Search Results (430)

Acute Trypanosoma cruzi infection induces an exuberant immune response; however, the host is unable to clear the parasite, and the infection progresses to a chronic phase. T and B cells play a crucial role in controlling infections. Although the parasite constitutes a myriad of antigenic determinants capable of activating many T and B cell clones, some antigens trigger a large proportion of CD8 T cells, implying TCR cross-reactivity targeting these determinants. Polyclonal activation may result in an inefficient immune response against the parasite, diverting it to less critical antigenic determinants, allowing infection persistence, and increasing the risk of autoimmunity. Cross-reactivity has been demonstrated in CD8 T cells but not in CD4 T cells. Herein, we demonstrate, by cytometry, that CD4+ T cells, carrying the DO11.10 transgenic TCR, which are responsive to OVA, are activated during the T. cruzi acute infection, becoming effector memory T cells that produce cytokines such as IFN-γ, TNF-α, IL-4, and IL-10. In addition, prior oral exposure to OVA altered cytokine production by these transgenic T cells upon infection. We also demonstrate that T. cruzi induces Foxp3 expression in a sizable pool of transgenic T cells. Full article

The survival and activation of both effector and regulatory CD4⁺T cells are promoted by cytokines in a complex series of interactions. Alloantigen-specific Regulatory T cells (Treg) constitutively express IL-2 receptor (CD25) and Foxp3. This discovery arose as the cells that transfer the alloantigen-specific transplant tolerance die in culture with specific alloantigens, unless the cultures are supplemented with cytokines from activated lymphocytes. One such cytokine was IL-2, but other cytokines are essential. We describe how the activation of Treg by antigens depends on cytokines produced by antigen-activated effector T cells. These cytokines also drive in parallel the activation of Treg. The Treg are induced to express similar transcription factors and chemokine receptors and have a similar cytokine responsiveness to the activated T effector cells. The activation of Treg by antigens is a two-step process: the first requires cytokines produced by effector T cells early in their activation, and the second step is driven by cytokines produced later by effector T cells during activation. Cytokines from Type 1 responses promote the induction of Th1-like Treg. Likewise, cytokines produced in Type 2, Type 3, and Tfh responses induce different pathways of Treg activation. Understanding the pathways for the activation and expansion of potent antigen-specific Treg will help produce Treg to control allograft rejection or autoimmunity. Currently, the complexity of the numerous potential pathways of activation of Treg remains incompletely understood. The dogma that IL-2 is the only driver of Treg activation may have hindered the development of highly potent antigen-specific Treg for therapy. Full article

IBD pathogenesis is underpinned by an imbalance between excess inflammation caused by effector T-cells and inadequate suppression by regulatory T-cells (Tregs). Interleukin-37 (IL-37) is a potent, anti-inflammatory cytokine that signals via its receptors IL-1R5 and IL-1R8. Hence, augmenting anti-inflammatory mechanisms that drive IL-37 expression is a strategy to control IBD-associated inflammation. However, the role of IL-37 and its receptors in T-cells remains incompletely understood. Here, we investigated T-cell expression profiles of IL-37 and its receptors to understand the drivers of dysregulated T-cell responses in IBD and develop novel, more effective therapies. T-cell subsets from healthy control (HC), Crohn’s disease (CD) and ulcerative colitis (UC) peripheral blood mononuclear cells (PBMC) and lamina propria mononuclear cells (LPMC) were assessed for expression of IL-37 and its receptors by flow cytometry. CD3+IL-1R8+ T-cell transcriptomes underwent RNA sequencing. The phenotype and suppressive capacity of Tregs supplemented with IL-37 was assessed in vitro. Our results indicate that IL-37 and its receptors were differentially expressed among PBMC and LPMC T-cell subsets in IBD patients compared to HC. Transcription signatures unique to IBD were revealed, particularly histone and mitochondrial pathways. Remarkably, culturing Tregs with IL-37 preserved FOXP3 expression and suppressiveness at a level comparable to treatment with the well-established Treg stabilizing agent rapamycin. Altogether, our study identified differences in T-cells expressing IL-37 and its receptors that are indicative of T-cell dysfunction in IBD. These findings highlight a novel and promising avenue for restoring immune homeostasis in IBD by targeting and boosting the IL-37 signalling pathway. Full article

Background/Objectives: PDZ-binding kinase (PBK) regulates mitosis, but its clinical significance and cellular localization in colorectal cancer (CRC) remain unclear. We evaluated PBK expression in CRC tissues and examined its association with clinicopathological features, immune contexture, and outcomes. Methods: PBK expression was assessed by RNA in situ hybridization in tumors from 246 CRC patients. Associations with TNM stage, vascular invasion, MMR status (dMMR/pMMR), immune cell infiltration, and stromal programmed death-ligand 1 (PD-L1) were analyzed. Overall survival (OS) and recurrence-free survival (RFS) were evaluated using Kaplan–Meier and Cox models. Public single-cell RNA sequencing datasets were analyzed to identify PBK-expressing cell populations. Results: Among 246 cases, 75 (30.5%) showed high PBK expression. High PBK expression was associated with lower TNM stage, absence of vascular invasion, and dMMR status. High-PBK tumors showed an immune-activated microenvironment, including increased CD4⁺, CD8⁺, and FOXP3⁺ T-cell infiltration, higher stromal PD-L1 expression, and higher tumor-infiltrating lymphocyte scores. Single-cell analysis indicated that PBK expression was enriched mainly in proliferative tumor epithelial cell populations. High PBK expression was associated with longer OS and RFS and remained an independent favorable prognostic factor in multivariate analysis. Conclusions: PBK expression in CRC is linked to proliferative tumor epithelial states, an immune-activated microenvironment, and favorable outcomes, supporting its utility as a prognostic biomarker. Full article

As the lineage-defining transcription factor for regulatory T cells (Tregs), FOXP3 plays a critical role in maintaining immune homeostasis. However, FOXP3 has not been found to regulate the expression of immune suppressive cytokines so far, and the specific molecular mechanisms of its function remain an ongoing debate. Emerging evidence reveals that FOXP3 has functions beyond its traditional role as a DNA-binding transcriptional regulator. It possesses unique characteristics distinct from other Forkhead (FKH) family members or lineage-defining transcription factors, including its distinctive sequence recognition preferences, multimeric structure, and function as a central hub for multiprotein complex assembly. Critically, FOXP3 mediates long-range chromatin interactions through its DNA-bridging capacity and multimerization. Furthermore, it integrates environmental signals by interacting with diverse context-dependent cofactors to dynamically regulate gene expression. This review focuses on recent advances elucidating these novel functions of FOXP3, aiming to provide a reference for a deeper understanding of its multifaceted roles in Treg biology. Full article

The neonatal heart possesses a unique capacity for reparative healing after myocardial injury, unlike the adult heart. While immune cells, particularly T cells, regulate post-infarction inflammation, their role in age-dependent cardiac repair remains unclear. This study aimed to characterize the temporal activation of T cell subsets and their contribution to immune homeostasis and myocardial repair. Myocardial infarction was induced in mice of different ages, and T cell subsets (CD4+ T cells, CD8+ T cells, and CD4+Foxp3+ T [T-reg] cells) were analyzed using flow cytometry and RNA sequencing. Neonatal hearts exhibited CD4+ T cells, CD8+ T cells, and T-reg cells that gradually increased until seven days post-injury. Transcriptome analysis identified Rcn3 as a neonatal-specific, injury-responsive gene in T-reg cells, with minimal induction in adult and aged hearts, promoting a reparative microenvironment and exerting anti-fibrotic effects via the PI3K/Akt pathway. Under endoplasmic reticulum stress, Rcn3 activated unfolded protein response genes, and Rcn3-conditioned media reduced fibrosis-associated gene expression in adult cardiac fibroblasts. In a conditional knockout mouse model (Lck-cre; Rcn3^fl/fl), Rcn3 deletion in T cells led to impaired cardiac function recovery and increased fibrosis post-injury. These findings suggest that neonatal T-reg cells play a crucial role in cardiac repair, with Rcn3 as a potential therapeutic target for enhancing immune-mediated cardiac repair and limiting pathological remodeling in the adult heart. Full article

Diabetic nephropathy (DN) is the most common cause of kidney failure worldwide. Mesenchymal stromal cells (MSCs) have demonstrated promise for treating DN by promoting kidney repair and regulating inflammation. Allogeneic (Allo)-MSCs may have similar or superior anti-inflammatory effects to autologous (Auto)-MSCs but also have potential to elicit adverse immune responses due to major histocompatibility complex (MHC) mismatches. To better understand how MSC-delivered allo-antigens influence therapeutic effects of Allo-MSCs compared to Auto-MSCs in DN, lentiviral transduction was used to generate adipose-derived MSCs (ADSCs) from DBA/2J (H-2^d) mice which expressed an allogeneic class I MHC protein (H-2K^b). H-2K^b-ADSCs were injected intravenously into male DBA/2J mice at 11 and 13 weeks after initiation of diabetes, and their effects on renal functional and structural indices were compared at week 15 with those of diabetic DBA/2J recipients of vehicle alone or of empty vector-transduced DBA/2J ADSCs (EV-ADSCs). Both EV-ADSCs and H-2K^b-ADSCs resulted in reduced kidney/total body weight ratio, blood urea nitrogen (BUN), urine albumin creatinine ratio (uACR), mesangial matrix expansion (MME) and renal fibrosis compared to vehicle alone, without influencing glycemia or survival. However, H-2K^b-ADSCs recipients had greater reductions in BUN and uACR, reduced intra-renal myeloid cell infiltration, increased splenic regulatory T cell (Treg) proportions and increased intra-renal Treg infiltration and FOXP3 and IL-10 mRNA. Nonetheless, recipients of H-2K^b-ADSCs also had decreased splenic CD4/CD8 T cell ratios, increased circulating anti-H-2K^b IgG antibodies and histological and biochemical evidence of inflammatory liver injury. These novel findings demonstrated that ADSCs expressing an MHC-I allo-antigen had superior beneficial effects on DN than fully autologous ADSCs. Improved DN severity was associated with immune modulation, including Treg enhancement, but also had potentially detrimental immunological effects in mice with established diabetes. The results highlight the need for further investigation of the immune modulatory effects of Allo-MSCs in diabetes and its organ-specific complications. Full article

Chronic ulcerative colitis disrupts mucosal-acquired immunity; however, the relationship between mucosal regeneration and mucosa-associated lymph tissue (MALT) development remains unclear. We explored crypt responses, MALT phenotypes, and regulatory T cells (Tregs) in a mouse model of chronic colitis following two cycles of dextran sodium sulfate (DSS) exposure. The mucosal regeneration score correlated with crypt expression of Ki-67 and LGR5, submucosal FOXP3-positive Treg expression, and MALT scores. MALT can be categorized into solitary-isolated lymphoid structures, tertiary lymphoid structures, and colonic patches. Regenerative crypts adjacent to tertiary lymphoid structures exhibit reduced expression of Ki-67, LGR5, and SOX9, which might favor mucosal differentiation. These findings were further supported by correlations between crypt stem cell- and Treg-related colonic gene expression of Lgr5, Sox9, Wnt6, Ccl20, and IL10, and between Tgfb1 and Cxcl13. These results suggested that chronic colitis is repaired by stem cell-mediated mucosal regeneration and differentiation, potentially driven by the development of MALT-containing Tregs. Full article

Background: Loneliness (LON) is a heritable psychosocial trait that frequently co-occurs with major depressive disorder (MDD) and sleep traits. Despite known genetic contributions, the shared genetic architecture and molecular mechanisms underlying their co-occurrence remain largely unknown. This study aimed to uncover novel genetic risk loci and cross-trait gene expression effects. Methods: Large-scale genome-wide association study (GWAS) datasets were analyzed using the causal mixture model (MiXeR) to estimate polygenicity and shared genetic architecture. Genetic correlation analyses were performed using linkage disequilibrium score regression (LDSC) and local analysis of [co]variant annotation (LAVA). Conditional and conjunctional FDR methods further identified single nucleotide polymorphisms (SNPs). FUMA was used for gene mapping and annotation, and transcriptome-wide association studies (TWAS) assessed cross-trait gene expression effects. Results: Analyses revealed extensive polygenic overlap between LON, MDD, and sleep-related traits, with concordant and discordant effects. Several novel loci were identified, and cross-trait gene expression effects were observed in multiple brain-expressed genes, including WNT3, ARHGAP27, PLEKHM1, and FOXP2. These findings provide insight into the shared genetic architecture and relevance of these traits. Conclusions: This study demonstrates a significant shared polygenic architecture among LON, MDD, and sleep traits, providing new biological insights. It advances our understanding of cross-trait genetic mechanisms and identifies potential targets for future research, offering broader implications for trait co-occurrence. Full article

Background/Objectives: Soft tissue sarcomas (STS) remain a therapeutic challenge due to their limited response to radiation and conventional chemotherapies. While recent advances in immunotherapy have improved outcomes in several cancers, these strategies have been largely disappointing in STS patients. Naturally occurring STS in dogs have been suggested as a spontaneous, immunocompetent model of human STS, but further characterization of its tumor immune microenvironment is needed to validate its relevance. This study aimed to identify the shared immune-related components of canine and human STS and to determine how these factors influence the tumor biology, progression, and prognosis. Results: Data from 75 dogs with STS was analyzed. In addition, we characterized the tumor immune microenvironment using immunohistochemistry and compared gene expression between canine and human STS. Progression-free survival and time to metastasis was significantly longer in castrated males in comparison to females. In addition, dogs with appendicular tumors had better progression- and recurrence-free survival, whereas tumor recurrence following surgical excision was associated with a shorter time to metastasis. Immunohistochemistry revealed infiltration of CD204⁺ cells in most of the tumors examined, and disease-free intervals were shorter in dogs with tumors exhibiting FOXP3⁺ cell infiltration. Gene expression profiling demonstrated similarities between canine STS and human undifferentiated pleomorphic sarcomas, with MYC dysregulation emerging as a poor prognostic indicator for dogs. Conclusions: The comparative analysis between the human and canine STS microenvironment offers a valuable insight into the clinical behavior and immune landscape of canine STS, underscoring its potential as a relevant preclinical model for the translation and development of future immunotherapies. Full article

Blackground/Objectives: Tributyrin (TB), a stable derivative of butyric acid, has been widely used in animal feeds for its health-promoting effects. This study evaluated the efficacy of dietary TB serving as a functional feed additive in enhancing intestinal health of mandarin fish (Siniperca chuatsi), with a focus on elucidating the associated molecular mechanisms. Methods: A total of 300 juvenile mandarin fish (200.0 ± 5.2 g) were randomly assigned to one of three dietary groups: a control group (0 mg/kg TB), a low-dose TB group (TB1, 500 mg/kg), or a high-dose TB group (TB2, 1000 mg/kg). The one-month feeding trial was conducted under strictly controlled conditions, with water quality maintained within optimal range. Fish were fed their respective diets twice daily to apparent satiety. Results: Results showed that TB supplementation significantly increased villus height in the mid- and hindgut, with the TB2 group showing the most pronounced improvement. Furthermore, transcriptome analysis revealed that TB altered the expression of genes involved in energy metabolism, fatty acid oxidation, and steroid biosynthesis pathways. Notably, TB supplementation up-regulated key genes such as gls2b (energy metabolism) and cpt1b (fatty acid oxidation), and modulated especially modulated steroid biosynthesis through genes sqlea and dhcr24h. Co-expression network analysis further identified hub genes associated with energy metabolism (etfb), immune regulation (il20ra, foxp1b), and cell cycle regulation (cdc20, ccnb1). Conclusions: These findings elucidate the mechanism of action of TB as a functional feed additive, providing a theoretical foundation for its application in aquaculture to enhance intestinal health. Full article

Teleost fish are the first evolutionary group to exhibit an innate and adaptive immune system. Within the mechanisms of adaptive immunity, fish possess, among others, T-helper cells (CD4-like) and their differentiation machinery, regulated by the master transcription factors T-bet, GATA3, Foxp3, and RORγ. Many studies support the existence of a non-neuronal cholinergic system involved in the immune response, named after the ability of leukocytes to synthesize de novo acetylcholine (ACh). Organophosphorus pesticides (OPs), such as diazoxon (DXN), are examples of compounds that act as cholinergic disruptors with immunotoxic effects. The present study aimed to evaluate the expression of transcription factors in leukocytes (spleen mononuclear cells, SMNCs) of Nile tilapia by modulating cholinergic pathways in immune cells using agonists, antagonists, and diazoxon (DXN), an anticholinesterase substance. The obtained data showed a significant increase in RORγ mRNA expression upon stimulation with the nicotinic agonist, whereas activation of the muscarinic receptor with its agonist increased T-bet mRNA expression. An alteration in RORγ expression levels induced by DXN exposure was also observed. The results suggest a probable directing of the immune response towards a pro-inflammatory profile orchestrated mainly by RORγ and T-bet transcription factors in response to cholinergic stimuli. Full article

The adoptive transfer of Tregs is a promising immunotherapeutic strategy for type 1 diabetes mellitus (T1D). A key focus in this field is the creation of antigen-specific CAR-Tregs targeted against pancreatic islet antigens. However, the efficacy of such therapies is potentially limited by the instability of the Treg phenotype in the inflammatory conditions of T1D. This review discusses molecular approaches to overcome this limitation. These include the genetic engineering of cytokine signaling pathways (IL2, IL33/ST2, and IL35) and the cAMP cascade, the management of FOXP3 splicing to ensure stable expression of concrete splice variants, and the use of epigenetic mechanisms to promote a durable Treg identity. Full article

Background/Objectives: Ovarian cancer remains one of the most lethal gynecologic malignancies, primarily due to late diagnosis and the development of chemoresistance. Adriamycin (ADR) is effective but limited by systemic toxicity. Natural bioflavonoids such as hesperidin (Hes) may enhance chemotherapy efficacy through oxidative, apoptotic, and immune modulation. This study investigated the antiproliferative, pro-apoptotic, and immunomodulatory effects of Hes and ADR in human ovarian adenocarcinoma cells (SKOV3), focusing on Forkhead box P3 (FOXP3) and epidermal growth factor receptor (EGFR) signaling pathways. Methods: SKOV3 were treated with increasing concentrations of Hes (10–400 µM) and ADR (0.01–0.4 µM), either individually or in combination at their half-maximal inhibitory concentration (IC₅₀) ratios. Cell viability (MTT assay), gene expression (qRT-PCR), cytokine levels (ELISA), and total antioxidant capacity (TAC) were assessed to evaluate treatment responses. Results: Both agents reduced cell viability in a dose- and time-dependent manner, with the combination exhibiting synergistic cytotoxicity after 48 h. Co-treatment markedly upregulated Caspase-3 and Bax while downregulating FOXP3 and EGFR. Antioxidant capacity was significantly enhanced in the Hes-treated and combination groups (p < 0.001). Conclusions: Hes and ADR synergistically suppressed proliferation, induced apoptosis, and modulated cytokine balance by inhibiting FOXP3- and EGFR-mediated oncogenic signaling. This combination demonstrates strong potential as an adjuvant therapeutic strategy for ovarian cancer. Full article

Foxp3+ regulatory T (Treg) cells play a pivotal role in inducing immune tolerance. The expression of Foxp3 in Treg cells depends on the stability of transcription factors that are directly linked to the molecular interplay between Stat5a and cyclin-dependent kinase CDK8/19. In this study, dendritic cells obtained from C57BL/6 male mice were co-cultured with CD4⁺ splenocytes obtained from Balb/c male mice to obtain alloantigen-specific CD4⁺ T cells. Next, these alloantigen-specific CD4⁺ T cells were cultured with the addition of the CDK8/19 inhibitor AS2863619 compound, TGF-β1, and IL-2 to induce their transdifferentiation into alloantigen-specific CD4⁺ Foxp3+ Treg cells. The efficacy of this cocktail in promoting the transdifferentiation of activated CD4⁺ lymphocytes into alloantigen-specific Treg cells (ag-Tregs) was further evaluated using Nanostring gene expression profiling, flow cytometry, ELISA, and in vivo migration assays. The results showed that the addition of the AS2863619 compound along with IL-2 generated effector memory ag-Tregs exhibiting tolerogenic activity, migration properties, and mechanisms for regulating immune homeostasis in the spleen. In conclusion, these findings suggest that the AS2863619-derived effector memory Tregs possess functional properties that support immune tolerance and regulate homeostasis in the spleen, thereby regulating the affinity of naïve T cells to alloantigens, highlighting their potential relevance in transplantology. Full article