Helix Transcription Factor P3 Research Articles

Clinical significance of the expression of FOXP3 and TIGIT in Merkel cell carcinoma

The pathogenesis of 80% of Merkel cell carcinoma (MCC) cases is associated with Merkel cell polyomavirus (MCPyV). Forkhead helix transcription factor P3 (FOXP3) and the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT)–CD155 pathway, which are targets for immunotherapy, were assessed as prognostic factors of MCC. We analyzed mRNA expression data of 111 patients with MCC and performed immunohistochemical analysis to detect the expression of programmed death ligand 1 (PD-L1), CD8, FOXP3, TIGIT, and CD155 in 65 cases of MCC. In CD8 and FOXP3 immunostaining, the number of expressing-infiltrating cells was determined by dividing the region into tumor center and invasive front areas. FOXP3 expression was evaluated separately in cells with high and low intensities. Aberrant TIGIT expression and weak CD155 staining were observed in MCC cells. CD8- and FOXP3-positive cell infiltrations were higher in the invasive front than in the tumor center. Multivariate Cox hazard analysis revealed that high infiltration of cells with low-intensity FOXP3 expression in the invasive front is a favorable prognostic factor (p = 0.025). Thus, targeting TIGIT–CD155 signaling and FOXP3 as well as PD-L1 may be a therapeutic strategy for MCC.

P53 promotes the expansion of regulatory T cells via DNMT3a- and TET2- mediated Foxp3 expression in sepsis.

Immunosuppression is an important characteristic of sepsis and is closely related to poor outcomes. Regulatory T cells (Tregs) contribute to immune suppression by inhibiting effector T cell (Teff) proliferation and differentiation. We aimed to investigate the role of p53 in Treg expansion after sepsis. We constructed a sepsis model in wild-type (WT) and p53f/f/CD4-Cre+ mice by cecal ligation and puncture (CLP) and evaluated the proportions of CD4+CD25+ Foxp3+ Tregs by flow cytometry. The expression levels of forkhead/winged helix transcription factor p3 (Foxp3), DNA methyltransferase enzyme (DMNT)3a and ten-eleven translocation (TET)2 were examined using quantitative real-time PCR and Western blot analysis. Treg-specific demethylation region (TSDR) methylation sites in cells were analyzed by bisulfite-sequencing PCR. Furthermore, the direct binding of p53 to the Dnmt3a and TET2 promoters was illustrated using a luciferase assay. The suppressive ability of Tregs was indicated by enzyme-linked immunosorbent assay analysis of cytokine levels and the proliferation of cocultured Teffs. Finally, mortality rates after CLP were compared among WT and p53f/f/CD4-Cre+ mice. The proportion of CD4+CD25+ Foxp3+ Tregs was significantly reduced in p53f/f/CD4-Cre+ mice compared to WT mice after CLP. The enhanced expression of Foxp3 in WT mice was downregulated in the p53f/f/CD4-Cre+ group. We found decreased DMNT3a and increased TET2 levels after CLP. However, the dysregulation of DNMT3a and TET2 was significantly reversed in p53f/f/CD4-Cre+ mice. TSDR underwent increased demethylation in p53f/f/CD4-Cre+ mice. Luciferase activity indicated direct binding of p53 to the promoter regions of DNMT3a and TET2 to regulate their transcription. Consequently, Tregs from p53f/f/CD4-Cre+ CLP mice exhibited limited suppressive ability, as indicated by the reduced production of transforming growth factor-β and interleukin 10 (IL-10). In the coculture system, Teffs showed preserved production of IL-2, differentiation into Th1 cells and proliferation in the presence of Tregs isolated from p53f/f/CD4-Cre+ CLP mice. Finally, the mortality rate of the p53f/f/CD4-Cre+ group after CLP was significantly reduced in comparison to that of the WT group. p53 appears to be critical for Foxp3 expression and consequent Treg expansion by regulating the induction of DNMT3a and TET2, thereby resulting in Foxp3-TSDR demethylation in the context of sepsis.

The α7 nicotinic acetylcholine receptor agonist PNU-282987 ameliorates sepsis-induced acute kidney injury through CD4+CD25+ regulatory T cells in rats.

The ameliorative effects of α7 nicotinic acetylcholine receptor (α7nAChR) agonists have been demonstrated in acute kidney injury (AKI) caused by multiple stimulations. However, the ameliorative effect of α7nAChR on sepsis-induced acute kidney injury (SAKI) in the cecal ligation and puncture (CLP) model is unclear. Previous studies have demonstrated that α7nAChR is highly expressed on the surface of CD4+CD25+ regulatory T cells (Tregs). However, the role of Tregs in SAKI is unclear. We hypothesized that Tregs might play a role in the ameliorative effect of α7nAChR on SAKI. Hence, in this study, we determined the effects of PNU-282987 (a selective α7nAchR agonist) on SAKI and evaluated whether PNU-282987 would attenuate SAKI via regulating Tregs. Our study showed that immediate administration of PNU-282987 after CLP surgery in rats improved renal function, reduced levels of systemic inflammatory factors (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), etc.), inflammatory cell infiltration and tubular apoptosis in renal tissues, and increased forkhead/winged helix transcription factor p3 (Foxp3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expression indicating activated Tregs. Moreover, in in vitro experiments, isolated Tregs co-cultured with PNU-282987 also displayed enhanced expression of CTLA-4 and Foxp3. Furthermore, Tregs were co-cultured with PNU-282987 for 24 hours and then reinfused into rats through the tail vein immediately after CLP surgery, and a significant renal protective effect was observed 24 hours postoperatively. These results demonstrate that PNU-282987 exerts its renal protective effects on SAKI through activation of Tregs.

Protective Effect of the α7 Nicotinic Receptor Agonist PNU-282987 on Dopaminergic Neurons Against 6-Hydroxydopamine, Regulating Anti-neuroinflammatory and the Immune Balance Pathways in Rat.

Neuroinflammation and inner immune dysfunction are increasingly accepted as important components of the etiopathogenesis of Parkinson’s disease (PD). According to emerging evidence, a7 nicotinic acetylcholine receptor (α7nAChR), a ligand-gated ion channel, plays an important role in inflammatory reactions and is also expressed on the surface of T cells. In particular, regulatory T cells (Tregs) are critical for the maintenance of immunological tolerance. In the present study, we investigated the roles of α7nAChR in inhibiting inflammation and maintaining the immune balance in rats with 6-hydroxydopamine (6-OHDA)-induced lesions and the possible mechanisms regulating the proportion of Tregs in vivo. Adult male Wistar rats (n = 90) were subjected to a unilateral injection of 6-OHDA into the left medial forebrain bundle, and PNU-282987, an α7nAChR agonist, was intraperitoneally injected 2 h prior to the induction of lesions by 6-OHDA and again at days 1, 7, and 13 postlesion. Behavioral tests and immunohistochemical staining to detect the expression of tyrosine hydroxylase (TH) in the bilateral substantial nigra (SN) were performed. Subsequently, CD4+ T lymphocytes and the expression of forkhead/winged helix transcription factor p3 (Foxp3, which is a marker of Treg cells) in the SN were also assessed using immunofluorescence staining. The expression of glial fibrillary acidic protein (GFAP) in the SN was determined by performing immunohistochemical staining. Additionally, the protein levels of α7nAChR, extracellular signal-regulated kinase (Erk) phosphorylated-Erk (p-Erk) and Foxp3 in the ventral midbrain were determined using Western blotting, and the relative expression of the TNF-α, IL-1β, and IL-10 mRNAs were detected using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). We found that PNU-282987 significantly improved the motor deficits induced by 6-OHDA, reduced the loss of TH in the SN, suppressed the overactivation of GFAP+ cells and expression of related inflammatory cytokines, and increased the number of Foxp3+ cells. In addition, we also showed that PNU-282987 significantly increased the protein expression of the a7nAchR, p-Erk, and Foxp3 in 6-OHDA-lesioned rats (p < 0.05). These results indicated that α7nAChR activation could exert an anti-inflammatory effect and participate in the process of modulating the immune balance during 6-OHDA-induced injury, potentially through the α7nAChR/p-Erk/Foxp3 signaling pathway.

Lactobacillus rhamnosus 2016SWU.05.0601 regulates immune balance in ovalbumin-sensitized mice by modulating expression of the immune-related transcription factors and gut microbiota.

Probiotics regulate host immune balance, which may reduce immune-related diseases. The effects and mechanisms of Lactobacillus rhamnosus 2016SWU.05.0601 (Lr-0601) on the immune response in ovalbumin (OVA)-sensitized mice were explored. Lr-0601 reduced serum immunoglobulin (Ig)E and OVA-IgE and attenuated the alteration in lung pathology in OVA-sensitized mice. Lr-0601 blocked OVA-induced up-regulation in serum T helper (Th) 2 and Th17 cytokines but increased the serum levels of Th1 and regulatory T (Treg) cytokines in OVA-sensitized mice. OVA also markedly reduced the protein levels of spleen T-box transcription factor and forkhead/winged helix transcription factor p3, leading to the reduced mRNA expression of interferon-γ and interleukin (IL)-10. By contrast, OVA markedly increased the protein expression of spleen GATA-binding protein 3 and retinoid-related orphan receptor γt, as well as the mRNA expression of spleen IL-4 and IL-17. These changes induced by OVA were reversed by Lr-0601. Moreover, Lr-0601 helped alleviate OVA-induced intestinal microbiota dysbiosis. A correlation was found between specific genera and immune-associated cytokines. The combined results indicate that Lr-0601 modulated the balance of Th1/Th2 and Treg/Th17 in OVA-sensitized mice, which was associated with the regulation of immune-related transcription factors and gut microbiota. Lr-0601 can potentially be used as a probiotic for preventing immune-related diseases. © 2020 Society of Chemical Industry.

Effect of Modified Xijiao Dihuang Decoction () on Intestinal Flora and Th17/Treg in Rats with Radiation Enteritis.

To observe the effect of Modified Xijiao Dihuang Decoction (, MXDD) on rats with radiation enteritis, and explore its action mechanism. Thirty female Sprague Dawley rats were divided into the control, model, dexamethasone (DXM), golden bifid (GB) and MXDD groups using random number table, 6 rats in each group. Except the control group, the other rats were developed into radiation enteritis model by exposing to a single 60Co-γ ray at a dose of 11 Gy. The rats in the DXM, GB and MXDD groups were treated with DXM (1.425 mg/kg), GB (0.8 g/kg) and MXDD (36.0 g/kg) for 3 days, respectively. Body weight and diarrhea condition of rats were evaluated daily. On day 3, the feces of rats were collected for intestinal flora detection and the small intestinal tissues were also collected. Bacterial species annotation, alpha and beta diversities as well as composition of intestinal flora were detected and compared. The protein and mRNA expressions of interleukin 17 (IL-17), retinoid-related orphan nuclear receptor gamma t (ROR-γt) and forkhead/ winged helix transcription factor p3 (FoxP3) were determined by Western blot and polymerase chain reaction, respectively. The abundance and diversity of intestinal flora as well as the proportion at the phylum and genus levels were assayed by 16S rRNA metagenome sequencing. Correlation between intestinal flora and Th17/Treg was analyzed by heatmap method. On day 1 to 3 after radiation, compared with the control group, the body weight in model group was decreased (P<0.05 or P<0.01). Compared with the model group, MXDD could alleviate weight loss and diarrhea caused by irradiation. At the phylum level, MXDD cause a significant increase in Firmicutes, and a decrease in Proteobacteria (P<0.05 or P<0.01). At the genus level, MXDD reduced the proportion of Escherichia Shigella (P<0.01). In addition, IL-17 and FoxP3 mRNA and protein expression levels were down-regulated and ROR-γt was up-regulated by MXDD treatment (P<0.05). Besides, Firmicutes and Lactobacillus were positively correlated with FoxP3 (r=0.73, 0.79, respectively; P<0.01), negatively correlated with IL-17 (r=0.66, 0.64, respectively; P<0.01 or P<0.05) and ROR-γt (r0.73, 0.81, respectively; P<0.01). Proteobacteria and Escherichia Shigella both had positive correlation with IL-17 (r 0.77, 0.57, respectively; P<0.01 or P<0.05 ) and ROR-γt (r=0.94, 0.79, respectively; P<0.01) and negative correlation with FoxP3 (r0.74, 0.65; P<0.01). MXDD could improve the survival status of irradiated rats by regulating the richness, diversity and composition of intestinal flora, and restoring the balance of Th17/Treg.

Effects and mechanism of interleukin-17-modified mouse bone marrow mesenchymal stem cells on rejection reaction of allogeneic skin transplantation in mice

Effects and mechanism of interleukin-17-modified mouse bone marrow mesenchymal stem cells on rejection reaction of allogeneic skin transplantation in mice

Synergistic association of FOXP3+ tumor infiltrating lymphocytes with CCL20 expressions with poor prognosis of primary breast cancer: A retrospective cohort study.

Studies have shown that forkhead/winged helix transcription factor P3 (FOXP3)+ tumor infiltrating lymphocytes (TILs) are intimately associated with invasion and survival of many invasive tumors. The inflammatory chemokine ligand 20 (CCL20) and its receptor CCR6 were found to be associated with tumor prognosis in some studies. Although increases in FOXP3+ TILs infiltration and CCL20 expression have been revealed in several malignancies, their correlation in human breast tumors is as yet unclear.Surgically resected samples from 156 patients with invasive breast cancer (BC) were assessed for the expression of FOXP3 and CCL20 by immunohistochemistry. Correlation between their expressions and the association with clinicopathological characteristics and patient's prognosis were studied. Forty pairs of fresh BC and their nontumor adjacent tissues (NATs) in BC were carried out by real-time quantitative PCR (qRT-PCR) to evaluate the correlation between FOXP3 and CCL20 mRNA expression.CCL20 and FOXP3+ TILs mRNA expression in tumor tissue demonstrated a high correlation (rs = 0.359, P < .001) in this cohort of breast cancer patients. Both elevated CCL20 expression and FOXP3+ TILs infiltration were significantly correlated with high histological grade, positive human epidermal growth factor receptor-2 (HER2), high Ki67 index, and axillary lymph node metastases. Tumors with concomitant high expressions of both markers had the worst prognosis. Multivariate analysis showed that these 2 markers were independent predictors of overall survival. The patients with axillary lymph node metastases with the concomitant CCL20 high expression and increased FOXP3+ TILs infiltration had the worst overall survival (OS) (P < .001), In lymph node-negative breast cancer patients, the status of CCL20 and FOXP3 was not related to OS (P = .22).The results suggest that CCL20 and FOXP3+ TILs may have synergistic effects, and their upregulated expressions may lead to immune evasion in breast cancer. Combinatorial immunotherapeutic approaches aiming at blocking CCL20 and depleting FOXP3 might improve therapeutic efficacy in breast cancer patients.

The effect of exosome derived from gastric cancer cell line MKN-28, MKN-45, SGC-7901 on CD8+ T cell

Objective To detect exosome from gastric cancer cell line MKN-28, MKN-45, SGC-7901 on CD8+ T cell. Methods CD8+ T cell was isolated from health person peripheral blood by density gradient centrifugation and immunomagnetic bread, exosome of SGC-7901, MKN-45 and MKN-28 cell lines was obtained by ultracentrifugation. After coculture exosome and CD8+ T cell with different concentration for 48 h, CD8+ T cell was collected, and analyzed cell cycle by flow cytometry, cell apoptosis by Annexin V-propidium iodide (PI) stain, expression of cytokine by enzyme linked immunosorbent assay (ELISA), gene expression by real-time quantitative polymerase chain reaction (Real-time PCR). Results Exosome was isolated successfully from three gastric cancer cell lines and expressed molecular surface markers TSG101 and Alix. CD8+ T cells were isolated in peripheral blood mononuclear cell (PBMC) with a purity of over 98%. The effect of MKN-28 exosome on apoptosis was dose dependent. After stimulation with 100 mg/L MKN-45 exosome for 48 h, CD8+ T cells secreted IL-2, IL-6, IL-10, IFN-γ [(305.44±42.07) ng/L vs. (129.89±11.07) ng/L, P<0.01; (344.39±25.34) ng/L vs. (149.67±15.23) ng/L, P<0.01; (413.31±38.76) ng/L vs. (35.19±24.95) ng/L, P<0.01; (303.78±44.98) ng/L vs. (277.67±40.66) ng/L, P<0.05], and the difference was statistically significant. After SGC-7901 exosome stimulated, CD8+ T cells secreted IL-4, IL-6, IL-10, IFN-γ [(318.61±41.56) ng/L vs. (238.89±35.84) ng/L, P<0.05; (501.06±55.05) ng/L vs. (149.67 ±15.23) ng/L, P<0.01; (486.75±71.20) ng/L vs. (35.19±24.95) ng/L, P<0.01; (621.00±55.14) ng/L vs. (277.67±40.66) ng/L, P<0.01], the difference was statistically significant. After MKN-28 exosome stimulated, CD8+ T cells secreted IL-2, IL-6, IL-10, IFN-γ [ (411.56±48.62) ng/L vs. (129.89±11.07) ng/L, P<0.01; (403.83±52.29) ng/L vs. (149.67±15.23) ng/L, P<0.01; (678.31±78.02) ng/L vs. (35.19±24.95) ng/L, P<0.01; (751.88± 63.16) ng/L vs. (277.67±40.66) ng/L, P<0.01], and the difference was statistically significant. The expression of IL-10 secreted by CD8+ T cells stimulated by 100 mg/L MKN-28 exosome was about 19.53 times compared to the control group. After MKN-45 exosome stimulated, CD8+ T cells expressed forkhead/winged helix transcription factor P3 (Foxp3), interleukin (IL)-10, interferon (IFN)-γ, phosphatase and tensin homologue deleted on chromosome ten (PTEN), signal transducer and activators of transcription 3 (STAT3) (3.46±0.39 vs. 1.00±0.09, P<0.01; 3.29±0.39 vs. 1.01±0.16, P<0.01; 2.24±0.30 vs. 1.00±0.06, P<0.01; 2.14±0.12 vs. 1.00±0.08, P<0.01; 1.24±0.12 vs. 1.00±0.07, P<0.05). After SGC-7901 exosome stimulated, CD8+ T cell expressed Eomes, Foxp3, IL-10, IFN-γ, 2B4, CD160, GATA3, STAT3, PTEN (2.35±0.17 vs. 1.01±0.13, P<0.01; 3.19±0.21 vs. 1.00±0.09, P<0.01; 2.38±0.31 vs. 1.01±0.16, P<0.01; 5.44±0.71 vs. 1.00±0.06, P<0.01; 3.20±0.31 vs. 1.00±0.12, P<0.01; 3.19±0.13 vs. 1.01±0.16, P<0.01; 1.35±0.17 vs. 1.00±0.07, P<0.05; 1.44±0.18 vs. 1.00±0.07, P<0.05; 1.31±0.15 vs. 1.00±0.08, P<0.05) mRNA; after MKN-28 exosome stimulated, CD8+ T cell expressed Eomes, Foxp3, IL-10, IFN-γ, STAT3, PTEN, CD160, 2B4 (3.36±0.18 vs. 1.01±0.13, P<0.01; 4.35±0.30 vs. 1.00±0.09, P<0.01; 5.40±0.63 vs. 1.10±0.16, P<0.01; 6.43±0.84 vs. 1.00±0.06, P<0.01; 1.54±0.28 vs. 1.00±0.07, P<0.05; 0.78±0.11 vs. 1.00±0.08, P<0.01; 1.68±0.42 vs. 1.01±0.16, P<0.05; 1.31±0.22 vs. 1.01±0.12, P<0.05) mRNA expression. The gene expression of CD8+ T cells stimulated by MKN-28 exosome was relatively more changes, such as Foxp3, IL-10 and IFN-γ. Conclusion Gastric cancer cell line exosome stimulated CD8+ T cells to induce cell apoptosis, and change gene expression and cytokine secretion, but the proportion of negative regulatory molecules was much higher. Cancer exosome interacted with CD8+ T cells, which inhibited its immune function, resulting in tumor immune escape, which may be an important factor to promote disease progression. Key words: Gastric cancer; Exosome; CD8+ T cell; Gene expression; Cytokine

Hepatocellular carcinoma cell-derived exosomes regulates Treg cells via cyclic adenosine monophosphate response element binding protein/forkhead/winged helix transcription factor P3 pathway

Objective To investigate whether hepatocellular carcinoma cell line HepG2 derived exosomes regulates Treg cells via cyclic adenosine monophosphate response element binding protein/forkhead/winged helix transcription factor P3 (CREB/Foxp3) pathway. Methods Ultracentrifugation was used to isolate exosomes of hepatocellular carcinoma cell line HepG2 and normal hepatocellular cell line L02. Transmission electron microscopy was used to determine the morphology of exosomes and Western blotting was used to detect the protein markers of exosomes and CREB/Foxp3 expression. HepG2-exo and L02-exo were co-cultured with peripheral blood mononuclear cells. The percent of Treg cells were determined by flow cytometry. Results Exosomes was about 30-100 nm with a circular or oval shape vesicular structure. CD81 and CD63 were highly expressed in exosomal proteins, while not expressed in cell proteins derived from HepG2 or L02 cells. Compared to L02-exo [(1.87±0.18)%] and blank control group [(1.43±0.12)%], HepG2-exo strongly increased the percent of Treg cells [(6.87±0.87)%], with P value of 0.005 and 0.004 respectively. Phosphorylation of CREB in HepG2-exo group was 1.74 and 1.63 fold higher than it in L02-exo and blank control group, and both of the P=0.001. Phosphorylation of Foxp3 in HepG2-exo group was 1.93 and 1.78 fold higher than it in L02-exo and blank control group, and both of the P=0.001. Conclusion These results provided evidence that hepatocellular carcinoma cell HepG2 derived exosomes could regulates Treg cells via CREB/Foxp3 pathway. Key words: Exsomes; Treg cell; Cyclic adenosine monophosphate response element binding protein; Forkhead/winged helix transcription factor P3; Hepatocellular carcinoma

The effects of miR-10a on the immune function of splenic CD4 + CD25 + Treg cells in septic mice

Objective To investigate the role of miR-10a in CD4+CD25+Treg-mediated immunosuppression during sepsis and its potential role in immunotherapy for sepsis. Methods Sepsis mouse model was established by cecal ligation and puncture(CLP). Balb/c mice of clean grade were sacrificed 1, 3, 5, and 7 days after operation. Blood as well as spleen samples were harvested at given intervals. The splenic CD4+CD25+Treg cells and CD4+T cells were isolated by MACS microbeads. Cells were cultured, and phenotypes were analyzed by flow cytometry. The miR-10a expressed in Treg cells were detected by Real-time PCR. After administration of LV-mmu-miR-10a-5p-inhibition, the immunosuppressive function have been detected. Statistical analyses were performed using one-way analysis of variance (SPSS19.0, Chicago, USA) test followed by Dunnett-t test to compare among three or more groups or by Student’s t-test to compare between two groups. Results The percentages of splenic Tregs (CD4+CD25+/CD4+T) was (7.34±1.2)% in normal group, and the increase in percentage of Tregs in spleen has been observed in septic mice (P<0.05). The mean fluorescence intensity (MFI) of Foxp3+Treg was increased in septic mice compared with sham group (P<0.05). The expression of miR-10a was significantly elevated on CLP 1-7 day (P<0.05). After down-regulation of miR-10a in septic mice, the percentages of Tregs (CD4+CD25+/CD4+T) was significantly increased in septic mice (P<0.05), the MFI of Foxp3+Treg was increased in septic mice compared with control group (P<0.05). The CD4+T cell proliferative activity in CLP-induced mice was significantly suppressed on CLP 3 day compared with sham group (P<0.05).After down-regulation of miR-10a in septic mice, the CD4+T cell proliferative activity was significantly suppressed compared with control group (P<0.05). Conclusions Treg plays a critical role in immunosuppression in septic mice. Inhibition of miR-10a in vivo could enhence immunesuppression of CD4+CD25+Treg. Therefore miR-10a may participate in the regulation of CD4+CD25+Treg immunosuppression in sepsis and become the target for immunotherapy . Key words: Regulatory T cells; Sepsis; MicroRNA-10a; Forkhead/winged helix transcription factor p3; Immune function; Effector T cell; Proliferative activity; Mean fluorescence intensity

Toll-like receptor 4 deficiency increases resistance in sepsis-induced immune dysfunction

Sepsis constitutes a serious life-threatening syndrome associated with complications of deregulated inflammatory response against endotoxin/lipopolysaccharide (LPS)-mediated severe infection. Toll-like receptor 4 (TLR4) plays a critical role in the activation of innate immunity through recognition of LPS. However, the impact of TLR4 signaling on the development of sepsis-induced immune dysfunction remains unclear. The aim of this study was to investigate the effect of TLR4 on regulatory T cells (Tregs) and its potential mechanism. To simulate sepsis, male C57BL/6 (wild-type) and C57BL/10ScNJNJU (TLR4−/−) mice were subjected to cecal ligation and puncture (CLP). After 24h, pro- and anti-inflammatory cytokine secretion, neutrophil and macrophage lung and liver infiltration were assessed to evaluate the sepsis-induced inflammatory response. The quantity and apoptotic rate of Tregs were measured. The expression of cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) and forkhead/winged helix transcription factor p3 (Foxp3) were analyzed. Cytokine (i.e., TNF-α, IL-2, IL-10, and IL-4) secretion by Tregs in the cell suspensions and the suppressive activity on CD4+CD25− T cell proliferation were also determined in vitro. At 24h after the CLP procedure, the wild-type mice exhibited increased Treg levels and expression, and secreted inflammatory factors in the serum were markedly overproduced. However, the TLR4−/− mice attenuated the increased Treg expression and inflammatory factor overproduction. These results indicate that in a model of post-septic mice, TLR4 deficiency improves immune paralysis by attenuating Treg activity and restoring a pro-inflammatory cytokine balance. Thus, modulation of the TLR4 activity may be useful in preventing immune dysfunction in sepsis.

The expression of Foxp3 and TLR4 in cervical cancer: association with immune escape and clinical pathology.

To explore the expression of forkhead/winged helix transcription factor p3(Foxp3) and toll-like receptor 4(TLR4) in cervical cancer and evaluate their clinical significance. Foxp3 and TLR4 protein expression was detected in 105 cervical tissue specimens including cervical cancer, cervical intraepithelial neoplasia (CIN), and healthy control samples using immunohistochemistry. Their relationship with clinicopathologic parameters was also determined. Foxp3 and TLR4 had high levels of expression in cervical cancer cells (91.43 and 82.86%, respectively). Foxp3 levels were significantly associated with FIGO stage (P<0.001) and tumor size (P=0.034), while TLR4 levels were associated with clinical FIGO stage (P=0.033) and lymph node metastasis (P=0.031). Their expression levels were not correlated with age, histologic type, or differentiation (all P>0.05). These findings suggest that Foxp3 and TLR4 may be useful prognostic indicators of cervical carcinoma. In addition, there were significant positive relationships between Foxp3 and TLR4 expression (r=0.703, P<0.001), which shows a possible link and synergistic role of Foxp3 and TLR4 in promoting the immune escape of cervical cancer. Foxp3 and TLR4 may be useful biomarkers for patient prognosis and cervical cancer prediction and treatment.

Interleukin-37 Enhances the Suppressive Activity of Naturally Occurring CD4+CD25+ Regulatory T Cells.

Naturally occurring CD4+CD25+ regulatory T cells (Tregs) are essential for the suppression of autoimmunity and can control the immune-mediated pathology during the early phase of sepsis. Our previous data showed that silencing interleukin-37 (IL-37) in human CD4+CD25+ Tregs obviously reduced the suppressive activity of CD4+CD25+ Tregs. Here, we found that rhIL-37 stimulation markedly enhanced the suppressive activity of CD4+CD25+ Tregs isolated from naive C57BL/6 J mice in the absence or presence of lipopolysaccharide (LPS). Treatment with rhIL-37 could significantly upregulate the expression of cytotoxic T-lymphocyte-associated antigen (CTLA)-4 and forkhead/winged helix transcription factor p3 (Foxp3) on CD4+CD25+ Tregs. Also, rhIL-37 stimulation promoted the production of transforming growth factor-β1 (TGF-β1) but not IL-10 in the supernatants of cultured CD4+CD25+ Tregs. Pretreated CD4+CD25+ Tregs with rhIL-37 in the presence or absence of LPS were cocultured with CD4+CD25− T cells, ratio of IL-4/interferon-γ in the supernatants obviously increased in IL-37-stimulated groups. In addition, early administration of IL-37 significantly improved the survival rate of septic mice induced by cecal ligation and puncture. Taken together, we concluded that rhIL-37 enhances the suppressive activity of CD4+CD25+ Tregs and might be a potential immunomodulator for the treatment of septic complications.

Triptolide Upregulates Myocardial Forkhead Helix Transcription Factor p3 Expression and Attenuates Cardiac Hypertrophy.

The forkhead/winged helix transcription factor (Fox) p3 can regulate the expression of various genes, and it has been reported that the transfer of Foxp3-positive T cells could ameliorate cardiac hypertrophy and fibrosis. Triptolide (TP) can elevate the expression of Foxp3, but its effects on cardiac hypertrophy remain unclear. In the present study, neonatal rat ventricular myocytes (NRVM) were isolated and stimulated with angiotensin II (1 μmol/L) to induce hypertrophic response. The expression of Foxp3 in NRVM was observed by using immunofluorescence assay. Fifty mice were randomly divided into five groups and received vehicle (control), isoproterenol (Iso, 5 mg/kg, s.c.), one of three doses of TP (10, 30, or 90 μg/kg, i.p.) for 14 days, respectively. The pathological morphology changes were observed after Hematoxylin and eosin, lectin and Masson’s trichrome staining. The levels of serum brain natriuretic peptide (BNP) and troponin I were determined by enzyme-linked immunosorbent assay and chemiluminescence, respectively. The mRNA and protein expressions of α- myosin heavy chain (MHC), β-MHC and Foxp3 were determined using real-time PCR and immunohistochemistry, respectively. It was shown that TP (1, 3, 10 μg/L) treatment significantly decreased cell size, mRNA and protein expression of β-MHC, and upregulated Foxp3 expression in NRVM. TP also decreased heart weight index, left ventricular weight index and, improved myocardial injury and fibrosis; and decreased the cross-scetional area of the myocardium, serum cardiac troponin and BNP. Additionally, TP markedly reduced the mRNA and protein expression of myocardial β-MHC and elevated the mRNA and protein expression of α-MHC and Foxp3 in a dose-dependent manner. In conclusion, TP can effectively ameliorate myocardial damage and inhibit cardiac hypertrophy, which is at least partly related to the elevation of Foxp3 expression in cardiomyocytes.

Expression of soluble programmed death-1 protein in peripheral blood regulatory T cells and its effects on rheumatoid arthritis progression.

The present study aimed to investigate the role of the soluble programmed death‑1 (sPD-1) protein, which is released by peripheral blood regulatory T cells (Treg) during the progression of rheumatoid arthritis (RA). From October 2012 to May 2014, 82 RA patients (RA group) and 90 healthy volunteers (healthy controls; HC) were recruited. Cluster of differentiation (CD)4, CD25 and forkhead/winged helix transcription factor p3 (Foxp3) and expression of cytotoxic T lymphocyte associated antigen 4 (CTLA-4) and Foxp3 were detected by flow cytometry. Expression of sPD‑1 in Treg was detected by western blot analysis. Immunosuppressive activity of CD4+CD25‑ Treg was measured via thiazolyl blue in an MTT assay. ELISA was used to detect interleukin‑10 (IL‑10), transforming growth factor beta (TGF-β), interleukin-4 (IL-4), interferon‑γ (IFN-γ) and nuclear factor of activated T cells (NF‑AT). It was observed that in peripheral blood, CD4+CD25-FOXP3+/CD4+ levels were reduced in the RA group (P<0.001), and sPD‑1 levels were markedly higher (P<0.001), compared with the HC group. Additionally, it was observed that relative sPD‑1 protein expression in the small interfering RNA (siRNA)-sPD-1 treated group was reduced compared with the untreated and scrambled siRNA groups (all P<0.0001). The mean fluorescence intensity of CTLA-4 and Foxp3 decreased markedly upon transfection with siRNA-sPD-1 (P<0.001). Compared with the normal CD4+CD25‑ T group, optical density (OD)540 values, IFN-γ/IL-4 concentration ratio and NF‑AT activity in siRNA untreated and scramble groups reduced significantly (all P<0.001). OD540 value, IFN-γ/IL-4 concentration ratio and NF‑AT activity in the siRNA‑sPD‑1 group were significantly upregulated (all P<0.001). Therefore, sPD-1 may suppress the level of CD4+CD25‑ Tregs in the peripheral blood of RA patients, and may be involved in a variety of immune processes mediated by CD4+CD25‑ Tregs.

Regulatory T cells, especially ICOS+ FOXP3+ regulatory T cells, are increased in the hepatocellular carcinoma microenvironment and predict reduced survival.

Hepatocellular carcinoma (HCC) is a common malignant tumour, especially in Asia. Its prognosis is poor, and there are limited methods for predicting patient survival. This study was carried out to analyse the prognostic value of tumour-infiltrating lymphocytes (TILs), especially regulatory T cells (Tregs), in HCC patients. TILs were analysed in 57 randomly selected HCC patients. The prognostic effects of groups with high and low numbers were evaluated by the Kaplan-Meier and Cox model analyses. Although higher densities of CD3+, CD4+, and CD8+ cytotoxic lymphocytes (CTLs) as well as CD56+ NK cells and CD68+ macrophages were observed in peritumoural tissue, increased numbers of forkhead/winged helix transcription factor P3+ (FOXP3+) Tregs were found in intratumoural tissue. Additionally, regarding ICOS+ FOXP3+ Tregs, an increased prevalence in carcinoma was not only associated with the absolute number but also with the percentage of FOXP3+ cells. Higher Treg levels in tumour tissues indicated a worse prognosis, and the FOXP3+ Tregs/CD4+ T cells ratio was an independent prognostic factor for OS. Therefore, FOXP3+ Tregs, especially ICOS+ FOXP3+ Tregs, contribute to the immunosuppressive HCC microenvironment. High tumour-infiltrating Tregs are thought to be an unfavourable prognostic indicator of HCC.

Rapamycin ameliorates CCl4-induced liver fibrosis in mice through reciprocal regulation of the Th17/Treg cell balance.

Previous investigations have suggested that the activation of Th17 cells and/or deficiency of regulatory T cells (Tregs) are involved in the pathogenesis of liver fibrosis. The aim of the present study was to investigate the effect of rapamycin on immune responses in a carbon tetrachloride (CCl4)-induced murine liver fibrosis model. Liver fibrosis was induced by intraperitoneal administration with CCl4. Following injection of CCl4, the mice were treated intraperitoneally with rapamycin (1.25 mg/kg/day) for 8 weeks. Hematoxylin and eosin staining and Masson's trichrome staining were used for histological examination. The protein levels of forkhead/winged helix transcription factor P3, retinoic-acid-related orphan receptor (ROR)-γt in liver tissue were determined by western blotting, the frequency of Th17 and Treg cells in the liver was evaluated by flow cytometry, and a suppression assay was measured by incorporating [3H]-thymidine. In addition, to explore the effect of Tregs expanded with rapamycin on hepatic stellate cells (HSC), HSCs were co-cultured with Tregs from rapamycin or phosphate-buffered saline-treated mice. It was found that rapamycin treatment led to a significant reduction in the number of Th17 cells and in the expression levels of ROR-γt in the liver tissues. Simultaneously, the results of the present study showed a significant increase in the frequency of Tregs and a marked enhancement in the expression of forkhead/winged helix transcription factor P3 in the rapamycin-treated mice. Furthermore, the Tregs in rapamycin-treated mice had significantly higher suppressive effects, compared with the cells from mice treated with phospphate-buffered saline. Consequently, rapamycin treatment prevented the development of CCl4-induced hepatic fibrosis, which was shown by its histological appearances. These results suggested that the immunosuppressive effect of rapamycin on liver fibrosis was associated with the suppression of hepatic fibrogenesis and regulation of the Th17/Treg cell balance.

Effects of ulinastatin on immune function of spleen in severely burned rats and its mechanism

To observe the effects of ulinastatin on immune function of splenic CD4(+) T lymphocytes and CD4(+) CD25(+) regulatory T lymphocytes (Tregs) and content of high mobility group box 1 (HMGB1) in peripheral blood of severely burned rats, and to analyze the possible mechanisms. Ninety-six male SD rats were divided into sham injury group, burn group, and ulinastatin group according to the random number table, with 32 rats in each group. Rats in sham injury group were sham injured on the back by immersing in 37 ℃ warm water for 12 s. Rats in burn group and ulinastatin group were inflicted with 30% total body surface area full-thickness scald (hereinafter referred to as burn) on the back by immersing in 94 ℃ hot water for 12 s. Immediately after injury, rats in each group were intraperitoneally injected with saline (40 mL/kg), meanwhile rats in ulinastatin group were intraperitoneally injected with ulinastatin (4×10(4) U/kg), once per 12 h, till post injury hour 72. Eight rats of each group were respectively selected on post injury day (PID) 1, 3, 5, and 7 to collect abdominal aortic blood samples. Serum content of HMGB1 was detected by enzyme-linked immunosorbent assay (ELISA). And then, rats of the 3 groups were sacrificed immediately to collect spleens and separate CD4(+) CD25(+) Tregs and CD4(+) T lymphocytes. Flow cytometer was used to detect positive expression rates of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and forkhead-winged helix transcription factor p3 (Foxp3) in CD4(+) CD25(+) Tregs. Content of IL-10 in culture supernatant of CD4(+) CD25(+) Tregs, and content of interleukin 2 (IL-2), IL-4, and γ interferon (IFN-γ) in culture supernatant of CD4(+) T lymphocytes was detected by ELISA. The proliferative activity of CD4(+) T lymphocytes was determined by microplate reader. The sample number of above-mentioned experiments was 8 at each time point in each group. Data were processed with analysis of variance of factorial design and LSD test. (1) Compared with that in sham injury group, serum content of HMGB1 of rats in burn group was significantly increased from PID 1 to 7 (with P values below 0.01). Compared with that in burn group, serum content of HMGB1 of rats in ulinastatin group was significantly decreased from PID 1 to 7 (with P values below 0.01). (2) Compared with those in sham injury group, the positive expression rates of CTLA-4 and Foxp3 in CD4(+) CD25(+) Tregs and content of IL-10 in culture supernatant of CD4(+) CD25(+) Tregs of rats in burn group were significantly increased from PID 1 to 7 (with P values below 0.01), peaking on PID 3 [(65±10)%, (76±10)%, and (28.2±4.4) pg/mL respectively]. These 3 indexes of rats in sham injury group on PID 3 were (45±7)%, (46±7)%, and (11.2±2.3) pg/mL respectively. Compared with those in burn group, the positive expression rates of CTLA-4 and Foxp3 in CD4(+) CD25(+) Tregs and content of IL-10 in culture supernatant of CD4(+) CD25(+) Tregs of rats in ulinastatin group were significantly decreased from PID 1 to 7 (P<0.05 or P<0.01), reaching the nadir on PID 7 [(43±6)%], PID 1 [(50±8)%], and PID 7 [(12.4±3.4) pg/mL] respectively. These 3 indexes of rats in burn group on PID 7, 1, and 7 were (58±8)%, (71±9)%, and (19.7±2.8) pg/mL respectively. (3) Compared with those in sham injury group, the content of IL-2 and IFN-γ in culture supernatant of CD4(+) T lymphocytes of rats was significantly decreased, while the content of IL-4 in culture supernatant of CD4(+) T lymphocytes of rats was significantly increased in burn group from PID 1 to 7, with P values below 0.01. Compared with that in burn group, the content of IL-2 and IFN-γ in culture supernatant of CD4(+) T lymphocytes of rats was significantly increased, while the content of IL-4 in culture supernatant of CD4(+) T lymphocytes of rats was significantly decreased in ulinastatin group from PID 1 to 7, P<0.05 or P<0.01. (4) Compared with that in sham injury group, the proliferative activity of CD4(+) T lymphocytes of rats in burn group was significantly decreased from PID 1 to 7 (with P values below 0.01). Compared with that in burn group, the proliferative activity of CD4(+) T lymphocytes of rats in ulinastatin group was significantly increased from PID 1 to 7 (with P values below 0.01). Ulinastatin can weaken the immunosuppressive function mediated by splenic CD4(+) CD25(+) Tregs in severely burned rats, and improve proliferative function and secretory function of splenic CD4(+) T lymphocytes, which may be attributed to the inhibiting effect of ulinastatin on the release of HMGB1 in large amount.

Expression of IL-37 contributes to the immunosuppressive property of human CD4+CD25+ regulatory T cells.

Interleukin-37 (IL-37) possesses the function of down-regulate systemic and local inflammation. It is unknown whether IL-37 is expressed in human regulatory T cells (Tregs) and its role in modulating the immune response of Tregs. In the present study, cell surface molecules and secretory cytokines were analyzed in order to determine the function of IL-37 in regulating inhibitory effect of human CD4+CD25+Tregs. Meanwhile, the effects of IL-37 on T cell differentiation and proliferation as co-culture of CD4+CD25+Treg/CD4+CD25−T cell were also investigated. It was showed that IL-37 was expressed in cytoplasm of CD4+CD25+Tregs, and the levels of IL-37 were gradually elevated with the enhanced activity of CD4+CD25+Tregs. Secretory cytokines such as transforming growth factor (TGF)-β and interleukin (IL)-10, and expressions of cell surface molecules, including forkhead/winged helix transcription factor p3 (FOXP3) and cytotoxic T-lymphocyte associated antigen (CTLA)-4, were significantly decreased when IL-37 gene was silenced by siRNA. Furthermore, down-regulation of IL-37 expression in human CD4+CD25+Tregs obviously promoted proliferation of co-cultured T cell and differentiation, together with observably enhancement of IL-2 formation. These results demonstrated that IL-37 might manifest as a critical protein involving in immunosuppression of human CD4+CD25+Tregs.