PPAR-γAgonist Alleviates Liver and Spleen Pathology via Inducing Treg Cells duringSchistosoma japonicumInfection

Background. Peroxisome proliferator-activated receptor- (PPAR-)γplays critical roles in human metabolic disorders and has recently been implicated as a regulator of cellular proliferation and inflammatory responses. Regulatory T cells (Tregs), which express high levels of PPAR-γprotein, have the ability to maintain immune tolerance to self-antigens and regulate immune response toSchistosomainfection. However, mechanisms involved in the resolution of these responses are elusive.Methods. Liver and spleen tissue samples inSchistosoma japonicum-infected mice after administration of pioglitazone (a PPAR-γagonist) were collected. The hepatic and splenic pathologies were detected by H&E and Masson staining. The percentages of Th1/2 and Treg cells in the liver and spleen of each mouse were determined using flow cytometry. Levels of gene expression of PPAR-γand Foxp3 in tissues or cells were determined using real-time PCR (RT-PCR). Macrophages were treated with pioglitazonein vitroor cocultured with normal purified CD4+T cells for detecting Treg cells by flow cytometry. The interactions of PPAR-γwith Foxp3 in CD4+T cells were detected by coimmunoprecipitation.Results. Administration of pioglitazone resulted in the prevention of the development of hepatic and splenic pathologies. Activation of PPAR-γby pioglitazone resulted in increased percentages of CD4+CD25+Foxp3+Treg cells and decreased percentages of CD3+CD4+IFN-γ+and CD3+CD4+IL-4+cells in the liver and spleen ofSchistosoma japonicum-infected mice. In addition, the PPAR-γagonist can induce Treg cellsin vitrodirectly or by modulating the macrophage’s function indirectly. Furthermore, through interaction with Foxp3 in CD4+T cells, the PPAR-γagonist can promote the expression of Foxp3; however, the inhibitor of PPAR-γweakened the expression of Foxp3 by modifying the coexpression of Foxp3 and PPAR-γ.Conclusions. Our study reveals a previously unrecognized role for PPAR-γ/Foxp3 signaling in regulating the immunopathology that occurs duringSchistosomainfection through induction of Treg cells.

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CD36-Mediated Lipid Accumulation and Activation of NLRP3 Inflammasome Lead to Podocyte Injury in Obesity-Related Glomerulopathy

Mediators of Inflammation ◽

10.1155/2019/3172647 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Jing Zhao ◽

Hong-liang Rui ◽

Min Yang ◽

Li-jun Sun ◽

Hong-rui Dong ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Lipid Accumulation ◽

Inflammatory Responses ◽

Regulatory Element ◽

Animal Experiments ◽

Receptor Protein ◽

Peroxisome Proliferator ◽

Podocyte Injury ◽

Peroxisome Proliferator Activated Receptor

Podocyte injury critically contributes to the pathogenesis of obesity-related glomerulopathy (ORG). Recently, lipid accumulation and inflammatory responses have been found to be involved in podocyte injury. This study is to explore their role and relationship in podocyte injury of ORG. In animal experiments, the ORG mice developed proteinuria, podocyte injury, and hypertriglyceridemia, accompanied with deregulated lipid metabolism, renal ectopic lipid deposition, activation of NOD-like receptor protein 3 (NLRP3) inflammasome, and secretion of IL-1β of the kidney. The expression of adipose differentiation-related protein (ADRP), CD36, sterol regulatory element-binding protein 1 (SREBP-1), and peroxisome proliferator-activated receptor α (PPARα) in renal tissue were increased. In in vitro cell experiments, after cultured podocytes were stimulated with leptin, similar to ORG mice, we found aggravated podocyte injury, formatted lipid droplet, increased expression of ADRP and CD36, activated NLRP3 inflammasome, and released IL-1β. In addition, after blocking CD36 with inhibitor sulfo-N-succinimidyl oleate (SSO) or CD36 siRNA, activation of NLRP3 inflammasome and release of IL-1β are downregulated, and podocyte injury was alleviated. However, after blocking NLRP3 with MCC950, although podocyte injury was alleviated and release of IL-1β was decreased, there was no change in the expression of CD36, ADRP, and intracellular lipid droplets. Taken together, our study suggests that CD36-mediated lipid accumulation and activation of NLRP3 inflammasome may be one of the potential pathogeneses of ORG podocyte injury.

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The role of Toll-like receptor proteins (TLR) 2 and 4 in mediating inflammation in proximal tubules

AJP Renal Physiology ◽

10.1152/ajprenal.00398.2012 ◽

2013 ◽

Vol 305 (2) ◽

pp. F143-F154 ◽

Cited By ~ 74

Author(s):

Harshini Mudaliar ◽

Carol Pollock ◽

Muralikrishna Gangadharan Komala ◽

Steven Chadban ◽

Huiling Wu ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Inflammatory Responses ◽

Proximal Tubules ◽

Peroxisome Proliferator ◽

Tlr2 Expression ◽

Peroxisome Proliferator Activated Receptor ◽

Ppar Γ ◽

Diagnostic Threshold

Inflammatory responses are central to the pathogenesis of diabetic nephropathy. Toll-like receptors (TLRs) are ligand-activated membrane-bound receptors which induce inflammatory responses predominantly through the activation of NF-κB. TLR2 and 4 are present in proximal tubular cells and are activated by endogenous ligands upregulated in diabetic nephropathy, including high-mobility group box-1 (HMGB1) and fibronectin. Human proximal tubules were exposed to 5 mM (control), 11.2 mM (approximating the clinical diagnostic threshold for diabetes mellitus), and 30 mM (high) glucose for 72 h or 7 days. Cells were harvested for protein, mRNA, and nuclear extract to assess for TLR2, 4, and inflammatory markers. Glucose (11.2 mM) maximally increased TLR2 and 4 expression, HMGB1 release, and NF-κB activation with increased expression of cytokines. However, only TLR2 expression and subsequent NF-κB binding were sustained at 7 days. Recombinant HMGB1 induced NF-κB activation, which was prevented by both TLR2 silencing [small interfering (si)RNA] and TLR4 inhibition. Peroxisome proliferator-activated receptor-γ (PPAR-γ) transcription was reduced by exposure to 11.2 mM glucose with an increase observed at 30 mM glucose at 24 h. This may reflect a compensatory increase in PPAR-γ induced by exposure to 30 mM glucose, limiting the inflammatory response. Therefore, short-term moderate increases in glucose in vitro increase HMGB1, which mediates NF-κB activation through both TLR2 and 4. Furthermore, in vivo, streptozotocin-induced diabetic mice exhibited an increase in tubular TLR2 and HMGB1 expression. These results collectively suggest that TLR2 is likely to be the predominant long-term mediator of NF-κB activation in transducing inflammation in diabetic nephropathy.

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Inhibition of PPARγ in myeloid-lineage cells induces systemic inflammation, immunosuppression, and tumorigenesis

Blood ◽

10.1182/blood-2011-06-363093 ◽

2012 ◽

Vol 119 (1) ◽

pp. 115-126 ◽

Cited By ~ 53

Author(s):

Lingyan Wu ◽

Cong Yan ◽

Magdalena Czader ◽

Oded Foreman ◽

Janice S. Blum ◽

...

Keyword(s):

T Cells ◽

Cd4 T Cells ◽

Suppressor Cells ◽

Dominant Negative ◽

Peroxisome Proliferator ◽

Myeloid Lineage ◽

Peroxisome Proliferator Activated Receptor ◽

Anti Inflammatory ◽

Spleen And Lymph Nodes

Abstract Peroxisome proliferator–activated receptor-γ (PPARγ) is an anti-inflammatory molecule. To study its biologic function in myeloid cells, dominant-negative PPARγ (dnPPARγ) was overexpressed in a myeloid-specific bitransgenic mouse model. In this bitransgenic system, overexpression of the dnPPARγ-Flag fusion protein in myeloid-lineage cells abnormally elevated frequencies and total numbers of IL-7Rα−Lin−c-Kit+Sca-1−, Lin−/Scal+/c-Kit+, common myeloid, and granulocyte-monocyte progenitor populations in the BM. dnPPARγ overexpression led to up-regulation of IL-1β, IL-6, and TNFα in the blood plasma. As a result, CD11b+Ly6G+ cells were systemically increased in association with activation of Stat3, NF-κB, Erk1/2, and p38 molecules. Myeloid-derived suppressor cells (MDSCs) inhibited the proliferation and lymphokine production of wild-type CD4+ T cells in vitro. CD4+ T cells from doxycycline-treated bitransgenic mice displayed reduced proliferation and lymphokine release. Both CD4+ and CD8+ T-cell populations were decreased in doxycycline-treated bitransgenic mice. Multiple forms of carcinoma and sarcoma in the lung, liver, spleen, and lymph nodes were observed in doxycycline-treated bitransgenic mice. BM transplantation revealed that a myeloid-autonomous defect was responsible for MDSC expansion, immunosuppression, and tumorigenesis in these mice. These studies suggest that anti-inflammatory PPARγ in myeloid-lineage cells plays a key role in controlling pro-inflammatory cytokine synthesis, MDSC expansion, immunosuppression, and the development of cancer.

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Melatonin, an Endogenous Hormone, Modulates Th17 Cells via the Reactive Oxygen Species/TXNIP/HIF-1α Axis to Alleviate Autoimmune Uveitis

10.21203/rs.3.rs-1192974/v1 ◽

2022 ◽

Author(s):

Dan Liang ◽

Jun Huang ◽

Zhuang Li ◽

Yunwei Hu ◽

Zuoyi Li ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Flow Cytometry ◽

T Cells ◽

Th17 Cells ◽

Reactive Oxygen ◽

Treg Cells ◽

Oxygen Species ◽

T Helper ◽

Autoimmune Uveitis

Abstract Background Melatonin, an indoleamine produced by the pineal gland, plays a pivotal role in maintaining circadian rhythm homeostasis. Recently, the strong antioxidant and anti-inflammatory properties of melatonin have attracted attention of researchers. We evaluated the therapeutic efficacy of melatonin in experimental autoimmune uveitis (EAU), which is a representative animal model of human autoimmune uveitis. Methods EAU was induced in mice via immunization with the peptide interphotoreceptor retinoid binding protein 1-20 (IRBP1−20). melatonin was then administered via intraperitoneal injection to induce protection against EAU. With EAU induction for 14 days, clinical and histopathological scores were employed to evaluate the disease progression. T lymphocytes accumulation, the expression of inflammatory cytokines in the retinas were assessed via flow cytometry and RT-PCR. In vivo and in vitro experiments, T helper 1 (Th1), T helper 17 (Th17) and regulatory T (Treg) cells were detected via flow cytometry, the level reactive oxygen species(ROS) from CD4+ cells were tested via flow cytometry, and the expression of thioredoxin-interacting protein (TXNIP) and hypoxia-inducible factor 1 alpha (HIF-1α)proteins were also quantified via western blot analysis, to elucidate the mechanism of melatonin inhibiting EAU. Results Melatonin treatment resulted in notable attenuation of ocular inflammation in EAU mice, evidenced by decreasing optic disc edema, few signs of retinal vasculitis, and minimal retinal and choroidal infiltrates. Mechanistic studies revealed that melatonin restricted the proliferation of peripheral Th1 and Th17 cells and potentiated Treg cells by suppressing their transcription factors. In vitro studies corroborated that melatonin restrains the polarization of retina-specific T cells towards Th17 and Th1 cells in addition to enhancing the proportion of Treg cells. Pretreatment of retina-specific T cells with melatonin failed to induce EAU in naïve recipients. Furthermore, the ROS/ TXNIP/ HIF-1α pathway was shown to mediate the therapeutic effect of melatonin in EAU. Conclusions Melatonin regulates autoimmune T cells by restraining effector T cells and facilitating Treg generation, indicating that melatonin could be a hopeful treatment alternative for autoimmune uveitis.

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SOCS1 is essential for regulatory T cell functions by preventing loss of Foxp3 expression as well as IFN-γ and IL-17A production

Journal of Experimental Medicine ◽

10.1084/jem.20110428 ◽

2011 ◽

Vol 208 (10) ◽

pp. 2055-2067 ◽

Cited By ~ 109

Author(s):

Reiko Takahashi ◽

Shuhei Nishimoto ◽

Go Muto ◽

Takashi Sekiya ◽

Taiga Tamiya ◽

...

Keyword(s):

T Cells ◽

Inflammatory Responses ◽

Foxp3 Expression ◽

Treg Cells ◽

Negative Regulator ◽

Cytokine Signaling ◽

Cell Integrity ◽

Cell Functions ◽

Ifn Γ

Regulatory T cells (Treg cells) maintain immune homeostasis by limiting inflammatory responses. SOCS1 (suppressor of cytokine signaling 1), a negative regulator of cytokine signaling, is necessary for the suppressor functions of Treg cells in vivo, yet detailed mechanisms remain to be clarified. We found that Socs1−/− Treg cells produced high levels of IFN-γ and rapidly lost Foxp3 when transferred into Rag2−/− mice or cultured in vitro, even though the CNS2 (conserved noncoding DNA sequence 2) in the Foxp3 enhancer region was fully demethylated. Socs1−/− Treg cells showed hyperactivation of STAT1 and STAT3. Because Foxp3 expression was stable and STAT1 activation was at normal levels in Ifnγ−/−Socs1−/− Treg cells, the restriction of IFN-γ–STAT1 signaling by SOCS1 is suggested to be necessary for stable Foxp3 expression. However, Ifnγ−/−Socs1−/− Treg cells had hyperactivated STAT3 and higher IL-17A (IL-17) production compared with Ifnγ−/−Socs1+/+ Treg cells and could not suppress colitis induced by naive T cells in Rag2−/− mice. In vitro experiments suggested that cytokines produced by Socs1−/− Treg cells and Ifnγ−/−Socs1−/− Treg cells modulated antigen-presenting cells for preferential Th1 and Th17 induction, respectively. We propose that SOCS1 plays important roles in Treg cell integrity and function by maintaining Foxp3 expression and by suppressing IFN-γ and IL-17 production driven by STAT1 and STAT3, respectively.

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Plasticity of Treg and imbalance of Treg/Th17 cells in patients with systemic sclerosis modified by FK506

International Journal of Immunopathology and Pharmacology ◽

10.1177/2058738421998086 ◽

2021 ◽

Vol 35 ◽

pp. 205873842199808

Author(s):

Xinjuan Liu ◽

Yu Wu ◽

Mengtao Li ◽

Jianyu Hao ◽

Qian Wang ◽

...

Keyword(s):

Flow Cytometry ◽

T Cells ◽

Systemic Sclerosis ◽

Th17 Cells ◽

Treg Cells ◽

Proliferation Capacity ◽

Healthy Control ◽

Immune Imbalance

To determine the effects of Tacrolimus (FK506) on Treg cells and subpopulations in SSc patients and assess the ability of FK506 to modify the immune imbalance of Treg/Th17 cells. We analyzed PBMC from five SSc patients and six healthy control by flow cytometry after cultured with 0, 0.1, 1, or 10 ng/ml FK506 in vitro. The number of Treg cells decreased in SSc patients treated with FK506. The number of FrI cells were decreased in SSc following FK506 treatment. The drug did increase the frequency of FrII/Treg cells, but not FrII cells. However, FK506 significantly decreased FrIII in both SSc patients and controls. FK506 clearly decreased the numbers of Th17 cells and FoxP3+IL-17+ cells. The proliferation capacity of cells was also inhibited by FK506, which had a greater effect on FoxP3− cells than FoxP3+ cells. FK506 did inhibit the proliferation of FrIII cells, but not FrI or FrII cells. Our study provides that FK506 reduced the number of FoxP3low CD45RA− T cells (FrIII) by inhibiting its proliferation. Therefore, FK506 modifies Treg cells and the immune imbalance between Tregs and Th17 cells in SSc patients.

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Expression of recombinant Schistosoma japonicum protein rSjE16 and its effects on LX-2 cells in vitro

Journal of International Medical Research ◽

10.1177/0300060520972228 ◽

2020 ◽

Vol 48 (12) ◽

pp. 030006052097222

Author(s):

Wenxi Gao ◽

Wenxia Peng ◽

Xingpei Ji ◽

Dandan Zhu ◽

Jinling Chen ◽

...

Keyword(s):

Schistosoma Japonicum ◽

Smooth Muscle Actin ◽

Stellate Cells ◽

Peroxisome Proliferator ◽

Muscle Actin ◽

Transmembrane Region ◽

Peroxisome Proliferator Activated Receptor ◽

Expression Levels ◽

Mtt Assays

Objective The activation of hepatic stellate cells (HSCs) is a key event in schistosome-induced liver fibrosis. Previous studies have shown that soluble egg antigens and the recombinant P40 protein from Schistosoma japonicum eggs inhibit HSC activation. In the present study, we observed the direct effect of the S. japonicum recombinant (r)SjE16 protein on HSCs. Methods The sequence of SjE16 was analyzed by bioinformatics. Then western blotting, quantitative PCR, and MTT assays were performed to observe the effects of rSjE16 on HSCs. Results The SjE16 protein has no signal peptide or transmembrane region. rSjE16 significantly inhibited expression levels of α-smooth muscle actin and collagen I protein in LX-2 cells. rSjE16 also significantly increased the expression levels of interleukin (IL)-6 and IL-8, and enhanced the expression of matrix metalloproteinase (MMP)-2, MMP-9, and peroxisome proliferator-activated receptor-γ in LX-2 cells. LX-2 cell viability was not inhibited by rSjE16. Conclusion rSjE16 may be involved in the progression of HSC activation via a complex molecular mechanism, which requires further study to fully understand.

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Kuijieling-Containing Serum Regulates Th17 and Treg Cell Differentiation by Inhibiting STAT3 Signaling In Vitro

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2019/7837989 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9

Author(s):

Yu Long ◽

Yuqing He ◽

Fengming Jie ◽

Sixin Li ◽

Yanli Wu ◽

...

Keyword(s):

Flow Cytometry ◽

T Cells ◽

Mononuclear Cells ◽

Transforming Growth Factor ◽

Treg Cells ◽

Orphan Receptor ◽

Cell Culture Supernatant ◽

T Helper 17 ◽

Peripheral Blood Mononuclear

Object. To investigate the effect of Kuijieling (KJL) on the balance between T helper 17 (Th17) and regulatory T (Treg) cells in peripheral blood mononuclear cells (PBMC) in vitro and explore the underlying mechanism. Materials and Methods. PBMCs isolated from rats were stimulated with transforming growth factor-β, interleukin (IL)-6, and IL-23 to induce the imbalance of Th17 and Treg cells and were treated with 10, 5, or 2.5% KJL-containing serum. The proportion of Th17 or Treg cells in CD4+ T cells was analyzed by flow cytometry, the concentrations of IL-17, IL-21, and IL-10 were assayed by ELISA, mRNA expressions of retinoic acid-related orphan receptor γt (RORγt), forkhead box protein 3 (Foxp3), and signal transducer and activator of transcription 3 (STAT3) were quantified by PCR, and phosphorylated STAT3 (p-STAT3) was analyzed by flow cytometry. Results. KJL-containing serum decreased the proportion of Th17 cells and increased the proportion of Treg cells in CD4+ T cells, decreased the concentration of IL-17 and IL-21, enhanced the level of IL-10 in the cell culture supernatant, promoted the expression of Foxp3, and inhibited the levels of RORγt, STAT3, and p-STAT3. Conclusion. KJL suppresses the STAT3 pathway to remedy the imbalance between Th17 and Treg cells.

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PD-1+ regulatory T cells amplified by PD-1 blockade promote hyperprogression of cancer

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1822001116 ◽

2019 ◽

Vol 116 (20) ◽

pp. 9999-10008 ◽

Cited By ~ 139

Author(s):

Takahiro Kamada ◽

Yosuke Togashi ◽

Christopher Tay ◽

Danbee Ha ◽

Akinori Sasaki ◽

...

Keyword(s):

T Cells ◽

Cancer Immunotherapy ◽

Cancer Progression ◽

Treg Cells ◽

Effector Memory ◽

Tissue Samples ◽

Genetic Ablation ◽

Before And After ◽

Reliable Marker

PD-1 blockade is a cancer immunotherapy effective in various types of cancer. In a fraction of treated patients, however, it causes rapid cancer progression called hyperprogressive disease (HPD). With our observation of HPD in ∼10% of anti–PD-1 monoclonal antibody (mAb)-treated advanced gastric cancer (GC) patients, we explored how anti–PD-1 mAb caused HPD in these patients and how HPD could be treated and prevented. In the majority of GC patients, tumor-infiltrating FoxP3highCD45RA−CD4+ T cells [effector Treg (eTreg) cells], which were abundant and highly suppressive in tumors, expressed PD-1 at equivalent levels as tumor-infiltrating CD4+ or CD8+ effector/memory T cells and at much higher levels than circulating eTreg cells. Comparison of GC tissue samples before and after anti–PD-1 mAb therapy revealed that the treatment markedly increased tumor-infiltrating proliferative (Ki67+) eTreg cells in HPD patients, contrasting with their reduction in non-HPD patients. Functionally, circulating and tumor-infiltrating PD-1+ eTreg cells were highly activated, showing higher expression of CTLA-4 than PD-1− eTreg cells. PD-1 blockade significantly enhanced in vitro Treg cell suppressive activity. Similarly, in mice, genetic ablation or antibody-mediated blockade of PD-1 in Treg cells increased their proliferation and suppression of antitumor immune responses. Taken together, PD-1 blockade may facilitate the proliferation of highly suppressive PD-1+ eTreg cells in HPDs, resulting in inhibition of antitumor immunity. The presence of actively proliferating PD-1+ eTreg cells in tumors is therefore a reliable marker for HPD. Depletion of eTreg cells in tumor tissues would be effective in treating and preventing HPD in PD-1 blockade cancer immunotherapy.

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CD8 Treg-Mediated Suppression of Naive CD4+ T Cell Differentiation into Follicular Helper T Cells

International Archives of Allergy and Immunology ◽

10.1159/000521427 ◽

2021 ◽

pp. 1-11

Author(s):

Taissa M. Kasahara ◽

Sudhir Gupta

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Inflammatory Responses ◽

Treg Cells ◽

Follicular Helper ◽

And Function ◽

Proliferation In Vitro

Background: The regulatory CD8+ T (CD8+ Treg) cells play an important role in immune tolerance and have been implicated in several human autoimmune diseases. In this context, follicular helper T (TFH) cells contribute by controlling the antibody production. In mice, CD8+ Treg cells control the number and function of TFH cells however the role of human CD8+ Treg cells on the differentiation of naive CD4+ T cells into TFH cells has not been studied. Objectives: Here, we evaluated the ability of human CD183+ CD8+ Treg cells to suppress TFH cell differentiation in vitro. Methods: Activated CD183+CCR7+CD45RA−CD8+ Treg and CD183+CD25highICOS+CD8+ Treg cells were sorted and cocultured with naïve CD4+ T cells under TFH differentiation condition. The differentiation of TFH cells was evaluated by flow cytometry. Results: Our results showed that activated CD183+CD8+ Treg cells upregulated the expression of Forkhead box P3 transcription factor, inducible T-cell co-stimulator (ICOS), and CD25 compared to CD183−CD8+ T cells. The CD183+CD25highICOS+CD8+ Treg cells suppressed TFH cell differentiation and CD4+ T cell proliferation in vitro which was not observed when CD183+CCR7+CD45RA−CD8+ Treg were cocultured with naïve CD4+ T cells under TFH cell differentiation condition. Conclusion: These results suggest that CD25highICOS+CD183+CD8+ Treg cells may regulate autoimmune and inflammatory responses mediated by TFH cells.

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