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Background: Atopic dermatitis (AD) is a chronic inflammatory skin condition whose origins remain unclear. Existing epidemiological evidence suggests that inflammation and immune factors play pivotal roles in the onset and progression of AD. However, previous research on the connection between immune inflammation and AD has yielded inconclusive results. Methods: To evaluate the causal relationship between immunological characteristics and AD, this study employed a bidirectional, two‐sample Mendelian randomization (MR) approach. We utilized large‐scale, publicly available genome‐wide association studies to investigate the causal associations between 731 immunological feature cells and the risk of AD. Results: Significant associations were identified between six immune phenotypes and AD risk: increased Basophil %CD33dim HLA DR−CD66b−, CD25 on IgD+ CD24+, CD40 on monocytes, HLA DR on CD14+ CD16−monocytes, HLA DR on CD14+monocytes correlated with higher AD risk, while elevated CD3 on CD4 Treg was linked to lower risk. Reverse MR analysis revealed AD as a risk factor for IgD+ CD38br AC and IgD+ CD38br %B cell, but a protective factor against CD20 on IgD+ CD38− naive and CD8 on NKT. Conclusion: Our findings elucidate the intricate interplay between immune cells and AD, informing future research into AD pathophysiology and therapeutics. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly affects the joints. Studies have shown that memory CD4+ T cells play an important role in the pathogenesis of RA. This study investigated the expression and function of CD305 on human memory CD4+ T cells and the effects of CD305 activating antibody on collagen-induced arthritis. The results showed that CD305 expression was significantly decreased on circulating memory CD4+ T cells from patients with RA and its mean fluorescence intensity (MFI) was negatively correlated with DAS28. Moreover, CD305 inhibited the activation of memory CD4+ T cells by down-regulating CD69 and CD25 and the production of IFN-γ, IL-4, and IL-17A induced by anti-CD3/CD28 antibodies. In addition, activation of CD305 inhibited the severity of disease in collagen-induced arthritis. In summary, CD305 reduction may mediate the excessive activation of memory CD4+ T cells and participate in the development of RA. It can be used as a predictive marker of disease activity and has potential medicinal value in the treatment of RA. • CD305 decreases prominently on circulating memory CD4+ T cells and is negatively correlated with DAS28 of patients with RA. • CD305 participates in the abnormal activation of memory CD4+ T cells in patients with RA. • CD305 inhibits secretion of IFN-γ, IL-4 and IL-17A by memory CD4+ T cells. • CD305 attenuates arthritis severity in Collagen-induced arthritis. [ABSTRACT FROM AUTHOR]

Human T-cell lymphotropic virus (HTLV) infection affects over ten million people worldwide, but there is no effective treatment so far. This review describes the virological, immunological, and clinical outcomes of antiretroviral therapy (ART) in people with HTLV infection. This systematic review followed PRISMA reporting guidelines and was registered in PROSPERO: CRD42022350076. The Newcastle–Ottawa Scale, adapted for cross-sectional studies, and Rob-2 were used to assess the methodological quality of these studies. Systematic searches were conducted in the Medline (PubMed), Scopus (Elsevier), Cochrane Library, and Web of Science (Clarivate Analytics) databases. We retrieved data from eight methodologically diverse articles on treatment of patients infected by HTLV-1 or HTLV-2 alone, or coinfected by HIV-1, who received Raltegravir, Tenofovir, Lamivudine, or Zidovudine. The proviral load decreased in three out of seven studies over 4 to 48 weeks of antiretroviral use. Cellular immune response (CD4, CD8, CD25, CD69, and CD71 cells) was evaluated in six studies. While no significant clinical improvement was observed, all studies reported clinical stability during treatment. Despite the demonstrated antiviral activity of ART, in vitro, clinical improvement was not proven. Most studies showed disease stability during ART use, suggesting potential clinical benefits. There is a need of larger, well-controlled trials to define the role of ART in the treatment of HTLV infection. [ABSTRACT FROM AUTHOR]

The multifaceted IL‐2/IL‐2R biology and its modulation by promising therapeutic agents are highly relevant topics in the cancer immunotherapy field. A novel CD25‐Treg‐depleting antibody (Vopikitug, RG6292) has been engineered to preserve IL‐2 signaling on effector T cells to enhance effector activation and antitumor immunity, and is currently being evaluated in the clinic. The Entry into Human‐enabling framework described here investigated the characteristics of RG6292, from in vitro quantification of CD25 and RG6292 pharmacology using human tissues to in vivo assessment of PK/PD/safety relationships in cynomolgus monkeys as non‐human primate species (NHP). Fundamental knowledge on CD25 and Treg biology in healthy and diseased tissues across NHP and human highlighted the commonalities between these species in regard to the target biology and demonstrated the conservation of RG6292 properties between NHP and human. The integration of in vitro and in vivo PK/PD/safety data from these species enabled the identification of human relevant safety risks, the selection of the most appropriate safe starting dose and the projection of the pharmacologically‐relevant dose range. The first clinical data obtained for RG6292 in patients verified the appropriateness of the described approaches as well as validated the full clinical relevance of the projected safety, PK, and PD profiles from animal to man. This work shows how the integration of mechanistic non‐clinical data increases the predictive value for human, allowing efficient transition of drug candidates and optimizations of early clinical investigations. [ABSTRACT FROM AUTHOR]

Summary Camidanlumab tesirine (ADCT‐301) is a CD25‐specific antibody‐drug conjugate (ADC) employing SG3199, a highly cytotoxic DNA minor groove cross‐linking pyrrolobenzodiazepine dimer. The ADC has shown early clinical antitumour activity in various cancers, including B‐ and T‐cell lymphomas. We assessed its preclinical activity as a single agent in 57 lymphoma cell lines and in combination with selected drugs in T‐cell lymphoma‐derived cell lines. Cells were exposed to increasing concentrations of the ADC or SG3199 for 96 h, followed by an MTT proliferation assay. CD25 expression was measured at cell surface and RNA levels. Experiments with PDX‐derived cell lines were used for validation studies. Camidanlumab tesirine presented more potent single agent in vitro cytotoxic activity in T‐ than B‐cell lymphomas. In vitro activity was correlated with CD25 cell surface and RNA expression. In vitro activity was correlated with CD25 cell surface and RNA expression. When camidanlumab tesirine‐containing combinations were evaluated in four T‐cell lymphoma models, the most active partners were everolimus, copanlisib, venetoclax, vorinostat, and pralatrexate, followed by bortezomib, romidepsin, bendamustine, and 5‐azacytidine. The strong camidanlumab tesirine single‐agent anti‐lymphoma activity and the in vitro synergisms with targeted agents identify potential combination partners for future clinical studies. [ABSTRACT FROM AUTHOR]

Introduction: Our study investigated the potential of peripheral blood T cell CD25, CD28, and CTLA-4 gene transcription levels as predictive biomarkers for acute graft-versus-host disease (aGVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Real-time reverse transcription fluorescent quantitative PCR (RTqPCR) analysis was conducted on day +7, +14, and +21 post-transplantation in patients undergoing allo-HSCT. Results: Elevated levels of CD25 and CTLA-4 mRNA were found to be associated with the occurrence of aGVHD, as well as severe and gastrointestinal aGVHD. Receiver operating characteristic (ROC) curve analysis was utilized to assess the predictive value of each biomarker. Combined analysis of CD25 and CTLA-4 mRNA levels demonstrated promising predictive potential for aGVHD. Conclusion: Our results confirmed that the transcription levels of CD25 and CTLA-4 genes could be used as early predictive biomarkers for aGVHD post-allo-HSCT. [ABSTRACT FROM AUTHOR]

The T-helper 17 (Th17) cell and regulatory T cell (Treg) axis plays a crucial role in the development of multiple sclerosis (MS), which is regarded as an immune imbalance between pro-inflammatory cytokines and the maintenance of immune tolerance. Mesenchymal stem cell (MSC)-mediated therapies have received increasing attention in MS research. In MS and its animal model experimental autoimmune encephalomyelitis, MSC injection was shown to alter the differentiation of CD4+T cells. This alteration occurred by inducing anergy and reduction in the number of Th17 cells, stimulating the polarization of antigen-specific Treg to reverse the imbalance of the Th17/Treg axis, reducing the inflammatory cascade response and demyelination, and restoring an overall state of immune tolerance. In this review, we summarize the mechanisms by which MSCs regulate the balance between Th17 cells and Tregs, including extracellular vesicles, mitochondrial transfer, metabolic reprogramming, and autophagy. We aimed to identify new targets for MS treatment using cellular therapy by analyzing MSC-mediated Th17-to-Treg polarization. [ABSTRACT FROM AUTHOR]

The effectiveness and safety of allogeneic mesenchymal stem/stromal cells (MSCs) can be affected by patient's immune recognition. Thus, MSC immunogenicity and their immunomodulatory properties are crucial aspects for therapy. Immune responses after allogeneic MSC administration have been reported in different species, including equine. Interactions of allogenic MSCs with the recipient's immune system can be influenced by factors like matching or mismatching for the major histocompatibility complex (MHC) between donor-recipient, and by the levels of MHC expression in MSCs. The latter can vary upon MSC inflammatory exposure or differentiation, such as chondrogenic induction, making both priming and differentiation interesting therapeutic strategies. This study investigated the systemic in vivo immune cellular response against allogeneic equine MSCs in these situations. Either MSCs in basal conditions (MSC-naïve), pro-inflammatory primed (MSCprimed) or chondrogenically differentiated (MSC-chondro) were repeatedly administered subcutaneously into autologous, MHC-matched or MHCmismatched allogeneic equine recipients. At different time-points after each administration, lymphocytes were obtained from recipient horses and exposed in vitro to the same type of MSCs to assess the proliferative response of different T cell subsets (cytotoxic, helper, regulatory), B cells, and interferon gamma (IFNγ) secretion. Higher proliferative response of helper and cytotoxic T lymphocytes and IFNγ secretion was observed in response to all types of MHC-mismatched MSCs over MHC-matched ones. MSC-primed produced the highest immune response, followed by MSCnaïve, and MSC-chondro. However, MSC-primed activated Treg and had a mild effect on B cells, and the response after their second administration was similar to the first one. On the other hand, both MSC-chondro and MSC-naïve barely induced Treg response but promoted B lymphocyte activation, and proportionally induced a higher cell response after the second administration. In conclusion, both the type of MSC conditioning and the MHC compatibility influenced systemic immune recognition of equine MSCs after single and repeated administrations, but the response was different. Selecting MHC-matched donors would be particularly recommended for MSC-primed and repeated MSC-naïve administrations. While MHC-mismatching in MSC-chondro would be less critical, B cell response should not be ignored. Comprehensively investigating the in vivo immune response against equine allogeneic MSCs is crucial for advancing veterinary cell therapies. [ABSTRACT FROM AUTHOR]

Objectives: Hepatitis C virus (HCV) is one of the most global health problems with 2.5% prevalence worldwide. It seems that regulatory T (Treg) cells, which are able to modulate the host immune responses, play a substantial role in the immunopathogenesis of HCV infection. In this study, we evaluated the distribution of Treg cells in HCV-infected patients and its correlation with viral load and clinical manifestations. Methods: Peripheral blood mononuclear cells (PBMCs) were collected from 14 newly diagnosed HCV-infected patients and 23 age- and sex-matched healthy subjects, and the frequency of CD4+CD25+CD127−/low Treg cells was determined by flow cytometry. Results: Our results showed that the mean level of CD4+CD25+CD127−/low Treg cells in HCV-infected patients was significantly higher than that in healthy control subjects (8.2 ± 1.48% vs 5.4 ± 0.36%, p <.05). However, there was no statistical correlation between Treg cells frequency and viral load or clinical manifestations. Conclusion: A higher proportion of Treg cells in HCV-infected patients might indicate their critical role in viral persistence and candidate them as a new target of immunotherapy to improve antiviral immunity. [ABSTRACT FROM AUTHOR]

Objectives Flow cytometric immunophenotyping (FCI) is a fast and sensitive method for characterizing hematolymphoid neoplasms. It is not widely used in the workup of systemic mastocytosis (SM), in part because of the technical challenges and in part because the utility of FCI in assessing mast cells is not well understood. The objectives of this study were to assess the diagnostic utility of FCI in establishing a diagnosis of SM and distinguishing SM from nonneoplastic mast cells and to examine the immunophenotypic findings among SM subtypes. Methods We performed FCI on bone marrow samples suspicious for SM using a panel consisting of CD2, CD25, CD30, CD45, CD117, and HLA-DR. Results The cohort included 88 SM cases: 67 without an associated hematologic neoplasm (AHN) (PureSM) and 21 with an AHN (SM-AHN). We also assessed 40 normal/reactive controls. Overall, FCI was adequate for interpretation in 87 of 88 (99%) cases and detected at least 1 immunophenotypic aberrancy in 100% of SM cases. CD2, CD25, and CD30 were positive in 78%, 98%, and 90% of SM cases vs 0%, 13%, and 13% of cases with normal/reactive mast cells (P <.0001 for all). Two or 3 abnormalities were observed in 92% of SM cases but not in normal/reactive mast cells. Among SM cases, SM-AHN showed statistically significant less CD2 (38% vs 91%, P <.0001) and less co-expression of all 3 aberrant markers (CD2, CD25, and CD30 positive in 38% vs 86% of cases; P <.0001) than PureSM. Immunohistochemical analysis showed consistently weaker or focal expression of CD2, CD25, and CD30 than FCI, with CD2 and CD30 being falsely negative in 40% and 50% cases, respectively. A KIT D816V mutation was detected in 67% of PureSM cases and 76% of SM-AHN cases. Conclusions Flow cytometric immunophenotyping is a quick, sensitive, high-yield tool for evaluating the immunophenotype of mast cells. An abnormal FCI finding should prompt careful histologic evaluation and sensitive KIT D816V mutation testing to address the possibility of SM. CD2, CD25, and CD30 are important markers for the detection of immunophenotypic aberrancy of mast cells, and their frequencies of aberrancy differ across SM subtypes. [ABSTRACT FROM AUTHOR]

This article discusses the impact of precore and basal core promoter (BCP) mutations in the hepatitis B virus (HBV) on hepatocyte homeostasis. These mutations are common in chronic hepatitis B patients and are associated with an increased risk of liver fibrosis and hepatocellular carcinoma. The article presents conflicting findings regarding the effects of these mutations on HBsAg and HBcAg accumulation in infected hepatocytes. The authors recommend further research to determine the specific HBV mutations and their impact on hepatocyte damage. They also suggest using models that better replicate real-world conditions to study HBV pathogenesis. [Extracted from the article]

Introduction: Immunotherapy is becoming a promising approach for unresectable-hepatocellular carcinoma (HCC); the anti-tumor response is affected by the tumor microenvironment (TME). Although Wnt/β-catenin mutations are reported to cause non-inflamed phenotype, their role on TME remains controversial. We aimed to clarify the heterogeneity of immunophenotype in HCC with Wnt/β-catenin mutations. Methods: This study includes 152 resected HCCs; mutations in the catenin beta-1, adenomatous polyposis coli, or AXIN1, or AXIN2 genes were defined as Wnt/β-catenin mutations. With hierarchical cluster analyses, TME was classified into inflamed or non-inflamed classes based on the gene expressions associated with T-cell activation. Expression profiles of molecules related to cell differentiation and biliary-stem cell markers were compared between the TME classes to investigate whether differences in tumor traits were associated with TME. Results: Forty of 152 (26.3%) HCCs carried the Wnt/β-catenin mutations. Of these, 33 were classified as non-inflamed (33/40, 82.5%) and 7 as inflamed (7/40, 17.5%). Non-inflamed class was characterized by low number of CD3+, CD4+, and CD8+ cells on immunostaining, and high mRNA expressions of AXIN2 and GLUL, which are involved in the canonical Wnt/β-catenin signaling and hepatocyte differentiation, respectively. Non-inflamed tumors showed higher enhancement on the hepatobiliary-phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) compared to inflamed tumors. HCCs classified as inflamed class are revealed to have high numbers of CD3+, CD4+, and CD8+ tumor infiltrating lymphocytes on immunostaining. This class is associated with increased expression of anti-epithelial cell adhesion molecule and FOXM1 accompanied by upregulation of genes related to interferon-gamma signaling, dendritic cell migration, regulatory T cells, and myeloid-derived suppressor cell activation and recognized as low enhancement nodule on Gd-EOB-DTPA-enhanced MRI. Conclusion: Heterogeneity of tumor traits and TME was observed in HCC with Wnt/β-catenin mutation. The potential was indicated that tumor traits and TME are determined not only by the activation of the HNF4A but also by FOXM1, both of which are downstream transcription factor of the Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

BCG vaccination affects other diseases beyond tuberculosis by unknown—potentially immunomodulatory—mechanisms. Recent studies have shown that BCG vaccination administered during overt type 1 diabetes (T1D) improved glycemic control and affected immune and metabolic parameters. Here, we comprehensively characterized Ghanaian T1D patients with or without routine neonatal BCG vaccination to identify vaccine-associated alterations. Ghanaian long-term T1D patients (n = 108) and matched healthy controls (n = 214) were evaluated for disease-related clinical, metabolic, and immunophenotypic parameters and compared based on their neonatal BCG vaccination status. The majority of study participants were BCG-vaccinated at birth and no differences in vaccination rates were detected between the study groups. Notably, glycemic control metrics, i.e., HbA1c and IDAA1c, showed significantly lower levels in BCG-vaccinated as compared to unvaccinated patients. Immunophenotype comparisons identified higher expression of the T cell activation marker CD25 on CD8+ T cells from BCG-vaccinated T1D patients. Correlation analysis identified a negative correlation between HbA1c levels and CD25 expression on CD8+ T cells. In addition, we observed fractional increases in glycolysis metabolites (phosphoenolpyruvate and 2/3-phosphoglycerate) in BCG-vaccinated T1D patients. These results suggest that neonatal BCG vaccination is associated with better glycemic control and increased activation of CD8+ T cells in T1D patients. [ABSTRACT FROM AUTHOR]

Introduction: Buffalo/Mna rats spontaneously develop nephrotic syndrome (NS) which recurs after renal transplantation. The immunosuppressive drug LF15-0195 can promote regression of the initial and post-transplantation nephropathy via induction of regulatory T cells. We investigate if this drug has an additional effect on the expression and localization of podocyte specific proteins. Methods: Buffalo/Mna kidney samples were collected before and after the occurrence of proteinuria, and after the remission of proteinuria induced by LF15-0195 treatment and compared by quantitative RT-PCR, Western blot, electron, and confocal microscopy to kidney samples of age-matched healthy rats. Cytoskeleton changes were assessed in culture by stress fibers induction by TNFα. Results: We observed, by electron microscopy, a restoration of foot process architecture in the LF15-0195-treated Buff/Mna kidneys, consistent with proteinuria remission. Nephrin, podocin, CD2AP, and α-actinin-4 mRNA levels remained low during the active disease in the Buff/Mna, in comparison with healthy rats which increase, while podocalyxin and synaptopodin transcripts were elevated before the occurrence of the disease but did not differ from healthy animals after. No difference in the mRNA and protein expression between the untreated and the LF15-0195-treated proteinuric Buff/Mna were seen for these 6 proteins. No changes were observed by confocal microscopy in the protein distribution at a cellular level, but a more homogenous distribution similar to healthy rats, was observed within the glomeruli of LF15-0195-treated rats. In addition, LF15-0195 could partially restore actin cytoskeleton of endothelial cells in TNFα-induced-cell stress experiment. Conclusion: The effect of LF15-0195 treatment appears to be mediated by 2 mechanisms: an immunomodulatory effect via regulatory T cells induction, described in our previous work and which can act on immune cell involved in the disease pathogenesis, and an effect on the restoration of podocyte cytoskeleton, independent of expression levels of the proteins involved in the slit diaphragm and podocyte function, showed in this article. [ABSTRACT FROM AUTHOR]

Background: Psoriasis is an immune-mediated disorder influenced by environmental factors on a genetic basis. Despite advancements, challenges persist, including the diminishing efficacy of biologics and small-molecule targeted agents, alongside managing recurrence and psoriasis-related comorbidities. Unraveling the underlying pathogenesis and identifying valuable biomarkers remain pivotal for diagnosing and treating psoriasis. Methods: We employed a series of bioinformatics (including single-cell sequencing data analysis and machine learning techniques) and statistical methods to integrate and analyze multi-level data. We observed the cellular changes in psoriatic skin tissues, screened the key genes Fatty acid binding protein 5 (FABP5) and The killer cell lectin-like receptor B1 (KLRB1), evaluated the efficacy of six widely prescribed drugs on psoriasis treatment in modulating the dendritic cell-associated pathway, and assessed their overall efficacy. Finally, RT-qPCR, immunohistochemistry, and immunofluorescence assays were used to validate. Results: The regulatory influence of dendritic cells (DCs) on T cells through the CD70/CD27 signaling pathway may emerge as a significant facet of the inflammatory response in psoriasis. Notably, FABP5 and KLRB1 exhibited upregulation and co-localization in psoriatic skin tissues and M5-induced HaCaT cells, serving as potential biomarkers influencing psoriasis development. Conclusion: Our study analyzed the impact of DC-T cell crosstalk in psoriasis, elucidated the characterization of two biomarkers, FABP5 and KLRB1, in psoriasis, and highlighted the promise and value of tofacitinib in psoriasis therapy targeting DCs. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate immunophenotypic profiles of infiltrating cells in surgically excised tissues of chalazion and pyogenic granuloma associated with chalazion. Methods: Eighty-two surgical specimens from 74 consecutive patients newly diagnosed with chalazion or chalazion-associated pyogenic granuloma at Tokyo Medical University Hospital between 2016 and 2022 were studied. Sixty specimens were chalazion lesions and 22 specimens were pyogenic granuloma lesions (from 15 men and 7 women, mean age 36.6 ± 14.4 years). All patients were immunocompetent Asian Japanese adults. Specimens were analyzed by immunohistochemistry and flow cytometry. Flow cytometry was performed using the following antibodies: CD3, CD4, CD8, CD11b, CD11c, CD16, CD19, CD20, CD23, CD25, CD34, CD44, CD56, CD69, and CD138. Results: In flow cytometric analysis, the proportion of cells expressing the T cell marker CD3 was significantly higher compared with other immune cells expressing specific markers (p < 0.0001), and the proportion of CD4-positive T cells was significantly higher than that of CD8-positive T cells (p < 0.0001), in both chalazion and pyogenic granuloma specimens. The chalazion and pyogenic granuloma lesions shared similar immunophenotypic profile characterized by predominant T cell infiltration, and CD4 T cells dominating over CD8 cells. The pattern of expression of CD4 and CD8 in the specimens was confirmed by immunohistochemistry. Conclusion: The present study demonstrates immunophenotypic features of chalazion and chalazion-associated pyogenic granuloma. Although various inflammatory cells are involved in the pathology of chalazion and pyogenic granuloma, a significantly higher proportion of CD4-positive T cells may be closely related to the pathological mechanisms of both lesions. [ABSTRACT FROM AUTHOR]

Excessive immune activation contributes to the onset of early dysfunction of the maternal-fetal interface, and it is closely linked to the development of pre-eclampsia. However, the effect of specific immune cells on the risk of pre-eclampsia and eclampsia remains controversial. We investigated the causal relationship between immune cells and pre-eclampsia and eclampsia. For exposure, we extracted genetic variants associated with immune cell-related traits, and for outcomes, we used summary genetic data of pre-eclampsia/eclampsia. A two-sample Mendelian randomization (MR) analysis was then performed to assess the causal relationship. Robustness of the MR results was then evaluated through colocalization analysis. We found that genetically proxied circulating lymphocyte absolute count was causally associated with total eclampsia (odds ratio OR = 1.53 , 95% confidence interval (CI) (1.31-1.79), p = 1.15 E − 07) and pre-eclampsia (OR = 1.50 , 95% CI (1.28-1.77), p = 9.18 E − 07); T cell absolute count was causally associated with total eclampsia (OR = 1.49 , 95% CI (1.28-1.73), p = 2.73 E − 07) and pre-eclampsia (OR = 1.47 , 95% CI (1.25-1.72), p = 1.76 E − 06). And CD28- CD25+ CD8+ T cell absolute count was causally associated with total eclampsia (OR = 1.83 , 95% CI (1.44-2.32), p = 7.11 E − 07) and pre-eclampsia (OR = 1.77 , 95% CI (1.38-2.26), p = 6.55 E − 06). Colocalization analysis revealed that immune cell-related traits shared the same variant with pre-eclampsia/eclampsia. Our study suggested causal effects of genetic predisposition to high lymphocyte absolute count levels, T cell absolute count, and CD28- CD25+ CD8+ T cell absolute count on eclampsia, particularly pre-eclampsia risk, providing crucial new insights into the potential prevention target for eclampsia and pre-eclampsia. [ABSTRACT FROM AUTHOR]

Carbon ion beams have the unique property of higher linear energy transfer, which causes clustered damage of DNA, impacting the cell repair system. This sometimes triggers apoptosis and the release in the cytoplasm of damaged DNA, leading to type I interferon (IFN) secretion via the activation of the cyclic GMP–AMP synthase-stimulator of interferon genes pathway. Dendritic cells phagocytize dead cancer cells and damaged DNA derived from injured cancer cells, which together activate dendritic cells to present cancer-derived antigens to antigen-specific T cells in the lymph nodes. Thus, carbon ion radiation therapy (CIRT) activates anti-cancer immunity. However, cancer is protected by the tumor microenvironment (TME), which consists of pro-cancerous immune cells, such as regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. The TME is too robust to be destroyed by the CIRT-mediated anti-cancer immunity. Various modalities targeting regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages have been developed. Preclinical studies have shown that CIRT-mediated anti-cancer immunity exerts its effects in the presence of these modalities. In this review article, we provide an overview of CIRT-mediated anti-cancer immunity, with a particular focus on recently identified means of targeting the TME. [ABSTRACT FROM AUTHOR]

Hyperglycemia is a dangerous condition in which too much glucose circulates in the blood plasma and is the leading cause of diabetes mellitus. It is a complex condition with varying degrees that can change over time, mainly owing to metabolic factors that reduce insulin secretion, decrease glucose use, and increase glucose production. This study aims to evaluate Muntingia calabura leaf extract's effect on glucose control and immune cell modulation in high-fat dietadministrated mice. According to the result, we found that M. calabura leaf extract significantly reduced the fasting blood sugar. Importantly, M. calabura leaf extract exerts immunomodulation effects by suppressing the relative number of regulatory T cells in the hypoglycemic mice model. Finally, this study showed M. calabura leaf extract exerts ameliorative potency against hyperglycemia by lowering the blood sugar level and suppressing the regulatory T cells. These results suggested that M. calabura leaf extract could develop into complementary and alternative medicine. [ABSTRACT FROM AUTHOR]

Regulatory T lymphocytes expressing the transcription factor Foxp3 (Tregs) play an important role in the prevention of autoimmune diseases and other immunopathology's. Aberrations in Treg-mediated immunosuppression are therefore thought to be involved in the development of autoimmune pathologies, but few have been documented. Recent reports indicated a central role for Tregs developing during the neonatal period in the prevention of autoimmune pathology. We therefore investigated the development of Tregs in neonatal NOD mice, an important animal model for autoimmune type 1 diabetes. Surprisingly, we found that, as compared with seven other commonly studied inbred mouse strains, in neonatal NOD mice, exceptionally large proportions of developing Tregs express high levels of GITR and PD-1. The latter phenotype was previously associated with high Treg autoreactivity in C57BL/6 mice, which we here confirm for NOD animals. The proportions of newly developing GITRhighPD-1+ Tregs rapidly drop during the first week of age. A genome-wide genetic screen indicated the involvement of several diabetes susceptibility loci in this trait. Analysis of a congenic mouse strain confirmed that Idd5 contributes to the genetic control of GITRhighPD-1+ Treg development in neonates. Our data thus demonstrate an intriguing and paradoxical correlation between an idiosyncrasy in Treg development in NOD mice and their susceptibility to type 1 diabetes. [ABSTRACT FROM AUTHOR]

MYC activation is a known hallmark of cancer as it governs the gene targets involved in various facets of cancer progression. Of interest, MYC governs oncometabolism through the interactions with its partners and cofactors, as well as cancer immunity via its gene targets. Recent investigations have taken interest in characterizing these interactions through multi-Omic approaches, to better understand the vastness of the MYC network. Of the several gene targets of MYC involved in either oncometabolism or oncoimmunology, few of them overlap in function. Prominent interactions have been observed with MYC and HIF-1a, in promoting glucose and glutamine metabolism and activation of antigen presentation on regulatory T cells, and its subsequent metabolic reprogramming. This review explores existing knowledge of the role of MYC in oncometabolism and oncoimmunology. It also unravels how MYC governs transcription and influences cellular metabolism to facilitate the induction of pro- or anti-tumoral immunity. Moreover, considering the significant roles MYC holds in cancer development, the present study discusses effective direct or indirect therapeutic strategies to combat MYC-driven cancer progression. [ABSTRACT FROM AUTHOR]

Non-muscle invasive papillary urothelial carcinoma is a prevalent disease with a high recurrence tendency. Good prognostic and reproducible biomarkers for tumor recurrence and disease progression are lacking. Currently, WHO grade and tumor stage are essential in risk stratification and treatment decision-making. Here we present the prognostic value of proliferation markers (Ki67, mitotic activity index (MAI) and PPH3) together with p53, CD25 and CK20 immunohistochemistry (IHC). In this population-based retrospective study, 349 primary non-muscle invasive bladder cancers (NMIBC) were available. MAI and PPH3 were calculated manually according to highly standardized previously described methods, Ki-67 by the semi-automated QPRODIT quantification system, p53 and CD25 by the fully automated digital image analysis program Visipharm® and CK20 with the help of the semi-quantitative immunoreactive score (IRS). Survival analyses with log rank test, as well as univariate and multivariate Cox regression analyses were performed for all investigated variables. Age and multifocality were the only significant variables for tumor recurrence. All investigated variables, except gender, were significantly associated with stage progression. In multivariate analysis, MAI was the only prognostic variable for stage progression (p<0.001). [ABSTRACT FROM AUTHOR]

Regulatory T cells (Tregs) are a very specialized subset of T lymphocytes: their main function is controlling immune responses during inflammation. T-regs involvement in autoimmune and immune-mediated rheumatic diseases is welldescribed. Here, we critically review the up-to-date literature findings on the role of Tregs in spondyloarthropathies, particularly in ankylosing spondylitis (AS), a polygenic inflammatory rheumatic disease that preferentially affects the spine and the sacroiliac joints. Genetics discoveries helped in elucidating pathogenic T-regs gene modules and functional involvement. We highlight T-regs tissue specificity as crucial point, as T-regs might have a distinct epigenomic and molecular profiling depending on the different site of tissue inflammation. Furthermore, we speculate about possible therapeutic interventions targeting, or enhancing, Treg cells in spondyloarthropathies. [ABSTRACT FROM AUTHOR]

Background: The chimeric antigen receptor-expressing T (CAR-T) cells for cancer immunotherapy have obtained considerable clinical importance. CAR T cells need an optimized intracellular signaling domain to get appropriately activated and also for the proper antigen recognition, the length and composition of the extracellular spacer are critical factors. Results: We constructed two third-generation nanobody-based VEGFR2-CARs containing either IgG1 hinge-CH2-CH3 region or hinge-only as long or short extracellular spacers, respectively. Both CARs also contained intracellular activating domains of CD28, OX40, and CD3ζ. The T cells from healthy individuals were transduced efficiently with the two CARs, and showed increased secretion of IL-2 and IFN-γ cytokines, and also CD69 and CD25 activation markers along with cytolytic activity after encountering VEGFR2+ cells. The VEGFR2-CAR T cells harboring the long spacer showed higher cytokine release and CD69 and CD25 expression in addition to a more efficient cytolytic effect on VEGFR2+ target cells. Conclusions: The results demonstrated that the third-generation anti-VEGFR2 nanobody-based CAR T cell with a long spacer had a superior function and potentially could be a better candidate for solid tumor treatment. [ABSTRACT FROM AUTHOR]

This study explores the synergistic impact of Programmed Death Ligand 1 (PD-L1) and Protein Kinase B (Akt) overexpression in adipose-derived mesenchymal stem cells (AdMSCs) for ameliorating cardiac dysfunction after myocardial infarction (MI). Post-MI adult Wistar rats were allocated into four groups: sham, MI, ADMSC treatment, and ADMSCs overexpressed with PD-L1 and Akt (AdMSC-PDL1-Akt) treatment. MI was induced via left anterior descending coronary artery ligation, followed by intramyocardial AdMSC injections. Over four weeks, cardiac functionality and structural integrity were assessed using pressure–volume analysis, infarct size measurement, and immunohistochemistry. AdMSC-PDL1-Akt exhibited enhanced resistance to reactive oxygen species (ROS) in vitro and ameliorated MI-induced contractile dysfunction in vivo by improving the end-systolic pressure–volume relationship and preload-recruitable stroke work, together with attenuating infarct size. Molecular analyses revealed substantial mitigation in caspase3 and nuclear factor-κB upregulation in MI hearts within the AdMSC-PDL1-Akt group. Mechanistically, AdMSC-PDL1-Akt fostered the differentiation of normal T cells into CD25+ regulatory T cells in vitro, aligning with in vivo upregulation of CD25 in AdMSC-PDL1-Akt-treated rats. Collectively, PD-L1 and Akt overexpression in AdMSCs bolsters resistance to ROS-mediated apoptosis in vitro and enhances myocardial protective efficacy against MI-induced dysfunction, potentially via T-cell modulation, underscoring a promising therapeutic strategy for myocardial ischemic injuries. [ABSTRACT FROM AUTHOR]

Immune tolerance is maintained in lymphoid organs (LOs). Despite the presence of complex immune cell networks in non-LOs, it is unknown whether self-tolerance is maintained in these tissues. We developed a technique to restrict genetic recombination to regulatory T cells (Tregs) only in skin. Selective depletion of skin Tregs resulted in T cell–mediated inflammation of hair follicles (HFs). Suppression did not rely on CTLA-4, but instead on high-affinity interleukin-2 (IL-2) receptor expression by skin Tregs, functioning exclusively in a cell-extrinsic manner. In a novel model of HF stem cell (HFSC)–driven autoimmunity, we reveal that skin Tregs immunologically protect the HFSC niche. Finally, we used spatial transcriptomics to identify aberrant IL-2 signaling at stromal-HF interfaces in a rare form of human alopecia characterized by HFSC destruction and alopecia areata. Collectively, these results reveal the fundamental biology of Tregs in skin uncoupled from the systemic pool and elucidate a mechanism of self-tolerance. Editor's summary: Regulatory T cells (Tregs) are critical for maintaining peripheral tolerance, but delineation of their tissue-specific functions has been challenging because of limited availability of tools that selectively target tissue Tregs. By developing a technique to induce genetic recombination specifically in murine skin Tregs, Cohen et al. demonstrated that skin Tregs protect the hair follicle from steady-state inflammation. Suppression of hair follicle inflammation required skin Treg expression of the high-affinity interleukin-2 (IL-2) receptor but not CTLA-4. In a mouse model of T cell–mediated autoimmune attack, skin Tregs prevented destruction of hair follicle stem cells. Patients with autoimmune alopecia displayed an enhanced IL-2/STAT5 gene signature around hair follicles, indicating that dysregulation of skin Treg-mediated immunosuppression may contribute to the pathogenesis of autoimmune skin diseases. —Claire Olingy [ABSTRACT FROM AUTHOR]

Foxp3+ regulatory T (Treg) cells of thymic (tTreg) and peripheral (pTreg) developmental origin are thought to synergistically act to ensure immune homeostasis, with self-reactive tTreg cells primarily constraining autoimmune responses. Here we exploited a Foxp3-dependent reporter with thymus-specific GFP/Cre activity to selectively ablate either tTreg (ΔtTreg) or pTreg (ΔpTreg) cell development, while sparing the respective sister populations. We found that, in contrast to the tTreg cell behavior in ΔpTreg mice, pTreg cells acquired a highly activated suppressor phenotype and replenished the Treg cell pool of ΔtTreg mice on a non-autoimmune C57BL/6 background. Despite the absence of tTreg cells, pTreg cells prevented early mortality and fatal autoimmunity commonly observed in Foxp3-deficient models of complete Treg cell deficiency, and largely maintained immune tolerance even as the ΔtTreg mice aged. However, only two generations of backcrossing to the autoimmune-prone non-obese diabetic (NOD) background were sufficient to cause severe disease lethality associated with different, partially overlapping patterns of organ-specific autoimmunity. This included a particularly severe form of autoimmune diabetes characterized by an early onset and abrogation of the sex bias usually observed in the NOD mouse model of human type 1 diabetes. Genetic association studies further allowed us to define a small set of autoimmune risk loci sufficient to promote β cell autoimmunity, including genes known to impinge on Treg cell biology. Overall, these studies show an unexpectedly high functional adaptability of pTreg cells, emphasizing their important role as mediators of bystander effects to ensure self-tolerance. [ABSTRACT FROM AUTHOR]

Echinococcosis is a common human and animal parasitic disease that seriously endangers human health and animal husbandry. Although studies have been conducted on vaccines for echinococcosis, to date, there is no human vaccine available for use. One of the main reasons for this is the lack of in-depth research on basic immunization with vaccines. Our previous results confirmed that recombinant antigen P29 (rEg.P29) induced more than 90% immune protection in both mice and sheep, but data on its induction of sheep-associated cellular immune responses are lacking. In this study, we investigated the changes in CD4+ T cells, CD8+ T cells, and antigen-specific cytokines IFN-γ, IL-4, and IL-17A after rEg.P29 immunization using enzyme-linked immunospot assay (ELISPOT), enzyme-linked immunosorbent assay (ELISA), and flow cytometry to investigate the cellular immune response induced by rEg.P29 in sheep. It was found that rEg.P29 immunization did not affect the percentage of CD4+ and CD8+ T cells in peripheral blood mononuclear cells (PBMCs), and was able to stimulate the proliferation of CD4+ and CD8+ T cells after immunization in vitro. Importantly, the results of both ELISPOT and ELISA showed that rEg.P29 can induce the production of the specific cytokines IFN-γ and IL-17A, and flow cytometry verified that rEg.P29 can induce the expression of IFN-γ in CD4+ and CD8+ T cells and IL-17A in CD4+ T cells; however, no IL-4 expression was observed. These results indicate that rEg.P29 can induce Th1, Th17, and Tc1 cellular immune responses in sheep against echinococcosis infection, providing theoretical support for the translation of rEg.P29 vaccine applications. [ABSTRACT FROM AUTHOR]

Intrinsic metabolism shapes the immune environment associated with immune suppression and tolerance in settings such as organ transplantation and cancer. However, little is known about the metabolic activities in an immunosuppressive environment. In this study, we employed metagenomic, metabolomic, and immunological approaches to profile the early effects of the immunosuppressant drug tacrolimus, antibiotics, or both in gut lumen and circulation using a murine model. Tacrolimus induced rapid and profound alterations in metabolic activities within two days of treatment, prior to alterations in gut microbiota composition and structure. The metabolic profile and gut microbiome after seven days of treatment was distinct from that after two days of treatment, indicating continuous drug effects on both gut microbial ecosystem and host metabolism. The most affected taxonomic groups are Clostriales and Verrucomicrobiae (i.e., Akkermansia muciniphila), and the most affected metabolic pathways included a group of interconnected amino acids, bile acid conjugation, glucose homeostasis, and energy production. Highly correlated metabolic changes were observed between lumen and serum metabolism, supporting their significant interactions. Despite a small sample size, this study explored the largely uncharacterized microbial and metabolic events in an immunosuppressed environment and demonstrated that early changes in metabolic activities can have significant implications that may serve as antecedent biomarkers of immune activation or quiescence. To understand the intricate relationships among gut microbiome, metabolic activities, and immune cells in an immune suppressed environment is a prerequisite for developing strategies to monitor and optimize alloimmune responses that determine transplant outcomes. [ABSTRACT FROM AUTHOR]

Background: Vitiligo is a common autoimmune depigmented dermatology due to destruction of melanocytes. Much evidence suggests that vitiligo is associated with systemic immune activation. Previous studies have focused on immune cell infiltration in and around lesion areas, but few studies have investigated the cell types and function of circulating immune cells in peripheral blood. Here, single cell RNA-sequencing (scRNA-seq) was used to investigate the mechanisms of peripheral immune responses in vitiligo patients. Methods: Peripheral blood was collected from five patients with progressive non-segmental vitiligo and three healthy controls. Peripheral blood mononuclear cells (PBMCs) were obtained by Ficoll-Paque density gradient centrifugation, and scRNA-seq was performed on isolated cell populations to obtain single cell transcriptomes and characterize important genes and intracellular signaling pathways. The key findings were validated with qPCR and flow cytometry assays. Results: We identified 10 major cell types by scRNA-seq. Among these cell types, neutrophils were specifically observed in our scRNA-seq data from PBMCs. Peripheral blood effector CD8+ T cells from vitiligo patients did not show significant differences at the transcriptome level compared with healthy controls, whereas regulatory T cells showed pro-inflammatory TH1-like properties. Innate immune cells, including natural killer cells and dendritic cells, showed increased antigen processing and presentation as well as upregulated interferon responses. B cells, monocytes, and neutrophils all showed activation. B cells, especially memory B cells, had upregulated expression of genes related to humoral immunity. Monocytes showed production of proinflammatory cytokines and chemokines. Neutrophils showed strong chemokine ligand-receptor (L-R) pair (CXCR8-CXCR2) autocrine signaling pathway. Conclusion: This study revealed the genetic profile and signaling pathway characteristics of peripheral blood immune cells in vitiligo patients, providing new insights into its pathogenesis, which may facilitate identification of potential therapeutic targets. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore single nucleotide polymorphisms (SNPs) and gene expression of immune and antioxidant markers associated with reproductive disorders in Baladi goats. A total of one hundred adults Baladi does were allocated into two equal-sized groups: normal reproductive performance and does have a history of reproductive disorders. DNA sequencing of PRLR (304-bp), LTF (904-bp), TLR2 (420-bp), TLR4 (335-bp), CLA-DRB3.2 (285-bp), SOD3 (735-bp), CAT (1526-bp), GPX4 (782-bp), and GST (690-bp) revealed SNPs associated with reproductive disorders tolerance/susceptibility in investigated does. Nonetheless, DNA sequencing of beta defensin (483-bp), CCL5 (840-bp), and ATOX1 (374-bp) genes elicited a monomorphic pattern. Levels of PRLR, LTF, TLR2, TLR4, CLA-DRB3.2, beta defensin, and CCL5 genes were significantly up-regulated in does affect with reproductive disorders than tolerant ones; while SOD3, CAT, GPX4, GST and ATOX1 genes pattern elicited an opposite trend. The results herein confirmed the potential significance of SNPs in immune and antioxidant genes as genetic markers for reproductive disorders tolerance/susceptibility in Baladi does. The Gene expression profile of investigated genes could be also used as proxy biomarkers for the prediction of the most susceptible risk time for disease occurrence and for building up an effective management protocol. [ABSTRACT FROM AUTHOR]

This article discusses the factors that determine the differentiation of autoreactive thymocytes into regulatory T cells (Tregs). Tregs are a subset of CD4+ T cells that play a crucial role in maintaining peripheral tolerance and immune homeostasis. The majority of Tregs are generated in the thymus upon recognition of self-antigens, while others can be generated in specialized peripheral tissues. The differentiation of Tregs is influenced by factors such as T-cell receptor signaling, co-stimulation, and the presence of TGF-β and retinoic acid. The study also highlights the role of late agonist signaling and the disruption of TCR signaling in the generation of Tregs. The findings contribute to our understanding of thymocyte selection and central tolerance, and may have implications for future therapeutic interventions involving Tregs. [Extracted from the article]

Immune-checkpoint inhibitors (ICI) are promising modalities for treating triple negative breast cancer (TNBC). However, hyperglycolysis, a hallmark of TNBC cells, may drive tumor-intrinsic PD-L1 glycosylation and boost regulatory T cell function to impair ICI efficacy. Herein, we report a tumor microenvironment-activatable nanoassembly based on self-assembled aptamer-polymer conjugates for the targeted delivery of glucose transporter 1 inhibitor BAY-876 (DNA-PAE@BAY-876), which remodels the immunosuppressive TME to enhance ICI response. Poly β-amino ester (PAE)-modified PD-L1 and CTLA-4-antagonizing aptamers (aptPD-L1 and aptCTLA-4) are synthesized and co-assembled into supramolecular nanoassemblies for carrying BAY-876. The acidic tumor microenvironment causes PAE protonation and triggers nanoassembly dissociation to initiate BAY-876 and aptamer release. BAY-876 selectively inhibits TNBC glycolysis to deprive uridine diphosphate N-acetylglucosamine and downregulate PD-L1 N-linked glycosylation, thus facilitating PD-L1 recognition of aptPD-L1 to boost anti-PD-L1 therapy. Meanwhile, BAY-876 treatment also elevates glucose supply to tumor-residing regulatory T cells (Tregs) for metabolically rewiring them into an immunostimulatory state, thus cooperating with aptCTLA-4-mediated immune-checkpoint inhibition to abolish Treg-mediated immunosuppression. DNA-PAE@BAY-876 effectively reprograms the immunosuppressive microenvironment in preclinical models of TNBC in female mice and provides a distinct approach for TNBC immunotherapy in the clinics. A tumor cell-intrinsic hyperglycolytic state has been associated with immunosuppression and resistance to immune checkpoint blockade in triple negative breast cancer (TNBC). Here the authors describe an aptamer-based nanoassembly for tumor cell selective inhibition of glycolysis combined with bispecific immune checkpoint blockade, promoting anti-tumor immune responses in preclinical TNBC models. [ABSTRACT FROM AUTHOR]

Purpose: Acute exercise elicits a transient anti-inflammatory state during the early recovery period. Since recent studies reported on regimen-specific effects on immune-related humoral factors and cellular subsets, this study compared the effects of intensity- and time-matched acute interval and continuous exercise on peripheral anti-inflammatory cellular and humoral immune parameters with a particular focus on the PD-1 expression in CD4+ regulatory T cells (Tregs). Methods: Twenty-four recreationally active runners (age: 29.7 ± 4.3 years, BMI: 22.2 ± 2.4, VO2peak: 56.6 ± 6.4 ml × kg−1 × min−1) participated in this crossover RCT. Each subject conducted a moderate continuous (MCE) and a high-intensity interval exercise (HIIE) session in a counterbalanced design. Blood was drawn before, immediately after, and 1 h after exercise. Treg subsets and levels of PD-1 and Foxp3 were assessed by flow cytometry. Serum levels of IL-10 and IL-6 were quantified by ELISA. Results: PD-1 levels on Tregs increased within the recovery period after HIIE (p <.001) and MCE (p < 0.001). Total counts of Tregs (HIIE: p = 0.044; MCE: p =.021), naïve Tregs (HIIE: p < 0.001; MCE: p < 0.001), and PD-1+ effector Tregs (eTregs) (HIIE: p =.002) decreased 1 h after exercise. IL-10 increased 1 h after HIIE (p < 0.001) and MCE (p = 0.018), while IL-6 increased immediately after both HIIE (p = 0.031) and MCE (p = 0.021). Correlations between changes in IL-6 and IL-10 (p = 0.017, r = 0.379) and baseline VO2peak and Treg frequency (p = 0.002, r = 0.660) were identified. Conclusion: This is the first study that investigates PD-1 expression in circulating Tregs after acute exercise, revealing an increase in PD-1 levels on eTregs during the early recovery period after intensity- and time-matched HIIE and MCE. Future studies are needed to investigate the PD-1 signalosome in eTregs, together with the expression of key effector molecules (i.e., IL-10, TGF-β, IL-35, CTLA-4) to elucidate PD-1-dependent changes in cellular function. Based on changes in serum cytokines, this study further reveals a regimen-independent establishment of an anti-inflammatory milieu and underpins the role of the IL-6/IL-10 axis. [ABSTRACT FROM AUTHOR]

The IL-2 receptor α chain (IL-2Rα/CD25) is constitutively expressed on double-negative (DN2/DN3 thymocytes and regulatory T cells (Tregs) but induced by IL-2 on T and natural killer (NK) cells, with Il2ra expression regulated by a STAT5-dependent super-enhancer. We investigated CD25 regulation and function using a series of mice with deletions spanning STAT5-binding elements. Deleting the upstream super-enhancer region mainly affected constitutive CD25 expression on DN2/DN3 thymocytes and Tregs, with these mice developing autoimmune alopecia, whereas deleting an intronic region decreased IL-2–induced CD25 on peripheral T and NK cells. Thus, distinct super-enhancer elements preferentially control constitutive versus inducible expression in a cell type–specific manner. The mediator-1 coactivator colocalized with specific STAT5-binding sites. Moreover, both upstream and intronic regions had extensive chromatin interactions, and deletion of either region altered the super-enhancer structure in mature T cells. These results demonstrate differential functions for distinct super-enhancer elements, thereby indicating previously unknown ways to manipulate CD25 expression in a cell type–specific fashion. Editor's summary: Regulation of the gene encoding IL-2Rα (CD25) has been studied extensively to understand discrete patterns of expression on lymphocyte subsets, including the influence of Il2ra super-enhancer elements. Spolski et al. undertook an exhaustive investigation of CD25 regulation and function using a panel of mice bearing different deletions within Il2ra super-enhancer elements that modulate binding of STAT5. Deletion of the upstream super-enhancer region markedly affected constitutive CD25 expression on double-negative (DN)2/DN3 thymocytes and Tregs and resulted in the development of mice with autoimmune alopecia. By contrast, deletion of an intronic region reduced IL-2–driven CD25 expression on peripheral NK and T cells. The upstream and intronic regions also exhibited chromatin interactions, and deletions resulted in changes in super-enhancer structures in mature T cells. These findings highlight roles of different super-enhancer elements in controlling CD25 expression. —Christiana Fogg [ABSTRACT FROM AUTHOR]

CD (cluster of differentiation) 69 and CD25 are considered early and late markers of the activation of lymphocytes, respectively. CD25 is a part of the IL-2 receptor and is present on the surface of immune and non-immune cells, with high amounts on activated lymphocytes and regulatory T cells. CD69 is expressed on various types of white blood cells, including newly activated lymphocytes, lymphocytes infiltrating tissues isolated from subjects with chronic auto-inflammatory diseases, several subtypes of memory T cells and regulatory T cells. Primarily, CD69 was considered to be an early marker of the activation of lymphocytes, but, right now, data derived from in vitro and in vivo studies have revealed the immunomodulatory role of this surface antigen. In 84 patients with psoriasis, of whom 28 were treated with different biologic drugs, as well as in 29 healthy control subjects, the expression of CD25 and CD69 on different subtypes of peripheral blood mononuclear cells (PBMCs) was studied with the use of flow cytometry. Significantly higher levels of CD3/CD69-, CD8/CD69- and CD19/CD69-positive PBMCs as well as within CD3+ cells were present in subjects suffering from psoriasis when compared to healthy controls. In patients with psoriasis who were treated with biologic drugs, the levels of CD3/CD69-, CD4/CD69- and CD19/CD69-positive PBMCs, and CD3/CD69 within CD3+ cells, CD4/CD69 within CD4+ cells, CD4/CD25 within CD4+ cells and CD19/CD69 within CD19+ cells were significantly higher than before therapy. Our results support a role for activation markers, especially CD69, in psoriasis. Further research is warranted to fully clarify their significance in this common dermatosis, especially during biologic treatment. [ABSTRACT FROM AUTHOR]

Bone resorption can be caused by excessive differentiation and/or activation of bone‐resorbing osteoclasts. While microbe‐associated molecular patterns can influence the differentiation and activation of bone cells, little is known about the role of lipoteichoic acid (LTA), a major cell wall component of Gram‐positive bacteria, in the regulation of bone metabolism. In this study, we investigated the effect of LTA on bone metabolism using wild‐type Staphylococcus aureus and the LTA‐deficient mutant strain. LTA‐deficient S. aureus induced higher bone loss and osteoclast differentiation than wild‐type S. aureus. LTA isolated from S. aureus (SaLTA) inhibited osteoclast differentiation from committed osteoclast precursors in the presence of various osteoclastogenic factors by downregulating the expression of NFATc1. Remarkably, SaLTA attenuated the osteoclast differentiation from committed osteoclast precursors of TLR2−/− or MyD88−/− mice and from the committed osteoclast precursors transfected with paired immunoglobulin‐like receptor B‐targeting siRNA. SaLTA directly interacted with gelsolin, interrupting the gelsolin‐actin dissociation which is a critical process for osteoclastogenesis. Moreover, SaLTA suppressed the mRNA expression of dendritic cell‐specific transmembrane protein, ATPase H+ transporting V0 subunit D2, and Integrin, which encode proteins involved in cell‐cell fusion of osteoclasts. Notably, LTAs purified from probiotics, including Bacillus subtilis, Enterococcus faecalis, and Lactobacillus species, also suppressed Pam2CSK4‐ or RANKL‐induced osteoclast differentiation. Taken together, these results suggest that LTAs have anti‐resorptive activity through the inhibition of osteoclastogenesis by interfering with the gelsolin‐actin dissociation and may be used as effective therapeutic agents for the prevention or treatment of inflammatory bone diseases. [ABSTRACT FROM AUTHOR]

Celiac disease (CeD) is a T-cell-mediated immune disease, in which gluten-derived peptides activate lamina propria effector CD4+ T cells. While this effector T cell subset produces proinflammatory cytokines, which cause substantial tissue injury in vivo, additional subsets of T cells exist with regulatory functions (Treg). These subsets include CD4+ type 1 regulatory T cells (Tr1) and CD4+ CD25+ T cells expressing the master transcription factor forkhead box P3 (Foxp3) that may have important implications in disease pathogenesis. In this review, we provide an overview of the current knowledge about the effects of immunomodulating cytokines on CeD inflammatory status. Moreover, we outline the main Treg cell populations found in CeD and how their regulatory activity could be influenced by the intestinal microenvironment. Finally, we discuss the Treg therapeutic potential for the development of alternative strategies to the gluten-free diet (GFD). [ABSTRACT FROM AUTHOR]

The development of highly effective malaria vaccines and improvement of drug-treatment protocols to boost antiparasitic immunity are critical for malaria elimination. However, the rapid establishment of parasite-specific immune regulatory networks following exposure to malaria parasites hampers these efforts. Here, we identified stimulator of interferon genes (STING) as a critical mediator of type I interferon production by CD4+ T cells during blood-stage Plasmodium falciparum infection. The activation of STING in CD4+ T cells by cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) stimulated IFNB gene transcription, which promoted development of IL-10– and IFN-γ–coproducing CD4+ T (type I regulatory [Tr1]) cells. The critical role for type I IFN signaling for Tr1 cell development was confirmed in vivo using a preclinical malaria model. CD4+ T cell sensitivity to STING phosphorylation was increased in healthy volunteers following P. falciparum infection, particularly in Tr1 cells. These findings identified STING expressed by CD4+ T cells as an important mediator of type I IFN production and Tr1 cell development and activation during malaria. [ABSTRACT FROM AUTHOR]

Background: Graves' disease (GD) is a T cell‐mediated organ‐specific autoimmune disease. Forkhead box P3 (FoxP3) is an excellent marker for the induction and development of regulatory T cells (Tregs). Recent studies showed that single‐nucleotide polymorphisms (SNPs) in the FoxP3 gene were associated with the increased susceptibility to several autoimmune diseases. In the present study, we investigated the association of FoxP3 gene polymorphisms with GD in a Southwest Chinese Han population. Methods: A two‐stage case‐control study was performed in 890 healthy controls (male, 282; female, 608) and 503 patients with GD (male, 138; female, 365). Four SNPs (rs3761548, rs3761549, rs3761547, and rs2280883) were genotyped by the polymerase chain reaction‐restriction fragment length polymorphism assay. The χ2 test was used to compare the genotype distributions and allele frequencies between GD patients and healthy controls. Results: In the first stage, the significantly increased frequencies of the A allele (p =.031, odds ratio [OR] = 1.635) and AA genotype (p =.023, OR = 3.257), together with a significantly decreased frequency of the C allele (p =.031, OR = 0.611) of FoxP3/rs3761548 were found in female patients with GD. None of the other FoxP3 SNPs was associated with GD susceptibility. Subsequent validation and combination of data confirmed the association between FoxP3/rs3761548 and the female patients with GD (A allele: p <.001, OR = 1.672; AA genotype: p =.005, OR = 2.488; CC genotype: p =.001, OR = 0.622; C allele: p <.001, OR = 0.615, respectively). Conclusion: Our findings suggest that FoxP3/rs3761548 is significantly associated with female GD patients in a Southwest Chinese Han population. [ABSTRACT FROM AUTHOR]

Rapid and accurate methods for the diagnosis of tuberculous pleurisy (TP) are urgently needed. Activation markers of tuberculosis (TB)–reactive T cells are considered promising for the diagnosis of active TB (ATB). Different activation indexes may play different roles in the progression of TB, but there are few reports on T cell activation indicators, except for HLA-DR. Hence, we evaluated the expression of early (CD25 and CD69) and late (CD134) activation markers on TB antigen-stimulated CD4+ T cells in populations with different TB infection status and investigated their diagnostic value for ATB, particularly, for TP. Moreover, we compared the differences in the diagnostic efficacy among the indexes from peripheral blood (PB) and pleural fluid (PF) for TP. The expression of each activation marker was significantly increased in TB-infected populations (patients with ATB and latent TB infection vs. healthy individuals; patients with TP vs. non-TP) and was significantly higher in the PF than in the PB of patients with TP. The diagnostic performance of the coexpressed activation markers was superior to that of single expression markers in the differential diagnosis of ATB and non-TB, with CD25+CD134+ showing the best diagnostic efficiency (AUC: 0.93, 95% CI, 0.87–0.99; sensitivity: 86.7%, 95% CI, 72.5%–94.5%; and specificity: 94.0%, 95% CI, 82.5%–98.4%). Except for TB-IGRA, the activation indexes were more accurate than conventional laboratory methods for ATB diagnosis. In addition, the expression of CD25+CD134+ in PB and PF was the best values for differential diagnosis of TP and NTP, with AUCs of 0.87 (95% CI, 0.77–0.96) and 0.95 (95% CI, 0.90–1.00), respectively. Our study provides information on the diagnostic value of different activation markers for TB and shows that the expression of CD25+CD134+ on CD4+ T cells in PF can serve as a potential marker for TP diagnosis. [ABSTRACT FROM AUTHOR]

Objectives: Previous research has indicated a potential association between immune factors and osteoarthritis (OA), but the causal relationship between CD25 expression on immune cells and hip OA remains enigmatic. To shed light on this relationship, this study utilized the two-sample Mendelian Randomization (MR) method. Methods: Leveraging genome-wide association studies (GWAS) data from the UK Biobank and arcOGEN, the investigation encompasses a substantial European cohort comprising 15,704 hip OA cases and 378,169 controls. Genetic insights into CD25 stem from a subgroup of 3,757 individuals with European ancestry, encompassing 77 CD25-related traits. Several MR methods were applied, and robustness was assessed through heterogeneity and sensitivity analysis. Results: Among the 77 traits examined, 66 shared the same single nucleotide polymorphisms (SNPs) with hip OA. Of these, 7 CD25-related traits were found to be causally associated with hip OA (adjusted P><0.05), with F-statistics ranging from 33 to 122. These traits are specifically related to CD4+CD25+ T cells, exhibiting odds ratios (OR) and 95% confidence intervals (CI) less than 1. Notably, no causal link was discerned with the CD8+CD25+ T cell subset. Within absolute count (AC) and relative count (RC) trait types, a significant causal relationship was observed solely between CD4+CD25+ T cells and hip OA, without subtype localization. A more intricate examination of CD25 expression levels within the CD4+CD25+ T cell subset revealed a correlation with the CD39+ regulatory T (Treg) subset and hip OA, particularly within the CD39+ activated Treg subset. Furthermore, a notable causal relationship emerged between CD25 expression levels in the CD45RA- not Treg subset and hip OA. However, no significant causal link was established with any subsets of B cells. Conclusion: The genetic prediction suggests that CD25, particularly within the realm of CD4+CD25+ T cells, may exert a protective influence against the development of hip OA. These findings provide a novel therapeutic approach for the prevention and treatment of hip OA. [ABSTRACT FROM AUTHOR]

• Ruxolitinib promotes expansion of Tregs in murine bone marrow failure (BMF). • GITR is a surrogate marker for FoxP3 in ruxolitinib-treated BMF mice. • Ruxolitinib suppresses Tregs in normal and sublethal irradiation conditions. • The effects of ruxolitinib on Tregs are immune-context dependent. Aplastic anemia is a bone marrow failure (BMF) disorder characterized by pancytopenia and hypocellular marrow from an immune-mediated etiology. Regulatory T cells (Tregs) prevent autoimmunity by suppressing autoreactive T cells. We recently demonstrated the efficacy of ruxolitinib (RUX), a JAK 1/2 inhibitor, in attenuating murine BMF. Herein, we investigated the changes of Tregs in the context of RUX treatment for murine BMF. Tregs are conventionally identified by surface expression of CD4 and CD25, in addition to intracellular transcription factor FoxP3. RUX promoted the expansion of Tregs in BMF mice defined by increased expression of FoxP3 in CD4 T cells but suppressed expression of activation marker CD25 in CD4 and CD8 T cells. In this context, CD25 is no longer a reliable surface marker for Tregs. We observed strong co-expression of FoxP3 with surface marker GITR instead of CD25 in RUX-treated BMF mice. Fluorescence-activated cell sorting (FACS)-sorted CD4+GITRhi cells showed high FoxP3 expression and intact suppressive function in vitro, suggesting GITR to be a surrogate marker for Tregs. In contrast to its expansive effect on Tregs in BMF, RUX suppressed Tregs in normal and sublethal irradiation conditions, indicating that the effects of RUX on Tregs are immune-context dependent. [ABSTRACT FROM AUTHOR]

Malnourished children are susceptible to an increased risk of mortality owing to impaired immune functions. However, the underlying mechanism of altered immune functions and its interaction with malnutrition is poorly understood. This study investigates the immune function and evaluates the effect of a particular nutritional intervention on the immune cells of undernourished children. Stunted (LAZ <−2) and at‐risk of being stunted (length‐for‐age Z‐scores, LAZ <−1 to −2) children aged between 12 and 18 months were enrolled and were provided with the daily nutritional intervention of one egg and 150 mL cow's milk for 90 days. Peripheral blood mononuclear cells (PBMCs) were isolated at enrolment and upon completion of the intervention. Phenotypic profiles for CD3+ cells, CD4+ cells, CD8+ cells, NKT cells, and B cells were similar in both cohorts, both before and after the intervention. However, activated B cells (CD25+) were increased after nutritional intervention in the at‐risk of being stunted cohort. Several pro‐inflammatory cytokines, IL‐6, IFN‐γ, and TNF‐α, were elevated in the stunted children following the nutritional intervention. The results of the study indicate that nutritional intervention may have a role on activated B cells (CD25+) s in children who are at‐risk of being stunted and may alter the capacity of PBMC to produce inflammatory cytokines in stunted children. [ABSTRACT FROM AUTHOR]

This article evaluates a diagnostic algorithm for mastocytosis in skin biopsies and CD25 expression in skin mast cells of 49 patients at a Tertiary Hospital in Sao Paulo, Brazil. Mastocytosis is characterized by the accumulation of neoplastic mast cells in the skin or other organs. The study found that the algorithm was able to correctly diagnose all mastocytosis cases, but the significance of CD25 expression in skin mast cells is still unclear. Further research is needed to identify skin mast cell markers that can correlate with disease chronicity and severity. [Extracted from the article]

Introduction: Human Granzyme B (GZMB) regulatory B cells (Bregs) have suppressive properties on CD4+ effector T cells by a mechanism partially dependent on GZMB. Moreover, these cells may be easily induced in vitro making them interesting for cell therapy. Methods: We characterized this population of in vitro induced GZMB+Bregs using single cell transcriptomics. To investigate their regulatory properties, Bregs or total B cells were also co-cultured with T cells and scRNAseq was used to identify receptor ligand interactions and to reveal gene expression changes in the T cells. Results: We find that Bregs exhibit a unique set of 149 genes differentially expressed and which are implicated in proliferation, apoptosis, metabolism, and altered antigen presentation capacity consistent with their differentiated B cells profile. Notably, Bregs induced a strong inhibition of T cell genes associated to proliferation, activation, inflammation and apoptosis compared to total B cells. We identified and validated 5 receptor/ligand interactions between Bregs and T cells. Functional analysis using specific inhibitors was used to test their suppressive properties and we identified Lymphotoxin alpha (LTA) as a new and potent Breg ligand implicated in Breg suppressive properties. Discussion: We report for the first time for a role of LTA in GZMB+Bregs as an enhancer of GZMB expression, and involved in the suppressive properties of GZMB+Bregs in human. The exact mechanism of LTA/GZMB function in this specific subset of Bregs remains to be determined. [ABSTRACT FROM AUTHOR]

T follicular regulatory (Tfr) cells, a subset of CD4+ Foxp3+ regulatory T (Treg) cells, locate to the lymphoid follicle and germinal center (GC) and regulate antibody responses. Tfr cells express the functional molecules of follicular helper T (Tfh) cells, including CXCR5 and Bcl6. CD25− mature Tfr cells differentiate from CD25+ Treg cells through CD25+ immature Tfr cells. Others and we have shown that Achaete-scute complex homolog 2 (Ascl2) plays a role in Tfh cell development; however, the role of Ascl2 in the development of Tfr cells remains unclear. Here, we found that Ascl2 was highly and preferentially expressed in CD25+ Tfr cells and CD25− Tfr cells, and that the differentiation from CD25+ Tfr cells to CD25− Tfr cells was impaired by the absence of Ascl2. Furthermore, the forced Ascl2 expression in Treg cells downregulated CD25 expression and suppressed IL-2-induced phosphorylation of STAT5, which is known to suppress CD25− Tfr cell development. Finally, we found that the downregulation of CD25 by Ascl2 in Treg cells is independent of Bach2, which also regulates CD25 downregulation in CD25+ Tfr cells. These results suggest that Ascl2 plays a vital role in developing Tfr cells, possibly by downregulating CD25 expression in a Bach2-independent mechanism. • Ascl2 was preferentially expressed in CD25+ Tfr cells and CD25− Tfr cells. • The development of CD25− Tfr cells was impaired in Ascl2-deficient Tregs. • The forced expression of Ascl2 downregulated CD25 expression and suppressed IL-2-STAT5 signaling in Treg cells. • The attenuation of CD25 expression by the forced Ascl2 expression was observed even in Bach2-knockdown cells. [ABSTRACT FROM AUTHOR]

Introduction: Multiple Sclerosis (MS) has a complex pathophysiology that involves genetic and environmental factors. DNA methylation (DNAm) is one epigenetic mechanism that can reversibly modulate gene expression. Cell specific DNAm changes have been associated with MS, and some MS therapies such as dimethyl fumarate can influence DNAm. Interferon Beta (IFNb), was one of the first disease modifying therapies in multiple sclerosis (MS). However, how IFNb reduces disease burden in MS is not fully understood and little is known about the precise effect of IFNb treatment on methylation. Methods: The objective of this study was to determine the changes in DNAm associated with INFβ use, using methylation arrays and statistical deconvolutions on two separate datasets (total ntreated = 64, nuntreated = 285). Results: We show that IFNb treatment in people with MS modifies the methylation profile of interferon response genes in a strong, targeted, and reproducible manner. Using these identified methylation differences, we constructed a methylation treatment score (MTS) that is an accurate discriminator between untreated and treated patients (Area under the curve = 0.83). This MTS is time-sensitive and in consistent with previously identified IFNb treatment therapeutic lag. This suggests that methylation changes are required for treatment efficacy. Overrepresentation analysis found that IFNb treatment recruits the endogenous anti-viral molecular machinery. Finally, statisticaldeconvolution revealed that dendritic cells and regulatory CD4+ T cells were most affected by IFNβ induced methylation changes. Discussion: In conclusion, our study shows that IFNβ treatment is a potent and targeted epigenetic modifier in multiple sclerosis. [ABSTRACT FROM AUTHOR]

The autoimmune pathogenesis of type 1 diabetes (T1D) involves cellular infiltration from innate and adaptive immune subsets into the islets of Langerhans within the pancreas; however, the direct cytotoxic killing of insulin-producing b-cells is thought to be mediated primarily by antigenspecific CD8+ T cells. Despite this direct pathogenic role, key aspects of their receptor specificity and function remain uncharacterized, in part, due to their low precursor frequency in peripheral blood. The concept of engineering human T cell specificity, using T cell receptor (TCR) and chimeric antigen receptor (CAR)- based approaches, has been demonstrated to improve adoptive cell therapies for cancer, but has yet to be extensively employed for modeling and treating autoimmunity. To address this limitation, we sought to combine targeted genome editing of the endogenous TCRa chain gene (TRAC) via CRISPR/Cas9 in combination with lentiviral vector (LV)-mediated TCR gene transfer into primary human CD8+ T cells. We observed that knockout (KO) of endogenous TRAC enhanced de novo TCR pairing, which permitted increased peptide:MHCdextramer staining. Moreover, TRAC KO and TCR gene transfer increased markers of activation and effector function following activation, including granzyme B and interferon-g production. Importantly, we observed increased cytotoxicity toward an HLA-A*0201+ human b-cell line by HLA-A*02:01 restricted CD8+ T cells engineered to recognize islet-specific glucose-6-phosphatase catalytic subunit (IGRP). These data support the notion of altering the specificity of primary human T cells for mechanistic analyses of autoreactive antigen-specific CD8+ T cells and are expected to facilitate downstream cellular therapeutics to achieve tolerance induction through the generation of antigenspecific regulatory T cells. [ABSTRACT FROM AUTHOR]

γδT cells are produced in the thymus throughout life and provide immunity at epithelial‐rich sites. Unlike conventional αβT cells, γδT‐cell development involves intrathymic acquisition of effector function, with priming for either IL17 or IFN‐γ production occurring during embryonic or adult life, respectively. How the thymus controls effector‐primed γδT‐cell generation in adulthood is poorly understood. Here, we distinguished de novo γδT cells from those undergoing thymus recirculation and/or retention using Rag2GFP mice alongside markers of maturation/effector priming including CD24, CD25, CD73, and IFN‐γ, the latter by crossing with IFN‐γYFP GREAT mice. We categorize newly developing γδT‐cells into an ordered sequence where CD25+CD73−IFN‐γYFP− precursors are followed sequentially by CD25−CD73+IFN‐γYFP− intermediates and CD25−CD73+IFN‐γYFP+ effectors. To determine intrathymic requirements controlling this sequence, we examined γδT‐cell development in Relb−/− thymus grafts that lack medullary microenvironments. Interestingly, medulla deficiency did not alter CD25+ γδT‐cell precursor generation, but significantly impaired development of effector primed stages. This impact on γδT‐cell priming was mirrored in plt/plt mice lacking the medullary chemoattractants CCL19 and CCL21, and also Ccl21a−/− but not Ccl19−/− mice. Collectively, we identify the medulla as an important site for effector priming during adult γδT‐cell development and demonstrate a specific role for the medullary epithelial product CCL21 in this process. [ABSTRACT FROM AUTHOR]