Immunomodulation of Ethyl pyruvate on gestational diabetes mellitus in Mice; The impact on Th17/Treg balance.

Gestational diabetes mellitus (GDM) is recognized as one of the most common diseases among pregnant women and inflammatory responses can be a major reason for its induction and development. T helper 17 (Th17)/regulatory T cells (Tregs) imbalance resulting in the increased levels of pro-inflammatory and decreased levels of anti-inflammatory cytokines has been showed as major mechanisms involved in the pathogenesis of GDM. There are various treatment options, but none of them are completely therapeutic. Ethyl pyruvate (EP) is a stable derivate of pyruvate that showed anti-oxidant and anti-inflammatory properties in an in-vivo and in-vitro models. To examine the therapeutic efficacy of EP in GDM, mice were mated and EP (100 mg/kg) was administered intraperitoneally to C57BL/6 mice. EP-treated mice exhibited improved symptoms of GDM by decreased blood glucose levels and body-weight and increased insulin levels and insulin sensitivity. Furthermore, EP could significantly attenuate the impairments to offspring, including birth size and birth weight. The inflammatory responses were also decreased by EP through regulating the production of Th17-related cytokines, such as interleukin (IL)- 17 and IL-21. The levels of other inflammatory cytokines were also inhibited, including IL-1ß, IL-6, and tumor necrosis factor (TNF)-α. In addition, it was found that EP increased the population of Tregs and Treg-related cytokines, IL-10 and transforming Growth Factor-ß TGF-ß, in GDM mice. In conclusion, EP could modulate GDM in mice and might be a potential therapeutic strategy candidate for the treatment of patients with GDM.

LAT1-specific inhibitor ameliorates severe autoimmune arthritis in SKG mouse.

L-type amino acid transporter 1 (LAT1, slc7a5) supplies large neutral amino acids to highly proliferative cells. LAT1 is an attractive therapeutic target for treating overactive T cell-mediated immune disorders due to its high expression in activated T cells, but not in resting T cells. Here, we demonstrate that LAT1 plays a crucial role in T helper (Th) 17-mediated autoimmune arthritis in SKG mice, an animal model of human rheumatoid arthritis (RA). Administration of JPH203, a LAT1-specific inhibitor, suppressed mannan-induced joint swelling, synoviocyte proliferation and inflammatory cell infiltration in SKG mice. A diminished metabolic reprogramming, including a decrease in oxidative phosphorylation that regulates Hif-1α expression and subsequent control of glycolysis enzymes, was involved in the downregulation of Th17 differentiation by LAT1 inhibition. Moreover, publicly released database analysis revealed facilitated expression of LAT1 in T cells with cytotoxic features in patients with RA. Our results demonstrate the essential contribution of LAT1 to the development of RA, proposing a potential therapeutic approach targeting amino acid transporters for treating hypersensitive immune diseases.

[Effects of astragaloside â £ on inflammatory response and percentage of peripheral blood Th17 cells in mice with ulcerative colitis].

This study aimed to investigate the anti-inflammatory effect of astragaloside Ⅳ in mice with ulcerative colitis(UC) and its effect on the percentage of peripheral blood T helper(Th17) cells. Following the establishment of UC mouse model with 2% sodium dextran sulfate(DSS), mice in the positive control group and low-and high-dose astragaloside Ⅳ groups were treated with corresponding drugs by gavage. Disease activity index(DAI) was calculated, and serum interleukin-17(IL-17), tumor necrosis factor-α(TNF-α), and transforming growth factor-ß(TGF-ß) levels were assayed by ELISA. The pathological changes in colon tissue were observed by HE staining, and Th17/regulatory T cells(Treg) ratio in the peripheral blood was determined by flow cytometry. Western blot was conducted for detecting the relative protein expression levels of forkhead box protein P3(Foxp3) and retinoic acid-related orphan nuclear receptor γT(ROR-γt). The findings demonstrated that in normal mice, the colonic structure was intact. The goblet cells were not reduced and the glands were neatly arranged, with no mucosal erosion, bleeding, or positive cell infiltration. In the model group, the colonic mucosal structure was seriously damaged, manifested as disordered arrangement or missing of glands, vascular dilatation, congestion, and massive inflammatory cell infiltration. The pathological injury of colon tissue was alleviated to varying degrees in drug treatment groups. Compared with the normal group, the model group exhibited elevated percentage of Th17 cells, increased IL-17 and TNF-α content, up-regulated relative ROR-γt protein expression, lowered TGF-ß, reduced percentage of Treg cells, and down-regulated relative Foxp3 protein expression. The comparison with the model group showed that DAI score, pathological score, percentage of Th17 cells, IL-17 and TNF-α content, and relative ROR-γt protein expression in the positive control group, low-dose astragaloside Ⅳ group, and high-dose astragaloside Ⅳ group were decreased, while TGF-ß content, percentage of Treg cells, and relative Foxp3 protein expression were increased. The DAI score, pathological score, percentage of Th17 cells, IL-17 and TNF-α content, and relative ROR-γt protein expression in the low-dose astragaloside Ⅳ group were higher than those in the positive control group, whereas the content of TGF-ß, percentage of Treg cells, and relative Foxp3 protein expression were lower. DAI score, pathological score, percentage of Th17 cells, IL-17 and TNF-α content, relative ROR-γt protein expression in the high-dose astragaloside Ⅳ group declined in contrast to those in the low-dose astragaloside Ⅳ group, while the TGF-ß content, percentage of Treg cells, and relative Foxp3 protein expression rose. There was no significant difference between the positive control group and the high-dose astragaloside Ⅳ group. Astragaloside Ⅳ is able to inhibit inflammatory response and diminish the percentage of Th17 cells in mice with UC.

Neonatal T Helper 17 Responses Are Skewed Towards an Immunoregulatory Interleukin-22 Phenotype.

Newborns are frequently affected by mucocutaneous candidiasis. Th17 cells essentially limit mucosal invasion by commensal Candida spp. Here, we sought to understand the molecular basis for the developmental lack of Th17 cell responses in circulating blood neonatal T cells. Naive cord blood CD4 T cells stimulated in Th17-differentiating conditions inherently produced high levels of the interleukin-22 immunoregulatory cytokine, particularly in the presence of neonatal antigen-presenting cells. A genome-wide transcriptome analysis comparing neonatal and adult naïve CD4 T cells ex vivo revealed major developmental differences in gene networks regulating Small Drosophila Mothers Against Decapentaplegic (SMAD) and Signal Transducer and Activator of Transcription 3 (STAT3) signaling. These changes were functionally validated by experiments showing that the requirement for TGF-ß in human Th17 cell differentiation is age-dependent. Moreover, STAT3 activity was profoundly diminished while overexpression of the STAT3 gene restored Th17 cell differentiation capacity in neonatal T cells. These data reveal that Th17 cell responses are developmentally regulated at the gene expression level in human neonates. These developmental changes may protect newborns against pathological Th17 cell responses, at the same time increasing their susceptibility to mucocutaneous candidiasis.

Decipher manifestations and Treg /Th17 imbalance in multi-staging rheumatoid arthritis and correlation with TSDR/RORC methylation.

T regulatory (Treg)/T-helper (Th) 17 imbalance has been shown to integrate with epigenetics to result in the development of autoimmune diseases. We aim to investigate the influence of disease staging on Treg/Th17 cells and whether the aberrant DNA methylation is implicated in the development of rheumatoid arthritis (RA). By recruiting 65 patients with multi-staging RA and 20 healthy controls (HC), we found that patients with active RA exhibited relative lymphopenia and higher WBC, neutrophils, and PLT. Circulating Treg/Th17 in patients with early active RA was significantly decreased. The expression of IL-6 and IL-17A was significantly increased in early active RA, whereas that of IL-10 and TGF-ß was on the contrary. Furthermore, the frequency of Treg cells and Treg/Th17 were negatively correlated with DAS28, and the frequency of Th17 cells was on the contrary. Levels of DNA methylation related enzymes had significant difference between early active RA and HC. Relative hypermethylation was observed at the gene level for Treg-specific demethylated region (TSDR) and hypomethylation for retinoic acid-related orphan receptor (ROR)-C in early active RA. Thus, manifestations of RA and Treg/Th17 imbalance vary with disease staging, and the aberrant DNA methylation pattern may contribute to RA disease pathogenesis. Our results highlight the importance of disease staging in clinical research.

IL-17 and IL-22 elicited by a DNA vaccine encoding ROP13 associated with protection against Toxoplasma gondii in BALB/c mice.

Toxoplasma gondii, an intracellular parasitic protozoan, is capable of infecting man and all warm-blooded animals. Cell-mediated immunity is vital in mounting protective responses against T. gondii infection. Recent studies have shown that T-helper (Th) 17 responses may play a key role in parasite control. In this current study, we constructed a DNA vaccine encoding T. gondii ROP13 in a pcDNA vector. Groups of BALB/c mice were immunized intramuscularly with pcROP13 or controls and challenged with the RH strain of T. gondii. The results showed that immunization with pcROP13 could elicit an antibody response against T. gondii. The expression of the canonical Th17 cytokines, interleukin (IL)-17 and IL-22, were significantly increased after immunization with pcROP13 compared with control groups ( p < 0.05). Furthermore, vaccination resulted in a significant decrease in parasite load ( p < 0.05). The induction of Th17 related cytokines, using a ROP13 DNA vaccine, against T. gondii should be considered as a potential vaccine approach for the control of toxoplasmosis.

The role of salt for immune cell function and disease.

The immune system evolved to protect organisms from invading pathogens. A network of pro- and anti-inflammatory cell types equipped with special effector molecules guarantees efficient elimination of intruders like viruses and bacteria. However, imbalances can lead to an excessive response of effector cells incurring autoimmune or allergic diseases. An interplay of genetic and environmental factors contributes to autoimmune diseases and recent studies provided evidence for an impact of dietary habits on the immune status and related disorders. Western societies underwent a change in lifestyle associated with changes in food consumption. Salt (sodium chloride) is one component prevalent in processed food frequently consumed in western countries. Here we summarize recent advances in understanding the mechanisms behind the effects of sodium chloride on immune cells like regulatory T cells (Tregs) and T helper (TH ) 17 cells and its implication as a risk factor for several diseases.

Molecular mechanisms underpinning T helper 17 cell heterogeneity and functions in rheumatoid arthritis.

T helper 17 (Th17) cells are important mediators of immune responses against extracellular bacteria and fungi, and as such play critical regulatory roles in maintaining mucosal homeostasis. Conversely, Th17 cells and their effector molecules interleukin 17A (IL-17A), IL-17F, interferon (IFN)γ, tumor necrosis factor (TNF)α, and granulocyte-macrophage colony-stimulating factor (GM-CSF) are implicated in the pathology of rheumatoid arthritis (RA). Interactions between Th17 cells and other immune cells or stromal cells that are present in the synovial tissue during the earliest phases of the disease, may eventually lead to chronic inflammation, irreversible cartilage degradation and bone erosions. Recent evidence points towards Th17 cell plasticity as an essential contributing process in RA pathology, since Th17 cells are able to adopt a pathogenic phenotype under the influence of environmental, inflammatory and genetic factors. A remarkable feature of this pathogenic Th17 cell phenotype is the high production of GM-CSF and TNFα and the co-appearance of Th1 cell characteristics, such as transcription factor T-box 21 (T-bet) and IFNγ expression. Recently, much progress has been made in unravelling the mechanisms underlying Th17 cell plasticity and pathogenicity. Of interest, many of the environmental and inflammatory factors associated with RA pathology, such as pro-inflammatory mediators and cytokines, microbiome dysbiosis, metabolism and diet, obesity, vitamins, steroids and hormones are linked to the development of pathogenic Th17 cells. Moreover proteins encoded by established genetic risk factors for RA including CCR6, CD226, CSF2, EOMES, ETS1, GATA3, IL2, IL6R, IL23R, IKZF3, IRAK1, IRF4, IRF8, PRKCQ, PRDM1, RBPJ, RUNX1 and TAGAP are directly involved in Th17 cell differentiation and/or function. This review provides a detailed overview of the molecular mechanisms involved in the heterogeneity and pathogenicity of Th17 cells in the context of autoimmune diseases, with a focus on RA. Understanding these mechanisms creates great potential to identify and select novel therapeutic targets which could improve current therapies or lead to development of new treatment strategies in RA.

Role of interleukin (IL)-17 and T-helper (Th)17 cells in cancer.

Interleukin-17 (IL-17), a pleiotropic proinflammatory cytokine, is reported to be significantly generated by a distinct subset of CD4+ T-cells, upgrading cancer-elicited inflammation and preventing cancer cells from immune surveillance. T-helper (Th)17 cells produced from naive CD4+ T cells have recently been renowned and generally accepted, gaining eminence in cancer studies and playing the effective role in context of cancer. Th17 cells are the main source of IL-17-secreting cells, It was found that other cell types produced this cytokine as well, including Group 3 innate lymphoid cells (ILC3), δγT cells, invariant natural killer T (iNKT) cells, lymphoid-tissue inducer (LTi)-like cells and Natural killer (NK) cells. Th17-associated cytokines give impetus to tumor progression, or inducing angiogenesis and metastasis. This review demonstrates an understanding on how the pro- or antitumor function of Th17 cells and IL-17 may change cancer progression, leading to the appearance of complex and pivotal biologic activities in tumor.