanism is that translocation of mitochondrial nucleic acid species from the mitochondrial matrix to the cytosol and endolysosomal lumen in response to an array of microbial and non-microbial environmental stressors has been found to serve as a second messenger event in the cell signaling of the innate immune response. Thus, mitochondrial DNA and RNA have been shown to access the cytosol through several regulated mechanisms involving remodeling of the mitochondrial inner and outer membranes and to access lysosomes via vesicular transport, thereby activating cytosolic (e.g., cyclic GMP-AMP synthase [cGAS]; retinoic acid-inducible gene-I [RIG-I]-like receptors) and endolysosomal (Toll-like Receptor [TLR]7, -9) nucleic acid receptors that induce type I interferons and pro-inflammatory cytokines. In this mini-review, we discuss these molecular mechanisms of mitochondrial nucleic acid mislocalization and their roles in host defense, autoimmunity, and auto-inflammatory disorders. The emergent paradigm is one in which host-derived DNA interestingly serves as a signal amplifier in the innate immune response and also as an alarm signal for disturbances in organellar homeostasis. The apparent vast excess of mitochondria and mitochondrial DNA nucleoids per cell may thus serve to sensitize the cell response to stressors while ensuring an underlying reserve of intact mitochondria to sustain cellular metabolism. An improved understanding of these molecular mechanisms will hopefully afford future opportunities for therapeutic intervention in human disease.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatial diversity of in vivo tissue immunity.","authors":"Yu Miyamoto, Masaru Ishii","doi":"10.1093/intimm/dxae051","DOIUrl":"https://doi.org/10.1093/intimm/dxae051","url":null,"abstract":"<p><p>The immune system exhibits spatial diversity in in vivo tissues. Immune cells are strategically distributed within tissues to maintain the organ integrity. Advanced technologies such as intravital imaging and spatial transcriptomics have revealed the spatial heterogeneity of immune cell distribution and function within organs such as the liver, kidney, intestine, and lung. In addition, these technologies visualize nutrient and oxygen environments across tissues. Recent spatial analyses have suggested that a functional immune niche is determined by interactions between immune and non-immune cells in an appropriate nutrient and oxygen environment. Understanding the spatial communication between immune cells, environment, and surrounding non-immune cells is crucial for developing strategies to control immune responses and effectively manage inflammatory diseases.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Identification and characterization of putative enhancer regions that direct Il6 transcription in murine macrophages.","authors":"Norisuke Kano, Takeo Miki, Yurina Uehara, Daisuke Ori, Taro Kawai","doi":"10.1093/intimm/dxae024","DOIUrl":"10.1093/intimm/dxae024","url":null,"abstract":"<p><p>Interleukin-6 (IL-6) plays a crucial role in various cellular functions, including innate and adaptive immune responses. Dysregulated expression of IL-6 is associated with hyperinflammation and chronic inflammatory diseases. In this study, we aimed to identify the enhancer regions responsible for robust Il6 mRNA expression in murine macrophages. Through comprehensive genome-wide ChIP- and ATAC-seq analyses, we identified two distinct clusters, termed E1 and E2 regions, located at -144 to -163 kb relative to the Il6 transcription start site in lipopolysaccharide (LPS)-activated murine macrophages. These clusters exhibited an accumulation of histone modification marks (H3K27ac and H3K4me1), as well as open chromatin, and were found to contain binding sites for the transcription factors PU.1, NF-κB, C/EBPβ, and JunB. Upregulation of non-coding RNA (ncRNA) transcripts from the E1 and E2 regions was observed upon LPS stimulation, and repression of these ncRNAs resulted in abrogation of Il6 expression. Additionally, deletion of either E1 or E2 region significantly impaired Il6 expression, while CRISPR/dCas9 activation-mediated recruitment of the co-activator p300 to the E1 and E2 regions facilitated Il6 expression. Collectively, our findings suggest that the E1 and E2 regions serve as putative enhancers for Il6 expression.</p>","PeriodicalId":13743,"journal":{"name":"International immunology","volume":" ","pages":"471-481"},"PeriodicalIF":4.8,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140851224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}