Forkhead Box P3 Expression Research Articles

Clinical and Biological Significance of PD-L1 Expression Within the Tumor Microenvironment of Oral Squamous Cell Carcinoma.

Programmed death-ligand 1 (PD-L1) expression in tumor cells is regulated by a close interrelation between tumor and stromal cells within the tumor microenvironment. Our aim was to evaluate the clinical and biological significance of PD-L1 expression in oral squamous cell carcinoma (OSCC). PD-L1, cluster of differentiation (CD)4, CD8, and forkhead box P3 (FOXP3) expression in tumor tissues obtained from 77 patients with OSCC was evaluated by immunohistochemical staining, and then analyzed for associations with clinical and biological factors. Among the clinicopathological factors tested, only vascular invasion showed a trend toward lower PD-L1 expression (p=0.05). Metabolic tumor volume (MTV), and total lesion glycolysis (TLG) significantly positively correlated with PD-L1 expression (MTV, p=0.04; TLG, p=0.03). In patients with OSCC with high PD-L1 expression, those whose tumors had abundant infiltrating CD4+ T-cells showed a longer progression-free survival than those with low CD4+ T-cell infiltration (p=0.0452). As regulation of PD-L1 expression is complex, its evaluation combined with other markers may be useful to determine clinical applications of PD-L1 expression.

Assessment of intrahepatic regulatory T cells in children with autoimmune hepatitis

Background. T-cell populations regulate the balance of immune responses. The CD (Cluster of differentiation) 4+CD25+ regulatory T cells (Tregs) are crucial for maintaining negative control of various immune responses. There are different T-cell subpopulations with regulatory functions, as natural killer T cells, CD8+ and CD28. The forkhead box P3 (FOXP3) regulates Treg development and is required for its suppressive function.Aim. To evaluate the hepatic expression of the intrahepatic Tregs, Ig (immunoglobulin) G and IgM plasma cells in autoimmune hepatitis (AIH) and other chronic liver diseases (CLDs).Material and methods. This study included 100 pediatric patients; 50 AIH and 50 CLDs other than AIH. All patients were subjected to routine investigations of CLDs plus immune-staining of liver tissue for FOXp3, IgG and IgM plasma cells, CD4 and CD8 T-cells.Results. The FOXP3+ T cells in patients with AIH (6.3 ± 5) were significantly higher than that in the non-AIH (2.1 ± 2.6). FOXP3+ T cells were abundant in liver tissue with marked inflammatory cellular infiltrate. CD4+ and CD8+ infiltrating the liver tissue and IgG positive cells were significantly higher in AIH group, while the expression of IgM positive cells showed no significant difference. The IgG/IgM was significantly higher in the AIH treatment responders (3 ± 3) than non-responders (1.6 ± 0.5), while there was no significant difference regarding the intrahepatic expression of FOXP3+, CD4+, CD8+ cells, T-cells, IgG and IgM plasma cells.Conclusion. Intrahepatic Tregs were increased in number in patients with AIH in the initial presentation, and their presence is associated with increased activity and inflammation in liver biopsy.

Regulation of FOXP3 Expression by c-Rel O-GlcNAcylation

Abstract The NF-kappaB protein c-Rel plays a critical role in controlling autoimmunity through regulating T cell function and T regulatory cell development. Type 1 diabetes is a T cell-mediated autoimmune disease associated with hyperglycemia and chronic inflammatory complications. Previously, we discovered that hyperglycemia induces hyper O-GlcNAcylation of c-Rel at serine residue 350 and enhances the transcription of c-Rel-dependent pro-autoimmune cytokines interleukin-2 (IL-2), interferon gamma (IFNG) and granulocyte macrophage colony-stimulating factor (GM-CSF). In contrast, our recent results show that c-Rel O-GlcNAcylation decreases forkhead boxP3 (FOXP3) expression in T cells. Chemically enhancing cellular O-GlcNAcylation decreases the DNA binding ability of c-Rel at the FOXP3 promoter as demonstrated both by oligonucleotide pulldown and chromatin immunoprecipitation assays. Moreover, mutation of serine 350 in c-Rel to alanine augments T cell receptor-induced FOXP3 expression. O-GlcNAcylation-dependent suppression of FOXP3 was also found in vivo in streptozotocin-induced diabetic mouse model. This study reveals a novel molecular mechanism that regulates hyperglycemia-dependent c-Rel function in autoimmune diabetes, with potential to develop novel therapeutics targeting c-Rel O-GlcNAcylation.

FOXP3, CD48 and autophagy confer the protection of CD4 and CD8 human T cells from T cell receptor restimulation-induced cell death

Abstract The proliferation and contraction of activated effector T cells must be carefully coordinated to maintain immune homeostasis. This is achieved in part through restimulation-induced cell death (RICD), a pre-programmed apoptosis program triggered by antigen restimulation through the T cell receptor (TCR). Forkhead box P3 (FOXP3)+ regulatory T cells (Tregs) also constrain conventional T cell (Tcon) responses, but can resist RICD themselves despite frequent TCR stimulation. We previously showed that FOXP3 protects Tregs from RICD by suppressing SLAM-associated protein (SAP), a key adaptor protein that amplifies TCR signal strength. Mysteriously, FOXP3 expression is also transiently induced in human Tcons after activation, with a kinetic expression profile that correlates inversely with acquired RICD sensitivity. Hence we asked whether FOXP3 protects expanding human effector T cells from premature RICD by modulating SAP expression. Our results show that although siRNA-mediated FOXP3 knockdown sensitizes early effector CD4 and CD8 T cells to RICD, SAP expression remains unaffected. Unlike late stage effector T cells, a low level of RICD in expanding Tcons was entirely dependent on de novo transcription, and knockdown of SAP failed to reduce death. Subsequent RNA-Seq analyses revealed that CD48, a SLAM family receptor, was markedly reduced upon FOXP3 knockdown. Blockade or knockdown of CD48 also increased RICD in CD4 and CD8 T cells. We now show that CD48 protects early effector T cells both by promoting autophagy and upregulation of pro-survival genes such as BATF. These findings implicate FOXP3 as the central governor of a distinct transcriptional program that promotes RICD resistance early in the effector T cell response.

Epigallocatechin gallate ameliorates airway inflammation by regulating Treg/Th17 imbalance in an asthmatic mouse model

Epigallocatechin gallate (EGCG) is a polyphenol that is found in green tea that has been shown to ameliorate airway inflammation in an ovalbumin-sensitized asthmatic mouse model. The purpose of this study was to investigate whether the immunomodulatory and anti-inflammatory effects of EGCG by regulating the regulatory T cell (Treg)/Th 17 cells balance in this model. Female BALB/c mice were sensitized and challenged with ovalbumin by intraperitoneal injection. EGCG was administered to asthmatic mice intraperitoneally 1 h before each OVA challenge. Airway hyperresponsiveness (AHR) was measured, and lung inflammatory infiltrations were assessed by hematoxylin and eosin (HE) staining. Serum OVA-specific IgE levels, Interleukin-10 (IL-10) levels and Interleukin-17A (IL-17A) levels in the bronchoalveolar lavage fluid (BALF), serum, and splenocyte culture supernatants were measured by ELISA. Flow cytometry was used to assess the effects of EGCG on the frequency of CD4+CD25+Foxp3+Treg cells in the splenocytes and real-time PCR method was used to measure the expression of Forkhead box P3 (Foxp3) mRNA and retinoid-related orphan receptor gammat (RORγt) mRNA in the lung tissue. The results showed that administration of EGCG significantly decreased AHR and OVA specific IgE in the serum, increased IL-10 levels in the BALF, serum, and splenocyte culture supernatant, and the frequency of CD4+CD25+Foxp3+Treg cells in the splenocytes in asthmatic mice. Administration of EGCG also ameliorated airway inflammation and eosinophil infiltrations in asthmatic mice. These results suggested that EGCG likely ameliorated OVA-induced airway inflammation by increasing the production of IL-10, the number of CD4+CD25+Foxp3+Treg cells and expression of Foxp3 mRNA in the lung tissue, and it could be an effective agent for treating asthma.

P045 - Prognostic impact of expression of forkhead boxp3 (FOXP3) and cyclooxygenase-2 (COX2) in breast cancer: a single-institutional study

P045 - Prognostic impact of expression of forkhead boxp3 (FOXP3) and cyclooxygenase-2 (COX2) in breast cancer: a single-institutional study

A Phenotypic Screening Approach Using Human Treg Cells Identified Regulators of Forkhead Box p3 Expression.

Regulatory T (Treg) cells, expressing the transcription factor forkhead box p3 (FOXP3), are the key cells regulating peripheral autoreactive T lymphocytes by suppressing effector T cells. FOXP3+ Treg cells play essential roles controlling immune responses in autoimmune diseases and cancer. Several clinical approaches (e.g., polyclonal expansion of Treg cells with anti-CD3 and anti-CD28 coated beads in the presence of drugs) are under evaluation. However, expression of FOXP3, recognized as the master regulator of Treg cells, in induced Treg cells have been shown to be instable, and molecular targets involved in regulating FOXP3 expression and Treg cell function have not been well-defined. Thus, new targets directly regulating FOXP3 expression and the expression of its downstream genes (e.g., cytotoxic T-lymphocyte-associated protein 4 (CTLA4)) have the potential to stabilize the Treg cell phenotype and function. This report describes the development of an automated medium-throughput 384-well plate flow cytometry phenotypic assay meauring the protein expression of FOXP3 and CTLA4 in human Treg cells. Screening a library of 4213 structurally diverse compounds allowed us to identify a variety of compounds regulating FOXP3 and CTLA4 expression. Further evaluation of these and related small molecules, followed by confirmation using siRNA-mediated gene knockdown, revealed three targets: euchromatic histone-lysine N-methyltransferase (EHMT2) and glycogen synthase kinase 3 alpha/beta (GSK3α/β) as potent positive regulators of FOXP3 expression, and bromodomain and extra-terminal domain (BET) inhibitors as negative regulators of FOXP3 and CTLA4 expression. These targets have potential implications for establishing novel therapies for autoimmune diseases and cancer.

Association of Ulcerative Colitis with FOXP3 Gene Polymorphisms and Its Colonic Expression in Chinese Patients.

Abnormalities of forkhead box P3 (FOXP3) are implicated in various autoimmune diseases. This study is aimed at investigating the association of ulcerative colitis (UC) with FOXP3 polymorphisms and its colonic expression in Chinese patients. Polymorphisms of rs3761548, rs2232365, rs2294021, and rs3761547 were examined in 472 UC patients and 525 healthy controls using the SNaPshot method. The colonic expression of FOXP3 mRNA and protein was assayed in inflammatory mucosa of 34 UC patients and normal mucosa of 36 patients with benign sigmoid polyps (normal controls) using real-time quantitative polymerase chain reaction and immunohistochemical analysis. All data were handled separately for females and males. As a result, the carrier frequencies with at least one variant allele of rs3761548, rs2232365, and rs229402 increased in female and male UC patients compared with healthy controls. Significant differences in these carrier frequencies were also observed between patients with mild and moderate UC and patients with severe UC. The expression of FOXP3 was higher in UC patients (both males and females), especially those with severe UC, than in normal controls. The expression of FOXP3 was downregulated in UC patients having at least one variant allele compared with UC patients having no variant allele of rs3761548, rs2232365, and rs2294021. Male gender (β = −0.341), rs2294021 variation (β = −0.503), and severe UC (β = 0.361) were independently related to the mRNA expression of FOXP3 in UC patients. Together, our findings indicated that FOXP3 (rs3761548, rs2232365, and rs2294021) variations increased the risk of UC and were associated with the lower colonic expression of FOXP3 in UC patients.

Association between FOXP3+ regulatory T-cells and occurrence of peritoneal lesions in women with ovarian endometrioma and dermoid cysts.

Is there any relationship between numbers of FOXP3+ regulatory T-cells (Treg) and occurrence of peritoneal lesions in women with ovarian endometrioma and dermoid cysts? Retrospective and prospective case-controlled cohort study. Peritoneal lesions were collected from 27 women with ovarian endometrioma and 25 women with dermoid cysts. Peritoneal fluid was collected from 36 women with ovarian endometrioma and 42 women with dermoid cysts. Tissue expression of Forkhead box P3 (FOXP3), one of the transcription factors of Treg cells, and transforming growth factor-beta (TGF-β) were examined by immunohistochemistry. Interleukin-6 (IL-6) and TGF-β levels in the peritoneal fluid were measured by enzyme-linked immunosorbent assay. Ovarian endometrioma cases with coexisting peritoneal lesions were significantly more frequent than dermoid cyst cases with coexistent peritoneal lesions (269/350 [76.9%] versus 74/414 [17.9%]; P<0.001). Numbers of FOXP3+ Treg cells were significantly higher in peritoneal lesions of women coexistent with ovarian endometrioma (F = 21.52, P<0.001) and dermoid cysts (F = 22.01, P<0.001) compared with women without peritoneal lesions. Higher FOXP3+ Treg cell numbers in pathological lesions corresponded with significantly higher TGF-β (P<0.001) and lower IL-6 (P = 0.020) levels in peritoneal fluid of women with peritoneal lesions compared with women without lesions. This study confirms current speculation that endometriosis is related to alteration in Treg cells, causing survival and implantation of ectopic endometrial lesions in women with endometrioma and dermoid cysts. The findings may clarify why only 10% of women in the general population develop endometriosis despite cyclic menstruation with retrograde flow occurring in >90% of women.

Epigenetical Targeting of the FOXP3 Gene by S-Adenosylmethionine Diminishes the Suppressive Capacity of Regulatory T Cells Ex Vivo and Alters the Expression Profiles.

Regulatory T cells (Treg cells), a subgroup of CD4 lymphocytes, play a crucial role in serving as an immune suppressor and in maintaining peripheral tolerance. As the accumulation of Treg cells in the tumor microenvironment is significantly associated with a decreased survival time of patients, they are considered as an important therapeutic target in the immunotherapy of human cancers. These cells are either derived from the thymus, which are called (CD4CD25CD127) natural Treg cells (nTreg cells), or they are generated from CD4CD25 naive T cells by transforming growth factor-beta 1 and interleukin 2 (IL-2) in the periphery, which are called induced Treg cells (iTreg cells). Although iTreg cells are unstable, nTreg cells stably express forkhead box P3 (FOXP3) protein. Moreover, nTreg cells can be classified as memory (CD45RA) and naive (CD45RA) Treg cells, and this classification is based on the expression of CD45RA. FOXP3, which is a master regulator transcription factor, is essential for the functions of Treg cells, and it is mainly controlled by epigenetic mechanisms. The cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) pathway is also reported to contribute to the regulatory functions of tumor-infiltrating Treg cells. As a new approach, we investigated whether S-adenosylmethionine (SAM), a substrate of DNA methyltransferase, attenuates the immune-suppressive capacity of the naive subtype of nTreg cells (CD4CD25CD127CD45RA). Moreover, we examined the effects of PGE2/COX2 pathway blockers on the suppressive capacity of Treg cells. We found that SAM diminished the suppression competency of Treg cells by decreasing the FOXP3 mRNA and protein levels in a dose-dependent manner. SAM increased the DNA methylation of FOXP3 at the first intron site. In addition, SAM decreased the mRNA and protein levels of the IL-10 cytokine, which has suppressive roles in the immune system. Moreover, mRNA levels of interferon gamma (IFNG) were found to be increased. COX2 inhibition and blockage of PGE2 receptors also reduced the protein and mRNA levels of IL-10, but they did not exhibit any significant effect on Treg cells' suppression in the coculture system. Our results show that SAM might be considered and investigated as a promising agent for immunotherapy in the future.

MiR-23a-3p-regulated abnormal acetylation of FOXP3 induces regulatory T cell function defect in Graves' disease.

This study aims to investigate the mechanism of miR-23a-3p in regulating Treg dysfunction in Graves' disease (GD). The percentage of Treg cells and interleukin (IL)-17+ T cells were determined by flow cytometry. The expression of forkhead box P3 (FOXP3), sirtuin 1 (SIRT1), RAR-related orphan receptor gamma t (RORγt) and miR-23a-3p was analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or Western blot. CD4+ T cells were treated with SIRT1 specific inhibitor EX-527 or left untreated. MiR-23a-3p mimic or inhibitor were transfected into CD4+ T cells. Acetylation expression of FOXP3 was analyzed by immunoprecipitation. The suppressive function of Treg was analyzed by the carboxyfluorescein succinimidyl ester (CFSE) assay. The results showed that GD patients have significantly less Treg cells and more IL-17+ T cells. FOXP3 and miR-23a-3p were significantly down-regulated meanwhile SIRT1 and RORγt were up-regulated in GD patients. FOXP3 acetylation level of the GD group was lower than that of control groups. After EX-527 treatment, the percentage of Treg cells, expression and acetylation level of FOXP3 were significantly increased in the GD group. GD Tregs exhibited weaker suppressive activity, miR-23a-3p mimic suppressed SIRT1 expression and suppressive-activity of Tregs whereas it promoted the expression and acetylation level of FOXP3 in the GD group. Our findings suggest that the Treg function defect in GD patients is mediated by the abnormal acetylation of FOXP3, which is regulated by miR-23a-3p via targeting SIRT1.

Immunoglobulin G Enhances Generation of Inducible T Regulatory Cells and Increases Their Regulatory Function.

Intravenous immunoglobulin (IVIg) has been shown to be effective in the treatment of a variety of autoimmune diseases. To clarify the role of T regulatory cells (Tregs) in the immunoregulatory effect of IVIg, we focused on human inducible T regulatory cells (iTregs) and investigated the mechanism of action of IVIg. When immunoglobulin G (IgG) was added to a culture system that differentiates iTregs from anti-CD3 antibody activated CD4+CD25- T cells in the presence of syngeneic immature dendritic cells, interleukin (IL)-2 and transforming growth factor-β (TGF-β), the expression of forkhead box P3 (FoxP3), which is the master transcription factor for Tregs in CD4+CD25+ T cells, increased in an IgG concentration-dependent manner. The expression of FoxP3 in iTregs in the 20 mg/mL IgG group was twice as high as that in the saline group. iTregs that highly expressed FoxP3 not only partially suppressed the polyclonal proliferative response of T cells derived from the same individual but also produced significantly more inhibitory cytokines IL-10 and TGF-β. The ability of IgG to enhance iTregs differentiation was also observed in the Fc fragment, but not in the F(ab')2 fragment. These results suggest the clinical regulation of immune responses by IVIg administration may contribute at least to enhancing the differentiation of iTregs and partial immunosuppressive functions.

Human CD8+HLA-DR+ Regulatory T Cells, Similarly to Classical CD4+Foxp3+ Cells, Suppress Immune Responses via PD-1/PD-L1 Axis.

We have previously identified a human CD8+HLA-DR+ regulatory T cell subset with the ability to suppress proliferation of autologous PBMCs responder cells through cell contact and CTLA-4 co-inhibitory molecule. The present study characterizes the complete phenotype of CD8+HLA-DR+ Treg cells which showed great similarities with classical CD4+ cells expressing forkhead box P3 (FOXP3). The shared features included the expression of programmed cell death protein 1 (PD-1), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), C-C chemokine receptor type 4 and 5 (CCR4 and CCR5), low expression of CD127, and a memory and effector-like phenotype. CD8+HLA-DR+ Treg-induced suppression on CD8+ responder T cells was abrogated by an anti-PD1 neutralizing antibody. Anti-PD-1 did not abrogate the suppressor effect induced on responder CD4+ T cells. In addition, CD8+HLA-DR+ Treg induced a preferential death on responder CD8+ T cells. This effect was not reversed by PD-1 neutralization. After activation, most CD8+HLA-DR+ Treg acquire programmed death-ligand 1 (PD-L1) expression. Interestingly, PD-L1 may induce apoptosis through CD80 expressed on activated CD8+ responder T cells. After PBMCs stimulation, CD8+HLA-DR+ Treg cells showed an increased frequency of IFN-γ and TNFα positive cells and higher degranulation. These data strongly argue against CD8+HLA-DR+ Treg being exhausted cells. Overall, the data presented in this study indicate that CD8+HLA-DR+ Treg and CD4+FOXP3+ Treg share phenotypic and functional features, which may provide cues to similar involvements in the control of antitumor immune responses and autoimmunity.

PVAX1-A20 alleviates colitis in mice by promoting regulatory T cells

AimTo investigate whether the intrarectal administration of the ubiquitin E3 ligase A20 (A20) attenuates intestinal inflammation and influences regulatory T cells in experimental colitis. MethodsA dextran sulfate sodium induced chronic colitis mouse model was established. The symptoms and manifestations of colitis and the severity of colonic mucosal inflammation were evaluated. The protective role of A20 expression in the intestine was analyzed after the administration of a pVAX1-A20 recombinant eukaryotic vector, which was encapsulated into poly(L-lactide-co-glycolide) as a nanoparticle. ResultspVAX1-A20 administration markedly ameliorated colonic tissue damage and reduced intestinal inflammation via the suppression of the mucosal mitogen-activated protein kinase and nuclear factor (NF)-κB signaling cascade. Furthermore, pVAX1-A20 promoted the splenic regulatory T cell population and forkhead box P3 expression in colonic tissue. ConclusionA20 plays a key role in the regulation of intestinal inflammation and that the overexpression of A20 in the intestine protects mice from dextran sulfate sodium induced chronic colitis.

Altered expression of CD39 on memory regulatory T cells in type 1 diabetes patients.

Type 1 diabetes (T1D) is an autoimmune disease resulting from an attack by autoreactive T lymphocytes against pancreatic islet β- cells. In recent studies, regulatory T cells (Tregs) have been implicated in the process of T1D. Furthermore, cluster of differentiation 39 (CD39), which is involved in the suppression of inflammation, has been shown to be expressed on Tregs. However, the pathological importance of CD39 to the memory Treg population remains unclear. This study investigated Treg subsets, focusing on resting, effector, and memory Tregs, and determined CD39 expression on Tregs. In addition, changes in Treg subsets and Treg-associated cytokine secretion after CD3/CD28 stimulation of peripheral blood mononuclear cells were evaluated in diabetic patients and healthy controls. The suppressive function of Tregs was measured using the mixed lymphocyte reaction (MLR) test. There was a higher percentage of memory Tregs in T1D patients than healthy controls. However, Tregs in T1D patients showed impaired suppression, with low forkhead box P3 (Foxp3) expression and low serum interleukin (IL)-10 levels. Furthermore, CD39 expression on Tregs, and on memory Tregs in particular, was lower in T1D patients than healthy controls. After stimulation, the percentage of resting Tregs was decreased and that of effector/memory Tregs was increased in both healthy controls and T1D patients, but CD39 expression on effector/memory Tregs was still lower and there was no increase in IL-10 secretion in T1D patients. The defective suppressive function of Tregs in T1D patients is due to lower expression of CD39 on memory Tregs.

Regulatory T cells and Toll-like receptor 2 and 4 mRNA expression in infants with colic treated with Lactobacillus reuteri DSM17938.

Regulatory T cells induce immune homeostasis and the expression of Toll like receptors (TLRs); subsequent inflammatory cytokine release may be involved. Recent studies have shown a microbial imbalance in the gut of colicky infants (with a prevalence of gram-negative bacteria, such as Escherichia coli), and accumulating evidence has shown the efficacy of a probiotic (Lactobacillus reuteri) in breastfed subjects, but the underlying mechanism remains undefined. The study enrolled 59 infants younger than 60 days, of whom 34 subjects had colic and 25 were healthy controls. With a double-blind, placebo-controlled randomised study performed in our unit from October 2016 to July 2017, infants with colic were randomly assigned to receive oral daily L. reuteri DSM17938 (1×108 cfu) or placebo for 28 days. Peripheral blood was collected to assess the expression of FoxP3, TLR2 and TLR4 mRNA using real-time TaqMan RT-PCR at baseline and after the study period. Our findings showed increased mRNA expression of the transcription factor forkhead box P3 (FoxP3) in infants treated with L. reuteri DSM 17938 for 28 days (P<0.009) and increased TLR2 and TLR4 mRNA expression in both treated and placebo subjects. After L. reuteri administration for 28 days in infants with colic, we observed a significant decrease in daily crying time (302.3±19.86 min/day on day 0 vs 76.75±22.15 min/day on day 28, P=0.001). This study provides evidence that the observed increase in FoxP3 expression and reduction in crying time might be responses to probiotic treatment, while the increase in TLR2 and TLR4 mRNA expression might be related to age. Exploiting these new findings may lead to an unprecedented level of therapeutic control over immune tolerance using probiotics.

Crosstalk between PPARγ Ligands and Inflammatory-Related Pathways in Natural T-Regulatory Cells from Type 1 Diabetes Mouse Model.

Immunomodulation, as a means of immunotherapy, has been studied in major research and clinical laboratories for many years. T-Regulatory (Treg) cell therapy is one of the modulators used in immunotherapy approaches. Similarly, nuclear receptor peroxisome proliferator activated receptor gamma (PPARγ) has extensively been shown to play a role as an immuno-modulator during inflammation. Given their mutual roles in downregulating the immune response, current study examined the influence of PPARγ ligands i.e., thiazolidinedione (TZD) class of drugs on Forkhead Box P3 (Foxp3) expression and possible crosstalk between PPARγ and nTreg cells of Non-Obese Diabetes (NOD) and Non-Obese Diabetes Resistant (NOR) mice. Results showed that TZD drug, ciglitazone and natural ligand of PPARγ 15d-prostaglandin downregulated Foxp3 expression in activated nTreg cells from both NOD and NOR mice. Interestingly, addition of the PPARγ inhibitor, GW9662 further downregulated Foxp3 expression in these cells from both mice. We also found that PPARγ ligands negatively regulate Foxp3 expression in activated nTreg cells via PPARγ-independent mechanism(s). These results demonstrate that both natural and synthetic PPARγ ligands capable of suppressing Foxp3 expression in activated nTreg cells of NOD and NOR mice. This may suggest that the effect of PPARγ ligands in modulating Foxp3 expression in activated nTreg cells is different from their reported effects on effector T cells. Given the capability to suppress Foxp3 gene, it is possible to be tested as immunomodulators in cancer-related studies. The co-lateral use of PPARγ ligands in nTreg cells in inducing tolerance towards pseudo-self antigens as in tumor microenvironment may uphold beneficial outcomes.

High dosage of zinc modulates T-cells in a time-dependent manner within porcine gut-associated lymphatic tissue.

Zn serves as a powerful feed additive to reduce post-weaning diarrhoea in pigs. However, the mechanisms responsible for Zn-associated effects on the adaptive immune responses following feeding of a very high dosage of Zn remain elusive. In this study, we examined the T-cell response in gut-associated lymphatic tissues of seventy-two weaned piglets. Piglets received diets with 57 mg Zn/kg (low Zn concentration, LZn), 164 mg Zn/kg (medium Zn concentration, MZn) or 2425 mg Zn/kg (high Zn concentration, HZn) mg Zn/kg feed for 1, 2 or 4 weeks. We observed that feeding the HZn diet for 1 week increased the level of activated T-helper cells (CD4+ and CD8α dim) compared with feeding MZn and LZn (P<0·05). In addition, we observed higher transcript amounts of interferon γ and T-box 21 (TBET) in the HZn group compared with the MZn and LZn groups (P<0·05). A gene set enrichment analysis revealed an over-representation of genes associated with 'cytokine signalling in immune system'. Remarkably, feeding of a very high Zn dosage led to a switch in the immune response after 2 weeks. We detected higher relative cell counts of CD4+CD25high regulatory T-helper cells (P<0·05) and a higher expression of forkhead box P3 (FOXP3) transcripts (P<0·05). After 4 weeks of feeding a high-dosage Zn diet, the relative CD4+ T-cell count (P<0·05) and the relative CD8β + T-cell count (P<0·1) were reduced compared with the MZn group. We hypothesise that after 1 week the cellular T-helper 1 response is switched on and after 2 weeks it is switched off, leading to decreased numbers of T-cells.

GENETIC TESTING IDENTIFIES CAUSE OF ENTEROPATHY AND GROWTH FAILURE IN A 10 YEAR OLD MALE

Introduction Enteropathies with features of celiac disease or inflammatory bowel disease (IBD) should spark consideration of an immunodeficiency when presenting at an early age. Case Description We present a 10-year old male with chronic diarrhea starting at 6 weeks of life, initially improved with TPN, steroids, and cow's milk free diet. By 2 years of age, diarrhea returned, and he required frequent courses of steroids to manage his symptoms. The patient had mild dermatitis and poor growth, with otherwise negative review of systems. Endoscopies found duodenitis with severe villous blunting and pancolitis. Laboratory evaluations were notable for negative anti-enterocyte antibodies, elevated antigliadin and tissue transglutaminase IgA levels, and normal T regulatory (Treg) cells and forkhead box P3 (FOXP3) expression. He was diagnosed with Celiac Disease and years later, Crohn's Disease. His clinical course did not improve with gluten avoidance or various immunomodulators. Eventually, sequencing of the FOXP3 gene was performed, revealing a missense mutation consistent with Immune dysregulation Polyendocrinopathy Enteropathy X-linked (IPEX) syndrome. Discussion IPEX is a rare syndrome caused by a mutation in the FOXP3 transcription factor of CD4+ Treg cells. The classic IPEX syndrome includes protracted diarrhea, dermatitis, and endocrinopathies, but phenotypes vary. Endoscopic findings of the IPEX enteropathy can mimic those seen in Celiac Disease and IBD, thus a high index of suspicion should be maintained in select patients with early onset of symptoms. Finally, this case highlights the importance of genetic analysis of the FOXP3 gene itself, as IPEX patients can have normal FOXP3 protein expression and Treg numbers.

Blockade of Hypoxia: The Impact on Tumor Growth in an Experimental Tumor Model

Background: Tumor microenvironment is an active factor participating in immunoregulation, thereby preventing immunosurveillance and limiting the efficacy of anticancer therapies. Hypoxia as a major characteristic of solid tumors causes the expression of Hypoxia-Inducible Factor-1α (HIF-1α). This is a transcription factor that mediates hypoxic responses of tumor cells and involves in the expression of tumor immunosuppression-related genes. Materials and Methods: In this study, we used a mouse 4T1 breast cancer model.Results: Our obtained data revealed that in vivo administration of PX-478, an inhibitor of oxygen sensitive HIF-1α, reduced the expression of Forkhead box P3 (Foxp3) transcript, a molecule that is directly controlled by HIF-1. The level of vascular endothelial growth factor, another gene controlled by HIF-1, remained unchanged. The observed results were in correlation with delayed tumor growth in tumor-bearing mice.Conclusion: Our findings indicate that the reduction in Foxp3 expression through HIF-1α inhibition using PX-478 may contribute to tumor regression.