CD25 Foxp3 Research Articles

MBL Binding with AhR Controls Th17 Immunity in Silicosis-Associated Lung Inflammation and Fibrosis.

ObjectiveMannan-binding lectin (MBL), a soluble pattern recognition molecule of the innate immune system, is primarily synthesized in the liver and secreted into the circulation. Low serum level of MBL has been reported to be related to an increased risk of lung diseases. Herein, we aimed to investigate the function of MBL in silicosis-associated pulmonary inflammation.MethodsSerum collected from silicosis patients was tested for correlation between serum MBL levels and Th17 immunity. In vitro studies were performed to further demonstrated the effect of MBL on Th17 polarization. Silica was intratracheally injected in wild type (WT) or MBL-deficient (MBL–/–) mice to induce silicosis-associated lung inflammation and fibrosis. Th17 response was evaluated to explore the effect of MBL on silicosis in vivo.ResultsSilicosis patients with high serum MBL levels displayed ameliorative lung function. We demonstrated that serum MBL levels negatively correlated to Th17 cell frequency in silicosis patients. MBL protein markedly reduced expression of IL-17 but enhanced expression of Foxp3 in CD4+ T cells in vitro when subjected to Th17 or Treg polarizing conditions, respectively. The presence of MBL during Th17 cell polarization significantly limited aryl hydrocarbon receptor (AhR) expression and suppressed the signal transducer and activator of transcription 3 (STAT3) phosphorylation. Treatment with the AhR antagonist abolished the effect of MBL on Th17 response. Strikingly, MBL directly bound to AhR and affected its nuclear translocation. Furthermore, MBL–/– mice displayed elevated Th17 cell levels compared with WT mice in response to the silica challenge. The CD4+ T lymphocytes from silica-administrated MBL–/– mice exhibited more AhR expression than the wild-type counterparts.ConclusionOur study suggested that MBL limited the Th17 immunity via controlling the AhR/STAT3 pathway, thus providing new insight into silicosis and other inflammatory diseases in patients with MBL deficiency.

Prognostic value of regulatory T cells and T helper 17 cells in high grade serous ovarian carcinoma

PurposeIn recent years the tumor microenvironment and its interaction with the tumor has emerged into research focus with increased attention to the composition of Tumor-infiltrating lymphocytes. We wanted to quantify the composition of Regulatory T cells (Tregs) and T helper 17 cells (Th17 cells) and their prognostic impact in high-grade serous tubo-ovarian carcinoma.MethodsTregs and Th17 cells were determined by immunohistochemical analysis of CD25 FoxP3 and RORγt, respectively on tissue microarrays of a cohort of 222 patients with reviewed histology and available clinical data. Expression was analyzed with Qupath for quantification and integration with clinical data enabled calculation of prognostic impact. For validation FOXP3 and RORC mRNA expression levels from 502 patients with HGSC in publicly available datasets were evaluated.ResultsAn average percentage of 0.93 Tregs and of 0.06 Th17 cells was detected per cells in overall tissue. Optimal cut-offs were determined and higher Tregs were associated with a better overall survival in stroma (p = 0.006), tumor area (p = 0.0012) and overall tissue (p = 0.02). After accounting for well-known prognostic factors age at diagnosis, residual tumor and FIGO stage, this association remained significant for stromal Tregs with overall survival (p = 0.02). Survival analysis for Th17 cells revealed no significant association with survival rates. Moreover, lower Th17/Treg ratios had a positive impact on patient overall survival (p = 0.025 tumor, p = 0.049 stroma and p = 0.016 overall tissue).ConclusionOur results outline a positive prognostic effect for higher Tregs but not for Th17 in high grade serous tubo-ovarian carcinoma.

PPAR-α Agonist Fenofibrate Ameliorates Sjögren Syndrome-Like Dacryoadenitis by Modulating Th1/Th17 and Treg Cell Responses in NOD Mice.

PurposeTo investigate the effects and mechanisms of fenofibrate, a synthetic ligand of peroxisome proliferator-activated receptor α (PPAR-α), on autoimmune dacryoadenitis in a mouse model of Sjögren syndrome (SS) dry eye.MethodsMale nonobese diabetic (NOD) mice were fed chow with or without 0.03% fenofibrate for 8 weeks, and clinical scores were determined by assessing tear secretion, fluorescein, and hematoxylin and eosin staining. Intracellular IFN-γ, IL-17, and Foxp3 in CD4+ T cells were measured by flow cytometry. The expressions of Th1, Th17, and Treg cell-related transcription factors and cytokines were detected by real-time PCR. The levels of PPAR-α and liver X receptor β (LXR-β) were detected with real-time PCR and Western blotting.ResultsFenofibrate efficiently diminished the lymphocytic inflammation in lacrimal glands (LGs), increased tear secretion, and decreased corneal fluorescein staining in NOD mice. Meanwhile, treatment of fenofibrate evidently reduced the proportion of Th1 and Th17 cells and increased the proportion of Treg cells in vivo and vitro, together with decreased expression of T-bet, IFN-γ, RORγt, and IL-17, as well as increased expression of Foxp3 and TGF-β1 in LGs. Furthermore, fenofibrate significantly upregulated the expressions of PPAR-α and LXR-β at the protein and mRNA levels.ConclusionsFenofibrate potently attenuated LG inflammation in a model of autoimmune dry eye, and this effect might partially result from regulating Th1/Th17/Treg cell responses by activating PPAR-α/LXR-β signaling. These data suggest that fenofibrate may be a novel class of therapeutic agent for SS-associated dacryoadenitis.

The Aryl Hydrocarbon Receptor Modulates T Follicular Helper Cell Responses to Influenza Virus Infection in Mice.

T follicular helper (Tfh) cells support Ab responses and are a critical component of adaptive immune responses to respiratory viral infections. Tfh cells are regulated by a network of signaling pathways that are controlled, in part, by transcription factors. The aryl hydrocarbon receptor (AHR) is an environment-sensing transcription factor that modulates many aspects of adaptive immunity by binding a range of small molecules. However, the contribution of AHR signaling to Tfh cell differentiation and function is not known. In this article, we report that AHR activation by three different agonists reduced the frequency of Tfh cells during primary infection of C57BL/6 mice with influenza A virus (IAV). Further, using the high-affinity and AHR-specific agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin, we show that AHR activation reduced Tfh cell differentiation and T cell-dependent B cell responses. Using conditional AHR knockout mice, we demonstrated that alterations of Tfh cells and T cell-dependent B cell responses after AHR activation required the AHR in T cells. AHR activation reduced the number of T follicular regulatory (Tfr) cells; however, the ratio of Tfr to Tfh cells was amplified. These alterations to Tfh and Tfr cells during IAV infection corresponded with differences in expression of BCL6 and FOXP3 in CD4+ T cells and required the AHR to have a functional DNA-binding domain. Overall, these findings support that the AHR modulates Tfh cells during viral infection, which has broad-reaching consequences for understanding how environmental factors contribute to variation in immune defenses against infectious pathogens, such as influenza and severe acute respiratory syndrome coronavirus.

The immune checkpoint B7x expands tumor-infiltrating Tregs and promotes resistance to anti-CTLA-4 therapy.

Immune checkpoint molecules play critical roles in regulating the anti-tumor immune response, and tumor cells often exploit these pathways to inhibit and evade the immune system. The B7-family immune checkpoint B7x is widely expressed in a broad variety of cancer types, and is generally associated with advanced disease progression and poorer clinical outcomes, but the underlying mechanisms are unclear. Here, we show that transduction and stable expression of B7x in multiple syngeneic tumor models leads to the expansion of immunosuppressive regulatory T cells (Tregs). Mechanistically, B7x does not cause increased proliferation of Tregs in tumors, but instead promotes the conversion of conventional CD4+ T cells into Tregs. Further, we find that B7x induces global transcriptomic changes in Tregs, driving these cells to adopt an activated and suppressive phenotype. B7x increases the expression of the Treg-specific transcription factor Foxp3 in CD4+ T cells by modulating the Akt/Foxo pathway. B7x-mediated regulation of Tregs reduces the efficacy of anti-CTLA-4 treatment, a therapeutic that partially relies on Treg-depletion. However, combination treatment of anti-B7x and anti-CTLA-4 leads to synergistic therapeutic efficacy and overcomes the B7x-mediated resistance to anti-CTLA-4. Altogether, B7x mediates an immunosuppressive Treg-promoting pathway within tumors and is a promising candidate for combination immunotherapy.

Immune effects of CDK4/6 inhibitors in patients with HR+/HER2- metastatic breast cancer: Relief from immunosuppression is associated with clinical response.

SummaryBackgroundCyclin-dependent kinase 4/6 inhibitors (CDK4/6i) are innovative small target molecules that, in combination with endocrine therapy, have recently been employed in the treatment of patients with HR+/HER2− metastatic breast cancer (mBC). In this prospective study, we investigate the impact of CDK4/6i on the immune profile of patients with HR+/HER2− mBC.MethodsImmune cell subsets were analysed using flow cytometry of peripheral blood mononuclear cells (PBMCs) isolated from patients with HR+/HER2− mBC, both before and during treatment. Regulatory T cells (Tregs) were identified using the markers CD4, CD25, CTLA4, CD45RA, and intracellular FOXP3. Monocytic and polymorphonuclear myeloid-derived suppressor cells (M-MDSCs and PMN-MDSCs) and other immune populations were analysed using CD45, CD14, CD66b, CD11c, HLA-DR, CD3, CD8, CD28, CD137, PD1, CD45RA, CCR7, and Ki67.FindingsThe percentage of circulating Tregs and M/PMN-MDSCs was significantly downregulated from baseline during CDK4/6i-treatment (p<0.0001 and p<0.05, respectively). In particular, the effector Treg subset (CD4+CD25+FOXP3highCD45RA−) was strongly reduced (p<0.0001). The decrease in Treg levels was significantly greater in responder patients than in non-responder patients. Conversely, CDK4/6i treatment was associated with increased levels of CD4+ T cells and anti-tumour CD137+CD8+ T cells (p<0.05).InterpretationCDK4/6i treatment results in downregulation of Tregs, M-MDSCs, and PMN-MDSCs, thus weakening tumour immunosuppression. This decrease is associated with response to treatment, highlighting the importance of unleashing immunity in cancer treatment efficacy. These results suggest a novel mechanism of immunomodulation in mBC and provide valuable information for the future design of novel treatments combining CDK4/6i with immunotherapy in other cancer settings.FundingSapienza University of Rome.

Association between effector-type regulatory T cells and immune checkpoint expression on CD8+ T cells in malignant ascites from epithelial ovarian cancer

BackgroundRegulatory T cells (Tregs) play an important role in the antitumor immune response in epithelial ovarian cancer (EOC). To understand the immune-inhibitory networks of EOC, we addressed the association between Tregs and immune checkpoint expression on T cells in the tumor microenvironment of EOC.MethodsA total of 41 patients with stage IIIC and IV EOC were included in the analysis. We harvested cells from malignant ascites and investigated them using multi-color flow cytometry. We categorized the Tregs into 3 groups: effector-type Tregs, naïve Tregs and non-Tregs, based on the expression patterns of CD45RA and Foxp3 in CD4+ T cells. Furthermore, the relationships between the expression of various immune checkpoint molecules, such as PD-1, on CD8+ T cells and each of the Treg subtypes was also evaluated.ResultsThe median frequency of naïve Tregs, effector-type Tregs and non-Tregs were 0.2% (0–0.8), 2.0% (0–11.4) and 1.5% (0.1–6.3) in CD4+ T cells of malignant ascites from EOC patients, respectively. A high frequency of effector-type Tregs was associated with high-grade serous carcinoma compared with the other histotypes. Patients with higher proportions of effector-type Tregs showed a trend towards increased progression-free survival. We also demonstrated a correlation between a higher proportion of effector-type Tregs and increased PD-1 expression on CD8+ T cells. In addition, C–C chemokine receptor 4 expression was also observed in effector-type Tregs.ConclusionThese data suggest that multiple immune-inhibitory networks exist in malignant ascites from EOC patients, suggesting an approach towards combinational immunotherapies for advanced EOC patients.

Efficacy of stanozolol and danazol in the treatment of non-severe aplastic anemia and their effects on CD4(+)CD25(+)Foxp3(+) regulatory T cells

Efficacy of stanozolol and danazol in the treatment of non-severe aplastic anemia and their effects on CD4(+)CD25(+)Foxp3(+) regulatory T cells

Pathogenesis of cutaneous T cell lymphoma: Involvement of Staphylococcus aureus.

Mycosis fungoides (MF) and Sézary syndrome (SS) are representative cutaneous lymphomas. In their early stage, a small number of tumor cells and a large number of non-malignant cells form a Th1-dominant tumor microenvironment. Increase in malignant T cells is accompanied by a decrease in CD8-positive T cells, with a shift toward a Th2-dominant milieu in advanced-stage lesions. The etiologies of MF/SS are diverse, and the underlying pathogenetic mechanisms are yet to be elucidated. Advanced MF/SS is known to be highly sensitive to Staphylococcus aureus, and the majority of deaths are caused by severe infections. The susceptibility to infection is associated with barrier dysfunction and immunosuppression, which are the main symptoms of MF. In recent years, skin-colonizing S.aureus has been identified to not only cause severe infections but also play an important role in the pathogenesis of MF/SS. Staphylococcal superantigens activate the proliferation of tumor cells and induce CD25 upregulation, FOXP3 expression, IL-17 expression, and miR-155 expression. Alpha-toxin eliminates non-neoplastic CD4-positive cells and CD8-positive cells and plays a major role in tumor cell selection. Lipoprotein may also be associated with the induction of Th2-dominant milieu. Antibiotic therapy for S.aureus eradication has been reported to cause considerable clinical improvement in the majority of individuals with advanced cutaneous T-cell lymphoma. Therefore, S.aureus may be a novel target for the treatment of advanced-stage MF/SS in the future.

Frequency of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in peripheral blood of pediatric patients with SARS CoV-2 Infection: a pilot study

Background: Cytokine storm has been observed in some patients with SARS-CoV-2 due to excessive pro-inflammatory response. Foxp3(+) regulatory T cells (Tregs) are a distinct population of CD4(+) lymphocytes identified by their expression of transcription factor forkhead homeobox protein-3 (Foxp3). These cells down-regulate immune responses in inflammatory and autoimmune diseases. Objective: This pilot study was aimed to investigate the levels of CD4(+)CD25(+)Foxp3(+) Tregs in children with SARS-CoV-2. Methods: frequency of Tregs was measured by flow cytometry in 20 patients with SARS-CoV-2, 6 months to 15 years old;6 had COVID-19 and 14 had multisystem inflammatory syndrome in children (MIS-C). They were compared to 20 age-and sex-matched healthy children as a control group. Results: There was no significant difference between patients with SARS-CoV-2 infection and healthy control children in the frequency of Tregs (P=0.068). Decreased numbers of Tregs was found in only 10% of SARS-CoV-2 patients. Patients with severe SARS-CoV-2 were comparable to those with moderate disease in terms of Tregs' levels. The frequency of Tregs correlated negatively with neutrophil counts in our series (p=0.036). Attempts of correlation with other inflammatory markers of SARS-CoV-2 were insignificant. Conclusion: Decreased levels of Tregs were found in only 10% of our SARS-CoV-2 infected children. The frequency did not correlate with the disease severity or levels of routine inflammatory markers of SARS-CoV-2. Thus, Tregs expression does not seem to have a role in the up-regulated immune response seen in moderate and severe SARS-CoV-2 infection. Our conclusions are limited by the sample size.

Protein phosphatase 6 (Pp6) is crucial for regulatory T cell function and stability in autoimmunity

Regulatory T (Treg) cells constitute a dynamic population that is critical in autoimmunity. Treg cell therapies for autoimmune diseases are mainly focused on enhancing their suppressive activities. However, recent studies demonstrated that certain inflammatory conditions induce Treg cell instability with diminished FoxP3 expression and convert them into pathogenic effector cells. Therefore, the identification of novel targets crucial to both Treg cell function and plasticity is of vital importance to the development of therapeutic approaches in autoimmunity. In this study, we found that conditional Pp6 knockout (cKO) in Treg cells led to spontaneous autoinflammation, immune cell activation, and diminished levels of FoxP3 in CD4+ T cells in mice. Loss of Pp6 in Treg cells exacerbated two classical mouse models of Treg-related autoinflammation. Mechanistically, Pp6 deficiency increased CpG motif methylation of the FoxP3 locus by dephosphorylating Dnmt1 and enhancing Akt phosphorylation at Ser473/Thr308, leading to impaired FoxP3 expression in Treg cells. In summary, our study proposes Pp6 as a critical positive regulator of FoxP3 that acts by decreasing DNA methylation of the FoxP3 gene enhancer and inhibiting Akt signaling, thus maintaining Treg cell stability and preventing autoimmune diseases.

Circulating regulatory T cells in adult-onset Still's disease: Focusing on their plasticity and stability.

We investigated the characteristics of regulatory T cells in adult-onset Still's disease (AOSD) with a focus on their plasticity, stability and relationship to disease severity. The proportion of circulating CD4+ CD25+ forkhead box protein 3 (FoxP3+ ) cells (Tregs ) and intracellular expression of effector cytokines, including interferon (IFN)-γ, interleukin (IL)-17 and IL-4, was analysed in 27 untreated patients with AOSD (acute AOSD), 11 of the 27 patients after remission and 16 healthy controls (HC) using flow cytometry. The suppressive ability of Tregs was also evaluated. Regression analyses of the results were performed. The proportion of Tregs was significantly lower in patients with acute AOSD than in the HC. The expression levels of IFN-γ, IL-17 and IL-4 in Tregs were significantly increased in patients with acute AOSD. IFN-γ and IL-4 expression levels were inversely correlated with the proportion of Tregs and positively correlated with serum ferritin levels. Decreased expression of FoxP3 in CD4+ CD25+ cells, which was correlated with increased expression of IL-17, and impaired suppressive function were observed in Tregs in acute AOSD. However, these aberrant findings in Tregs , including the reduced circulating proportion and functional ability and altered intracellular expression levels of cytokines and FoxP3, were significantly improved after remission. In acute AOSD, Tregs show plastic changes, including effector cytokine production and reductions in their proportion and functional activity. IFN-γ and IL-4 expression levels in Tregs may be associated with disease severity. Also, down-regulation of FoxP3 may be related to IL-17 expression in Tregs . Importantly, the stability of Tregs can be restored in remission.

Abstract 606: Pkm2 activation modulates the tumor-immune microenvironment and enhances response to checkpoint inhibitors in preclinical solid tumor models

Abstract Pyruvate kinase is a crucial enzyme responsible for the last step of glycolysis. Cancer cells can use the M2 isoform of pyruvate kinase (PKM2), to better balance respiration and biosynthesis due to allosteric switching between the less active dimeric and fully active tetrameric forms. Additionally, the dimeric form of PKM2 can translocate to the nucleus, altering transcription to enhance cancer cells' ability to grow and evade immune detection. Inducing tetramerization presents an opportunity to target PKM2 resulting in the metabolic reprogramming of tumor-immune microenvironment (TME). TP-1454 is a potent PKM2 activator with low nanomolar PKM2 activation in biochemical assays (AC50 = 10 nM) and multiple cell types (AC &amp;lt; 50 nM), tolerated in mice, rats and dogs after repeat doses as high as 1000 mg/kg/day and has recently entered a Phase I clinical trial (NCT04328740). We hypothesize that PKM2 activation may reverse the immune-suppressive TME. To test this hypothesis, we examined the activity of TP-1454 combination with immunotherapy (I/O) in multiple mouse syngeneic tumor models. TP-1454 and anti-PD-1 combination therapy in colorectal cancer models resulted in tumor growth inhibition versus vehicle (53% in CT26; 99% in MC38, P &amp;lt; 0.001). We observed decreases in multiple glycolytic intermediates in TP-1454-treated tumors versus vehicle. We conducted immunophenotyping of the TME in multiple models to identify targets of PKM2 activation. TP-1454 treatment reduced the CD4+ Foxp3+ T-regulatory (Treg) population in MC38, 4T1, RENCA models. Further, we assayed TP-1454 induced PKM2 activation in different immune cell types. To confirm the effect of PKM2 activation on Treg cells we conducted an in vitro assay to explore TP-1454 treatment response on polarization of Tregs and/or toxicity and proliferation. We further utilized LCMS to explore metabolic intermediates that play a critical role in Treg regulation, including regulation of the O-linked β-N-acetylglucosamine (O-GlcNac) post-translational modification, which is reported to stabilize Foxp3 in CD4+ cells. We are currently exploring the effect of TP-1454 treatment on O-GlcNac of Foxp3 and its stability in HEK293 cells, to support the link between PKM2 activation and stabilization of Foxp3. TP-1454 effects on tumor-specific immunity were validated using tumor rechallenge studies. The results of a tumor rechallenge study will be presented using murine MC38 or RENCA xenograft models that are treated with TP-1454 and I/O combination therapies that exhibited a complete response (CR) and were re-implanted. These preclinical studies indicate a unique mechanism modulating tumor metabolism and the TME to improve the response of cancer patients to immunotherapy. Citation Format: Salah Sommakia, Satya Pathi, Yuta Matsumura, Curtis Allred, Ethika Tyagi, Matthew Lalonde, Jason Foulks, Adam Siddiqui, Clifford Whatcott, David Bearss, Steven Warner. Pkm2 activation modulates the tumor-immune microenvironment and enhances response to checkpoint inhibitors in preclinical solid tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 606.

The fatty acid-binding protein (FABP) decreases the clinical signs and modulates immune responses in a mouse model of experimental autoimmune encephalomyelitis (EAE)

BackgroundAn increasing body of studies has shown that Fasciola hepatica can affect immune responses. This study explored whether the fatty acid-binding protein (FABP) of F. hepatica can modulate the immune system in a mouse model of experimental autoimmune encephalomyelitis (EAE). MethodsEAE-induced C57BL/6 mice were treated with vehicle, F. hepatica total extract (TE) or FABP. The clinical signs, body weights, and the expression of IFN-γ, T-bet, IL-4, GATA3, IL-17, RORγ, TGF-β, FOXP3, IL-10, TNF-α genes and proteins were determined in the isolated CD4+ splenocytes. Besides, the percentage of Treg cells and degree of demyelination were evaluated. ResultsWe found that TE and FABP treatments decreased the clinical scores, lymphocyte infiltration rate, and demyelinated plaques in EAE mice. The expressions of IL-4 and GATA3 were increased, whereas IL-17 and TNF-α were down-regulated. FABP did not affect the expression of IFN-γ, RORγ, IL-10, and TGF-β genes or proteins but reduced the expression of T-bet. TE administration did not affect the expression of IL-10 and the Tbet genes, and increased the expression levels of IFN-γ and FOXP3 in CD4+ lymphocytes. Both FABP and TE treatment did not affect the Treg cell percentage. ConclusionThis study indicates that F. hepatica FABP and TE can suppress the inflammatory responses in EAE-induced mice and shift the immune system toward Th2 responses. However, FABP exerts stronger anti-inflammatory effects and seems to be more effective than TE for EAE treatment.

Sex Hormones and Gender Influence the Expression of Markers of Regulatory T Cells in SLE Patients.

Regulatory T cells have been implicated in the regulation and maintenance of immune homeostasis. Whether gender and sex hormones differentially influence the expression and function of regulatory T cell phenotype and their influence on FoxP3 expression remains obscure. We provide evidence in this study that the number and percent of human regulatory T cells (Tregs) expressing CD4+ and CD8+ are significantly reduced in healthy females compared to healthy males. In addition, both CD4+CD25+hi and CD8+CD25+hi subsets in healthy males have a 2-3 fold increase in FoxP3 mRNA expression compared to healthy females. Female SLE patients, compared to healthy women, have elevated plasma levels of estradiol and decreased levels of testosterone. Higher levels of testosterone correlate with higher expression of FoxP3 in CD4+CD25hiCD127low putative Tregs in women with SLE. Incubation of CD4+ regulatory T cells with 17β-estradiol at physiological levels generally decreased FoxP3 expression in females with SLE. These data suggest that females may be more susceptible than males to SLE and other autoimmune diseases in part because they have fewer Tregs and reduced FoxP3 expression within those cells due to normal E2 levels which suppress FoxP3 expression. In addition, low levels of plasma testosterone in women may further reduce the ability of the Tregs to express FoxP3. These data suggest that gender and sex hormones can influence susceptibility to SLE via effects on regulatory T cells and FoxP3 expression.

Clophosome alleviate dextran sulphate sodium-induced colitis by regulating gut immune responses and maintaining intestinal integrity in mice.

Inflammatory bowel disease (IBD) is a chronic progressive disorder characterized by complicated gastrointestinal inflammation. Research on therapeutic agents is still urgent due to the lack of satisfactory treatments. Gut macrophages are considered to be predominant in excessive inflammatory responses. Thus, we aimed to investigate whether depletion of macrophages would have a beneficial effect on IBD and could be a potential therapeutic strategy. In this study, we established a 12-day Dextran sodium sulphate (DSS)-induced colitis mouse model and determined the effect of the macrophage depletion agent Clophosome (neutral clodronate liposomes; CNC). The results showed that CNC significantly alleviated the symptoms of colitis, as demonstrated by greater weight gain, decreased disease activity index (DAI) scores, and lower histopathological damage scores, as well was reduced levels of the proinflammatory cytokines interleukin (IL)-6 and tumour necrosis factor (TNF)-α. To investigate T cell subsets, cells were isolated from the lamina propria and cultured to analyse the expression of IL-17A, interferon (IFN)-γ and Foxp3 in CD4+ cells by flow cytometry. The data showed that during the process of colitis, the frequencies of CD4+ IL-17A+ T cells were significantly increased. Notably, CNC treatment markedly reduced the population of CD4+ IL-17A+ T cells, especially CD4+ IL-17A+ IFN-γ+ T cells. Furthermore, intestinal barrier integrity, as assessed by immunostaining of mucin and tight junction proteins, was severely disrupted in colitis. CNC improved the intestinal barrier by enhancing the expression of muc-2 and occludin. In summary, our findings demonstrated that CNC successfully ameliorated DSS-induced colitis and that its effect may be associated with inhibiting inflammatory responses and maintaining intestinal integrity.

The effects and immunologic mechanisms of Helicobacter pylori infection on AOM/DSS induced colitis-associated cancer in mice

Objective: To investigate the effects and potential mechanisms of Helicobacter pylori (H.pylori) infection on azoxymethane (AOM)/dextran sulfate sulphate (DSS) induced colitis-associated cancer (CAC) in mice. Methods: A total of 60 specific pathogen free C57BL/6J mice were randomly divided into four groups: normal control group (control group, n=9), H. pylori-infected group (Hp group, n=9), AOM/DSS-treated group (AOM/DSS group,n=21) and AOM/DSS-treated with H.pylori infection group (Hp+AOM/DSS group, n=21). Mice were sacrificed on day19, 45 or 85 after AOM/DSS challenge. Histopathological changes in colonic tissues were determined by hematoxylin and eosin staining. Flow cytometry analysis was performed to determine T helper cells 17 (Th17) and regulatory T cells (Treg) in colonic lamina propria. The expression levels of Th17-and Treg-associated cytokines and transcription factors [interleukin (IL)-10, IL-17A, retinoic acid receptor-related orphan receptor γt (RORγt) and forkhead box P3 (Foxp3)] were determined by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: There were no histopathological changes in colonic tissues of mice in control group and Hp group. H.pylori colonization reduced the histopathological scores at the stages of colitis (day 19) and dysplasia (day 45), and also decreased tumor load (day 85) in mice treated with AOM/DSS (all P<0.05). Compared with AOM/DSS group, the percentages of CD3(+)CD4(+)IL-17A(+)Th17 and CD3(+)CD4(+)IL-17A(+)Foxp3(+)Treg cells (1.88±0.17 vs 2.07±0.89, 1.06±0.13 vs 1.89±0.23) and the expression levels of RORγt and IL-17A (1.08±0.59 vs 2.35±1.35, 2.96±0.92 vs 7.78±4.57) were decreased in colonic tissues of Hp+AOM/DSS group (all P<0.05). The percentages of CD3(+)CD4(+)CD25(+)Foxp3(+)Treg and CD3(+)CD4(+)IL-10(+)Foxp3(+)Treg cells (20.60±3.39 vs 15.63±2.71, 2.94±0.52 vs 2.14±0.47) and the expression levels of Foxp3 and IL-10 [17.59(13.77,24.87) vs 6.27(4.41,13.36), 3.52(1.59,5.99) vs 1.17(1.15,2.75)] in colonic tissues were higher (all P<0.05) in mice of Hp+AOM/DSS group compared with AOM/DSS group on day 85. Conclusion: H.pylori infection slows the progress from inflammation to tumor in a AOM/DSS induced CAC modal, accompanied with the downregulation of Th17 response and upregulation of Treg response.

Influence of Xuebijing injection and its component paeoniflorin on immune function and survival rate of septic rats

Influence of Xuebijing injection and its component paeoniflorin on immune function and survival rate of septic rats

Immunophenotyping of Peripheral Blood, Lymph Node, and Bone Marrow T Lymphocytes During Canine Leishmaniosis and the Impact of Antileishmanial Chemotherapy.

Dogs are a major reservoir of Leishmania infantum, etiological agent of canine leishmaniosis (CanL) a zoonotic visceral disease of worldwide concern. Therapeutic protocols based on antileishmanial drugs are commonly used to treat sick dogs and improve their clinical condition. To better understand the impact of Leishmania infection and antileishmanial drugs on the dog's immune response, this study investigates the profile of CD4+ and CD8+ T cell subsets in peripheral blood, lymph node, and bone marrow of sick dogs and after two different CanL treatments. Two CanL groups of six dogs each were treated with either miltefosine or meglumine antimoniate combined with allopurinol. Another group of 10 clinically healthy dogs was used as control. Upon diagnosis and during the following 3 months of treatment, peripheral blood, popliteal lymph node, and bone marrow mononuclear cells were collected, labeled for surface markers CD45, CD3, CD4, CD8, CD25, and intracellular nuclear factor FoxP3, and T lymphocyte subpopulations were immunophenotyped by flow cytometry. CanL dogs presented an overall increased frequency of CD8+ and CD4+CD8+ double-positive T cells in all tissues and a decreased frequency of CD4+ T cells in the blood. Furthermore, there was a higher frequency of CD8+ T cells expressing CD25+FoxP3+ in the blood and bone marrow. During treatment, these subsets recovered to levels similar to those of healthy dogs. Nevertheless, antileishmanial therapy caused an increase of CD4+CD25+FoxP3+ T cells in all tissues, associated with the decrease of CD8+CD25−FoxP3− T cell percentages. These findings may support previous studies that indicate that L. infantum manipulates the dog's immune system to avoid the development of a protective response, ensuring the parasite's survival and the conditions that allow the completion of Leishmania life cycle. Both treatments used appear to have an effect on the dog's immune response, proving to be effective in promoting the normalization of T cell subsets.

Correction: IL-35 Decelerates the Inflammatory Process by Regulating Inflammatory Cytokine Secretion and M1/M2 Macrophage Ratio in Psoriasis.

Zhang, J., Y. Lin, C. Li, X. Zhang, L. Cheng, L. Dai, Y. Wang, F. Wang, G. Shi, Y. Li, Q. Yang, X. Cui, Y. Liu, H. Wang, S. Zhang, Y. Yang, R. Xiang, J. Li, D. Yu, Y. Wei, and H. Deng. 2016. IL-35 decelerates the inflammatory process by regulating inflammatory cytokine secretion and M1/M2 macrophage