Role of TGFß-producing regulatory T cells in scleroderma and end-stage organ failure.

Regulatory T cells (Tregs) are crucial immune cells that initiate a tolerable immune response. Transforming growth factor-beta (TGFß) is a key cytokine produced by Tregs and plays a significant role in stimulating tissue fibrosis. Systemic sclerosis, an autoimmune disease characterized by organ fibrosis, is associated with an overrepresentation of regulatory T cells. This review aims to identify Treg-dominant tolerable host immune reactions and discuss their association with scleroderma and end-stage organ failure. End-stage organ failures, including heart failure, liver cirrhosis, uremia, and pulmonary fibrosis, are frequently linked to tissue fibrosis. This suggests that TGFß-producing Tregs are involved in the pathogenesis of these conditions. However, the exact significance of TGFß and the mechanisms through which it induces tolerable immune reactions during end-stage organ failure remain unclear. A deeper understanding of these mechanisms could lead to improved preventive and therapeutic strategies for these severe diseases.

The Current Landscape of Hypotheses Describing the Contribution of CD4+ Heterogeneous Populations to ALS.

Amyotrophic Lateral Sclerosis (ALS) is a poorly understood and fatal disease. It has a low prevalence and a 2-4 year survival period. Various theories and hypotheses relating to its development process have been proposed, albeit with no breakthrough in its treatment. Recently, the role of the adaptive immune system in ALS, particularly CD4+ T cells, has begun to be investigated. CD4+ T cells are a heterogeneous group of immune cells. They include highly pro-inflammatory types such as Th1 and Th17, as well as highly anti-inflammatory cells such as Tregs. However, the landscape of the role of CD4+ T cells in ALS is still not clearly understood. This review covers current hypotheses that elucidate how various CD4+ T cells can contribute to ALS development. These hypotheses include the SWITCH model, which suggests that, in the early stages of the disease, Tregs are highly capable of regulating the immune response. However, in the later stages of the disease, it seems that pro-inflammatory cells such as Th1 and Th17 are capable of overwhelming Treg function. The reason why this occurs is not known. Several research groups have proposed that CD4+ T cells as a whole might experience aging. Others have proposed that gamma delta T cells might directly target Tregs. Additionally, other research groups have argued that less well-known CD4+ T cells, such as Emoes+ CD4+ T cells, may be directly responsible for neuron death by producing granzyme B. We propose that the ALS landscape is highly complicated and that there is more than one feasible hypothesis. However, it is critical to take into consideration the differences in the ability of different populations of CD4+ T cells to infiltrate the blood-brain barrier, taking into account the brain region and the time of infiltration. Shedding more light on these still obscure factors can help to create a personalized therapy capable of regaining the balance of power in the battle between the anti-inflammatory and pro-inflammatory cells in the central nervous system of ALS patients.

Inherent preference for polyunsaturated fatty acids instigates ferroptosis of Treg cells that aggravates high-fat-diet-related colitis.

Inflammatory bowel disease (IBD) has high prevalence in Western counties. The high fat content in Western diets is one of the leading causes for this prevalence; however, the underlying mechanisms have not been fully defined. Here, we find that high-fat diet (HFD) induces ferroptosis of intestinal regulatory T (Treg) cells, which might be the key initiating step for the disruption of immunotolerance and the development of colitis. Compared with effector T cells, Treg cells favor lipid metabolism and prefer polyunsaturated fatty acids (PUFAs) for the synthesis of membrane phospholipids. Therefore, consumption of HFD, which has high content of PUFAs such as arachidonic acid, cultivates vulnerable Tregs that are fragile to lipid peroxidation and ferroptosis. Treg-cell-specific deficiency of GPX4, the key enzyme in maintaining cellular redox homeostasis and preventing ferroptosis, dramatically aggravates the pathogenesis of HFD-induced IBD. Taken together, these studies expand our understanding of IBD etiology.

SPH7854, a gut-limited RORγt antagonist, ameliorates TNBS-induced experimental colitis in rat.

Multiple lines of evidence suggest that Retinoic Acid Related Orphan Nuclear Receptor gamma t (RORγt) is a potent therapeutic target for inflammatory bowel disease (IBD). However, systemic blockade of RORγt easily leads to thymic lymphoma and aberrant liver function. Therefore, the development of gut-limited RORγt antagonists may lead to the development of innovative IBD therapeutics that improve safety and retain effectiveness. We discovered SPH7854, a potent and selective RORγt antagonist. The effect of SPH7854 on the differentiation of T helper 1 (Th1)/Th17/regulatory T (Treg) cells was evaluated in mouse and human primary cells. SPH7854 (2-(4-(ethylsulfonyl)phenyl)-N- (6-(2-methyl-2-(pyridin-2-yl) propanoyl)pyridin-3-yl)acetamide) dose-dependently inhibited interleukin-17A (IL-17A) secretion from mouse CD4 + T cells and human peripheral blood mononuclear cells (PBMC). Additionally, SPH7854 strongly suppressed Th17 cell differentiation and considerably promoted Treg cell differentiation while slightly affected Th1 cell differentiation from mouse CD4 + T cells. The pharmacokinetic (PK) studies indicated that SPH7854 was restricted to the gut: the bioavailability and maximal plasma concentration of SPH7854 after oral administration (6 mg/kg) were 1.24 ± 0.33 % and 4.92 ± 11.81 nM, respectively, in rats. Strikingly, oral administration of SPH7854 (5 mg/kg and 15 mg/kg) twice daily significantly alleviated 2, 4, 6-trinitrobenzensulfonic acid (TNBS)-induced colitis in rats. SPH7854, especially at 15 mg/kg, significantly alleviated symptoms and improved macroscopic signs and microscopic structure in rat colitis, with decreased colonic mucosal levels of IL-17A, IL-6, tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1) and myeloperoxidase (MPO). These evidences indicated that blockade of RORγt activity via a gut-limited antagonist may be an effective and safe therapeutic strategy for IBD treatment.

Role of immune cells in the establishment of implantation and maintenance of pregnancy and immunomodulatory therapies for patients with repeated implantation failure and recurrent pregnancy loss.

Background: Immune cells play an important role in the establishment of pregnancy, and abnormalities in the immune system can cause implantation failure and miscarriage. Methods: Previous papers have been summarized and the role of immune cells in reproduction is reviewed. Results: The immune environment in the uterus changes drastically from before implantation to after pregnancy to maintain pregnancy. In allogeneic pregnancies, immature dendritic cells (DCs) that induce immune tolerance from outside the uterus flow into the uterus, and mature DCs that remain in the uterus express programmed cell death ligand 2, which suppresses the immune response. Macrophages are classified into M1-macrophages, which induce inflammation, and M2-macrophages, which suppress inflammation; M1-macrophages are required for luteinization, and M2-macrophages induce the differentiation of endometrial epithelial cells to enable implantation. Regulatory T cells, which suppress rejection, are essential for the implantation and maintenance of allogeneic pregnancies. Implantation failure and fetal loss are associated with decreased numbers or qualitative abnormalities of DCs, macrophages, and regulatory T cells. The clinical usefulness of immunomodulatory therapies in patients with repeated implantation failure and recurrent pregnancy loss has been reported. Conclusion: The provision of individualized medical care in cases of implantation failure or miscarriage may improve clinical outcomes.

Non-cell-autonomous suppression of tumor growth by RECK in immunocompetent mice.

RECK is a candidate tumor suppressor gene isolated as a gene that induces flat reversion in a cell line transformed by the KRAS oncogene. Since RECK knockout mice die in utero, they are not suitable for studying the effects of RECK on tumor formation. In this study, we found an increased incidence of spontaneous pulmonary adenomas in mice with reduced RECK expression (RECK-Hypo mice). To evaluate the effects of RECK expressed by either tumor cells or host cells on tumor growth, we established a tumorigenic cell line (MKER) from the kidney of a C57BL/6 mouse and performed syngeneic transplantation experiments. Our results indicate that when RECK expression is low in host cells, transplanted MKER cells grow faster and kill the animal more rapidly. Since RECK is required for the formation of proper fibrillin fibers that serve as a tissue reservoir for precursors of TGFß-family cytokines, we assessed the levels of TGFß1 in the peripheral blood. We found a significant increase in TGFß1 in RECK-Hypo mice compared to wild-type mice. We also found that the proportion of FOXP3-positive regulatory T (Treg) cells among splenocytes was higher in RECK-Hypo mice compared to the control mice. Furthermore, the number of FOXP3-positive cells in spontaneous hematopoietic neoplasms in the lungs as well as tumors that formed after MKER transplantation was significantly higher in RECK-Hypo mice compared to the control mice. These findings indicate that RECK-mediated tumor suppression involves a non-cell-autonomous mechanism and that possible roles of TGFß1 and Treg cells in such a mechanism warrant further study.

Regulatory T cell-based therapy in type 1 diabetes: Latest breakthroughs and evidence.

Autoimmune diseases (ADs) are among the most significant health complications, with their incidence rising in recent years. Type 1 diabetes (T1D), an AD, targets the insulin-producing ß cells in the pancreas, leading to chronic insulin deficiency in genetically susceptible individuals. Regulatory immune cells, particularly T-cells (Tregs), have been shown to play a crucial role in the pathogenesis of diabetes by modulating immune responses. In diabetic patients, Tregs often exhibit diminished effectiveness due to various factors, such as instability in forkhead box P3 (Foxp3) expression or abnormal production of the proinflammatory cytokine interferon-gamma (IFN-γ) by autoreactive T-cells. Consequently, Tregs represent a potential therapeutic target for diabetes treatment. Building on the successful clinical outcomes of chimeric antigen receptor (CAR) T-cell therapy in cancer treatment, particularly in leukemias, the concept of designing and utilizing CAR Tregs for ADs has emerged. This review summarizes the findings on Treg targeting in T1D and discusses the benefits and limitations of this treatment approach for patients suffering from T1D.

IL-35 promotes IL-35+IL-10+ Bregs and Conventional LAG3+ Tregs in the lung tissue of OVA-Induced Asthmatic Mice.

AIMS: This study aimed to investigate the effect of interleukin-35 (IL-35) on inflamed lung tissue in a murine model of asthma. IL-35 was examined for its potential to induce regulatory lymphocytes during ovalbumin (OVA)-induced acute lung injury. METHODS: Female BALB/c mice sensitized with OVA and were treated with recombinant IL-35 (rIL-35) via intranasal or intraperitoneal routes and were administered 4 h before OVA challenge. The effects of rIL-35 treatment on the lung and blood levels of regulatory B cells (Bregs) and regulatory T cells (Tregs), as well as their production of immunosuppressive cytokines, were determined using flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: Treatment of OVA-sensitized asthmatic mice with rIL-35, whether administered intranasally or intraperitoneally, resulted in reduced lung inflammation and injury. This reduction was accompanied by an increase in the frequency of IL-35 producing Bregs, IL-35 and IL-10 producing Bregs, and conventional LAG3+ Tregs in the lung tissues and blood. This increase was more pronounced with intranasal rIL-35. Furthermore, there was a positive correlation between the levels of these regulatory cells and lung gene expression of IL-35 and IL-10, and an inverse correlation with both lung gene expression and plasma level of IL-17. CONCLUSIONS: The results of this study suggest that IL-35, through its ability to increase Bregs and Tregs, is effective in reversing lung inflammation in the context of asthma. Since the increase was more pronounced with intranasal administration, this highlights the therapeutic potential of its local intrapulmonary application in managing asthma-related inflammation.

Transiently increased circulating CD39+FoxP3+ Treg cells predict the clinical response to Methotrexate in Early Rheumatoid Arthritis.

OBJECTIVES: A subset of human circulating FoxP3+ regulatory T cells expresses CD39 (cTreg39+) and hydrolyses pro-inflammatory adenine nucleotides released at inflammatory foci, rendering the anti-inflammatory agent adenosine. Methotrexate (MTX), inhibiting ATIC, enhances the extrusion of adenine nucleotides and may help Treg39+ cells control inflammation. Therefore, we examined the relation of cTreg39+ cells with the effect of MTX in early Rheumatoid Arthritis (eRA). METHODS: Freshly isolated peripheral blood lymphocytes from 98 untreated eRA patients and 98 healthy controls (HC) were examined by cytometry. Twelve months (12m) after initiating MTX, 82 patients were clinically re-evaluated and cytometry was repeated in 40 of them. The effect of MTX on Treg cell potency was assessed in Treg/Tresp cocultures. RESULTS: The baseline (0m) cTreg39+ cell frequency was elevated in eRA above HC levels. Patients who reached low disease activity at 12 months (12m-LDA, DAS28-ESR≤ 3.2, n = 51) had presented with a significantly higher 0m cTreg39+ frequency vs those who did not (n = 31). The 0m cTreg39+ cutoff for attaining 12 m-LDA was 42.0% (Sensitivity=90.4%/Specificity=96.8%). At 12m, the cTreg39+ frequency was no longer elevated but its association with disease activity remained: it was still significantly higher in patients who had reached LDA vs those who had not. In vitro, MTX augmented the Treg39+ cell potency but had no effect on Treg39- cells. CONCLUSION: MTX cooperates with Treg39+ cells and the baseline cTreg39+ frequency predicts the response to MTX in eRA. In addition, the transiently elevated baseline cTreg39+ frequency in eRA may provide a slot for prompt MTX initiation.

Regulatory T cells and immune escape in HCC: understanding the tumor microenvironment and advancing CAR-T cell therapy.

Liver cancer, which most commonly manifests as hepatocellular carcinoma (HCC), is the sixth most common cancer in the world. In HCC, the immune system plays a crucial role in the growth and proliferation of tumor cells. HCC achieve immune escape through the tumor microenvironment, which significantly promotes the development of this cancer. Here, this article introduces and summarizes the functions and effects of regulatory T cells (Tregs) in the tumor microenvironment, highlighting how Tregs inhibit and regulate the functions of immune and tumor cells, cytokines, ligands and receptors, etc, thereby promoting tumor immune escape. In addition, it discusses the mechanism of CAR-T therapy for HCC and elaborate on the relationship between CAR-T and Tregs.

NLRP3-mediated IL-1ß in regulating the imbalance between Th17 and Treg in experimental autoimmune prostatitis.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a urinary disorder that affects youthful to middle-aged men most frequently. It has been revealed that Th17/Treg imbalance is a crucial factor in the pathophysiological mechanisms behind this disease. However, this imbalance's mechanisms are unknown. In the experimental autoimmune prostatitis (EAP) mouse model, the NLRP3 inflammasome was turned on, IL-1ß levels went up. Moreover, there exists a discernible positive association between the upsurge in IL-1ß and the perturbation of Th17/Treg equilibrium. Additionally, we have revealed that IL-1ß plays a vital role in promoting the differentiation of Naïve CD4+ T cells into the Th17 cells and enhances the conversion of Treg cells into Th17 cells. Further studies revealed that IL-1ß promotes STAT3 phosphorylation, which is what causes Treg cells to become Th17 cells. All data strongly suggest that the NLRP3 inflammatory influence Th17 cell development and the conversion of Treg cells into Th17 cells through IL-1ß, disrupting the Th17/Treg balance and exacerbating EAP inflammation. In this article, we provide new theories for the pathogenesis of CP/CPPS and propose new prevention and therapy methods.

atRA Attenuates High Salt-Driven EAE Mainly Through Suppressing Th17-Like Regulatory T Cell Response Mediated by the Inhibition of IL-23R Signaling Pathway.

High salt diet (HSD) is implicated in numerous disorders, which boosts Th17 cell development and weakens immunosuppressive function of regulatory T cells (Treg cells) Treg cells, leading to the exacerbation of EAE. However, little is known regarding the harness of excessive proinflammatory responses evoked by HSD. Here we show that atRA, a key vitamin A metabolite with multifaceted immunoregulatory properties has the potential in inhibiting the proinflammatory reaction of high salt. Treatment with atRA in vivo elicited the Treg generation in cervical and axillary lymph nodes (CALs), and in CNS of experimental autoimmune encephalomyelitis (EAE). Meanwhile, the proportion of Th17-like Treg cells (RORγt-positive or GM-CSF-positive Treg cells) decreased in CALs. atRA also inhibited IL-17A expression in CD4+ effector T cells. In-vitro mechanistic studies showed that atRA inhibit IL-23R but not SGK1 expression in Treg cells and this results in maintained immunosuppressive function of Treg cells even in the presence of IL-6 and high salt. Furthermore, treatment of EAE with anti-IL-23R mAb attenuated HSD-provoked EAE progress. This was associated with a reduction in the number of CNS-infiltrating Th17 cells and an increase of CAL-Treg cells. Mechanically, treatment with atRA significantly promoted LP-CD103+CD11c+ dendritic cells, a subgroup of cells most closely involved in endogenous retinoic acid metabolism, and enhanced intestinal Aldh1a1 and Rdh10 expression from HSD-fed EAE mice. Interestingly, anti-IL-23R mAb administration also reduced IL-23R expression in Treg cells, along with the increased proportion of LP-CD103+CD11c+ dendritic cells and Rdh10 mRNA expression. In conclusion, administration of atRA might be a way to combat the proinflammatory effects of HSD. Meanwhile, systematic inhibition of IL-23R also had a moderate therapeutic potential in inhibiting inflammatory effects of high salt, which may serve as a basis for the identification of novel therapeutic strategies against HSD-driven autoimmune disorders.

Preclinical development of a novel CCR8/CTLA-4 bispecific antibody for cancer treatment by disrupting CTLA-4 signaling on CD8 T cells and specifically depleting tumor-resident Tregs.

Anti-CTLA-4 antibodies faced challenges due to frequent adverse events and limited efficacy, which spurred the exploration of next-generation CTLA-4 therapeutics to balance regulatory T cells (Tregs) depletion and CD8 T cells activation. CCR8, identified primarily on tumor-infiltrating Tregs, has become a target of interest due to the anti-tumor effects demonstrated by CCR8 antibody-mediated Tregs depletion. Single-cell RNA sequencing analysis reveals that CCR8-positive Tregs constitute a small subset, with concurrent expression of CCR8 and CTLA-4. Consequently, we proposed a novel bispecific antibody targeting CCR8 and CTLA-4 that had the potential to enhance T cell activation while selectively depleting intratumor Tregs. The candidate molecule 2MW4691 was developed in a tetravalent symmetric format, maintaining a strong binding affinity for CCR8 while exhibiting relatively weaker CTLA-4 binding. This selective binding ability allowed 2MW4691 to target and deplete tumor-infiltrating Tregs with higher specificity. In vitro assays verified the antibody's capacity for antibody-dependent cellular cytotoxicity (ADCC) to Tregs with high level of CTLA-4 expression, but not CD8 T cells with relatively low level of CTLA-4 on cell surface. Also, 2MW4691 inhibited the CTLA-4 pathway and enhanced T cell activation. The in vivo therapeutic efficacy of 2MW4691 was further demonstrated using hCCR8 or hCTLA-4 humanized mouse models and hCCR8/hCTLA-4 double knock-in mouse models. In cynomolgus monkeys, 2MW4691 was well-tolerated, exhibited the anticipated pharmacokinetic profile, and had a minimal impact on the peripheral T cell population. The promising preclinical results supported the further evaluation of 2MW4691 as a next-generation Treg-based therapeutics in clinical trials.

Vitamin E and GPX4 cooperatively protect treg cells from ferroptosis and alleviate intestinal inflammatory damage in necrotizing enterocolitis.

BACKGROUND: The notable decline in the number of Tregs within Necrotizing enterocolitis (NEC) intestinal tissues，contribute to excessive inflammation and necrosis, yet the precise underlying factors remain enigmatic. Ferroptosis, a novel cell death stemming from a disrupted lipid redox metabolism, is the focus of this investigation. Specifically, this study delves into the ferroptosis of Treg cells in the context of NEC and observes the protective effects exerted by vitamin E intervention, which aims to mitigate ferroptosis of Treg cells. METHODS: To investigate the reduction of Treg cells in NEC intestine, we analyzed its association with ferroptosis from multiple angles. We constructed a mouse with a specific knockout of Gpx4 in Treg cells, aiming to examine the impact of Treg cell ferroptosis on NEC intestinal injury and localized inflammation. Ultimately, we employed vitamin E treatment to mitigate ferroptosis in NEC intestine's Treg cells, monitoring the subsequent amelioration in intestinal inflammatory damage. RESULTS: The diminution of Treg cells in NEC is attributed to ferroptosis stemming from diminished GPX4 expression. Gpx4-deficient Treg cells exhibit impaired immunosuppressive function and are susceptible to ferroptosis. This ferroptosis of Treg cells exacerbates intestinal damage and inflammatory response in NEC. Notably, Vitamin E can inhibit the ferroptosis of Treg cells, subsequently alleviating intestinal damage and inflammation in NEC. Additionally, Vitamin E bolsters the anti-lipid peroxidation capability of Treg cells by upregulating the expression of GPX4. CONCLUSION: In the context of NEC, the ferroptosis of Treg cells represents a significant factor contributing to intestinal tissue damage and an exaggerated inflammatory response. GPX4 is pivotal for the viability and functionality of Treg cells. Vitamin E exhibits the capability to mitigate the ferroptosis of Treg cells, thereby enhancing their number and function, which plays a crucial role in mitigating intestinal tissue damage and inflammatory response in NEC.

T-regulatory cells require Sin3a for stable expression of Foxp3.

Histone deacetylases 1 and 2 play a major role in the transcriptional regulation of T-regulatory (Treg) cells via interactions with a myriad of coregulatory factors. Sin3a has been well established as a Hdac1/2 cofactor, while its role within Tregs has not been established. In this study, the effects of conditional deletion of Sin3a within Foxp3+ Tregs were evaluated. Developmental deletion of Sin3a from Foxp3+ Tregs resulted in the rapid onset of fatal autoimmunity. Treg numbers were greatly reduced, while residual Tregs had impaired suppressive function. Mice also showed effector T-cell activation, autoantibody production, and widespread tissue injury. Mechanistically, Sin3a deletion resulted in decreased transcription of Foxp3 with a complete lack of CNS2 CpG demethylation. In addition, Foxp3 protein stability was impaired with an increased ex-Treg population. Thus, Sin3a plays a critical role in the maintenance of Treg identity and function and is essential for the expression and stability of Foxp3.

[Expression and Significance of PD-1/PD-L1 in MDS Blast Cells, T Lymphocyte Cell Subsets and Treg Cells].

OBJECTIVE: To investigate the expression and significance of PD-1/PD-L1 in MDS blast cells, T lymphocyte cell subsets and Treg cells. METHODS: Eighty-eight MDS patients and 19 AML patients were collectd as the study subjects, and Iron deficiency anemia and healthy bone marrow donors were used as control group. The expression of PD-1/PD-L1 in MDS/AML blast cells, T lymphocyte cell subsets and Treg cells was detected by flow cytometry, and the expression level of Th1/Th2/Th17-related cytokines in peripheral serum was detected. RESULTS: The expression of PD-1/PD-L1 in blast cells, T lymphocyte cell subsets and Treg cells in low risk MDS group were lower than that in control group, medium and high risk MDS group and AML group（all P < 0.01）, and Th1/Th17 type cytokines were dominant. The expression of PD-1/PD-L1 in blast cells, T lymphocyte cell subsets and Treg cells of intermediate and high risk MDS group and AML group were higher than that of control group and low risk MDS group (all P < 0.01), and Th2 type and Treg type (IL-10、TGF-ß) cytokines were dominant. After treatment, the differences of PD-1/PD-L1 expression were not statisticatly significant in blast cells, T lymphocyte cell subsets and Treg cells between the MDS remission group and the control group (all P >0.05). The expression of PD-1/PD-L1 in blast cells, T lymphocyte cell subsets and Treg cells in MDS non-remission group were significantly higher than that in remission group and control group (all P < 0.01). CONCLUSION: The high expression of PD-1/PD-L1, dominance of Treg (IL-10、TGF-ß) and Th2-related cytokines and inhibition of effector T lymphocyte cells in patients with MDS is conducive to tumor cell proliferation and immune escape, which may promote the progression of MDS disease.

TGFß in malignant canine mammary tumors: relation with angiogenesis, immunologic markers and prognostic role.

Transforming growth factor-ß (TGFß) and FoxP3 regulatory T cells (Treg) are involved in human breast carcinogenesis. This topic is not well documented in canine mammary tumors (CMT). In this work, the tumoral TGFß expression was assessed by immunohistochemistry in 67 malignant CMT and its correlation to previously determined FoxP3, VEGF, and CD31 markers and other clinicopathologic parameters was evaluated. The high levels of TGFß were statistically significantly associated with skin ulceration, tumor necrosis, high histological grade of malignancy (HGM), presence of neoplastic intravascular emboli and presence of lymph node metastases. The observed levels of TGFß were positively correlated with intratumoral FoxP3 (strong correlation), VEGF (weak correlation) and CD31 (moderate correlation). Tumors that presented a concurrent high expression of TGFß/FoxP3, TGFß/VEGF, and TGFß/CD31 markers were statistically significantly associated with parameters of tumor malignancy (high HGM, presence of vascular emboli and nodal metastasis). Additionally, shorter overall survival (OS) time was statistically significantly associated with tumors with an abundant TGFß expression and with concurrent high expression of TGFß/FoxP3, TGFß/VEGF, and TGFß/CD31. The presence of lymph node metastasis increased 11 times the risk of disease-related death, arising as an independent predictor of poor prognosis in the multivariable analysis. In conclusion, TGFß and Treg cells seem involved in tumor progression emerging as potential therapeutic targets for future immunotherapy studies.

The potential therapeutic role of IL-35 in pathophysiological processes in type 1 diabetes mellitus.

A chronic autoimmune condition known as type 1 diabetes mellitus (T1DM) has characteristics marked by a gradual immune-mediated deterioration of the ß-cells that produce insulin and causes overt hyperglycemia. it affects more than 1.2 million kids and teenagers (0-19 years old). In both, the initiation and elimination phases of T1DM, cytokine-mediated immunity is crucial in controlling inflammation. T regulatory (Treg) cells, a crucial anti-inflammatory CD4+ T cell subset, secretes interleukin-35 (IL-35). The IL-35 has immunomodulatory properties by inhibiting pro-inflammatory cells and cytokines, increasing the secretion of interleukin-10 (IL-10) as well as transforming Growth Factor- ß (TGF-ß), along with stimulating the Treg and B regulatory (Breg) cells. IL-35, it is a possible target for cutting-edge therapies for cancers, inflammatory, infectious, and autoimmune diseases, including TIDM. Unanswered questions surround IL-35's function in T1DM. Increasing data suggests Treg cells play a crucial role in avoiding autoimmune T1DM. Throughout this review, we will explain the biological impacts of IL-35 and highlight the most recently progresses in the roles of IL-35 in treatment of T1DM; the knowledge gathered from these findings might lead to the development of new T1DM treatments. This review demonstrates the potential of IL-35 as an effective autoimmune diabetes inhibitor and points to its potential therapeutic value in T1DM clinical trials.

Distinct characteristics of unique immunoregulatory canine non-conventional TCRαßpos CD4negCD8αneg double-negative T cell subpopulations.

Conventional CD4pos regulatory T (Treg) cells characterized by expression of the key transcription factor forkhead box P3 (FoxP3) are crucial to control immune responses, thereby maintaining homeostasis and self-tolerance. Within the substantial population of non-conventional T cell receptor (TCR)αßpos CD4negCD8αneg double-negative (dn) T cells of dogs, a novel FoxP3pos Treg-like subset was described that, similar to conventional CD4pos Treg cells, is characterized by high expression of CD25. Noteworthy, human and murine TCRαßpos regulatory dn T cells lack FoxP3. Immunosuppressive capacity of canine dn T cells was hypothesized based on expression of inhibitory molecules (interleukin (IL)-10, cytotoxic T-lymphocyte associated protein 4, CTLA4). Here, to verify their regulatory function, the dnCD25pos (enriched for FoxP3pos Treg-like cells) and the dnCD25neg fraction, were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells (PBMC) of Beagle dogs and analyzed in an in vitro suppression assay in comparison to conventional CD4posCD25pos Treg cells (positive control) and CD4posCD25neg T cells (negative control). Canine dnCD25pos T cells suppressed the Concanavalin A-driven proliferation of responder PBMC to a similar extent as conventional CD4posCD25pos Treg cells. Albeit to a lesser extent than FoxP3-enriched dn and CD4posCD25pos populations, even dnCD25neg T cells reduced the proliferation of responder cells. This is remarkable, as dnCD25neg T cells have a FoxP3neg phenotype comparable to non-suppressive CD4posCD25neg T cells. Both, CD25pos and CD25neg dn T cells, can mediate suppression independent of cell-cell contact and do not require additional signals from CD4posCD25neg T cells to secrete inhibitory factors in contrast to CD4posCD25pos T cells. Neutralization of IL-10 completely abrogated the suppression by dnCD25pos and CD4posCD25pos Treg cells in a Transwell™ system, while it only partially reduced suppression by dnCD25neg T cells. Taken together, unique canine non-conventional dnCD25pos FoxP3pos Treg-like cells are potent suppressor cells in vitro. Moreover, inhibition of proliferation of responder T cells by the dnCD25neg fraction indicates suppressive function of a subset of dn T cells even in the absence of FoxP3. The identification of unique immunoregulatory non-conventional dn T cell subpopulations of the dog in vitro is of high relevance, given the immunotherapeutic potential of manipulating regulatory T cell responses in vivo.