RORγt Expression Research Articles

Methyl-CpG-Binding Domain Protein 2 is Involved in Th17 Cell Differentiation by Negatively Regulating Leptin Expression.

Among Th lineages from naïve CD4+T cells, Th17 cells producing IL-17 are strongly related to the pathogenesis of neutrophilic asthma. Leptin is involved in inflammation and immunity. Little is known about MBD2's epigenetic regulation in CD4+T cell differentiation. Our study is intended to delve into the mode by which MBD2 interacts with Leptin to govern Th17 cell differentiation. CD4+T cells were harvested from the spleen tissue of C57BL/6 mice. Th17 cell differentiation was determined by flow cytometry, and ELISA measured IL-17. Western blot and RT-qPCR were employed to detect the expression of MBD2, Leptin and RORγt. CO-IP was utilized to assess the relationship between MBD2 and Leptin. Under the overexpression or silencing of the MBD2 and Leptin genes, the differentiation of Th17 cells, IL-17 secretion, and RORγt expression all manifested positive changes. Leptin expression showed a positive variance upon overexpression or silencing of the MBD2 gene; however, there was no significant disparity in the expression of MBD2 under the overexpression or silencing of the Leptin gene. MBD2 can interact directly with Leptin. MBD2 is capable of inducing the differentiation of naïve CD4+T cells into Th17 cells by augmenting the expression of Leptin.

The PPAR-α selective agonist WY14643 improves lupus nephritis via the downregulation of the RORγT/STAT3 signaling pathway in MRL/lpr mice.

Systemic lupus erythematosus (SLE) is a classic autoimmune disorder that mostly affects young women and involves various organs, such as the skin, joints, central nervous system, and kidneys. WY14643, a selective agonist of peroxisome proliferator-activated receptor-α, has previously shown anti-inflammatory effects in various disease models. However, its effects on lupus nephritis are yet to be explored. Therefore, the efficacy of WY14643 on renal biomarkers and lupus nephritis was assessed in MRL/lpr mice. Flow cytometry was used to examinethe effects of WY14643 on the expression of IL-17A, STAT3, RORγT, IL-21, IL-21R, IL-22, and TNF-α in splenic CD4+ T cells. We further investigated the impact of WY14643 on the mRNA expression of IL-17A, STAT3, RORγT, IL-21, IL-21R, IL-22, and TNF-α in kidney tissue via RT-PCR analysis. The administration of WY14643 effectively improved the symptoms of lupus nephritis in MRL/lpr mice. The administration of WY14643 decreased serum albumin, urine protein, serum creatinine, and blood urea nitrogen levels in MRL/lpr mice. WY14643 reduced the levels of inflammatory markers, including CD4+IL-17A+, CD4+STAT3+, CD4+RORγT+, CD4+IL-21+, CD4+IL-21R+, CD4+IL-22+, and CD4+TNF-α+, in the spleen cells of MRL/lpr mice. Additionally, we discovered that the administration of WY14643 resulted in the suppression of mRNA levels of IL-17A, STAT3, RORγT, IL-21, IL-22, and TNF-α. The current work shows that the suppression of inflammatory cells by WY14643 may effectively reduce autoimmune characteristics, such as renal inflammation, in lupus-prone MRL/lpr mice. Therefore, WY14643, being a specific PPAR-α agonist, shows significant potential as a novel therapeutic option for treatingnephritis associated with SLE, offering hope for future treatments in this challenging field.

Higher T-bet and IFN-γ expression in advanced chagasic megaesophagus indicates Th1 response in the chronic phase.

Myenteric plexus injury is responsible for the morpho-functional alterations observed in chagasic megaesophagus (CME). The inflammatory response, characterized by elevated synthesis of IFN-γ, TNF-α, and IL-4, contributes to the persistence of parasitism and inflammation. This study assessed the mRNA expression of cytokines, transcription factors, and metalloproteases in subjects with CME. From 2011 to 2017, esophageal samples were collected from 54 subjects with CME (38 advanced and 16 nonadvanced) and eight subjects with idiopathic megaesophagus (IME). The quantitative mRNA expression of TNF-α, IFN-γ, IL-4, IL-10, IL-17, IL-22, IL-23, IL-27, T-bet, ROR-γT, GATA-3, MMP-1, MMP-2, and TIMP-3 genes was analyzed using SYBR Green systems. T-bet expression was significantly higher in the CME group compared to the IME group and the GATA-3 and ROR-γT expression in the CME group, corroborating the higher IFN-γ expression observed in subjects with advanced CME. The increased T-bet and IFN-γ expression in advanced CME reflects the maintenance of a Th1 response in situ and the morpho-functional changes seen in the organ.

Sp3 ameliorated experimental autoimmune encephalomyelitis by triggering Socs3 in Th17 cells.

Although it is believed that chronic inflammatory and degenerative diseases of the central nervous system are mediated by autoimmune Th17 cells, the underlying mechanisms remain largely unexplored. Recent studies and our research have revealed that Sp3 was blocked in multiple sclerosis (MS) patients and experimental autoimmune encephalomyelitis (EAE). However, it remained unclear why it is silent and how it regulates Th17 cell differentiation in MS. This study aimed to explore the impact of Sp3 on Th17 cell-mediated EAE and the underlying mechanism. The effect of Sp3 on the clinical symptoms of EAE was evaluated by scoring, histochemistry, and fast blue (FB) techniques, scRNA-seq data analysis, flow cytometry, ELISA, PCR, WB, immunofluorescence and reporter gene techniques were used to explore the molecular mechanism of Sp3 regulating Th17 cell differentiation. Injection of overexpression Sp3 lentivirus could significantly ameliorate the EAE progress and clinical symptoms and prevent the polarization of Th1 and Th17 cells both in vivo and in vitro. We confirmed the occurrence of EAE in Sp3+/+CD4Cre mice and Sp3+/- knockout mice. Furthermore, we identified Sp3 as a target of miR-223, which is found to be upregulated in the blood of MS patients, as well as in EAE and Th17 cells. Moreover, knockdown of miR-223 led to a marked improvement in EAE symptoms and a suppression of Th1 and Th17 cell polarization in vivo and in vitro. Mechanistically, Sp3 significantly suppressed RORγt expression and the phosphorylation of Stat3 and Smad2/3 by directly upregulating Socs3. Interestingly, Socs3 was found to regulate Sp3 expression in response to TGF-β1 via a feedback loop. Moreover, Socs3 modulated phospho-Smad2/3 by binding to and degrading the transforming growth factor-β receptor II (TβRII). Thus, our study suggests a novel mechanism involving miR-223/Sp3/Socs3/TGF-β signaling as a potential therapeutic strategy for targeting Th17 cells in immunotherapy.

San Huang Xiao Yan recipe promoted wound healing in diabetic ulcer mice by inhibiting Th17 cell differentiation.

Diabetic ulcer is a serious diabetes complication and a primary reason for amputations. For many years, the San Huang Xiao Yan (SHXY) recipe has served as a conventional remedy for these ulcers, effectively reducing inflammatory factors and exhibiting considerable therapeutic efficacy. However, the precise mechanism remains incompletely understood. To explore the efficacy and mechanisms of SHXY and its active ingredients in treating diabetic ulcer. A diabetic ulcer mouse model was established using C57BL/6J mice on a high-fat diet, followed by streptozotocin injection and skin damage. We investigated the bioactive compounds, key targets, and pharmacological mechanisms of SHXY in addressing diabetic ulcers through network pharmacology, molecular docking, both in vitro and in vivo validation experiments. One week after intragastric administration, SHXY can reduce inflammation and edema, increase collagen synthesis, and reduce the expression of RORγT and IL-17A without affecting Treg cells. In vitro, SHXY-containing serum inhibited the differentiation of Th17 cells but did not affect Treg and Th1 cells. Network pharmacology found that SHXY acts through inflammatory pathways, including TNF, IL-17, Th17 cell differentiation, HIF-1, and PI3K-Akt. SHXY and its candidate enhance healing in diabetic ulcers by modulating CD4+ T cells, particularly by inhibiting Th17 cell differentiation.

Acupoint Autohemotherapy Alleviates Airway Inflammation in Asthmatic Rats via Upregulating Expression of Hemeoxygenase-1.

Acupoint autohemotherapy (AA), a therapeutic technique involving the subcutaneous injection of autologous blood into acupoints, has been empirically validated as safe and effective for treating asthma by alleviating symptoms and decreasing acute attacks, though its mechanism is not well understood. The role of heme oxygenase-1 (HO-1) in AA-induced suppression of asthmatic airway inflammation is examined. Twenty rats were assigned randomly to four groups, namely the Control, OVA, OVA + AA, and (OVA + Snpp) + AA. Rats in the OVA + AA and (OVA + Snpp) + AA received autologous blood injections into acupoints (BL13 and BL23) following OVA challenge. Rats in the (OVA + Snpp) + AA were concurrently subjected to intraperitoneal injections of Snpp, a inhibitor of HO-1. Airway inflammation was evaluated through HE staining, while the concentrations of cytokines in BALF were quantified using ELISA. The mRNA and protein levels of RORγt (Th17-specific transcription factor), Foxp3 (Treg-specific transcription factor), and HO-1 in lung tissue were assessed through qRT-PCR and WB. HE staining indicated that airway inflammation was alleviated in the OVA + AA. The OVA + AA displayed significantly lower counts of total cells and eosinophils in the BALF compared to both the OVA and (OVA + Snpp) + AA. The ELISA demonstrated a significant decrease in levels of pro-inflamatory cytokines (IL-4, IL-17A), and an increase in levels of anti-inflamatory cytokines (IFN-γ, IL-10), in the OVA + AA when compared to both OVA and (OVA + Snpp) + AA. The qRT-PCR and WB analyses revealed an upregulation of HO-1 and Foxp3 expression, and a downregulation of RORγt expression, in the OVA + AA when compared to OVA and (OVA + Snpp) + AA. The involvement of HO-1 in the underlying mechanism responsible for the anti-inflammatory effects of AA is evident.

Evaluation of the immunomodulatory activity of probiotics mixture and sulfasalazine against acetic acid-induced colitis in a murine model.

Currently, the use of probiotics to treat inflammatory bowel diseases (IBD) is widely accepted because of their gut microbiota modulation capabilities and anti-inflammatory potential. The aim of this study is to examine the immunomodulatory outcomes of probiotics and sulfasalazine in the acetic acid-induced colitis murine model. The animals were randomly assigned to one of the seven groups. Following the induction of colitis, Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12, and sulfasalazine (SASP) were orally administered for 10 days. Subsequently, the in vitro anti-inflammatory effect on TNF-α and IL-10 in the supernatants of cultured spleen cells was assessed via ELISAs. Relative mRNA expression of ZO-1, MLCK, iNOS, TNFR2, ROR-γt, GATA-3, T-bet, and Foxp3 was determined using quantitative reverse‑transcription polymerase chain reaction (qRT‑PCR). The SASP plus probiotic mixture was more effective in alleviating colitis symptoms, and reducing disease activity scores, and mucosal inflammation. qRT-PCR analysis revealed a significant reduction in T-bet and RORγt levels, while Foxp3 and GATA-3 levels increased in the colons of colitis mice. In addition, the selected strains substantially inhibited the release of inflammatory markers. Administration of LA-5 + BB-12 + SASP resulted in considerably higher inhibition of NO production and cell proliferation than in the other groups (p < 0.001). Treatment with LA-5 + BB-12 + SASP also reduced TNF-α-mediated apoptosis in intestinal epithelial cells (IECs). Survey results highlight that the combination regimen could be a promising strategy for IBD therapy, warranting further study of its clinical application and long-term benefits.

Kunduan Yimu Decoction affected Th17/Treg balance through microRNA-124 to improve rheumatoid arthritis pathology

BackgroundRheumatoid arthritis (RA) is an autoimmune condition characterized by inflammation and the deterioration of joints. Current treatments often have side effects, highlighting the need for safer options. This study investigates the therapeutic effects of Kunduan Yimu Decoction (KDYMD) on RA, focusing on the role of miR-124 in regulating Th17/Treg differentiation. MethodsPBMCs from RA patients were analyzed before and after KDYMD treatment. RT-qPCR was used to measure the miR-124 expressions. Flow cytometry was used to assess the ratios of Th17 to Treg cells. ELISA was used to quantify the cytokine concentrations. The effects of KDYMD on JAK2/STAT3 signaling were evaluated by western blot analysis. A CIA mouse model was used to validate the in vivo effects of KDYMD. ResultsMiR-124 expression was significantly upregulated in PBMCs of RA patients after KDYMD treatment. This upregulation was associated with increased Tip60 and Foxp3 expression and decreased RORγt expression. In the cytokine analysis, IL-1, IL-6, and IL-17A were decreased, and IL-10 and TGF- were increased after treatment. Flow cytometry showed a restoration of the Th17/Treg balance, with a decrease in Th17 and an increase in Treg cells. In vivo, KDYMD treatment ameliorated ankle swelling and arthritis index in CIA mice, comparable to methotrexate (MTX). In addition, KDYMD modulated JAK2/STAT3 signaling and enhanced anti-inflammatory responses. ConclusionsKDYMD exerts significant anti-inflammatory effects in RA by upregulating miR-124, which in turn regulates Th17/Treg differentiation and modulates JAK2/STAT3 signaling. A novel mechanism involving miR-124 and immune cell balance suggests KDYMD could be a promising therapeutic agent for RA.

TIM-4 Identifies Effector B Cells Expressing a RORγt-Driven Proinflammatory Cytokine Module That Promotes Immune Responsiveness.

B cells can express pro-inflammatory cytokines that promote a wide variety of immune responses. Here we show that B cells expressing the phosphatidylserine receptor TIM-4, preferentially express IL-17A, as well as IL-22, IL-6, IL-1β, and GM-CSF - a collection of cytokines reminiscent of pathogenic Th17 cells. Expression of this proinflammatory module requires IL-23R signaling and selective expression of RORγt and IL-17A by TIM-4+ B cells. TIM-4+ B cell-derived-IL-17A not only enhances the severity of experimental autoimmune encephalomyelitis (EAE) and promotes allograft rejection, but also acts in an autocrine manner to prevent their conversion into IL-10-expressing B cells with regulatory function. Thus, IL-17A acts as an inflammatory mediator and also enforces the proinflammatory activity of TIM-4+ B cells. Thus, TIM-4 serves as a broad marker for RORγt+ effector B cells (Beff) and allows further study of the signals regulating Beff differentiation and effector molecule expression.

SO2 activates Th17 cells through the JAK1,2/STAT3 signaling pathway

ObjectiveTo investigate the effect of SO2 on Th1/Th2/Th17 cells in allergic rhinitis (AR) and the role of JAK1, 2/STAT3 signaling pathways.To Provide potential directions for the treatment of AR. MethodsFifteen AR patients were enrolled as the experimental group, while 15 healthy volunteers served as the normal control group. After collecting venous blood, peripheral blood mononuclear cells (PBMCs) were isolated and cultured, followed by the addition of SO2 derivatives and the JAK inhibitor Ruxolitinib. Flow cytometry was employed to assess alterations in the Th1/Th2 and Th17/Treg cell balance upon stimulation with SO2 and Ruxolitinib. qRT-PCR was utilized to detect the expression of Th1-related cytokines IL-2 and IFN-γ, Th2-related cytokines IL-4 and IL-5, Th17-related cytokines IL-17A and RORγt, as well as genes JAK1, JAK2, and STAT3. Flow cytometric cytokine analysis was conducted for quantitative assessment of the expression levels of inflammation-related cytokines in PBMC culture supernatants after stimulation. In addition, we stimulated the Jurkat T lymphocyte cell line with SO2 derivatives, added Ruxolitinib as an inhibitor, and used Western blot analysis to further determine the effects of SO2 on Th cells and the role of the JAK1,2/STAT3 signaling pathway in this process. ResultsStimulation with SO2 derivatives upregulated the expression levels of Th2 cells and associated cytokines, as well as Th1 cells and associated cytokines. both AR patients and healthy individuals displayed increased percentages of Th17 cells and Th17/Treg ratios in PBMCs. The expression of IL-17A, RORγt, and IL-6 was also elevated. Under SO2 stimulation, the expression of JAK1, JAK2, STAT3, and RORγt in Jurkat cells increased. Moreover, after the application of Ruxolitinib, the JAK/STAT signaling pathway was inhibited. This led to a reduction in Th17 cells and IL-17A levels in both AR patients and healthy individuals, as well as a decrease in RORγt expression in Jurkat cells. Additionally, the expression of IL-5 decreased in healthy individuals. ConclusionSO2 exposure exacerbated Th1/Th2/Th17 inflammation in AR patients and induced Th1 and Th17 inflammation in healthy individuals. The stimulatory effect of SO2 on Th17 cell differentiation could be inhibited by Ruxolitinib. This suggests that the Th17 inflammation induced by SO2 stimulation may be related to the activation of the JAK/STAT signaling pathway, and this has been confirmed in the Jurkat cell line.

Qingchang suppository ameliorates mucosal inflammation in ulcerative colitis by inhibiting the differentiation and effector functions of Th1 and Th17 cells

Ethnopharmacological relevanceQing Chang Suppository (QCS), a traditional Chinese medicine formula, has been shown to effectively alleviate mucosal inflammation in patients with ulcerative colitis (UC). While the mechanism of QCS appears to be related to the regulation of CD4+T cell subset responses, direct evidence demonstrating that QCS inhibits Th1 and Th17 cell activation in UC (particularly based on human data) remains lacking. Additionally, the precise mechanisms through which QCS affects these cells have yet to be fully elucidated. Aim of studyThis study aimed to investigate the effects of QCS on Th1 and Th17 cell responses in UC and to explore the underlying mechanisms. Materials and methodsTwenty-eight patients with mild-to-moderate UC were recruited and treated with QCS for 12 weeks. Symptoms were assessed every two weeks, with sigmoidoscopies performed at baseline and at week 12. Intestinal mucosal biopsies and peripheral blood (PB) were collected at these time points. At the end of the trial, patients were categorized into responder and non-responder groups based on a modified Mayo disease activity index score. Healthy controls (HCs) were defined as subjects without IBD or colorectal carcinoma but with colon polyps. The frequencies of IFN-γ+CD4+T cells and IL-17A+CD4+T cells in PB and colonic mucosa were measured using flow cytometry. The expression levels and localization of T-bet, RORγT, IFN-γ, TNF-α, and IL-17A were determined via immunofluorescence, and JNK signaling activation was assessed through immunoblotting and immunohistochemistry. All parameters were compared across the three groups. ResultsAt week 12, responders showed a significant reduction in colonic mucosal inflammation compared to baseline, accompanied by decreased frequencies of IFN-γ+CD4+T and IL-17A+CD4+ T cells in both PB and the colonic epithelial layer. Notably, Th1 and Th17 cell activity around intestinal epithelial cells (IECs) was nearly undetectable, as evidenced by the diminished expression of T-bet, RORγT, IFN-γ, TNF-α, and IL-17A. Additionally, JNK phosphorylation in these cells was significantly reduced. In contrast, non-responders exhibited no meaningful improvement; colonic pathology remained unchanged, and elevated levels of IFN-γ+CD4+T and IL-17A+CD 4+T cells persisted in both the PB and colonic epithelial layer. The presence of Th1 and Th17 cells and their associated cytokines around IECs remained substantial, and there was no significant change in JNK activation. ConclusionQCS attenuates mucosal inflammation in UC patients by inhibiting the differentiation and effector functions of Th1 and Th17 cells, primarily through the regulation of the JNK signaling pathway.

Evaluation of TNF-α and IFN-γ primed conditioned medium of mesenchymal stem cell in acetic acid-induced mouse model of acute colitis

IBD, an autoimmune-inflammatory disorder that affects people who are genetically prone to inflammation. There is a lot of interest in MSC-CM therapy, especially when primed with TNF-α + IFN-γ. Throughout the study, data were collected on the percentage of apoptotic cells, gene expression of ZO-1, Foxp3, GATA3, IDO-1, Muc2, T-bet, Notch1, TNFR2, and ROR-γt, colon weight and length, histopathological analysis, and DAI. TNF-α and IL-10 levels were assessed in addition to the NO level. The results suggest that primed MSC-CM improved DAI, mucosal deterioration, intestinal inflammation and NO concentration. The amount of TNF-α was decreased, but IL-10 and the colon’s percentage of apoptotic cells was increased. The mRNA expression of ZO-1, Foxp3, GATA3, IDO-1, and Muc2 genes increased greatly in the treatment groups, while the expression of T-bet, Notch1, TNFR2, and ROR-γt genes has decreased. These studies suggest that primed MSC-CM may combine with common treatments to improve responsiveness.

Regulation of targeted blocking cannabinoid receptor 1 on spleen immune function and inflammatory response in mice under chronic intermittent hypoxia

Objective: To observe the effects of targeting and blocking cannabinoid receptor 1 (CB1R) on mouse spleen immune function and inflammatory response under chronic intermittent hypoxia (CIH) conditions, and to explore its regulatory effort. Methods: Forty SPF male C57BL/6 mice aged 4 to 5 weeks,from May 2021 to August 2021 in Experimental Animal Center of the Second Hospital of Shanxi Medical University, were randomly divided into normal oxygen control group (NC), 6-week CIH group (6w CIH), 10-week CIH group (10w CIH), 6-week CIH+CB1R group (6w CIH+AM251) and 10-week CIH+CB1R group (10w CIH+AM251) according to the method of random number table. The advanced programmable intermittent low oxygen chamber was used to prepare the CIH mouse model. The morphological structure of spleen tissue of CIH mice was stained by hematoxylin-eosin (HE) staining. The expression levels of M1 and M2 macrophage surface markers CD86, CD206 were determined by immunofluorescence. The mRNA expression levels of CB1R, CD86, CD206 and the relative expression levels of RORγt and Foxp3,which are characteristic transcriptional regulators of T helper 17(Th17) and Treg cells were detected by quantitative reverse transcriptase PCR(qRT-PCR). The expression of inflammatory factors IL-6 and IL-10 was determined by ELISA. SPSS 26.0 and Graphpad prism 8.3 were used to analyze the data. Results: (1) Compared with NC group, spleen tissue structure was disordered, fibrous tissue hyperplasia, lymphocyte proliferation and disordered arrangement in periarteriole lymphatic sheath in CIH group. The expression of CB1R in CIH group was higher than that in NC group (P<0.05), and with the prolongation of CIH time, the expression of 10w CIH group was higher than that in 6w CIH group(P<0.05). The expression of CB1R in CIH+AM251 group was lower than that in the corresponding CIH group(all P<0.05). (2) Compared with NC group, the expression level of CD86 in macrophages in CIH group was higher than that in NC group(all P<0.05). The relative expression of RORγt in 6w and 10w CIH groups was 0.76±0.03 and 0.91±0.04, respectively, which was higher than that in NC group (0.65±0.06)(all P<0.05). The relative expression levels of inflammatory factor IL-6 were 10.80±1.73 and 14.86±0.01, respectively, which were higher than 6.69±0.23 in the NC group (all P<0.05). The expression level of CD206 in macrophages in the CIH+AM251 group was higher than that in the CIH group(all P<0.05). The relative expression levels of Foxp3 in 6w and 10w CIH+AM251 groups were 0.62±0.05 and 0.32±0.21, respectively, which were higher than those in 6w CIH group (0.28±0.02) and 10w CIH group (0.02±0.01)(P<0.05). The relative expression levels of anti-inflammatory factor IL-10 were 668.45±15.71 and 379.15±56.84, respectively, which were higher than those in CIH group (all P<0.05). Conclusion: Targeted sealing of CB1R may alleviate inflammatory response of mouse spleen under CIH conditions by regulating macrophage polarization and the expression of inflammatory factors, and may have some protective effect.

Expression of Transcriptional Factors of T Helper Differentiation (T-bet, GATA-3, RORγt, and FOXP3), MIF Receptors (CD44, CD74, CXCR2, 4, 7), and Th1, Th2, and Th17 Cytokines in PBMC from Control Subjects and Rheumatoid Arthritis Patients.

The macrophage migration inhibitory factor (MIF) plays a pivotal role in the development of rheumatoid arthritis (RA). Previous research indicates that MIF can trigger the expression of cytokine profiles associated with Th1, Th2, and Th17 responses in peripheral blood mononuclear cells (PBMC) from both RA patients and control subjects (CS). Despite these, few studies to date precisely elucidate the molecular mechanisms involved. The present study aimed to associate the expression of Th differentiation TF (T-bet, GATA-3, RORγt) with MIF receptors (CD44, CD74, CXCR2, 4, 7) and Th1, Th2, and Th17 cytokines in PBMC from CS and RA patients. PBMC from both groups was cultured for 24 h. The expression of the canonical and non-canonical MIF receptors and the TF was determined by flow cytometry. Additionally, multiplex bead analysis was employed to assess the levels of cytokines in the culture supernatants. The findings revealed that T CD4+ lymphocytes in the CS group exhibited a heightened expression of CD74 (p<0.05), whereas RA patients displayed an elevated expression of CXCR7 (p<0.001). Furthermore, T CD4+ lymphocytes from RA patients exhibited greater expression of GATA3, RORγt, and FOXP3, along with elevated levels of pro-inflammatory cytokines compared to the CS group (p<0.001). These results indicate that CD74 is more prominently expressed in PBMC from the CS group, whereas CXCR7 is more expressed in PBMC from RA patients. We also noted an increased secretion of Th17 profile cytokines in RA, potentially influenced by the activation of FOXP3 via CD74 and RORγt through CXCR7 using the endocytic pathway.

Homocysteine Promotes Intestinal Inflammation in Colitis Mice Through the PGE2/STAT3 Signaling Pathway.

Our previous study indicated that Hcy exacerbated DSS-induced colitis by facilitating the differentiation of intestinal T helper cell 17 (Th17), but the precise mechanism remains unidentified. Therefore, our current research aims to elucidate the signaling pathway through which Hcy promotes the differentiation of Th17 cells. BALb/c mice were randomly assigned into six groups. The model of mice colitis was induced using 3% DSS, while the model of Hyperhomocysteinemia was induced using 1.7% methionine. The concentrations of Hcy and prostaglandin E2 (PGE2) were measured using enzyme-linked immunosorbent assay (ELISA). The protein expressions of cytosolic phospholipase A2 (cPLA2), phosphorylated-cPLA2 (p-cPLA2), cyclooxygenase 2 (COX2), cyclic adenosine monophosphate (cAMP), signal transducer and activator of transcription 3 (STAT3), phosphorylated-STAT3 (p-STAT3), interleukin-17A (IL-17A), and retinoid-related orphan nuclear receptor-γt (RORγt) were assessed using western blot analysis. Compared to the DSS + HHcy group, the addition of the COX inhibitor did not significantly alter the protein expression of p-PLA2/PLA2, but led to significant decreases in serum PGE2 concentration, cAMP, and p-STAT3/STAT3 protein expression. The protein expressions of p-PLA2/PLA2, COX2, and cAMP upstream of STAT3 inhibitor addition did not exhibit significant changes. However, PGE2 concentration and p-STAT3/STAT3 protein expression were notably reduced. After the COX inhibitor and STAT3 inhibitor added, the protein expression of IL-17A and RORγt and the levels of IL-17A and IL-23R in CD4+ T cells were significantly reduced. HHcy aggravated DSS-induced colitis by promoting the differentiation and proliferation of Th17 cells through the PGE2 / STAT3 signaling pathway.

Digoxin attenuates bisphosphonate related osteonecrosis of the jaws by RORγt-dependent Th17 response in male rats

The study aimed to evaluate digoxin, an RORγt inhibitor, in Medication-Related Osteonecrosis of the Jaws (MRONJ) in male rats treated with zoledronic acid (ZA). Forty male Wistar rats were divided into a negative control group (0.1 mL/kg saline), a positive control group (ZA, 0.20 mg/kg), and three test groups treated with ZA and digoxin at 1 (DG1), 2 (DG2), or 4 (DG4) mg/kg. These groups received treatment three times weekly. ZA was administered intravenously on days 0, 7, and 14, followed by extraction of the left lower first molar on day 42, a final ZA dose on day 49, and euthanasia on day 70. Analyses included radiographic, histomorphometric, and immunohistochemical evaluation of the mandibles, western blotting of gingiva, and mechanical tests on femurs. Statistical analysis was performed using ANOVA/Bonferroni tests (P < .05). Digoxin reduced radiolucency of MRONJ (P < .001), inflammatory cells, empty osteocyte lacunae (P < .001), apoptotic osteoclasts (P < .001), and Caspase-3-positive osteocytes (P = .021). ZA increased immunoreactivity for most markers except c-Fos, while digoxin reduced interleukin 17, TNF-α, IL-6, IL-2, FOXP3, c-Jun, NFκB (P < .001), TGF-β (P = .009), RANKL (P = .035), and OPG (P = .034). Digoxin also reversed RORγt expression (P < .001), increased diarrhea scores (P = .028), renal and cardiac indexes (P < .001), and enhanced femur mechanical properties (P < .013). Digoxin attenuated MRONJ by inhibiting RORγt and reducing the Th17 response.

RORγt-dependent antigen-presenting cells direct regulatory T cell-mediated tolerance to food antigen.

The gastrointestinal tract is continuously exposed to foreign antigens in food and commensal microbes with potential to induce adaptive immune responses. Peripherally induced T regulatory (pTreg) cells are essential for mitigating inflammatory responses to these agents1-4. While RORγt+ antigen-presenting cells (RORγt-APCs) were shown to program gut microbiota-specific pTregs5-7, understanding of their characteristics remains incomplete, and the APC subset responsible for food tolerance has remained elusive. Here, we demonstrate that RORγt-APCs are similarly required for differentiation of food antigen-specific pTregs and establishment of oral tolerance. The ability of these cells to direct both food and microbiota-specific pTreg cell differentiation is contingent on expression of RORγt and on a unique cis-regulatory element within the Rorc gene locus (Rorc(t) +7kb). Absent this +7kb element, there was a notable increase in food antigen-specific T helper 2 (Th2) cells in lieu of pTregs, leading to compromised tolerance in a mouse asthma model. By employing single-cell analyses across these models, as well as freshly resected mesenteric lymph nodes from a human organ donor, we identified a rare subset of evolutionarily conserved APCs that are dependent on RORγt, uniquely express the Prdm16 transcription factor, and are endowed with essential mediators for inducing pTreg cell differentiation. Our findings suggest that a better understanding of how RORγt-APCs develop and how they regulate T cell responses to food and microbial antigens could offer new insights into developing therapeutic strategies for autoimmune and allergic diseases as well as organ transplant tolerance.

Nrf2 Deficiency Accelerates IL-17-Dependent Neutrophilic Airway Inflammation in Asthmatic Mice.

Asthma is a heterogeneous disease that can be broadly classified into type 2, which is primarily steroid-sensitive and eosinophilic, and non-type 2, which is primarily steroid-resistant and neutrophilic. While the mechanisms leading to the development of molecular-targeted therapies for type 2 asthma are being elucidated, much remains to be learned about non-type 2 asthma. To investigate the role of oxidative stress in refractory allergic airway inflammation, we compared asthma models generated by immunizing wild-type and nuclear factor erythroid-2-related factor 2 (Nrf2)-deficient mice with the house dust mite antigen. Both asthma models had similar levels of airway inflammation and hyperresponsiveness, but the Nrf2-deficient mice had increased oxidative stress and exacerbated neutrophilic airway inflammation compared with the wild-type mice. Type 2 cytokines and the expression of GATA3, a transcription factor that is important for Th2 cell differentiation, had decreased in Nrf2-deficient mice compared with the wild-type mice, whereas helper T (Th) 17 cytokines and the expression of RORγt, which is important for Th17 cell differentiation, had increased. Furthermore, the neutrophilic airway inflammation caused by Nrf2 deficiency was ameliorated by interleukin (IL)-17 neutralization. We have concluded that the disruption of the Nrf2-mediated antioxidant defense system contributed to the induction of Th17 differentiation and exacerbated allergic neutrophilic airway inflammation.

Changing Characteristics of Treg/Th17 Cells in the Nasal Mucosa of a Mouse Model of Allergic Rhinitis and the Effect of Intervention with Anti-IL-17 Antibody.

The incidence rate of allergic rhinitis (AR) is on the rise, which seriously affects the quality of life, work efficiency, mental state of patients, and sleeping in AR sleep. This experiment aimed to investigate the changes in Treg/Th17 cells in the nasal mucosa of an AR mouse model and the intervention effect of an Anti-IL-17 antibody. A mouse model of AR was induced by intraperitoneal ovalbumin (OVA) injection for sensitization and stimulation with nasal drops. The times of rubbing, sneezing, and symptomatology scores were counted and analyzed. Pathological damage to the nasal mucosa was observed by Hematoxylin-Eosin (HE) staining. Peripheral blood CD4+CD25+CD127- Treg cell levels and the content of Th17 cells were measured by flow cytometry (FCM). ELISA kits were used to detect the levels of relevant cytokines (IL-10 and TGF-β1) secreted by Treg cells. The intervention effect of Anti-IL-17 antibody was observed by giving Anti-IL-17 antibody treatment. The times of rubbing, sneezing, and symptomatology scores were significantly higher in mice in the OVA group than in the Control group (p < 0.001). The percentage of CD4+CD25+CD127- Treg cells in CD4+CD25+ T cells (p < 0.05) and the levels of IL-10 (p < 0.001) and TGF-β1 (p < 0.001) were significantly decreased. After OVA induction, the continuity of the nasal mucosa of mice was interrupted, the percentage of Th17 cells, IL-17, and IL-4 levels were increased, and IFN-γ levels were significantly reduced (p < 0.001). And protein expression of RORγt was significantly upregulated (p < 0.001). In addition, all of these results were reversed by Anti-IL-17 antibody treatment, significantly improving AR-related symptoms (p < 0.05). Anti-IL-17 antibodies may regulate the body's immune response by promoting CD4+CD25+CD127- Treg cell differentiation, thereby ameliorating the symptoms associated with AR.

Effector CD4+ T-cell subsets in Takayasu arteritis-differences between the peripheral blood and the aorta.

Takayasu arteritis (TAK) is a granulomatous vasculitis that affects large arteries. T cells are important in TAK pathophysiology as these cells orchestrate granulomatous infiltration in arteries. This study aims to evaluate effector CD4+ T cells in the peripheral blood and the aortic wall of TAK patients and to analyze associations with disease activity and therapy. We performed a longitudinal study including 30 TAK patients and 30 controls. CD3+ T cells, CD3+CD4- T cells, CD4+ T cells, and Th1, Th2, and Th17 cells were evaluated in peripheral blood by flow cytometry, and the expression of CD4, CD8, Tbet, GATA-3, and RORγT was analyzed in the aorta of six patients by immunohistochemistry. TAK patients presented lower CD3+ T cells and CD4+ T cells (P = 0.031 and P = 0.039, respectively) than controls. Patients with active disease and those in remission had higher proportions of Th17 cells than controls (P = 0.016 and P = 0.004, respectively). Therapy for TAK did not result in significant differences concerning CD4+ effector T-cell subpopulations. Disease duration correlated with the number and percentage of Th2 cells (rho = -0.610 and rho = -0.463, respectively) and with Th17 cells (rho = -0.365 and rho = -0.568). In the aorta, the expression of CD8 was higher than CD4, whereas GATA-3, Tbet, and RORγT were expressed in this order of frequency. In conclusion, TAK patients present an increased Th17 response in the peripheral blood regardless of disease activity, whereas in the aortic tissue CD8 cells and the Th2 response were predominant.