Regulatory CD4+ T cells redirected against pathogenic CD8+ T cells protect NOD mice from development of autoimmune diabetes.

Introduction: In this study, we report a novel therapeutic approach redirecting antigen-specific CD4+ T cells recognizing a hybrid insulin peptide (BDC2.5 T cell receptor (TCR) transgenic CD4+ T cells) to attract and suppress islet-specific CD8+ T cells T cells in the non-obese diabetic (NOD) mouse model, and prevent the development of autoimmune diabetes. Methods: Purified BDC2.5 CD4+ T cells were induced to differentiate into regulatory T cells (Tregs). The Tregs were then electroporated with mRNA encoding chimeric human ß2 microglobulin (hß2m) covalently linked to insulin B chain amino acids 15-23 (designated INS-eTreg) or islet-specific glucose-6-phosphatase related protein (IGRP) peptide 206-214 (designated IGRP-eTreg). Immunoregulatory functions of these engineered regulatory T cells (eTregs) were tested by in vitro assays and in vivo co-transfer experiments with ß-cell-antigen-specific CD8+ T cells in NOD.Scid mice or by adoptive transfer into young, pre-diabetic NOD mice. Results: These eTregs were phenotyped by flow cytometry, and shown to have high expression of FoxP3, as well as other markers of Treg function, including IL-10. They suppressed polyclonal CD4+ T cells and antigen-specific CD8+ T cells (recognizing insulin or IGRP), decreasing proliferation and increasing exhaustion and regulatory markers in vitro. In vivo, eTregs reduced diabetes development in co-transfer experiments with pathogenic antigen-specific CD8+ T cells (INS-CD8+ or IGRP-CD8+ cells) into NOD.Scid mice. Finally, when the eTreg were injected into young NOD mice, they reduced insulitis and prevented spontaneous diabetes in the recipient mice. Conclusion: Our results suggest a novel therapeutic strategy to protect NOD mice by targeting antigen-specific cytotoxic CD8+ T cells, using redirected antigen-specific CD4+ Treg cells, to suppress autoimmune diabetes. This may suggest an innovative therapy for protection of people at risk of development of type 1 diabetes.

Effects of two immunosuppression regimens on T-lymphocyte subsets in elderly kidney transplant recipients.

Background: Despite the growing number of elderly kidney transplant (Ktx) recipients, few studies have examined the effects of immunosuppression on their lymphocyte profiles. Methods: We evaluated the early conversion from mycophenolate sodium (MPS) to everolimus (EVL) after rabbit antithymocyte globulin (rATG) 2 mg/kg induction in elderly kidney recipients. Three groups of KTx patients were compared: (a) Young (n=20, 36 ± 7 y) receiving standard immunosuppression (Group A1) (prednisone, tacrolimus, and MPS), (b) Elderly (n=35, 65 ± 3 y) receiving standard immunosuppression (Group B1), and (c) Elderly (n=16, 65 ± 3 y) with early (mean 30 d) conversion from MPS to EVL (Group B2). Naive, memory, and regulatory peripheral blood TCD4+ lymphocytes were quantified at 0, 30, and 365 d. Results: Results are reported as [mean(p25-p75)]. Young recipients had higher lymphocyte counts at baseline [2,100(1,630-2,400) vs. 1,310 (1,000-1,600)/mm3, p<0.0001] maintained higher counts within 365 d [1,850(1,590-2,120) vs. 1,130(460-1,325)/mm3, p=0.018 and vs. 1,410(805-1,895)/mm3, p=0.268]. Elderly recipients showed a decrease in lymphocytes within 30 d [1,310(1,000-1,600) vs. 910(700-1,198)/mm3, p=0.0012] with recovery within 365 d. The same pattern was observed in total lymphocytes and TCD4+ counts. Rabbit antithymocyte globulin induced a reduction in central memory T-cell percentages at 30 d in both young recipients [6.2(3.77-10.8) vs. 5.32(2.49-7.28)% of CD4+, p=0.036] and in elderly recipients [8.17(5.28-12.88) vs. 6.74(4.36-11)% of CD4+, p=0.05] on standard immunosuppression, returning to baseline at 365 d in elderly recipients but not in young recipients. Regulatory T CD39+ cells (Treg) percentages decreased at 30 d in elderly recipients [2.1(1.23-3.51) vs. 1.69(0.8-2.66)% of CD4+, p=0.0028] and in young recipients [1.29(0.45-1.85) vs. 0.84(0.18-1.82)% of CD4+, p=0.0038], returning to baseline at 365 d in elderly recipients [2.1(1.23-3.51) vs. 2.042(0.88-2.42)% of CD4+], but not in young recipients [1.29(0.45-1.85) vs. 0.86(0.7-1.34) % of CD4+]. The elderly everolimus conversion group did not show significant changes in cell profile over time or compared to elderly recipients with standard immunosuppression. Conclusion: Aging favored the maintenance of Treg during the late transplantation period despite ongoing immunosuppression. Lymphocyte depletion due to rATG was more prominent in elderly recipients and affected memory subsets with a temporary reduction in central memory T cells. However, conversion to everolimus did not impact Treg profile. Reducing the dose of rATG in elderly recipients seems necessary for the expected lymphocyte changes with EVL to occur. Clinical trial registration: nEverOld Trial, identifier NTC01631058.

COL6A6 Peptide Vaccine Alleviates Atherosclerosis through Inducing Immune Response and Regulating Lipid Metabolism in Apoe-/- Mice.

Atherosclerosis is an autoimmune disease characterized by lipid imbalances and chronic inflammation within blood vessels, with limited preventive and treatment options currently available. In this study, a vaccine prepared with COL6A6 peptide (named the Pep_A6 vaccine) was administered to immunize Apoe-/- mice, and the immune mechanism of the Pep_A6 vaccine against atherosclerosis was first investigated. The results of arterial oil red O staining demonstrated that the Pep_A6 vaccine significantly reduced the atherosclerotic plaque area in Apoe-/- mice fed with a high-fat diet for 20 weeks. A flow cytometry analysis revealed that the Pep_A6 vaccine inhibited Th1 cell differentiation and increased the proportion of Treg cells. Furthermore, there was a significant increase in Ly6Clow monocytes observed in the vaccinated group. The ELISA results showed that the Pep_A6 vaccine induced a significant expression of Pep_A6-specific antibody IgG and IgG1 in mouse serum. Additionally, we found that the Pep_A6 vaccine significantly decreased serum LDL-C content and regulated the expression of genes related to liver lipid metabolism. Together, our findings suggest that the Pep_A6 vaccine alleviates atherosclerosis by inducing a positive immune response and regulating lipid metabolism, providing new insights into potential prevention strategies for atherosclerosis as an innovative vaccine.

Curcumin chitosan microspheres regulate Th17/Treg balance via IGF2BP1- mediated m6A modification of LRP5 in ulcerative colitis.

Objectives: Ulcerative colitis (UC) is a commonly recurrent inflammatory bowel disease. T helper 17 (Th17)/regulatory T (Treg) cell balance plays an essential role in UC progression. However, it is unknown whether curcumin chitosan microspheres (CCM) regulate the Th17/Treg cell balance. Materials and Methods: The UC mouse model was established by administering 3% dextran sodium sulfate and treated with CCM. The influence of CCM on the Th17/Treg balance was detected using flow cytometry. Cell experiments were conducted to investigate the role and mechanism of IGF2BP1 in Th17/Treg balance. Results: We revealed that CCM demonstrated a significant therapeutic effect on UC. CCM obviously decreased the Th17 cell percentage but boosted the Treg cell percentage in UC mice. CCM remarkably increased the mRNA expression of Foxp3 but suppressed RORγt and interleukin-10 mRNA expression. PCR array of RNA modification-related genes revealed that the m6A binding protein IGF2BP1 was a key molecule in CCM regulation of Th17/Treg balance. IGF2BP1 overexpression dramatically repressed the CCM-induced balance of Th17/Treg cell differentiation. Mechanically, IGF2BP1 targeted LRP5 and regulated LRP5 through m6A modification. Furthermore, the silencing of LRP5 canceled the suppressive effect of IGF2BP1 on Th17/Treg cell percentage. Conclusion: CCM modulated the Th17/Treg balance through IGF2BP1-mediated m6A modification, thereby alleviating UC, and providing new ideas for the treatment of UC.

CD25+FOXP3+CD45RA- regulatory T-cell infiltration as a prognostic biomarker for endometrial carcinoma.

BACKGROUND: Regulatory T (Treg) cells reportedly play crucial roles in tumor angiogenesis as well as antitumor immunity. In order to explore their therapeutic potential, we investigated the precise prognostic impact of Treg markers in endometrial carcinoma. METHODS: We performed multiplexed immunofluorescence and quantitative image analyses of CD25, FOXP3, CTLA4, and CD45RA in tumor specimens from 176 consecutive patients treated at our institution for primary endometrial carcinomas. Bioinformatics analyses were further conducted to corroborate the findings. RESULTS: High CD25+, FOXP3+, and CD25+FOXP3+CD45RA- stromal cell counts correlated with better overall survival (OS) (p = 0.00019, 0.028 and 0.0012) and MSI-high (p = 0.015, 0.016 and 0.047). High CD45RA+ stromal cell count was associated with superficial myometrial invasion (p = 0.0038). Bioinformatics survival analysis by Kaplan-Meier plotter showed that high CD25, FOXP3, CTLA4, and CD45RA mRNA expressions correlated with better OS (p = 0.046, 0.00042, 0.000044, and 0.0022). Univariate and multivariate analyses with various clinicopathologic prognostic factors indicated that high CD25+ or CD25+FOXP3+CD45RA- stromal cell count was significant and independent for favorable OS (p = 0.0053 and 0.0015). We subsequently analyzed the correlations between the multiplexed immunofluorescence results and treatment-free interval (TFI) after primary chemotherapy in recurrent cases, finding no significant associations. Further analysis revealed that high ratio of CD25+ : CD8+ cell count or CD25+FOXP3+CD45RA- : CD8+ cell count correlated with longer TFI (p = 0.021 and 0.021). CONCLUSION: The current observations suggest that the balance between CD25+ or CD25+FOXP3+CD45RA- cells and CD8+ cells, corresponding to promoting or inhibiting effect on tumor angiogenesis, affect tumor chemosensitivity leading to prognostic significance. CD25+FOXP3+CD45RA- effector Treg tumor infiltration may serve as a useful prognostic biomarker and a potential target for immunotherapeutic manipulation of tumor chemosensitivity by novel management for advanced/recurrent endometrial carcinomas.

Mitigating lead-induced osteoporosis: The role of butyrate in gut-bone axis restoration.

Lead (Pb) is an environmentally widespread bone toxic pollutant, contributes to the development of osteoporosis. Butyric acid, mainly produced by the fermentation of indigestible dietary fiber by gut microbiota, plays a pivotal role in the maintenance of bone homeostasis. However, the effects of butyric acids on the Pb induced osteoporosis have not yet been elucidated. In this study, our results showed that Pb exposure was negatively related to the abundance of butyric acid, in the Pb-exposed population and Pb-exposed mice. Pb exposure caused gut microbiota disorders, resulting in the decline of butyric acid-producing bacteria, such as Butyrivibrio_crossotus, Clostridium_sp._JN9, and the butyrate-producing enzymes through the acetyl-CoA pathway. Moreover, results from the NHANES data suggested that dietary intake of butyrate was associated with a reduced risk of osteoporosis in lead-burdened populations, particularly among men or participants aged 18-60 years. In addition, butyrate supplementation in mice with chronic Pb exposure improved the bone microarchitectures, repaired intestinal damage, upregulated the proportion of Treg cells. Taken together, these results demonstrated that chronic Pb exposure disturbs the gut-bone axis, which can be restored by butyric acid supplement. Our results suggest that butyrate supplementation is a possible therapeutic strategy for lead-induced bone toxicity.

The alterations in CD4+Treg cells across various phases of major depression.

BACKGROUND: Major depression (MD) is recurrent and devastating mental disease with a high worldwide prevalence. Mounting evidence suggests neuroinflammation triggers cellular immune dysregulation, characterized by increased proportions of circulating monocytes, and T helper 17 cells and proinflammatory cytokines, thereby increasing susceptibility to MD. However, there is ambiguity in the findings of clinical studies that investigate CD4+ T regulatory (Treg) cells in MD. METHODS: The proportion of CD4+ Treg cell from blood mononuclear cells was examined using flow cytometry in healthy controls (HCs: n = 96) and patients with first (FEMD: n = 62) or recurrent (RMD: n = 41) disease episodes of MD at baseline (T0; hospital admission) and after a two-week antidepressant treatment (T14). All participants underwent comprehensive neuropsychological assessments. RESULTS: The initial scores on emotional assessments in patients with MD significantly differed from those of HCs. Both FEMD and RMD patients exhibited a significant decrease in CD4+ Treg cell proportion at baseline compared to HCs. Treg cell proportion rose significantly from T0 to T14 in FEMD patients, who responded to antidepressant therapy, whereas no significant changes were observed in FEMD patients in non-response as well as RMD patients. The improvement of 24-item Hamilton Depression Scale was correlate with changes of Treg cell proportion from T0 to T14 in FEMD patients in response, and the change in Treg cell proportion over a 14-day period exhibited an AUC curve of 0.710. CONCLUSIONS: A decrease in the proportion of CD4+ Treg cells points towards immune system abnormalities in patients with MD. Furthermore, our finding suggests that the immune activation state varies across different stages of depression.

Fragile Treg cells: Traitors in immune homeostasis?

Regulatory T (Treg) cells play a key role in maintaining immune tolerance and tissue homeostasis. However, in some disease microenvironments, Treg cells exhibit fragility, which manifests as preserved FoxP3 expression accompanied by inflammation and loss of immunosuppression. Fragile Treg cells are formatively, phenotypically and functionally diverse in various diseases, further complicating the role of Treg cells in the immunotherapeutic response and offering novel targets for disease treatment by modulating specific Treg subsets. In this review, we summarize findings on fragile Treg cells to provide a framework for characterizing the formation and role of fragile Treg cells in different diseases, and we discuss how this information may guide the development of more specific Treg-targeted immunotherapies.

Resolution of inflammation, an active process to restore the immune microenvironment balance: A novel drug target for treating arterial hypertension.

The resolution of inflammation, the other side of the inflammatory response, is defined as an active and highly coordinated process that promotes the restoration of immune microenvironment balance and tissue repair. Inflammation resolution involves several key processes, including dampening proinflammatory signaling, specialized proresolving lipid mediator (SPM) production, nonlipid proresolving mediator production, efferocytosis and regulatory T-cell (Treg) induction. In recent years, increasing attention has been given to the effects of inflammation resolution on hypertension. Furthermore, our previous studies reported the antihypertensive effects of SPMs. Therefore, in this review, we aim to summarize and discuss the detailed association between arterial hypertension and inflammation resolution. Additional, the association between gut microbe-mediated immune and hypertension is discussed. This findings suggested that accelerating the resolution of inflammation can have beneficial effects on hypertension and its related organ damage. Exploring novel drug targets by focusing on various pathways involved in accelerating inflammation resolution will contribute to the treatment and control of hypertensive diseases in the future.

NECA alleviates inflammatory responses in diabetic retinopathy through dendritic cell toll-like receptor signaling pathway.

Introduction: This study examined the impact of 5'-(N- ethylcarboxamido)adenosine (NECA) in the peripheral blood of healthy individuals, those with diabetes mellitus, diabetic retinopathy (DR), and C57BL/6 mice, both in vivo and in vitro. Methods: Enzyme-linked immunosorbent assay (ELISA) and flow cytometry (FCM) were used to evaluate the effects of NECA on dendritic cells (DCs) and mouse bone marrow-derived dendritic cells (BMDCs) and the effects of NECA-treated DCs on Treg and Th17 cells. The effect of NECA on the Toll-like receptor (TLR) pathway in DCs was evaluated using polymerase chain reaction (PCR) and western blotting (WB). Results: FCM and ELISA showed that NECA inhibited the expression of surface markers of DCs and BMDCs, increased anti-inflammatory cytokines and decreased proinflammatory cytokines. PCR and WB showed that NCEA decreased mRNA transcription and protein expression in the TLR-4-MyD88-NF-kß pathway in DCs and BMDCs. The DR severity in streptozocin (STZ) induced diabetic mice was alleviated. NECA-treated DCs and BMDCs were co-cultivated with CD4+T cells, resulting in modulation of Treg and Th17 differentiation, along with cytokine secretion alterations. Conclusion: NECA could impair DCs' ability to present antigens and mitigate the inflammatory response, thereby alleviating the severity of DR.

Inhibition of Lck/Fyn kinase activity promotes the differentiation of induced Treg cells through AKT/mTOR pathway.

Regulatory T (Treg) cells are indispensable in maintaining the immune homeostasis and preventing autoimmune diseases. Regulatory T (Treg) cells include thymus derived Treg cells (tTregs) and peripherally induced Treg cells (iTreg), which are differentiated from antigen stimulated CD4+ naïve T cells in presence of TGFß. tTregs are quite stable, and more immune suppressive, while iTreg cells are less stable, and are prone to differentiate into inflammatory T cells. Therefore, identification of small molecules that could promote the differentiation of iTreg cells is an attractive strategy for autoimmune diseases. Inhibition of AKT/mTOR pathway promotes their differentiation. Whether inhibition of Lck/Fyn kinase activity (upstream of AKT/mTOR pathway) can be used to promote the differentiation of iTreg cells has not been determined. Here, we showed that Srci1, a small molecular inhibitor of Lck/Fyn, promoted the differentiation of FOXP3+ iTreg cells. Srci1 treatment resulted in inhibition of phosphorylation of key components of AKT/mTOR pathway, including mTOR, p70 S6K, 4EBP1, and promoted the expression of Foxp3 and its target genes, thereby promoted differentiation of in vitro iTreg cells. Srci1 treated iTreg cells showed more similar gene expression profile to that of tTreg cells. Our results thus suggest that inhibition of Lck/Fyn kinase activity can promote the differentiation of iTreg cells, and may have implication in autoimmune diseases.

CD200R activation on naïve T cells by B cells induces suppressive activity of T cells via IL-24.

CD200 is an anti-inflammatory protein that facilitates signal transduction through its receptor, CD200R, in cells, resulting in immune response suppression. This includes reducing M1-like macrophages, enhancing M2-like macrophages, inhibiting NK cell cytotoxicity, and downregulating CTL responses. Activation of CD200R has been found to modulate dendritic cells, leading to the induction or enhancement of Treg cells expressing Foxp3. However, the precise mechanisms behind this process are still unclear. Our previous study demonstrated that B cells in Peyer's patches can induce Treg cells, so-called Treg-of-B (P) cells, through STAT6 phosphorylation. This study aimed to investigate the role of CD200 in Treg-of-B (P) cell generation. To clarify the mechanisms, we used wild-type, STAT6 deficient, and IL-24 deficient T cells to generate Treg-of-B (P) cells, and antagonist antibodies (anti-CD200 and anti-IL-20RB), an agonist anti-CD200R antibody, CD39 inhibitors (ARL67156 and POM-1), a STAT6 inhibitor (AS1517499), and soluble IL-20RB were also applied. Our findings revealed that Peyer's patch B cells expressed CD200 to activate the CD200R on T cells and initiate the process of Treg-of-B (P) cells generation. CD200 and CD200R interaction triggers the phosphorylation of STAT6, which regulated the expression of CD200R, CD39, and IL-24 in T cells. CD39 regulated the expression of IL-24, which sustained the expression of CD223 and IL-10 and maintained the cell viability. In summary, the generation of Treg-of-B (P) cells by Peyer's patch B cells was through the CD200R-STAT6-CD39-IL-24 axis pathway.

ß-Indole-3-acetic acid attenuated collagen-induced arthritis through reducing the ubiquitination of Foxp3 via the AhR-TAZ-Tip60 pathway.

Massive evidence shows that intestinal tryptophan metabolites affected by intestinal flora can modulate the progression of rheumatoid arthritis (RA). However, the effects and mechanisms of intestinal tryptophan metabolites on RA are not yet detailed. Herein, we investigated the protective effects of intestinal tryptophan metabolites on RA and its detailed mechanisms. In this study, the collagen-induced arthritis (CIA) rat model was established. Based on metabolomics analysis, the contents of ß-indole-3-acetic acid (IAA), indolylpropionic acid, and indole-3-ß-acrylic acid in the sera of CIA rats were significantly less compared with those of the normal rats. Under the condition of Treg or Th17 cell differentiation, IAA significantly promoted the differentiation and activation of Treg cells instead of Th17 cells. Intestinal tryptophan metabolites are well-known endogenic ligands of aryl hydrocarbon receptor (AhR). Not surprisingly, IAA increased the level of Foxp3 through activating the AhR pathway. Interestingly, IAA had little impact on the level of Foxp3 mRNA, but reducing the ubiquitination and degradation of Foxp3. Mechanically, IAA reduced the expression of the transcriptional coactivator TAZ, which was almost completely reversed by either AhR antagonist CH223191 or siRNA. In vitro, IAA decreased the combination of TAZ and the histone acetyltransferase Tip60, while it increased the combination of Tip60 and Foxp3. In CIA rats, oral administration of IAA increased the number of Treg cells and relieved the inflammation. A combined use with CH223191 almost abolished the effect of IAA. Taken together, IAA attenuated CIA by promoting the differentiation of Treg cells through reducing the ubiquitination of Foxp3 via the AhR-TAZ-Tip60 pathway.

CD80 on skin stem cells promotes local expansion of regulatory T cells upon injury to orchestrate repair within an inflammatory environment.

Following tissue damage, epithelial stem cells (SCs) are mobilized to enter the wound, where they confront harsh inflammatory environments that can impede their ability to repair the injury. Here, we investigated the mechanisms that protect skin SCs within this inflammatory environment. Characterization of gene expression profiles of hair follicle SCs (HFSCs) that migrated into the wound site revealed activation of an immune-modulatory program, including expression of CD80, major histocompatibility complex class II (MHCII), and CXC motif chemokine ligand 5 (CXCL5). Deletion of CD80 in HFSCs impaired re-epithelialization, reduced accumulation of peripherally generated Treg (pTreg) cells, and increased infiltration of neutrophils in wounded skin. Importantly, similar wound healing defects were also observed in mice lacking pTreg cells. Our findings suggest that upon skin injury, HFSCs establish a temporary protective network by promoting local expansion of Treg cells, thereby enabling re-epithelialization while still kindling inflammation outside this niche until the barrier is restored.

Role of Treg cell subsets in cardiovascular disease pathogenesis and potential therapeutic targets.

In the genesis and progression of cardiovascular diseases involving both innate and adaptive immune responses, inflammation plays a pivotal and dual role. Studies in experimental animals indicate that certain immune responses are protective, while others exacerbate the disease. T-helper (Th) 1 cell immune responses are recognized as key drivers of inflammatory progression in cardiovascular diseases. Consequently, the CD4+CD25+FOXP3+ regulatory T cells (Tregs) are gaining increasing attention for their roles in inflammation and immune regulation. Given the critical role of Tregs in maintaining immune-inflammatory balance and homeostasis, abnormalities in their generation or function might lead to aberrant immune responses, thereby initiating pathological changes. Numerous preclinical studies and clinical trials have unveiled the central role of Tregs in cardiovascular diseases, such as atherosclerosis. Here, we review the roles and mechanisms of Treg subsets in cardiovascular conditions like atherosclerosis, hypertension, myocardial infarction and remodeling, myocarditis, dilated cardiomyopathy, and heart failure. While the precise molecular mechanisms of Tregs in cardiac protection remain elusive, therapeutic strategies targeting Tregs present a promising new direction for the prevention and treatment of cardiovascular diseases.

Human embryonic stem cell-derived mesenchymal stromal cells suppress inflammation in mouse models of rheumatoid arthritis and lung fibrosis by regulating T-cell function.

BACKGROUND AIMS: Rheumatoid arthritis (RA) is characterized by an overactive immune system, with limited treatment options beyond immunosuppressive drugs or biological response modifiers. Human embryonic stem cell-derived mesenchymal stromal cells (hESC-MSCs) represent a novel alternative, possessing diverse immunomodulatory effects. In this study, we aimed to elucidate the therapeutic effects and underlying mechanisms of hESC-MSCs in treating RA. METHODS: MSC-like cells were differentiated from hESC (hESC-MSCs) and cultured in vitro. Cell proliferation was assessed using Cell Counting Kit-8 assay and Ki-67 staining. Flow cytometry was used to analyze cell surface markers, T-cell proliferation and immune cell infiltration. The collagen-induced arthritis (CIA) mouse model and bleomycin-induced model of lung fibrosis (BLE) were established and treated with hESC-MSCs intravenously for in vivo assessment. Pathological analyses, reverse transcription-quantitative polymerase chain reaction and Western blotting were conducted to evaluate the efficacy of hESC-MSCs treatment. RESULTS: Intravenous transplantation of hESC-MSCs effectively reduced inflammation in CIA mice in this study. Furthermore, hESC-MSC administration enhanced regulatory T cell infiltration and activation. Additional findings suggest that hESC-MSCs may reduce lung fibrosis in BLE mouse models, indicating their potential to mitigate complications associated with RA progression. In vitro experiments revealed a significant inhibition of T-cell activation and proliferation during co-culture with hESC-MSCs. In addition, hESC-MSCs demonstrated enhanced proliferative capacity compared with traditional primary MSCs. CONCLUSIONS: Transplantation of hESC-MSCs represents a promising therapeutic strategy for RA, potentially regulating T-cell proliferation and differentiation.

Dihydroartemisinin alleviates erosive bone destruction by modifying local Treg cells in inflamed joints: A novel role in the treatment of rheumatoid arthritis.

Treg cell-based therapy has exhibited promising efficacy in combatting rheumatoid arthritis (RA). Dihydroartemisinin (DHA) exerts broad immunomodulatory effects across various diseases, with its recent spotlight on T-cell regulation in autoimmune conditions. The modulation of DHA on Treg cells and its therapeutic role in RA has yet to be fully elucidated. This study seeks to unveil the influence of DHA on Treg cells in RA and furnish innovative substantiation for the potential of DHA to ameliorate RA. To this end, we initially scrutinized the impact of DHA-modulated Treg cells on osteoclast (OC) formation in vitro using Treg cell-bone marrow-derived monocyte (BMM) coculture systems. Subsequently, employing the collagen-induced arthritis (CIA) rat model, we validated the efficacy of DHA and probed its influence on Treg cells in the spleen and popliteal lymph nodes (PLN). Finally, leveraging deep proteomic analysis with data-independent acquisition (DIA) and parallel accumulation-serial fragmentation (PASEF) technology, we found the alterations in the Treg cell proteome in PLN by proteomic analysis. Our findings indicate that DHA augmented suppressive Treg cells, thereby impeding OC formation in vitro. Consistently, DHA mitigated erosive joint destruction and osteoclastogenesis by replenishing splenic and joint-draining lymph node Treg cells in CIA rats. Notably, DHA induced alterations in the Treg cell proteome in PLN, manifesting distinct upregulation of alloantigen Col2a1 (Type II collagen alfa 1 chain) and CD8a (T-cell surface glycoprotein CD8 alpha chain) in Treg cells, signifying DHA's targeted modulation of Treg cells, rendering them more adept at sustaining immune tolerance and impeding bone erosion. These results unveil a novel facet of DHA in the treatment of RA.

[Adipose-derived stem cell-derived exosomes regulate Th2/Treg balance in peripheral blood of AR patients through the mTOR pathway].

Objective:To investigate the mechanism of adipose derived stem cell exosomes（ADSC-exos） regulating Th2/Treg balance in peripheral blood of patients with allergic rhinitis（AR）. Methods:Thirty patients with AR who were treated in Department of Otolaryngology Head and Neck Surgery, the First Affiliated Hospital of Zhengzhou University from March 2022 to October 2022 were selected, and 30 patients with simple deviation of nasal septum who were treated in our department during the same period were selected as the control group. 10 mL peripheral venous blood was collected from all patients. The levels of IL-4 and TGF-ß in plasma were analyzed by ELISA. PBMCs were isolated by density gradient centrifugation. Then, protein and RNA were further extracted, and the expression levels of IL-4, TGF-ß, GATA3 and Foxp3 genes were detected by qRT-PCR. Western Blotting detected p-PI3K（P85）, p-AKT（Ser473） in PBMCs of AR patients and healthy controls. Protein expression levels of p-mTOR（Ser2448）, p-p70S6K（Thr389）, and the proportion of Th2 and Treg cells were analyzed by flow cytometry. PBMCs of AR patients were stimulated to differentiate and co-cultured with exosomes of adipose stem cells. p-PI3K（P85）, p-AKT（Ser473）, p-mTOR（Ser2448） were detected in exosome treated group and untreated group by Western Blotting. The expression level of p-p70S6K（Thr389） protein, the proportion of Th2 and Treg cells were analyzed by flow cytometry, and the levels of IL-4 and TGF-ß in the supernatant of cell culture were detected by ELISA. Results:Compared with the control group, the mTOR pathway in peripheral blood of AR group was significantly activated, the level of IL-4 in plasma was increased, and the level of TGF-ß was decreased（P<0.05）. Compared with the control group, the proportion of Th2 cells in peripheral blood was increased, and the proportion of Treg cells was decreased（P<0.01）. Compared with the untreated group, the expression level of mTOR pathway protein decreased, the level of IL-4 decreased, and the level of TGF-ß increased. The proportion of Th2 cells decreased, and the proportion of Treg cells increased（P<0.01）. Conclusion:There is an imbalance of Th2 and Treg cells in peripheral blood mononuclear cells of AR patients; the PI3K/AKT/mTOR/p70S6K pathway is activated in peripheral blood mononuclear cells of AR patients Exosomes derived from adipose mesenchymal stem cells may regulate Th2/Treg balance in AR patients through the PI3K/AKT/mTOR/p70S6K pathway.

Remote Ischemic Post-conditioning Reduces Cognitive Impairment in Rats Following Subarachnoid Hemorrhage: Possible Involvement in STAT3/STAT5 Phosphorylation and Th17/Treg Cell Homeostasis.

The inflammatory response following subarachnoid hemorrhage (SAH) may lead to Early Brain Injury and subsequently contribute to poor prognosis such as cognitive impairment in patients. Currently, there is a lack of effective strategies for SAH to ameliorate inflammation and improve cognitive impairment in clinical. This study aims to examine the inhibitory impact of remote ischemic post-conditioning (RIPostC) on the body's inflammatory response by regulating Th17/Treg cell homeostasis after SAH. The ultimate goal is to search for potential early treatment targets for SAH. The rat SAH models were made by intravascular puncture of the internal carotid artery. The intervention of RIPostC was administered for three consecutive days immediately after successful modeling. Behavioral experiments including the Morris water maze and Y-maze tests were conducted to assess cognitive functions such as spatial memory, working memory, and learning abilities 2 weeks after successful modeling. The ratio of Th17 cells and Treg cells in the blood was detected using flow cytometry. Immunofluorescence was used to observe the infiltration of neutrophils into the brain. Signal transducers and activators of transcription 5 (STAT5) and signal transducers and activators of transcription 3 (STAT3) phosphorylation levels, receptor-related orphan receptor gamma-t (RORγt), and forkhead box protein P3 (Foxp3) levels were detected by Western blot. The levels of anti-inflammatory factors (IL-2, IL-10, IL-5, etc.) and pro-inflammatory factors (IL-6, IL-17, IL-18, TNF-α, IL-14, etc.) in blood were detected using Luminex Liquid Suspension Chip Assay. RIPostC significantly improved the cognitive impairment caused by SAH in rats. The results showed that infiltration of Th17 cells and neutrophils into brain tissue increased after SAH, leading to the release of pro-inflammatory factors (IL-6, IL-17, IL-18, and TNF-α). This response can be inhibited by RIPostC. Additionally, RIPostC facilitates the transfer of Treg from blood to the brain and triggers the release of anti-inflammatory (IL-2, IL-10, and IL-5) factors to suppress the inflammation following SAH. Finally, it was found that RIPostC increased the phosphorylation of STAT5 while decreasing the phosphorylation of STAT3. RIPostC reduces inflammation after SAH by partially balancing Th17/Treg cell homeostasis, which may be related to downregulation of STAT3 and upregulation of STAT5 phosphorylation, which ultimately alleviates cognitive impairment in rats. Targeting Th17/Treg cell homeostasis may be a promising strategy for early SAH treatment.

A lncRNA Dleu2-encoded peptide relieves autoimmunity by facilitating Smad3-mediated Treg induction.

Micropeptides encoded by short open reading frames (sORFs) within long noncoding RNAs (lncRNAs) are beginning to be discovered and characterized as regulators of biological and pathological processes. Here, we find that lncRNA Dleu2 encodes a 17-amino-acid micropeptide, which we name Dleu2-17aa, that is abundantly expressed in T cells. Dleu2-17aa promotes inducible regulatory T (iTreg) cell generation by interacting with SMAD Family Member 3 (Smad3) and enhancing its binding to the Foxp3 conserved non-coding DNA sequence 1 (CNS1) region. Importantly, the genetic deletion of Dleu2-17aa in mice by start codon mutation impairs iTreg generation and worsens experimental autoimmune encephalomyelitis (EAE). Conversely, the exogenous supplementation of Dleu2-17aa relieves EAE. Our findings demonstrate an indispensable role of Dleu2-17aa in maintaining immune homeostasis and suggest therapeutic applications for this peptide in treating autoimmune diseases.