Frequency Of Treg Cells Research Articles

Nuclear receptor corepressor 1 controls regulatory T cell subset differentiation and effector function.

FOXP3+ regulatory T cells (Treg cells) are key for immune homeostasis. Here, we reveal that nuclear receptor corepressor 1 (NCOR1) controls naïve and effector Treg cell states. Upon NCOR1 deletion in T cells, effector Treg cell frequencies were elevated in mice and in in vitro-generated human Treg cells. NCOR1-deficient Treg cells failed to protect mice from severe weight loss and intestinal inflammation associated with CD4+ T cell transfer colitis, indicating impaired suppressive function. NCOR1 controls the transcriptional integrity of Treg cells, since effector gene signatures were already upregulated in naïve NCOR1-deficient Treg cells while effector NCOR1-deficient Treg cells failed to repress genes associated with naïve Treg cells. Moreover, genes related to cholesterol homeostasis including targets of liver X receptor (LXR) were dysregulated in NCOR1-deficient Treg cells. However, genetic ablation of LXRβ in T cells did not revert the effects of NCOR1 deficiency, indicating that NCOR1 controls naïve and effector Treg cell subset composition independent from its ability to repress LXRβ-induced gene expression. Thus, our study reveals that NCOR1 maintains naïve and effector Treg cell states via regulating their transcriptional integrity. We also reveal a critical role for this epigenetic regulator in supporting the suppressive functions of Treg cells in vivo.

IL-33 Induces a Switch in Intestinal Metabolites Revealing the Tryptophan Pathway as a Target for Inducing Allograft Survival.

IL-33, a pleiotropic cytokine, has been associated with a plethora of immune-related processes, both inflammatory and anti-inflammatory. T regulatory (Treg) cells, the main leukocyte population involved in immune tolerance, can be induced by the administration of IL-33, the local microbiota, and its metabolites. Here, we demonstrate that IL-33 drastically induces the production of intestinal metabolites involved on tryptophan (Trp) metabolism. naïve mice were treated with IL-33 for 4 days and leukocyte populations were analyzed by flow cytometry, and feces were processed for microbiota and intestinal metabolites studies. Using a murine skin transplantation model, the effect of Kynurenic acid (KA) on allograft survival was tested. Under homeostatic conditions, animals treated with IL-33 showed an increment in Treg cell frequencies. Intestinal bacterial abundance analysis indicates that IL-33 provokes dysbiosis, demonstrated by a reduction in Enterobacteria and an increment in Lactobacillus genera. Furthermore, metabolomics analysis showed a dramatic IL-33 effect on the abundance of intestinal metabolites related to amino acid synthesis pathways, highlighting molecules linked to Trp metabolism, such as kynurenic acid (KA), 5-Hydroxyindoleacetic acid (5-HIAA), and 6-Hydroxynicotinic acid (6-HNA), which was supported by an enhanced expression of Ido and Kat mRNA in MLN cells, which are two enzymes involved on KA synthesis. Interestingly, animals receiving KA in drinking water and subjected to skin transplantation showed allograft acceptance, which is associated with an increment in Treg cell frequencies. Our study reveals a new property for IL-33 as a modulator of the intestinal microbiota and metabolites, especially those involved with Trp metabolism. In addition, we demonstrate that KA favors Tregs in vivo, positively affecting skin transplantation survival.

Regulatory T cells modulate monocyte functions in immunocompetent antiretroviral therapy naive HIV-1 infected people

We previously demonstrated that the overall number of regulatory T (Treg) cells decrease proportionately with helper CD4+ T cells and their frequencies increase in antiretroviral therapy (ART)-naive human immunodeficiency virus type-1 (HIV-1) infected individuals. The question now is whether the discrepancies in Treg cell numbers and frequencies are synonymous to an impairment of their functions. To address this, we purified Treg cells and assessed their ability to modulate autologous monocytes functions. We observed that Treg cells were able to down modulate autologous monocytes activation as well as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production during stimulation with polyinosinic-polycytidylic acid stabilized with poly-L-lysine and carboxymethylcellulose (poly-ICLC). This activity of Treg cells has been shown to be influenced by immunocompetence including but not limited to helper CD4+ T cell counts, in individuals with HIV-1 infection. Compared to immunosuppressed participants (CD4 < 500 cells/µL), immunocompetent participants (CD4 ≥ 500 cells/µL) showed significantly higher levels of transforming growth factor beta (TGF-β) and IL-10 (p < 0.001 and p < 0.05, respectively), key cytokines used by Treg cells to exert their immunosuppressive functions. Our findings suggest the contribution of both TGF-β and IL-10 in the suppressive activity of Treg cells.

Osteoporosis in postmenopausal women is associated with disturbances in gut microbiota and migration of peripheral immune cells

BackgroundPostmenopausal osteoporosis (PMO) results from a reduction in bone mass and microarchitectural deterioration in bone tissue due to estrogen deficiency, which may increase the incidence of fragility fractures. In recent years, the “gut-immune response-bone” axis has been proposed as a novel potential approach in the prevention and treatment of PMO. Studies on ovariectomized murine model indicated the reciprocal role of Th17 cells and Treg cells in the aetiology of osteoporosis. However, the relationship among gut microbiota, immune cells and bone metabolic indexes remains unknown in PMO.MethodsA total of 77 postmenopausal women were recruited for the study and divided into control (n = 30), osteopenia (n = 19), and osteoporosis (n = 28) groups based on their T score. The frequency of Treg and Th17 cells in lymphocytes were analyzed by flow cytometry. The serum levels of interleukin (IL)-10, 17 A, 1β, 6, tumor necrosis factor (TNF)-α, and lipopolysaccharide (LPS) were determined via enzyme-linked immunosorbent assay. Additionally, 16S rRNA gene V3-V4 region sequencing analysis was performed to investigate the gut microbiota of the participants.ResultsThe results demonstrated decreased bacterial richness and diversed intestinal composition in PMO. In addition, significant differences of relative abundance of the gut microbial community in phylum and genus levels were found, mainly including increased Bacteroidota, Proteobacteria, and Campylobacterota, as well as reduced Firmicutes, Butyricicoccus, and Faecalibacterium. Intriugingly, in the osteoporosis group, the concentration of Treg cells and associated IL-10 in peripheral circulation was negatively regulated, while other chronic systemic proinflammatory cytokines and Th17 cells showed opposite trends. Moreover, significantly elevated plasma lipopolysaccharide (LPS) in patients with osteoporosis indicated that disrupted intestinal integrity and permeability. A correlation analysis showed close relationships between gut bacteria and inflammation.ConclusionsCollectively, these observations will lead to a better understanding of the relationship among bone homeostasis, the microbiota, and circulating immune cells in PMO. The elevated LPS levels of osteoporosis patients which not only indicate a breach in intestinal integrity but also suggest a novel biomarker for assessing osteoporosis risk linked to gut health.

Epithelial RANKL Limits Experimental Periodontitis via Langerhans Cells

Due to its capacity to drive osteoclast differentiation, the receptor activator of nuclear factor kappa-β ligand (RANKL) is believed to exert a pathological influence in periodontitis. However, RANKL was initially identified as an activator of dendritic cells (DCs), expressed by T cells, and exhibits diverse effects on the immune system. Hence, it is probable that RANKL, acting as a bridge between the bone and immune systems, plays a more intricate role in periodontitis. Using ligature-induced periodontitis (LIP), rapid alveolar bone loss was detected that was later halted even though the ligature was still present. This late phase of LIP was also linked with immunosuppressive conditions in the gingiva. Further investigation revealed that the ligature prompted an immediate migration of RANK-expressing Langerhans cells (LCs) and EpCAM+ DCs, the antigen-presenting cells (APCs) of the gingival epithelium, to the lymph nodes, followed by an expansion of T regulatory (Treg) cells in the gingiva. Subsequently, the ligatured gingiva was repopulated by monocyte-derived RANK-expressing EpCAM+ DCs, while gingival epithelial cells upregulated RANKL expression. Blocking RANKL signaling with monoclonal antibodies significantly reduced the frequencies of Treg cells in the gingiva and prevented gingival immunosuppression. In addition, RANKL signaling facilitated the differentiation of LCs from bone marrow precursors. To further investigate the role of RANKL, we used K14-RANKL mice, in which RANKL is overexpressed by gingival epithelial cells. The elevated RANKL expression shifted the steady-state frequencies of LCs and EpCAM+ DCs within the epithelium, favoring LCs over EpCAM+ DCs. Following ligature placement, heightened levels of Treg cells were observed in the gingiva of K14-RANKL mice, and alveolar bone loss was significantly reduced. These findings suggest that RANKL-RANK interactions between gingival epithelial cells and APCs are crucial for suppressing gingival inflammation, highlighting a protective immunological role for RANKL in periodontitis that was overlooked due to its osteoclastogenic activity.

Leukemic B cells expression of CD200 and Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1, CD305) in Chronic Lymphocytic Leukemia patients in relation to Treg frequency

BackgroundChronic lymphocytic leukemia (CLL) is characterized by a wide range of tumor-induced immune alterations. Regulatory T cells (Treg) play a central role in these immune responses. CD200 and Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1, CD305) are inhibitory markers said to be involved in Treg immune response. We aimed to analyze the expression of CD200 and LAIR-1 on leukemic cells and assess their interactions with the Treg frequency to elucidate their role in the CLL course. Subjects and methodsThis study was conducted on 70 participants: 50 newly diagnosed CLL cases classified according to Rai staging system into group 1 (n = 25) patients with stages 0, I, and II, and group 2 (n = 25) of advanced patients with stages III and IV. In addition to control group (n = 20) of healthy adults. Flow cytometry was used to investigate Treg frequency in bone marrow (BM) proportional to CD4+ T cell and to assess leukemic cell expression of CD200 and LAIR-1. Also, in-silico database analysis was performed to identify study markers interactions for future personalized target therapy. ResultsComparison between CLL groups 1 and 2 revealed increased leukemic cell percentage expressing LAIR-1 (p = 0.021) in group 1. Group 2 showed significant increase in frequency of Treg in BM and leukemic cells expressing CD200. There was a strong positive correlation between frequency of Treg and leukemic cells expressing CD200 (r = 0.669, p = 0.000). On the other hand, there was a negative correlation between frequency of Treg and leukemic cell expressing LAIR-1 (r = −0.342, p = 0.015). ROC curve analysis revealed that increased frequency of leukemic cells expressing CD200 yielded sensitivity (SN) and specificity (SP) of 96 % and 84 %, respectively in detecting CLL progression, with an AUC of 0.965. Leukemic cell percentages expressing LAIR-1 yielded a lower SN (75 %), SP (72 %), with an AUC of 0.688. ConclusionTreg frequency in BM was significantly increased in CLL advanced stages according to Rai classification. Leukemic cells CD200 and LAIR-1 expression were differently associated with Treg frequency. Increased CD200 expressions on leukemic cells can be considered a sensitive and specific biomarker in detecting CLL progression. As demonstrated by the in-silico research, CD200 blockade targeting may offer therapeutic benefits for CLL treatment through Treg suppression.

Maternal High-Fat Diet Exacerbates Epicutaneous Sensitization and Oral Challenge-Induced Food Allergy to Ovalbumin in Offspring Mice.

Dietary factors have been associated with an increased prevalence of food allergy (FA). However, little is known about how an unhealthy diet in early life affects FA reactions in offspring. The objective of this study is to provide a scientific foundation for developing and promoting healthy dietary patterns in early life. In this study, we found that maternal high-fat diet (HFD) during pregnancy and lactation exacerbates FA (HFD-FA) in offspring mice, leading to increased serum levels of mast cell protease 1. First, we studied the systemic immunity of the HFD-FA mice and observed elevated levels of proinflammatory cytokines (IL-4, IL-6, and IL-1β) and a reduced frequency of Treg cells in splenocytes. Additionally, the HFD-FA mice showed increased gut permeability, accumulation of intestinal mast cells, and a decrease in the Treg cell frequency in the mesenteric lymph nodes. Furthermore, our findings also indicated a reduction in gut microbial diversity and abundance in HFD-FA mice. Importantly, lipid metabolism profiling revealed unique lipid profiles in the HFD-FA mice, with significant upregulation of triglycerides and downregulation of sphingolipids. Taken together, our results suggest that maternal HFD alters intestinal homeostasis and increases FA susceptibility in offspring mice.

PARP1 inactivation increases regulatory T / Th17 cell proportion in intestinal inflammation. Role of HMGB1

Inflammatory bowel diseases (IBD) are chronic relapsing disorders with increasing prevalence. Knowledge gaps still limit the possibility to develop more specific and effective therapies. Using a dextran sodium sulfate colitis mouse model, we found that inflammation increased the total number and altered the frequencies of leukocytes within colon mesenteric lymph nodes (cMLNs). Although the inflammation reduced the frequency of regulatory T (Treg) cells, their absolute numbers were increased. Increased frequency of colitogenic Th17 cells was also observed. Noteworthy, untreated mice lacking Poly(ADP-ribose)-Polimerase-1 functional gene (PARP-1KO) displayed higher frequency of Treg cells and lower percentage of Th17 cells in cMLNs. In colitic PARP-1KO mice the inflammation driven expansion of the Foxp3 Treg population was more pronounced than in WT mice. Conversely, colitis increased Th17 cells to a lower extent in PARP-1KO mice compared with WT mice, resulting in a more protective Treg/Th17 cell ratio. Consequently PARP-1KO mice developed less severe colitis with reduced expression of inflammatory cytokines. In ex vivo experiments PARP-1KO and WT CD11c dendritic cells (DCs) promoted naïve CD4 T cell differentiation differently, the former sustaining more efficiently the generation of Treg cells, the latter that of Th17 cells. Addition of HMGB1 B box or of dipotassium glycyrrhizate, which sequesters extracellular HMGB1, revealed a role for this alarmin in the regulation exerted by PARP-1 on the stimulating vs. tolerogenic function of DCs during colitis. Moreover, a higher percentage of CD11c DC from PARP-1KO mice expressed CD103, a marker associated with the ability of DC to induce Treg cells, compared with WT DC. Conversely, PARP-1KO DC were including a reduced percentage of CX3CR1+ DC, described to induce Th17 cells. These findings were observed in both splenic and colon lamina propria DC.

Yiqi Jiedu Xiaoying Decoction Improves Experimental Autoimmune Thyroiditis in Rats by Regulating Th17/Treg Cell Balance.

Experimental autoimmune thyroiditis (EAT) is a widely used animal model to study the pathogenesis and treatment of autoimmune thyroid diseases. Yiqi Jiedu Xiaoying Decoction (YJXD) is a traditional Chinese medicine formula with potential immunomodulatory effects. In this study, we investigated the therapeutic effects of YJXD on EAT in rats and explored its underlying mechanisms. Female Wistar rats were induced to develop EAT by immunization with thyroglobulin (Tg) and taken sodium iodide water (0.05%) and then treated with YJXD or sodium selenite. HE staining was used to observe the pathological changes of thyroid tissue in EAT rats. Th17 and Treg cell frequencies were analyzed by flow cytometry, and the expression levels of Th17- and Treg-related cytokines and thyroid autoantibody were determined by enzyme-linked immunosorbent assay (ELISA). The expression of Th17- and Treg-related transcriptional factors was detected by real-time polymerase chain reaction (RT-PCR) and Immunohistochemistry (IHC). Our results demonstrated that treatment with YJXD significantly attenuated the severity of EAT, as evidenced by reduced thyroid gland inflammatory infiltration and decreased serum thyroglobulin autoantibody levels. Importantly, YJXD treatment effectively modulated the Th17/Treg cell balance by suppressing Th17 cell differentiation and promoting Treg cell expansion. Moreover, YJXD was also found to regulate the expression levels of Th17- and Treg-related cytokines and transcriptional factors, further supporting its immunomodulatory effects in EAT. YJXD exerted therapeutic effects on EAT by regulating the Th17/Treg cell balance, modulating the production of Th17- and Treg-related cytokines and the expression of transcriptional factors.

Preclinical activity of allogeneic SLAMF7-specific CAR T-cells (UCARTCS1) in multiple myeloma

BackgroundAutologous BCMA-specific CAR T-cell therapies have substantial activity in multiple myeloma (MM). However, due to logistical limitations and BCMAlow relapses, there is a need for alternatives. UCARTCS1 cells are ‘off-the-shelf’...

Agrimonolide mitigated DSS-induced colitis by modulating the balance between Treg and Th17 cells through the suppression of the Notch and JAK2/STAT3 signaling pathways

PurposeThe objective of this study was to investigate the effects of agrimonolide (AM) on mice with dextran sulfate sodium (DSS)-induced colitis and elucidate its protective mechanisms. MethodsA 3 % DSS solution was used to induce colitis, and intragastric administration of AM at doses of 25 and 50 mg/kg was performed. A comprehensive assessment was conducted to evaluate inflammatory responses and mucosal integrity in the colon. Inflammatory factors were quantified using enzyme-linked immunosorbent assay (ELISA). The proportions of T helper cell 17 (Th17) and regulatory T cells (Treg) cells in mesenteric lymph nodes (MLNs) was analyzed through RT-qPCR and flow cytometry. Proteins associated with the Notch and JAK2/STAT3 pathways were examined via RT-qPCR, western blotting, and immunofluorescence. Additionally, the impact of AM on Treg and Th17 cell differentiation was investigated in vitro. ResultsPre-treatment with AM significantly alleviated colon inflammation in mice, as evidenced by reduced body weight loss, shorter colon length, lower disease activity index (DAI) score, and decreased myeloperoxidase (MPO) content. Notably, AM pre-treatment attenuated the production of pro-inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6, in mice with DSS-induced colitis. Additionally, AM pre-treatment significantly enhanced the expression of tight junction proteins (Occludin and ZO-1), thereby preserving gut barrier function. Moreover, we observed that AM administration decreased the ratio of Th17 cells while increasing the frequency of colonic Treg cells, thus modulating the Th17/Treg balance both in vivo and in vitro. Furthermore, in the AM-treated group, the expression of Notch-1, Jagged1, delta like 4 (DLL4), phospho-janus kinases 2 (p-JAK2)/JAK2, and p-signal transducer and activator of transcription 3 (STAT3)/STAT3 in colonic tissue was reduced compared to the DSS group. Remarkably, the therapeutic effects of AM in colitis mice were blocked by a Notch activator. ConclusionThese findings underscore the effectiveness of AM in alleviating symptoms and pathological damage in DSS-induced colitis mice by rebalancing Th17/Treg cell homeostasis through modulation of the Notch and JAK2/STAT3 signaling pathways. These insights into AM's mechanisms of action offer potential avenues for novel therapeutic strategies.

Metabolic Plasticity of Regulatory T Cells in Health and Autoimmunity.

Immunometabolism has been demonstrated to control immune tolerance and the pathogenic events leading to autoimmunity. Compelling experimental evidence also suggests that intracellular metabolic programs influence differentiation, phenotype, proliferation, and effector functions of anti-inflammatory CD4+CD25+Foxp3+ regulatory T (Treg) cells. Indeed, alterations in intracellular metabolism associate with quantitative and qualitative impairments of Treg cells in several pathological conditions. In this review, we summarize the most recent advances linking how metabolic pathways control Treg cell homeostasis and their alterations occurring in autoimmunity. Also, we analyze how metabolic manipulations could be employed to restore Treg cell frequency and function with the aim to create novel therapeutic opportunities to halt immune-mediated disorders.

The Effect of Exosomes Isolated from Poly (I:C) Treated Human Wharton's Jelly Mesenchymal Stem Cells on CD4+CD25+Foxp3+ Regulatory T Cells.

Mesenchymal stem cells (MSCs) are a potential cell therapy candidate for autoimmune and inflammatory diseases due to their multilineage capacity and immune modulating function. MSCs exert immunomodulatory effects on target cells through the secretion of exosomes. Inflammatory conditions such as Toll-like receptors (TLRs) engagement can change the biological functions and immunomodulatory activities of MSCs and the contents of exosomes derived from MSCs are changed. Regulatory T-cells (Treg) are crucial for maintaining immune cell homeostasis and self-tolerance. Our study aimed to investigate the impact of isolated exosomes from hWJ-MSCs that were treated with Poly (I:C) on regulatory CD4 CD25 Foxp3 T-cells. MSCs were harvested from human umbilical cord Wharton's Jelly by explant method. Stem cells were treated by Polyinosinic-polycytidylic acid sodium salt (Poly (I:C)) for 48 hours. Exosomes were extracted from supernatant of cells and Scanning electron microscopy (SEM) and Dynamic light scattering (DLS) were performed for them. Peripheral blood mononuclear cells (PBMCs) isolated from the healthy donors were stimulated with PHA (Phytohemagglutinin) and co-cultured with Poly (I:C) treated hWJ-MSCs derived exosome and untreated hWJ-MSCs derived exosome or without hWJ-MSCs-derived exosome for 6 days. Then, frequency of CD4+CD25+ Foxp3+ regulatory T cells was measured by flow cytometry. Our results showed that exosomes isolated from Poly (I:C) treated hWJ-MSCs significantly increased frequency of CD4+CD25+ Foxp3+ regulatory T cells compared to the untreated hWJ-MSCs derived exosome group and control group. Stimulation by TLR3 improved the anti-inflammatory features of exosomes that were derived from hWJ-MSCs by increasing the frequency of Treg cells.

Glycyrrhiza Glabra Extract Modulates Type 1 T Helper (TH1) and Regulatory T Cell-Related Immune Responses in an Animal Model of Breast Cancer.

It is well-known that TH1 and Treg cells exert anti- and pro-tumorigenic activity, respectively. Thus, TH1 cell suppression together with Treg cell hyperactivation contribute to tumor development. Glycyrrhiza glabra (G. glabra) has various immunomodulatory and anti-tumorigenic properties. To explore the impacts of G. glabra extract on different parameters related to TH1 and Treg cells using a breast cancer (BC) model. Four groups of Balb/C mice bearing 4T1 cell-induced BC were treated intraperitoneally with either saline or G. glabra extract at dosages of 50, 100 and 150 mg/kg (G. glabra-50, G. glabra-100, and G. glabra-150, respectively). After sacrificing animals on day 26, the frequency of splenic TH1 and Treg cells, the levels of serum IFN-γ, TGF-β, and IL-12, and intra-tumoral expressions of granzyme-B, T-bet, and FOXP3 were assessed. Compared to untreated tumor control (UTC) group, treatment with G. glabra-50, G. glabra-100, or G. glabra-150 increased the survival rate, percentage of TH1 cells, and T-bet expression. Conversely, they reduced the percentage of Treg cells, and serum TGF-β levels. In comparison to the UTC group, treatment with G. glabra-50 and G. glabra-150 increased the serum IL-12 levels. Treatment with G. glabra-100 and G. glabra-150 boosted granzyme-B expression. Treatment with G. glabra-150 elevated IFN-γ levels, while treatment with G. glabra-50 decreased the FOXP3 expression. IL-12 levels were higher in mice treated with G. glabra-150 compared to those treated with G. glabra-100. Treatment of mice with BC using G. glabra extract improved survival rate, reduced tumor growth, and modulated T cell-mediated immune responses.

Enhanced Therapeutic Effects of Human Mesenchymal stem Cells Transduced with Secreted Klotho in a Murine Experimental Autoimmune Encephalomyelitis Model.

Treatment of multiple sclerosis (MS) remains a major challenge. The aim of this study was to evaluate the therapeutic potential of mesenchymal stem cells (MSCs) engineered with secreted Klotho (SKL) in an experimental autoimmune encephalomyelitis (EAE) mouse model of MS. EAE was induced in mice. MSCs or MSCs engineered with SKL (SKL-MSCs) were administered to EAE mice at the onset of disease. Hematoxylin-eosin and luxol fast blue staining were performed to evaluate histopathological changes. Expression of pro-inflammatory (TNF-α, IFN-γ, and IL-17) and anti-inflammatory (IL-10) cytokines was determined in the spinal cord using real-time PCR. Spinal cords were then processed for immunohistochemistry of the aforementioned cytokines. The frequencies of Th1, Th17, and regulatory T (Treg) cells were evaluated by flow cytometry of the spleen. The results showed that SKL-MSCs decreased clinical scores and reduced demyelination and inflammatory infiltration in the spinal cord more significantly than MSCs. Compared to MSCs, SKL-MSCs also exhibited a more profound capability of decreasing expression of TNF-α, IFN-γ, and IL-17 and increasing expression of IL-10 in the spinal cord with an enhanced homing to the inflamed tissue. Moreover, SKL-MSCs decreased the frequencies of Th1 and Th17 cells and increased the frequency of Treg cells in the spleen more potently than MSCs. Taken together, these findings demonstrate that SKL overexpression enhances the therapeutic potential of MSCs, as evidenced by significantly improved disease severity, decreased inflammation and tissue damage in the spinal cord, and a promoted shift in the Th17/Treg balance towards the anti-inflammatory Treg side in the EAE mice.

Preparation and application of fluorescent monoclonal antibodies recognizing goat CD4+CD25+ regulatory T cells

Regulatory T cells (Tregs) are a subset of T cells participating in a variety of diseases including mycoplasmal pneumonia, contagious ecthyma, and so on. The role of Tregs in goat contagious ecthyma is not completely understood due to the lack of species-specific antibodies. Here, we developed a combination of CD4 and CD25 fluorescence monoclonal antibodies (mAb) to recognize goat Tregs and assessed its utility in flow cytometry, immunofluorescence staining. Using immunofluorescence staining, we found that the frequency of Treg cells was positively correlated with the viral load during orf virus infection. These antibodies could serve as important tools to monitor Tregs during orf virus infection in goats.Key points• A combination of fluorescent mAbs (C11 and D12) was prepared for the detection of goat Tregs.• C11 and D12 are effective in flow cytometry, immunofluorescence staining, and C11 has excellent species specificity.• The frequency of Treg cells was positively correlated with the viral load during orf virus infection.

Increased Th17 and Treg levels in peripheral blood positively correlate with minimal residual disease in acute myeloid leukaemia.

Immune dysregulation plays a key role in acute myeloid leukemia (AML). We aimed to explore the correlation between T helper cell 17 (Th17) and the regulatory cells (Tregs) in the peripheral blood of patients with newly diagnosed (ND) AML and bone marrow blast cells, as well as minimal residual disease (MRD) before and after treatment. Changes in Th17 and Treg cells in the peripheral blood of 32 patients with ND AML were observed before and after induction chemotherapy with cytarabine for seven days and anthracycline for three days. The levels of inflammatory cytokines were measured using an enzyme-linked immunosorbent assay. Correlation analysis between bone marrow blast cells and Th17 and Treg cell frequencies was performed using the Pearson's correlation test. Frequencies of Th17 and Treg cells and MRD were assessed using flow cytometry. IL-6, IL-10, IL-17A, and GM-CSF levels gradually increased in patients with ND AML and CR and NR patients. The percentages of Th17 and Treg cells positively correlated with those of blast cells. In addition, the frequencies of Th17 and Treg cells in MRD-positive patients were higher than those in MRD-negative patients at the initial induction and after three months of chemotherapy. The frequencies of Tregs and Th17 cells positively correlated with MRD onset. Increased Th17 and Treg cell levels were positively correlated with onset of AML, poor remission, and MRD.

Type 1 Diabetes Brazilian patients exhibit reduced frequency of recent thymic emigrants in regulatory CD4+CD25+Foxp3+T cells

To control immune responses, regulatory CD4+CD25+Foxp3+ T cells (Treg) maintain their wide and diverse repertoire through continuous arrival of recent thymic emigrants (RTE). However, during puberty, the activity of RTE starts to decline as a natural process of thymic involution, introducing consequences, not completely described, to the repertoire. Type 1 diabetes (T1D) patients show quantitative and qualitative impairments on the Treg cells. Our aim was to evaluate peripheral Treg and RTE cell frequencies, in T1D patients from two distinct age groups (young and adults) and verify if HLA phenotypes are concomitant associated. To this, blood samples from Brazilian twenty established T1D patients (12 young and 8 adults) and twenty-one healthy controls (11 young and 10 adults) were analyzed, by flow cytometry, to verify the percentages of CD4, Treg (CD4+CD25+Foxp3+) and the subsets of CD45RA+ (naive) and CD31+(RTE) within then. Furthermore, the HLA typing was also set. We observed that the young established T1D patients feature decreased frequencies in total Treg cells and naive RTE within Treg cells. Significant prevalence of HLA alleles, associated with risk, in T1D patients, was also identified. Performing a multivariate analysis, we confirmed that the cellular changes described offers significant variables that distinct T1D patients from the controls. Our data collectively highlight relevant aspects about homeostasis imbalances in the Treg cells of T1D patients, especially in young, and disease prognosis; that might contribute for future therapeutic strategies involving Treg cells manipulation.

MyD88 exacerbates inflammation-induced bone loss by modulating dynamic equilibrium between Th17/Treg cells and subgingival microbiota dysbiosis.

This study aimed to investigate the contribution of myeloid differentiation primary-response gene 88 (MyD88) on the differentiation of T helper type 17 (Th17) and regulatory T (Treg) cells and the emerging subgingival microbiota dysbiosis in Porphyromonas gingivalis-induced experimental periodontitis. Alveolar bone loss, infiltrated inflammatory cells, immunostained cells for tartrate-resistant acid phosphatase (TRAP), the receptor activator of nuclear factor-kB ligand (RANKL), and osteoprotegerin (OPG) were quantified by microcomputerized tomography and histological staining between age- and sex-matched homozygous littermates (wild-type [WT, Myd88+/+] and Myd88-/- on C57BL/6 background). The frequencies of Th17 and Treg cells in cervical lymph nodes (CLNs) and spleen were determined by flow cytometry. Cytokine expression in gingival tissues, CLNs, and spleens were studied by quantitative polymerase chain reaction (qPCR). Analysis of the composition of the subgingival microbiome and functional annotation of prokaryotic taxa (FAPROTAX) analysis were performed. P. gingivalis-infected Myd88-/- mice showed alleviated bone loss, TRAP+ osteoclasts, and RANKL/OPG ratio compared to WT mice. A significantly higher percentage of Foxp3+CD4+ T cells in infected Myd88-/- CLNs and a higher frequency of RORγt+CD4+ T cells in infected WT mice was noted. Increased IL-10 and IL-17a expressions in gingival tissue at D14-D28 then declined in WT mice, whereas an opposite pattern was observed in Myd88-/- mice. The Myd88-/- mice exhibited characteristic increases in gram-positive species and species having probiotic properties, while gram-negative, anaerobic species were noted in WT mice. FAPROTAX analysis revealed increased aerobic chemoheterotrophy in Myd88-/- mice, whereas anaerobic chemoheterotrophy was noted in WT mice after P. gingivalis infection. MyD88 plays an important role in inflammation-induced bone loss by modulating the dynamic equilibrium between Th17/Treg cells and dysbiosis in P. gingivalis-induced experimental periodontitis.

Targeted delivery of Fc-fused PD-L1 for effective management of acute and chronic colitis

The PD-1/PD-L1 pathway in mucosal immunity is currently actively explored and considered as a target for inflammatory bowel disease (IBD) treatment. However, systemic PD-L1 administration may cause unpredictable adverse effects due to immunosuppression. Here we show that reactive oxygen species (ROS)-responsive nanoparticles enhance the efficacy and safety of PD-L1 in a mouse colitis model. The nanoparticles control the accumulation and release of PD-L1 fused to Fc (PD-L1-Fc) at inflammatory sites in the colon. The nanotherapeutics shows superiority in alleviating inflammatory symptoms over systemic PD-L1-Fc administration and mitigates the adverse effects of PD-L1-Fc administration. The nanoparticles-formulated PD-L1-Fc affects production of proinflammatory and anti-inflammatory cytokines, attenuates the infiltration of macrophages, neutrophils, and dendritic cells, increases the frequencies of Treg, Th1 and Tfh cells, reshapes the gut microbiota composition; and increases short-chain fatty acid production. In summary, PD-L1-Fc-decorated nanoparticles may provide an effective and safe strategy for the targeted treatment of IBD.