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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Lysine acetyltransferase 6A maintains CD4+ T cell response via epigenetic reprogramming of glucose metabolism in autoimmunity

Augmented CD4+ T cell response in autoimmunity is characterized by extensive metabolic reprogramming. However, the epigenetic molecule that drives the metabolic adaptation of CD4+ T cells remains largely unknown. Here, we show that lysine acetyltransferase 6A (KAT6A), an epigenetic modulator that is clinically associated with autoimmunity, orchestrates the metabolic reprogramming of glucose in CD4+ T cells. KAT6A is required for the proliferation and differentiation of proinflammatory CD4+ T cell subsets in vitro, and mice with KAT6A-deficient CD4+ T cells are less susceptible to experimental autoimmune encephalomyelitis and colitis. Mechanistically, KAT6A orchestrates the abundance of histone acetylation at the chromatin where several glycolytic genes are located, thus affecting glucose metabolic reprogramming and subsequent CD4+ T cell responses. Treatment with KAT6A small-molecule inhibitors in mouse models shows high therapeutic value for targeting KAT6A in autoimmunity. Our study provides novel insights into the epigenetic programming of immunometabolism and suggests potential therapeutic targets for patients with autoimmunity.

Normalized circulating Tfh and Th17 associates with improvement in myasthenia gravis treated with ofatumumab

Objective

To assess the effect of B cell depletion therapy (BCDT) on circulating T follicular helper (cTfh) and circulating T helper 17 (cTh17) cells and its relation to clinical improvement in patients with myasthenia gravis (MG).

Methods

28 anti-AchR positive MG patients treated with ofatumumab and 28 healthy controls (HCs) were included. Frequencies of cTfh and cTh17 cells were monitored by flow cytometry at baseline and 4, and 12 weeks after the initial dose ofatumumab. Serum cytokines associated with cTfh and cTh17, including IL-6, IL-21, and IL-17, were also analyzed.

Results

The frequency of cTfh and cTh17 significantly increased in MG patients compared with HCs. Additionally, elevated levels of both T-cell subsets correlated with MG severity. During the follow-up, cTfh and cTh17 return to normal after BCDT. Furthermore, the decrease in cTfh and cTh17 was associated with MG scores improvement over time. Notably, cTfh- and cTh17-related cytokines, including IL-6, IL-21, and IL-17, exhibited a marked decrease following ofatumumab therapy.

Conclusions

Abnormal expansion of cTfh and cTh17 cells may be key features in the immunopathology of MG. Their levels returned to normal after BCDT, which was closely correlated with clinical amelioration. This result suggests that these two T-cell subsets may be targets for BCDT treatment of MG.

Unraveling the Impact of Blood Transfusion on Transcription Factors Regulating T Helper 1, 2, 17 and Regulatory T cells

T helper 1 (TH1) and TH2 lymphocytes are the most important components of the immune system affected by blood transfusion. This study aimed`` to evaluate the effect of blood transfusion on gene expression of transcription factors related to the development of TH1, TH2, TH17 and regulatory T cells (Tregs). In this cross-sectional study, 20 patients diagnosed with abdominal aortic aneurysms requiring surgical repair were studied from January 2018 to August 2020. We utilized real-time PCR to evaluate the expression of transcription factor genes associated with TH1, TH2, TH17, and Treg, namely T-box-expressed-in-T-cells (T-bet), GATA-binding protein 3 (GATA-3), retinoid-related orphan receptor (RORγt), and fork head box protein 3 (Foxp3), respectively. The sampling occurred before anesthesia, 24- and 72 hours post-transfusion, and at the time of discharge. The results showed that the T-bet gene expression, compared to the time before transfusion, was significantly decreased 24 hours after blood transfusion and upon discharge while GATA3 genes exhibited a significant reduction both 24 and 72 hours after the transfusion, as compared to the pre-transfusion levels and the time of patient discharge. The Foxp3 gene demonstrated an increase at all study stages, with a notable surge, particularly 72 hours after red blood cell (RBC) transfusion. Conversely, the expression of RORγt gene, consistently decreased throughout all stages of the study. RBC transfusion in abdominal aortic aneurysm patients altered the balance of transcription gene expression of TH1, TH2, TH17, and Treg cells.

Sirtuin2 suppresses the polarization of regulatory T cells toward T helper 17 cells through repressing the expression of signal transducer and activator of transcription 3 in a mouse colitis model

INTRODUCTION

Regulatory T cells (Tregs) play an important role in inflammatory bowel diseases (IBDs) through modulating intestinal inflammation. However, the factors affecting Treg function and plasticity during IBD progression are not thoroughly disclosed. The current study aims to reveal new molecular mechanisms affecting Treg plasticity.

METHODS

A mouse strain, in which tdTomato and enhanced green fluorescent protein were under the control of the Foxp3 promoter and Il17a promoter, was established and subjected to colitis induction with dextran sulfate sodium. The existence of Tregs and IL-17-expressing Tregs (i.e., Treg/T helper 17 [Th17] cells) were observed and sorted from the spleen, mesenteric lymph nodes, and lamina propria by flow cytometry, followed by measuring Sirtuin2 (Sirt2) expression using quantitative reverse transcription polymerase chain reaction and Immunoblotting. Lentivirus-induced Sirt2 silencing was applied to determine the impact of Sirt2 on Treg polarization to Treg/Th17 cells and even Th17 cells. The effect of Sirt2 on Stat3 was analyzed by flow cytometry and immunoblotting.

RESULTS

Sirt2 was highly expressed in lamina propria Tregs and it moderately suppressed Foxp3 expression as well as the immunosuppressive function of Tregs. Surprisingly, lentivirus-mediated Sirt2 silencing promoted the generation of Treg/Th17 cells out of Tregs. Sirt2 silencing also enhanced the generation of Th17 cells out of Tregs under the Th17 induction condition. Furthermore, Sirt2 inhibited Th17 induction by suppressing the protein level of the signal transducer and activator of transcription 3.

CONCLUSION

Sirt2 suppresses Treg function but also inhibits Treg polarization toward Treg/Th17 cells and Th17 cells. The ultimate effect of Sirt2 on colitis might depend on the balance among Tregs, Treg/Th17 cells, and Th17 cells.

Elevated serum IL-2 and Th17/Treg imbalance are associated with gout

Gout is considered an auto-inflammatory disorder, and the immunological drivers have not been fully unraveled. This study compared the peripheral lymphocyte and CD4+T cell subsets, and cytokines in gout and healthy controls (HCs) to explore the contributions of T helper 17 (Th17) cells, T regulatory (Treg) cells and cytokines to the pathogenesis of gout. We enrolled 126 gout patients (53 early-onset gout with age of first presentation < 40 years, and 73 late-onset gout with age of first presentation ≥ 40 years) and 77 HCs. Percentage and absolute numbers of peripheral lymphocyte and CD4+T cell subpopulations in each group were detected by flow cytometry. The serum cytokine levels were determined by flow cytometric bead array. For circulating CD4+T cell subsets, Th17/Treg ratio was significantly higher in early-onset gout, late-onset gout and gout without tophus than HCs; Th17 cells were significantly elevated in early-onset gout and gout without tophus, while the percentage of Treg cells was significantly decreased in early-onset and late-onset gout. Additionally, gout patients had significantly higher cytokines levels (including IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α) than HCs; IL-2 levels were positively correlated with Treg cells and negatively correlated with ESR. ROC analysis showed that disease duration, CRP and fibrinogen, had moderate predictive performances for tophus in gout (the AUCs were 0.753, 0.703 and 0.701, respectively). Our study suggests that early-onset and late-onset gout differ in Th17/Treg imbalance, which in early-onset gout is due to elevated Th17 cells and in late-onset gout is due to decreased Treg cells. And increased serum cytokine levels, especially IL-2, may play an essential role in that. Restoring Th17/Treg balance may be a crucial way to improve the prognosis of gout patients.

Regulatory Effects of Long Non-coding RNAs on Th17/Treg Differentiation and Imbalance

Scientific research over the past decades has proven the pivotal role of long non-coding RNAs (LncRNAs) in regulating gene expression. The immune responses are controlled through the interaction of pro-inflammatory (predominance of T helper 17 cells (Th17)) and anti-inflammatory cytokines excretion (predominance of Regulatory T cells (Treg)). Recent studies have marked the impact of many diverse LncRNAs on Treg/Th17 imbalances. Moreover, some of the roots and causes of human diseases can be associated with the alterations in the Th17/Treg ratio. In this review study, we overviewed the association between LncRNAs and Th17/Treg, with the potential of providing novel prognostic and diagnostic biomarkers and promising therapeutic targets in various diseases, particularly cancer.

SIRT3 Activator Honokiol Inhibits Th17 Cell Differentiation and Alleviates Colitis

BACKGROUND

Honokiol (HKL), a natural extract of the bark of the magnolia tree and an activator of the mitochondrial protein sirtuin-3 (SIRT3), has been proposed to possess anti-inflammatory effects. This study investigated the inhibitory effects of HKL on T helper (Th) 17 cell differentiation in colitis.

METHODS

Serum and biopsies from 20 participants with ulcerative colitis (UC) and 18 healthy volunteers were collected for the test of serum cytokines, flow cytometry analysis (FACS), and relative messenger RNA (mRNA) levels of T cell subsets, as well as the expression of SIRT3 and phosphorylated signal transducer and activator of transcription/retinoic acid-related orphan nuclear receptor γt (p-STAT3/RORγt) signal pathway in colon tissues. In vitro, naïve clusters of differentiation (CD) 4 + T cells isolated from the mouse spleen differentiated to subsets including Th1, Th2, Th17, and regulatory T (Treg) cells. Peripheral blood monocytes (PBMCs) from healthy volunteers were induced to the polarization of Th17 cells. After HKL treatment, changes in T cell subsets, related cytokines, and transcription factors were measured. The dextran sulfate sodium (DSS)-induced colitis and interleukin (IL)-10-deficient mice were intraperitoneally injected with HKL. These experiments were conducted to study the effect of HKL on the development, cytokines, and expression of signaling pathway proteins in colitis.

RESULTS

Patients with UC had higher serum IL-17 and a higher proportion of Th17 differentiation in blood compared with healthy participants; while IL-10 level and the proportion of Treg cells were lower. Higher relative mRNA levels of RORγt and a lower SIRT3 expression in colon tissues were observed. In vitro, HKL had little effect on the differentiation of naïve CD4+ T cells to Th1, Th2, or Treg cells, but it downregulated IL-17 levels and the Th17 cell ratio in CD4+ T cells from the mouse spleen and human PBMCs under Th17 polarization. Even with a STAT3 activator, HKL still significantly inhibited IL-17 levels. In DSS-induced colitis mice and IL-10 deficient mice treated with HKL, the length of the colon, weight loss, disease activity index, and histopathological scores were improved, IL-17 and IL-21 levels, and the proportion of Th17 cells were decreased. Sirtuin-3 expression was increased, whereas STAT3 phosphorylation and RORγt expression were inhibited in the colon tissue of mice after HKL treatment.

CONCLUSIONS

Our study demonstrated that HKL could partially protect against colitis by regulating Th17 differentiation through activating SIRT3, leading to inhibition of the STAT3/RORγt signaling pathway. These results provide new insights into the protective effects of HKL against colitis and may facilitate the research of new drugs for inflammatory bowel disease.

Zinc finger protein 189 promotes the differentiation of lamina propria T helper 17.1 cells in dextran sulfate sodium-induced colitis

The factors regulating the heterogeneity of interleukin-17A (IL-17A)-expressing CD4⁺ T cells in inflammatory bowel diseases remain unclear. In the current study, we characterised the expression and function of zinc finger protein 189 (ZFP189) in a murine colitis model. Mice were given dextran sulphate sodium to induce acute colitis. Flow cytometry was applied to recognise and enrich Th17 and Th17.1 cells based on the expression of IL-17A, interferon-γ (IFN-γ), C-X-C motif chemokine receptor 3 (CXCR3), and C-C motif chemokine receptor 4 (CCR4). The expression of ZFP189 in Th17 and Th17.1 cells was determined by Immunoblotting. Lentivirus-mediated ZFP189 knockdown was conducted to evaluate the effect of ZFP189 on the differentiation of Th17 and Th17.1 cells. The adoptive transfer was performed to analyse the pathogenicity of Th17.1 cells in vivo. We found that ZFP189 was mildly up-regulated in IL-17A-expressing CD4⁺ T cells in colonic lamina propria. Lamina propria Th17.1 cells expressed higher ZFP189 than Th17 cells. In vitro ZFP189 knockdown in CD4⁺ T cells did not impact Th17 cell differentiation but suppressed Th17.1 cell differentiation, as evidenced by lower T-box expressed in T cells (T-bet) and IFN-γ. When adoptively transferred into mice, ZFP189-deficient Th17.1 cells produced fewer IFN-γ, tumour necrosis factor-alpha (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF) than ZFP189-expressing Th17.1 cells. Moreover, ZFP189-deficient Th17.1 cells induced less severe colitis than ZFP189-expressing Th17.1 cells, as evidenced by less body weight loss, a lower disease activity index, and a lower colon histological score. In summary, ZFP189 acts as a positive regulator of the differentiation and pathogenicity of lamina propria Th17.1 cells in colitis.

Molecular mechanisms of long non-coding RNAs in differentiation of T Helper17 cells

T helper (Th) 17 cells are one of the most important T cell subsets in a number of autoimmune and chronic inflammatory diseases. During infections, Th17 cells appear to play an important role in the clearance of extracellular pathogens. Th17 cells, on the other hand, are engaged in inflammation and have been linked to the pathophysiology of a number of autoimmune illnesses and human inflammatory disorders. A diverse group of RNA molecules known as lncRNAs serve critical functions in gene expression regulation. They may interact with a wide range of molecules, including DNA, RNA, and proteins, and have a complex structure. LncRNAs, which have restricted or no protein-coding activity, are implicated in a number of illnesses due to their regulatory impact on a variety of biological processes such as cell proliferation, apoptosis, and differentiation. Several lncRNAs have been associated with Th7 cell development in the context of immune cell differentiation. In this article, we cover new studies on the involvement of lncRNAs in Th17 cell differentiation in a variety of disorders, including auto-immune diseases, malignancies, asthma, heart disease, and infections.

Elevated circulating CD19+CD24hiCD38hi B cells display pro-inflammatory phenotype in idiopathic membranous nephropathy

CD19+CD24hiCD38hi regulatory B cells exert immunosuppressive functions by producing IL-10, but their role in idiopathic membranous nephropathy (IMN) remains elusive. Here, we investigated the frequency and functional changes of circulating CD19+CD24hiCD38hi B cells and evaluated the correlation of CD19+CD24hiCD38hi B cells with clinical features and T helper cell subsets in IMN patients. Compared with healthy controls (HCs), IMN patients showed an increased frequency of CD19+CD24hiCD38hi B cells, but a significant reduction in the percentage of CD19+CD24hiCD38hi B cells was observed 4 weeks after cyclophosphamide treatment. The frequency of CD19+CD24hiCD38hi B cells was positively correlated with the levels of 24h urinary protein, but negatively correlated with serum total protein and serum albumin, respectively. CD19+CD24hiCD38hi B cells in IMN patients displayed a skewed pro-inflammatory cytokine profile with a higher level of IL-6 and IL-12, but a lower concentration of IL-10 than their healthy counterparts. Accompanied by upregulation of Th2 and Th17 cells in IMN patients, the percentage of CD19+CD24hiCD38hi B cell subset was positively associated with Th17 cell frequency. In conclusion, CD19+CD24hiCD38hi B cells were expanded but functionally impaired in IMN patients. Their altered pro-inflammatory cytokine profile may contribute to the pathogenesis of IMN.

A Species-Specific Anti-Human P2X7 Monoclonal Antibody Reduces Graft-versus-Host Disease in Humanised Mice

Graft-versus-host disease (GVHD) is a T cell-mediated inflammatory disorder that arises from allogeneic haematopoietic stem cell transplantation and is often fatal. The P2X7 receptor is an extracellular adenosine 5'-triphosphate-gated cation channel expressed on immune cells. Blockade of this receptor with small molecule inhibitors impairs GVHD in a humanised mouse model. A species-specific blocking monoclonal antibody (mAb) (clone L4) for human P2X7 is available, affording the opportunity to determine whether donor (human) P2X7 contributes to the development of GVHD in humanised mice. Using flow cytometric assays of human RPMI 8266 and murine J774 cells, this study confirmed that this mAb bound and impaired human P2X7. Furthermore, this mAb prevented the loss of human regulatory T cells (hTregs) and natural killer (hNK) T cells in vitro. NOD-scid IL2Rγnull mice were injected with 10 × 106 human peripheral blood mononuclear cells (Day 0) and an anti-hP2X7 or control mAb (100 μg i.p. per mouse, Days 0, 2, 4, 6, and 8). The anti-hP2X7 mAb increased hTregs and hNK cells at Day 21. Moreover, anti-hP2X7 mAb-treatment reduced clinical and histological GVHD in the liver and lung compared to the control treatment at disease endpoint. hTregs, hNK, and hNK T cell proportions were increased, and human T helper 17 cell proportions were decreased at endpoint. These studies indicate that blockade of human (donor) P2X7 reduces GVHD development in humanised mice, providing the first direct evidence of a role for donor P2X7 in GVHD.

Potential tactics with certain gut microbiota for the treatment of unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) constitutes an extremely malignant form of primary liver cancer. Intricate connections linking to the immune system might be associated with the pathogenesis of HCC. Meanwhile, immunotherapy with immune checkpoint inhibitors has been established to be a favorable therapeutic possibility for advanced HCC. Although curative opportunities for advanced HCC are restricted, the immune checkpoint immunotherapy has developed as the main choice for treating HCC. However, patients with metabolic-associated fatty liver disease (MAFLD)-linked HCC might be less likely to benefit from the immunotherapy alone. The limitation of the effect of the immunotherapy might be owing to the impaired T cell activation in MAFLD patients, which could be well explained by a dysfunctional gut-liver axis. Gut microbiota and their metabolites including several bile acids could contribute to modulating the responses of the immune checkpoint immunotherapy. Roles of gut microbiota in the development of cancers have expected great interest in the latest studies. Here, an interplay between the gut and liver has been presented, which might suggest to affect the efficacy of immune checkpoint immunotherapy against HCC.

Downregulated VISTA enhances Th17 differentiation and aggravates inflammation in patients with acute-on-chronic liver failure

BACKGROUND AND AIMS

Persistent inflammatory response and immune activation are the core mechanisms underlying acute-on-chronic liver failure (ACLF). Previous studies have shown that deficiency of V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA) exacerbates the progression of inflammatory diseases. We aimed to clarify the role of VISTA in the pathogenesis of ACLF.

METHODS

Blood and liver samples were collected from healthy subjects, stable cirrhosis, and ACLF patients to characterize VISTA expression and function. An ACLF mouse model was used to ascertain potential benefits of anti-VISTA monoclonal antibody (mAb) treatment.

RESULTS

VISTA expression was significantly reduced in the naïve and central memory CD4+ T cells from patients with ACLF. The expression of VISTA on CD4+ T cells was associated with disease severity and prognosis. VISTA downregulation contributed to the activation and proliferation of CD4+ T cells and enhanced the differentiation of T helper 17 cells (Th17) and secretion of inflammatory cytokines through the activated Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling pathway. Moreover, agonistic anti-VISTA mAb treatment inhibited the activation and cytokine production of CD4+ T cells and reduced mortality and liver inflammation of the ACLF mice.

CONCLUSIONS

The decreased expression of VISTA may facilitate development of Th17 cells and promote the progression of inflammation in ACLF patients. These findings are helpful for elucidating the pathogenesis of ACLF and for the identification of new drug targets.

Exploring probiotic effector molecules and their mode of action in gut-immune interactions

Probiotics, live microorganisms that confer health benefits when consumed in adequate amounts, have gained significant attention for their potential therapeutic applications. The beneficial effects of probiotics are believed to stem from their ability to enhance intestinal barrier function, inhibit pathogens, increase beneficial gut microbes, and modulate immune responses. However, clinical studies investigating the effectiveness of probiotics have yielded conflicting results, potentially due to the wide variety of probiotic species and strains used, the challenges in controlling the desired number of live microorganisms, and the complex interactions between bioactive substances within probiotics. Bacterial cell wall components, known as effector molecules, play a crucial role in mediating the interaction between probiotics and host receptors, leading to the activation of signaling pathways that contribute to the health-promoting effects. Previous reviews have extensively covered different probiotic effector molecules, highlighting their impact on immune homeostasis. Understanding how each probiotic component modulates immune activity at the molecular level may enable the prediction of immunological outcomes in future clinical studies. In this review, we present a comprehensive overview of the structural and immunological features of probiotic effector molecules, focusing primarily on Lactobacillus and Bifidobacterium. We also discuss current gaps and limitations in the field and propose directions for future research to enhance our understanding of probiotic-mediated immunomodulation.

PCSK9 promotes T helper 1 and T helper 17 cell differentiation by activating the nuclear factor-κB pathway in ankylosing spondylitis

OBJECTIVE

Our previous study reveals that proprotein convertase subtilisin/kexin type 9 (PCSK9) is positively related to inflammatory markers, T helper (Th)-17 cells, and treatment response in ankylosing spondylitis (AS) patients. Subsequently, this study aimed to explore the effect of PCSK9 on Th cell differentiation and its potential molecular mechanism in AS.

METHODS

Serum PCSK9 was determined by enzyme-linked immunosorbent assay in 20 AS patients and 20 healthy controls (HCs). Then naïve CD4⁺ T cells were isolated from AS patients and infected with PCSK9 overexpression or knockdown adenovirus followed by polarization assay. Afterward, PMA (an NF-κB activator) was administrated.

RESULTS

PCSK9 was increased in AS patients compared to HCs (p < .001), and it was positively related to Th1 cells (p = .050) and Th17 cells (p = .039) in AS patients. PCSK9 overexpression increased the CD4⁺ IFN-γ⁺ cells (p < .05), CD4⁺ IL-17A⁺ cells (p < .01), IFN-γ (p < .01), and IL-17A (p < .01), while it exhibited no effect on CD4⁺ IL-4⁺ cells or IL-4 (both p > .05); its knockdown displayed the opposite function on them. Moreover, PCSK9 overexpression upregulated the p-NF-κB p65/NF-κB p65 (p < .01), while it had no effect on p-ERK/ERK or p-JNK/JNK (both p > .05); its knockdown decreased p-NF-κB p65/NF-κB p65 (p < .01) and p-JNK/JNK (p < .05). Then, PMA upregulates p-NF-κB p65/NF-κB p65 (p < .001) and increased CD4⁺ IFN-γ⁺ cells, CD4⁺ IL-17A⁺ cells, IFN-γ, and IL-17A (all p < .01), also it alleviated the effect of PCSK9 knockdown on NF-κB inhibition and Th cell differentiation (all p < .01).

CONCLUSION

PCSK9 enhances Th1 and Th17 cell differentiation in an NF-κB-dependent manner in AS, while further validation is necessary.

Interleukin-35 Enhances Regulatory T Cell Function by Potentially Suppressing Their Transdifferentiation into a T Helper 17-Like Phenotype in Kawasaki Disease

Interleukin-35 (IL-35) modulates immune cell activity in inflammation and autoimmune disorders. However, its specific effects on regulatory T cells (Tregs) in Kawasaki disease remain ambiguous. We enrolled 37 patients with Kawasaki disease and 20 healthy controls in this study. The percentages of CD4⁺CD25⁺CD127^dim/- Tregs and CD4⁺IL-17A⁺ T helper 17 (Th17) cells were determined via flow cytometry. Tregs were enriched and stimulated by recombinant IL-35. Immunosuppressive activity of Tregs was via co-culture with autologous CD4⁺CD25^- T cells. Purified Tregs were cultured for Th17 polarization, and the influence of IL-35 on Tregs transdifferentiation into a Th17-like phenotype was determined. The percentage of Tregs was elevated in patients with Kawasaki disease and positively correlated with C-reactive protein levels. There was no significant difference in the percentage of Th17 cells between the two groups. IL-35 stimulation increased the percentage of Tregs in both groups, but decreased the percentage of Tregs Th17 cells in affected patients. IL-35 enhanced the immunosuppressive activity of Tregs in both groups, resulting in decreased cellular proliferation and increased IL-35 subunit mRNA relative levels in co-culture system. IL-35 did not affect the immune checkpoint molecule expression in Tregs, but inhibited the transdifferentiation of Tregs into a Th17-like phenotype in affected patients, indicating by the down-regulations of C-C motif chemokine receptor-4/6 expression, retinoid-related orphan nuclear receptor γt mRNA levels, and IL-17 secretion. IL-35 contributes to the immunosuppressive function of Tregs by inhibiting the cellular proliferation and transdifferentiation of Tregs into a Th17-like phenotype, which may be a protective mechanism against Kawasaki disease.

Preeclampsia-Derived Exosomes Imbalance the Activity of Th17 and Treg in PBMCs from Healthy Pregnant Women

The disturbance of maternofetal immune tolerance is identified as one of the important issues in the pathology of preeclampsia (PE). PE exosomes are believed to possess significant roles in immune abnormalities. In this study, to assess the possible effects of PE exosomes in the pathophysiology of preeclampsia patients, exosomes were isolated from the serum of PE patients and incubated with peripheral blood mononuclear cells (PBMCs) of healthy pregnant women. Also, exosomes from healthy pregnant women were utilized as the control. Th17/Treg ratio in PE and healthy pregnant women and the effects of PE exosomes on expression level of Th17 and Treg transcription factors, as well as their related cytokines in PBMCs of healthy pregnant women, were evaluated. A significant decrease in Treg cell number and increase in Th17 cells and Th17/Treg ratio were observed in PE patients. Following PE-exosome intervention, a significant increase in mRNA expression level of RORγt, IL-17, IL-23, IL-1β, and IL-6, and significant decrease in IL-10 and TGFβ were evident. On the other hand, no significant difference in FoxP3 level was detected. Additionally, increased IL-6, IL-17, IL-23, and IL-1β levels and decreased IL-10 level in the supernatant of cultured PBMCs from healthy pregnant women following PE-exosome intervention were exhibited. However, TGF-β level did not change significantly. Based on our findings, PE exosomes are able to alter the activity of Th17 and Treg cells as well as their related gene expression and cytokine profiles. These findings support the probable role of PE exosomes in PE pathogenesis.

T Helper 17-Like Regulatory T Cells in Equine Synovial Fluid Are Associated With Disease Severity of Naturally Occurring Posttraumatic Osteoarthritis

BACKGROUND

Infiltration of cluster of differentiation (CD) 3⁺ (CD3⁺) T cells into the synovium and synovial fluid occurs in most patients with posttraumatic osteoarthritis. During disease progression, proinflammatory T helper 17 cells and anti-inflammatory regulatory T cells infiltrate the joint in response to inflammation. This study aimed to characterize the dynamics of regulatory T and T helper 17 cell populations in synovial fluid from equine clinical patients with posttraumatic osteoarthritis to determine whether phenotype and function are associated with potential immunotherapeutic targets.

HYPOTHESIS

An imbalance of the ratio of regulatory T cells and T helper 17 cells would be associated with disease progression in posttraumatic osteoarthritis, suggesting opportunities for immunomodulatory therapy.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Synovial fluid was aspirated from the joints of equine clinical patients undergoing arthroscopic surgery for posttraumatic osteoarthritis resulting from intra-articular fragmentation. Joints were classified as having mild or moderate posttraumatic osteoarthritis. Synovial fluid was also obtained from nonoperated horses with normal cartilage. Peripheral blood was obtained from horses with normal cartilage and those with mild and moderate posttraumatic osteoarthritis. Synovial fluid and peripheral blood cells were analyzed by flow cytometry, and native synovial fluid was analyzed by enzyme-linked immunosorbent assay.

RESULTS

CD3⁺ T cells represented 81% of lymphocytes in synovial fluid, which increased in animals with moderate posttraumatic osteoarthritis to 88.3% (P = .02). CD14⁺ macrophages were doubled in those with moderate posttraumatic osteoarthritis compared with mild posttraumatic osteoarthritis and controls (P < .001). Less than 5% of CD3⁺ T cells found within the joint were forkhead box P3 protein⁺ (Foxp3⁺) regulatory T cells, but a 4- to 8-times higher percentage of nonoperated and mild posttraumatic osteoarthritis joint regulatory T cells secreted interleukin (IL)-10 than peripheral blood Tregs (P < .005). T regulatory-1 cells that secreted IL-10 but did not express Foxp3 accounted for approximately 5% of CD3⁺ T cells in all joints. T helper 17 cells and Th17-like regulatory T cells were increased in those with moderate posttraumatic osteoarthritis (P < .0001) compared with mild and nonoperated patients. IL-10, IL-17A, IL-6, chemokine (C-C motif) ligand (CCL) 2 (CCL2), and CCL5 concentrations detected by enzyme-linked immunosorbent assay in synovial fluid were not different between groups.

CONCLUSIONS

An imbalance of the ratio of regulatory T cells and T helper 17 cells and an increase in T helper 17 cell-like regulatory T cells in synovial fluid from joints with more severe disease provide novel insights into immunological mechanisms that are associated with posttraumatic osteoarthritis progression and pathogenesis.

CLINICAL RELEVANCE

Early and targeted use of immunotherapeutics in the mitigation of posttraumatic osteoarthritis may improve patient clinical outcomes.

Metabolic rewiring in keratinocytes by miR-31-5p identifies therapeutic intervention for psoriasis

Besides genetic alterations, the cellular environment also determines disease onset and progression. When different cell types contribute to disease outcome, this imposes environmental challenges as different cell types likely differ in their extracellular dependencies. Hsa-microRNA-31-5p (miR-31) is highly expressed in keratinocytes of psoriatic skin, and we show that expression in keratinocytes is induced by limited glucose availability and enables increased survival under limiting glucose conditions by increasing glutamine metabolism. In addition, miR-31 expression results in not only secretion of specific metabolites (aspartate and glutamate) but also secretion of immunomodulatory factors. We show that this miR-31-induced secretory phenotype is sufficient to induce Th17 cell differentiation, a hallmark of psoriasis. Inhibitors of miR31-induced metabolic rewiring and metabolic crosstalk with immune cells alleviate psoriasis pathology in a mouse model of psoriasis. Together our data illustrate an emerging concept of metabolic interaction across cell compartments that characterizes disease development, which can be employed to design effective treatment options for disease, as shown here for psoriasis.

PR-957 Suppresses Th1 and Th17 Cell Differentiation via Inactivating PI3K/AKT Pathway in Alzheimer's Disease

PR-957 [low molecular mass polypeptide (LMP)-7 selective inhibitor] regulates T helper (Th) cell differentiation and inflammatory response in multiple neurological diseases. Hence, this study aimed to explore the effect of PR-957 on Th1/Th2/Th17 cell differentiation, therapeutic efficacy and its potential mechanisms in Alzheimer's disease (AD). The LMP7 expressions in peripheral blood mononuclear cells from 30 AD patients and 30 healthy controls (HC) were detected. PR-957 was added for the incubation of naive cluster of differentiation (CD)4⁺ T cells from AD patients, then SC79 [phosphorylated protein kinase B (pAKT) agonist] was added. LMP7, Th1 cells, and Th17 cells were upregulated, while Th2 cells were downregulated in AD patients compared to HC. Also, LMP7 was positively related to Th1 cells and Th17 cells, but it did not correlate with Th2 cells in AD patients. PR-957 treatment downregulated Th1 cells, Th17 cells, and their secreted cytokines as well as phosphorylated phosphoinositide 3-kinase (pPI3K)/PI3K and pAKT/AKT expressions in AD CD4⁺ T cells. SC79 addition upregulated pAKT/AKT expression, Th1 cells, and Th17 cells, while downregulated Th2 cells; also SC79 could alleviate the effect of PR-957 on regulating PI3K/AKT pathway and Th1, Th2, and Th17 cell differentiation in AD CD4⁺ T cells. Furthermore, PR-957 attenuated cognitive impairment and neurofibrillary tangle; also it inhibited Th17 cell differentiation and PI3K/AKT pathway in the brain and spleen of AD mice. In conclusion, PR-957 suppresses Th1 and Th17 cell differentiation, attenuates neural injury and improves cognitive function via inactivating PI3K/AKT pathway in AD.

Patched 1 and C-C Motif Chemokine Receptor 6 Distinguish Heterogeneous T Helper 17 Subsets in Colitic Lamina Propria

T helper 17 (Th17) cells contribute to the pathogenesis of inflammatory bowel diseases (IBD). However, their heterogeneity and regulatory mechanisms in IBD are not completely disclosed. A mouse colitis model was established. Th17 cells were enriched from the mesenteric lymph nodes (mLN) and lamina propria (LP). The phenotypes and functions of Th17 subsets were analyzed by flow cytometry, Immunoblotting, and real-time RT-PCR. The contributions of the Th17 subsets to colitis pathogenesis were evaluated by histology, ELISA, and flow cytometry after adoptive transfer. Smoothened (SMO), GLI family zinc finger 1 (Gli1), and GLI family zinc finger 3 (Gli3) were markedly up-regulated while Patched 1 (PTCH1) was down-regulated in LP Th17 cells in colitic lamina propria. Based on the expression of PTCH1 and C-C motif chemokine receptor 6 (CCR6), LP Th17 cells were divided into a PTCH1^lowCCR6^low Th17 subset and a PTCH1^highCCR6^high Th17 subset. The former expressed higher T-bet, IFN-γ, TNF-α, IL-1β, and GM-CSF but lower IL-17A, IL-22, IL-17F, and Gli3 than the latter. The PTCH1^highCCR6^high Th17 subset was more resistant to polarization towards T helper 1 (Th1) than the PTCH1^lowCCR6^low Th17 subset. Moreover, the PTCH1^highCCR6^high Th17 subset was more competent to maintain Th17 identity. The PTCH1^highCCR6^high Th17 subset induced less severe colitis than the PTCH1^lowCCR6^low Th17 subset. PTCH1^highCCR6^high Th17 cells are Th17 cells whereas PTCH1^lowCCR6^low Th17 cells are Th1-like Th17 cells. Our study deepens the understanding of Th17 heterogeneity and plasticity in colitis.

The role of Th17 cells in inflammatory bowel disease and the research progress

Th17 cells play an important role in the abnormal immune response in inflammatory bowel disease (IBD) and are involved in the development and progression of inflammation and fibrosis. An increasing amount of data has shown that gut microbes are important parts of intestinal immunity and regulators of Th17 cellular immunity. Th17 cell differentiation is regulated by intestinal bacteria and cytokines, and Th17 cells regulate the intestinal mucosal immune microenvironment by secreting cytokines, such as IL-17, IL-21, and IL-26. Solid evidence showed that, regarding the treatment of IBD by targeting Th17 cells, the therapeutic effect of different biological agents varies greatly. Fecal bacteria transplantation (FMT) in the treatment of IBD has been a popular research topic in recent years and is safe and effective with few side effects. To further understand the role of Th17 cells in the progression of IBD and associated therapeutic prospects, this review will discuss the progress of related research on Th17 cells in IBD by focusing on the interaction and immune regulation between Th17 cells and gut microbiota.

Inhibition of Th17 cells by donepezil ameliorates experimental lung fibrosis and pulmonary hypertension

Rationale: Pulmonary hypertension (PH) secondary to lung fibrosis belongs to WHO Group III, one of the most common subgroups of PH; however, it lacks effective treatment options. Cholinesterase inhibitor donepezil (DON) has been shown to effectively improve Group I PH. However, its effects on Group III PH are unknown. Methods: A lung fibrosis-induced PH mouse model was constructed using a single intratracheal instillation of bleomycin (BLM), after which DON was administered daily. Pulmonary artery and right ventricle (RV) remodeling were evaluated at the end of the study. Lung tissue in each group was analyzed using RNA sequencing, and the results were further verified with datasets from patients with PH. The mechanisms underlying DON-induced effects on PH were verified both in vivo and in vitro. Results: DON effectively improved pulmonary artery and RV remodeling in the BLM-induced mouse model. Transcriptomic profiles of lung tissue indicated that the expression of inflammatory and fibrotic genes was significantly changed in this process. In the animal model and patients with PH, T helper 17 lymphocytes (Th17) were the most common inflammatory cells infiltrating the lung tissue. DON significantly inhibited lung fibroblast activation; thus, preventing lung fibrosis and reducing the inflammatory response and Th17 cell infiltration in the BLM-induced lung tissue. In addition, Th17 cells could activate lung fibroblasts by secreting IL17A, and DON-mediated inhibition of Th17 cell differentiation was found to depend on the α7nAchR-JAK2-STAT3 pathway. Conclusion: DON can alleviate lung fibrosis and PH in an experimental mouse model. It inhibited pro-inflammatory Th17 cell differentiation, which is dependent on a cholinergic receptor pathway, thereby regulating fibroblast activation.

Metformin may induce immunologic tolerance at the maternal-foetal interface in early human pregnancy

OBJECTIVE

Repeated pregnancy loss has been shown to be related to decidual immune imbalance. Metformin has been found to promote a shift in the Th17/Treg balance towards immune tolerance. Our research aims to evaluate and obtain further information on the role and potential mechanism of metformin on Th17/Treg balance in the early pregnancy decidua.

METHODS

Decidual immune cells from normal pregnancy women were treated with metformin, pro-inflammatory cytokines or metformin + cytokines respectively. The mRNA expression levels of STAT3, STAT5, RORC and Foxp3 were detected by qRT-PCR. The proportions of Th17 and Treg cells, the stability of Treg cells, and the STATs phosphorylation levels of T cells were evaluated by flow cytometry. The cytokine concentrations in the culture medium were detected by ELISA.

RESULTS

After treated with metformin, indicators related to immune tolerance, including the mRNA expression and phosphorylation levels of STAT5, mRNA expression level of Foxp3, the proportion of Treg cell, and the IL-10 concentration increased significantly. Indicators related to immune rejection including the mRNA expression level of STAT3, the proportion of Th17 cell, and the IL-17A concentration showed a significant decrease. In inflammatory conditions, the proportion of Th-like Treg cells increased. Metformin promoted CD25 expression to maintain Treg cell stability.

CONCLUSION

Metformin has beneficial effects on immunological tolerance at the maternal-foetal interface in early pregnancy. The underlying mechanism may be that metformin restores the Th17/Treg balance by changing the expression of STATs, which is conducive to establishing maternal-foetal immune tolerance.

γ-Tocotrienol inhibits T helper 17 cell differentiation via the IL-6/JAK/STAT3 signaling pathway

γ-Tocotrienol (GT3), a member of the vitamin E family, is well known for its medicinal value in clinical treatments. However, the role of GT3 in T helper 17 (Th17)/regulatory T cell (Treg) differentiation and function is not fully understood. Here, we demonstrated that GT3 suppressed Th17 differentiation in vitro by inhibiting signal transducer and activator of transcription 3 (STAT3) phosphorylation in the interleukin 6 (IL-6)/Janus kinase (JAK)/STAT3 signaling pathway. GT3 also inhibited HIF1A expression in Th17 metabolism. Additionally, we showed that GT3 treatment inhibited disease aggravation in an imiquimod (IMQ)-induced psoriasis-like mouse model by reducing the percentage of Th17 cells in the spleen in vivo. The findings of this study demonstrated the effects of GT3 on Th17 cells through the STAT3 signaling pathway.

Traumatic Brain Injury Induces a Differential Immune Response in Polytrauma Patients; Prospective Analysis of CD69 Expression on T Cells and Platelet Expansion

Background: Accidents and injuries are the leading causes of mortality in young people. CD4+ regulatory T cells (CD4+ Tregs), Th17 cells and platelets could be identified as key players in post-traumatic immunological dysfunction, which is a common cause of late mortality in trauma patients. The mechanisms of activation of these cell types and their interaction remain mostly unclear. Since CD69 is not only a leukocyte marker but has also immunoregulatory functions, we postulate a role for CD69 after trauma. The present study investigates the expression of CD69 on CD4+ Tregs and Th17 cells, as well as the posttraumatic expansion of platelets and hemostatic function. Subgroup analysis was performed to assess the differences between polytrauma patients with and without severe traumatic brain injury (TBI). Methods: In this non-interventional prospective clinical trial, we analyzed sequential blood samples over a period of 10 days from 30 patients after multiple traumas with an ISS ≥ 16. Platelet function was assessed by rotational thromboelastometry (ROTEM analysis). CD4+ Tregs and Th17 cells were stained with surface markers and analyzed by flow cytometry. Results: We were able to demonstrate a significantly increased expression of CD69 on CD4+ Tregs after trauma. Subgroup analysis revealed that the absence of severe TBI is associated with a significantly higher expression of CD69 on CD4+ Tregs and on Th17 cells. Platelets expanded and showed signs of dysfunction, while an overall tendency of posttraumatic hypercoagulation was detected. Conclusions: Our results support the concept of injury-specific immune responses and add to a further understanding of the complex pathophysiology of post-traumatic immune dysfunction.

T helper 17 axis and endometrial macrophage disruption in menstrual effluent provides potential insights into the pathogenesis of endometriosis

OBJECTIVE

To identify immune cells, cytokines, and immune cell transcriptome in the menstrual effluent (ME) of women with endometriosis compared with that of healthy donors.

DESIGN

Live immune cells were isolated from human ME samples and were analyzed by flow cytometry to identify various immune cell populations. Selected cytokines from the same patients were evaluated using multiplex cytokine analyses. The transcriptome of the immune cell population was subsequently profiled using NanoString nCounter's PanCancer Immune panel.

SETTING

Academic institution.

PATIENT(S)

Surgically confirmed endometriosis patients (n = 14) and healthy fertile donors (n = 19).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

In-depth immune cell profiling of ME obtained from women with endometriosis compared with that of healthy donors.

RESULT(S)

ME analysis revealed that the number of T helper 17 (T_H17) cells was significantly lower in patients with endometriosis compared with that of healthy donors; the number of macrophages was also lower (P=.06) in the former. Multiplex cytokine analysis revealed significantly lower transforming growth factor α in the ME "serum" of patients with endometriosis. Transcriptomic analysis of CD45⁺ cells revealed 47 differentially expressed genes, mainly associated with the T_H17 axis (IL10, IL23A, and IL6), as well as genes associated with macrophage signaling/activation (CD74, CD83, CXCL16, and CCL3).

CONCLUSION(S)

We demonstrate for the first time that the levels of T_H17 axis, macrophages, and transforming growth factor α were altered in the ME of women with endometriosis compared with that of healthy donors. These findings shed light on the potential immune pathways that could partly explain the pathogenesis and progression of endometriosis. Future large-scale studies on ME samples are warranted to exploit the use of these markers to study the pathogenesis of endometriosis.

Oncostatin M triggers brain inflammation by compromising blood-brain barrier integrity

Oncostatin M (OSM) is an IL-6 family member which exerts neuroprotective and remyelination-promoting effects after damage to the central nervous system (CNS). However, the role of OSM in neuro-inflammation is poorly understood. Here, we investigated OSM's role in pathological events important for the neuro-inflammatory disorder multiple sclerosis (MS). We show that OSM receptor (OSMRβ) expression is increased on circulating lymphocytes of MS patients, indicating their elevated responsiveness to OSM signalling. In addition, OSM production by activated myeloid cells and astrocytes is increased in MS brain lesions. In experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS, OSMRβ-deficient mice exhibit milder clinical symptoms, accompanied by diminished T helper 17 (Th17) cell infiltration into the CNS and reduced BBB leakage. In vitro, OSM reduces BBB integrity by downregulating the junctional molecules claudin-5 and VE-cadherin, while promoting secretion of the Th17-attracting chemokine CCL20 by inflamed BBB-endothelial cells and reactive astrocytes. Using flow cytometric fluorescence resonance energy transfer (FRET) quantification, we found that OSM-induced endothelial CCL20 promotes activation of lymphocyte function-associated antigen 1 (LFA-1) on Th17 cells. Moreover, CCL20 enhances Th17 cell adhesion to OSM-treated inflamed endothelial cells, which is at least in part ICAM-1 mediated. Together, these data identify an OSM-CCL20 axis, in which OSM contributes significantly to BBB impairment during neuro-inflammation by inducing permeability while recruiting Th17 cells via enhanced endothelial CCL20 secretion and integrin activation. Therefore, care should be taken when considering OSM as a therapeutic agent for treatment of neuro-inflammatory diseases such as MS.

Chronic stress-induced depression requires the recruitment of peripheral Th17 cells into the brain

Background

Depression is a recurrent and devastating mental disease that is highly prevalent worldwide. Prolonged exposure to stressful events or a stressful environment is detrimental to mental health. In recent years, an inflammatory hypothesis has been implicated in the pathogenesis of stress-induced depression. However, less attention has been given to the initial phases, when a series of stress reactions and immune responses are initiated. Peripheral CD4⁺ T cells have been reported as the major contributors to the occurrence of mental disorders. Chronic stress exposure-evoked release of cytokines can promote the differentiation of peripheral CD4⁺ cells into various phenotypes. Among them, Th17 cells have attracted much attention due to their high pathogenic potential in central nervous system (CNS) diseases. Thus, we intended to determine the crucial role of CD4⁺ Th17 cells in the development of specific subtypes of depression and unravel the underpinnings of their pathogenetic effect.

Methods

In the present research, a daily 6-h restraint stress paradigm was employed in rats for 28 successive days to mimic the repeated mild and predictable, but inevitable environmental stress in our daily lives. Then, depressive-like symptoms, brain–blood barrier (BBB) permeability, neuroinflammation, and the differentiation and functional changes of CD4⁺ cells were investigated.

Results

We noticed that restrained rats showed significant depressive-like symptoms, concomitant BBB disruption and neuroinflammation in the dorsal striatum (DS). We further observed a time-dependent increase in thymus- and spleen-derived naïve CD4⁺ T cells, as well as the aggregation of inflammatory Th17 cells in the DS during the period of chronic restraint stress (CRS) exposure. Moreover, increased Th17-derived cytokines in the brain can further impair the BBB integrity, thus allowing more immune cells and cytokines to gain easy access to the CNS. Our findings suggested that, through a complex cascade of events, peripheral immune responses were propagated to the CNS, and gradually exacerbated depressive-like symptoms. Furthermore, inhibiting the differentiation and function of CD4⁺ T cells with SR1001 in the early stages of CRS exposure ameliorated CRS-induced depressive-like behaviour and the inflammatory response.

Conclusions

Our data demonstrated that inflammatory Th17 cells were pivotal in accelerating the onset and exacerbation of depressive symptoms in CRS-exposed rats. This subtype of CD4⁺ T cells may be a promising therapeutic target for the early treatment of stress-induced depression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02543-6.

E74 Like ETS Transcription Factor 3 is a Negative Regulator of Pathogenic Lamina Propria T Helper 17.1 Cells in Murine Colitis

Interleukin-17A (IL-17A)-expressing T cells, including T helper 17 (Th17) and T helper 17.1 (Th17.1) cells, play a significant role in inflammatory bowel diseases (IBDs). Identifying the mechanisms underlying the heterogeneity and plasticity of IL-17A-expressing T cells is crucial for understanding and controlling their pathogenicity. The role of E74 like ETS transcription factor 3 (ELF3) in regulating the pathogenicity of IL-17A-expressing T cells has not been studied before. Dextran sulfate sodium was used to induce acute colitis in transgenic mice co-expressing IL-17A and enhanced green fluorescent protein (EGFP). IL-17A-expressing T cells were analyzed by flow cytometry. ELF3 expression was evaluated by reverse transcription and quantitative polymerase chain reaction. Lentivirus-mediated ELF3 overexpression was performed to assess the effect of ELF3 on Th17 and Th17.1 cells in vitro. The in vivo effect of ELF3 on Th17.1 cells was analyzed in an adoptive transfer colitis model. ELF3 was expressed by IL-17A-expressing T cells in the colonic lamina propria after colitis induction. Th17 cells and Th17.1 cells were distinguished based on the expression of C-X-C motif chemokine receptor 3, cytokine production, and key regulators. Th17 cells expressed higher ELF3 than Th17.1 cells. Ectopic ELF3 overexpression did not alter Th17 cell function while suppressing Th17.1 cell function in vitro. When adoptively transferred into Rag1 knockout mice to induce colitis, ELF3-overexpressing Th17.1 cells were less pathogenic than the control Th17.1 cells. ELF3 suppresses the pathogenicity of Th17.1 cells in colitis.

Evaluation of Th17 and Treg cytokines in patients with unexplained recurrent pregnancy loss

Background and Aim

The Th17/Treg balance in peripheral blood and reproductive tissues may have a role in the etiology of unexplained recurrent pregnancy loss (URPL). In this study, we evaluated the major cytokine of Treg cells transforming growth factor-beta (TGF-β), and their specific transcription factor Forkhead box P3 (FOXP3), as well as the most highlighted cytokine of Th17 cells (interleukin [IL]-17A) in both URPL patients and healthy women.

Methods

Samples were extracted from the peripheral blood, endocervix, endometrium, and vagina of 14 patients with URPL and 12 normal non-pregnant women as a control (normal) group. Quantitative reverse transcription polymerase chain reaction was used to determine gene expression. Enzyme-linked immunosorbent assay was used to determine the levels of cytokines in the serum and cervicovaginal fluid.

Results

We found that in the URPL group, FOXP3 gene expression was considerably higher in peripheral blood than in the normal group (P=0.043). TGF-β levels in the cervicovaginal fluid were different in the URPL and normal groups (P=0.015). In comparison to the control group, women with URPL had significantly greater IL-17 gene expression in the peripheral blood (P=0.01).

Conclusion

Lower TGF-β levels in the cervicovaginal fluid of patients compared to controls may be related with increased IL-17 and FOXP3 mRNA levels in patients with URPL. Dysregulation of local immune responses in reproductive tissues may represent dysregulation of systemic regulatory immunological responses in the pathogenesis of URPL.

Relevance for Patients

Dysregulation of immune responses may play a role in the pathogenesis of URPL at least in some patients with URPL. We conclude that the breakdown of tolerance in the local immune responses is more critical than the breakdown of tolerance in systemic tolerance in the pathogenesis of URPL. Therefore, modulating immune responses in the endometrium and decidua may be the focus of future therapeutic approaches in URPL. The impact of seminal plasma on the expansion of Tregs may provide a novel therapeutic intervention that has already been used in assisted reproductive technologies. Therefore, we suggest that transvaginal TGF-β in women with URPL may induce maternal tolerance which leads to the successful pregnancy.

Serum amyloid A/anti-CCL20 induced the rebalance of Th17/regulatory T cells in SodA-induced sarcoidosis

Sarcoidosis is a multisystemic granulomatous inflammation associated with Th17/regulatory T cell (Treg) polarization. As a marker of inflammation, serum amyloid A (SAA) could upregulate the expression of chemokine ligand 20 (CCL20), which induces the migration of Treg cells and Th17 cells by binding and activating thechemokine C-C receptor (CCR) 6. Our goal was to determine whether SAA/anti-CCL20 induces Th17/Treg rebalance in pulmonary sarcoidosis. The deposition of SAA- and Th17/Treg-related proteins in SodA-induced granulomas was tested using immunohistochemistry. Mice with SodA-induced sarcoidosis were treated with SAA or SAA + anti-CCL20, and then Th1/Th2 and Th17/Treg cells were detected by fluorescence-activated cell sorting (FACS) analysis. The expression of SAA/CCL20 and IL-23/IL-17A was detected by enzyme-linked immunosorbent assay (ELISA) and multiplex. Key proteins in the TGF-β/Smad signaling pathway were tested by western blot. SAA mainly plays a pro-inflammatory role by promoting the expression of CCL20 and IL-17A in bronchoalveolar lavage fluid (BALF) and serum, exacerbating this elevation of CD4+/CD8+ T cells in both mediastinal lymph nodes (LNs) and BALF, as well as proliferating Th1 in LNs in SodA-induced pulmonary sarcoidosis. In addition, SAA could also promote the proliferation of Tregs in LNs. Intriguingly, blocking of CCL20 could partially reverse the expression of Th17-related cytokine, ameliorate Th1/Th2 and Treg/Th17 bias in mice with SodA-induced pulmonary sarcoidosis, and rescue the overactivation of the TGF-β/Smad2/Smad3 signaling pathway. Anti-CCL20 may have the potential for therapeutic translation, targeting on the immunopathogenesis of pulmonary sarcoidosis.

Anti-CD20 therapy ameliorates β cell function and rebalances Th17/Treg cells in NOD mice

PURPOSE

Anti-CD20 therapy delays type 1 diabetes mellitus (T1DM) progression in both nonobese diabetic (NOD) mice and new-onset patients. The mechanism is not completely defined. This study aimed to investigate the effects of anti-CD20 therapy on T helper 17 (Th17) cells and regulatory T cells (Tregs) in NOD mice. The role of B cell depletion in T1DM development was also examined.

METHODS

NOD mice were randomly divided into two groups. The mice in the experimental group were treated with an anti-CD20 antibody, while the control mice were treated with an isotype-matched control antibody. After treatment, islet morphology and inflammation, Th17 and Treg cell frequencies in the pancreas and spleen, serum cytokine and anti-glutamic acid decarboxylase (GAD) antibody levels, interleukin (IL)-17A levels in the pancreas and spleen, insulin expression in islet cells and islet β cell function were measured.

RESULTS

Decreased blood glucose and increased insulin secretion were found in the exprimental group compared with the CON group. A lower islet inflammation score was also found in the experimental group. Decreased Th17 cell and IL-17A levels and augmented Treg cell levels were found in the spleen and pancreas after anti-CD20 treatment. The serum levels of B cell activating factor (BAFF), IL-17A, IL-17F, IL-23 and anti-GAD autoantibodies were decreased in the experimental group, while higher serum levels of IL-10 and transforming growth factor (TGF)-β were found.

CONCLUSION

Anti-CD20 therapy might have some beneficial effects that improve β cell function by relieving islet inflammation through regulation of Th17/Treg cells and the proinflammatory/anti-inflammatory balance.

Dysregulated TP53 Among PTSD Patients Leads to Downregulation of miRNA let-7a and Promotes an Inflammatory Th17 Phenotype

Post-traumatic stress disorder (PTSD) is a psychiatric disorder and patients diagnosed with PTSD often express other comorbid health issues, particularly autoimmune and inflammatory disorders. Our previous reports investigating peripheral blood mononuclear cells (PBMCs) from PTSD patients showed that these patients exhibit an increased inflammatory T helper (Th) cell phenotype and widespread downregulation of microRNAs (miRNAs), key molecules involved in post-transcriptional gene regulation. A combination of analyzing prior datasets on gene and miRNA expression of PBMCs from PTSD and Control samples, as well as experiments using primary PBMCs collected from human PTSD and Controls blood, was used to evaluate TP53 expression, DNA methylation, and miRNA modulation on Th17 development. In the current report, we note several downregulated miRNAs were linked to tumor protein 53 (TP53), also known as p53. Expression data from PBMCs revealed that compared to Controls, PTSD patients exhibited decreased TP53 which correlated with an increased inflammatory Th17 phenotype. Decreased expression of TP53 in the PTSD population was shown to be associated with an increase in DNA methylation in the TP53 promotor region. Lastly, the most significantly downregulated TP53-associated miRNA, let-7a, was shown to negatively regulate Th17 T cells. Let-7a modulation in activated CD4+ T cells was shown to influence Th17 development and function, via alterations in IL-6 and IL-17 production, respectively. Collectively, these studies reveal that PTSD patients could be susceptible to inflammation by epigenetic dysregulation of TP53, which alters the miRNA profile to favor a proinflammatory Th17 phenotype.

Effects of dihydroartemisinin, a metabolite of artemisinin, on colon cancer chemoprevention and adaptive immune regulation

BACKGROUND

Artemisinin (ART) is an anti-malaria natural compound with a moderate anticancer action. As a metabolite of ART, dihydroartemisinin (DHA) may have stronger anti-colorectal cancer (CRC) bioactivities. However, the effects of DHA and ART on CRC chemoprevention, including adaptive immune regulation, have not been systematically evaluated and compared.

METHODS

Coupled with a newly-established HPLC analytical method, enteric microbiome biotransformation was conducted to identify if the DHA is a gut microbial metabolite of ART. The anti-CRC potential of these compounds was compared using two different human CRC cell lines for cell cycle arrest, apoptotic induction, and anti-inflammation activities. Naive CD4⁺ T cells were also obtained for testing the compounds on the differentiation of Treg, Th1 and Th17.

RESULTS

Using compound extraction and analytical methods, we observed for the first time that ART completely converted into its metabolites by gut microbiome within 24 h, but no DHA was detected. Although ART did not obviously influence cancer cell growth in the concentration tested, DHA very significantly inhibited the cancer cell growth at relatively low concentrations. DHA included G2/M cell cycle arrest via upregulation of cyclin A and apoptosis. Both ART and DHA downregulated the pro-inflammatory cytokine expression. The DHA significantly promoted Treg cell proliferation, while both ART and DHA inhibited Th1 and Th17 cell differentiation.

CONCLUSIONS

As a metabolite of ART, DHA possessed stronger anti-CRC activities. The DHA significantly inhibited cell growth via cell cycle arrest, apoptosis induction and anti-inflammation actions. The adaptive immune regulation is a related mechanism of actions for the observed effects.

Human gut bacterial metabolism drives Th17 activation and colitis

Bacterial activation of T helper 17 (Th17) cells exacerbates mouse models of autoimmunity, but how human-associated bacteria impact Th17-driven disease remains elusive. We show that human gut Actinobacterium Eggerthella lenta induces intestinal Th17 activation by lifting inhibition of the Th17 transcription factor Rorγt through cell- and antigen-independent mechanisms. E. lenta is enriched in inflammatory bowel disease (IBD) patients and worsens colitis in a Rorc-dependent manner in mice. Th17 activation varies across E. lenta strains, which is attributable to the cardiac glycoside reductase 2 (Cgr2) enzyme. Cgr2 is sufficient to induce interleukin (IL)-17a, a major Th17 cytokine. cgr2+ E. lenta deplete putative steroidal glycosides in pure culture; related compounds are negatively associated with human IBD severity. Finally, leveraging the sensitivity of Cgr2 to dietary arginine, we prevented E. lenta-induced intestinal inflammation in mice. Together, these results support a role for human gut bacterial metabolism in driving Th17-dependent autoimmunity.

The changes in peripheral blood Th17 and Treg ratios in Hashimoto's thyroiditis are accompanied by differential PD-1/PD-L1 expression

OBJECTIVE

The aim of this study was to analyze the percentages of T helper 17 cells (Th17s) and T regulatory cells (Tregs) in autoimmune Hashimoto's thyroiditis (HT), and the expression of the checkpoint molecules programmed death receptor 1/programmed death ligand 1 (PD-1/PD-L1) on these cells.

METHODS

This is a case-control study involving 53 initially diagnosed HT patients (HT group) and 21 normal controls (NC group). The peripheral blood mononuclear cells from the individuals of the two groups were isolated and restimulated ex vivo; the percentage of Th17s, Tregs, PD-1⁺ Th17s, PD-L1⁺ Th17s, PD-1⁺ Tregs, and PD-L1⁺ Tregs was assessed by flow cytometric analysis.

RESULTS

(1) The percentage of Th17s in the peripheral blood of the HT group was significantly higher than that of the NC group [(6.38 ± 1.32)% versus (3.12 ± 0.66)%; t = 14.110, P < 0.001], while the percentage of peripheral blood Tregs was significantly lower [(3.82 ± 1.48)% versus (5.61 ± 1.60)%; t = -4.599, P < 0.001]. (2) HT patients' Th17s expressed PD-1 at a significantly lower frequency than their counterparts in the NC [(6.46 ± 2.77)% versus (18.51 ± 3.96)%; t = -14.842, P < 0.001], while no difference was observed for PD-L1 between the two groups. (3) In contrast, both PD-1 and PD-L1 were expressed at significantly higher frequency on HT patients' Tregs than on NC [respectively: (17.01 ± 3.04)% versus (10.23 ± 2.77)%; t = 8.850, P < 0.001 for PD-1; (16.60 ± 9.58)% versus (11.36 ± 10.14)%; t = 2.089, P < 0.005, for PD-L1].

CONCLUSION

(1) The increased percentage of Th17s and decreased percentage of PD-1⁺ Th17s in the HT group suggest that a loss of control on Th17 activity through the checkpoint inhibitory axis PD-1/PD-L1 may participate in disease pathogenesis. (2) While the decreased percentage of Tregs in HT patients may explain a lack of regulatory functions able to prevent the autoimmune destruction of the thyroid, the significance of the increased frequency of Tregs expressing PD-1 and PD-L1, previously reported to boost Tregs differentiation, remains to be established. Elucidating this apparent contradiction may reveal important mechanisms underlying HT pathogenesis.

Identification of heterogeneous subsets of aortic interleukin-17A-expressing CD4+ T cells in atherosclerotic mice

Objectives: T helper 17 (Th17) cells are involved in the inflammatory response of atherosclerosis. However, their heterogeneity in the atherosclerotic aorta remains elusive. This study was designed to identify aortic Th17 subsets. Methods: The surface markers and transcription factors of aortic interleukin-17A (IL-17A)-expressing T cells were determined by flow cytometry in an ApoE-deficient mouse atherosclerotic model. Viable aortic IL-17A-expressing T cell subsets were isolated by flow cytometry on the basis of surface markers, followed by characterizing their transcription factors by either flow cytometry or real-time RT-PCR. The effect of aortic IL-17A-expressing T cell subsets on aortic endothelial cells was determined in vitro. Results: C-X-C Motif Chemokine Receptor 3 (CXCR3), interleukin-17 receptor E (IL-17RE), CD200, and C-C Motif Chemokine Receptor 4 (CCR4) marked three subsets of aortic IL-17A-expressing T cells: CXCR3⁺IL-17RE^lowCD200⁺CCR4^- T cells expressing T-box protein expressed in T cells (T-bet) and interferon-gamma (IFN-γ), CXCR3⁺IL-17RE^lowCD200⁺CCR4⁺ T cells expressing T-bet but fewer IFN-γ, and CXCR3⁻IL-17RE^highCD200⁺CCR4⁺ T cells expressing very low T-bet and no IFN-γ. Based on these markers, viable aortic Th17 cells, Th17.1 cells, and transitional Th17.1 cells were identified. Both Th17.1 cells and transitional Th17.1 cells were more proliferative than Th17 cells. Compared with Th17 cells, Th17.1 cells plus transitional Th17.1 cells induced higher expression of C-X-C motif chemokine ligand 1 (CXCL1), C-C motif chemokine ligand 2 (CCL2), C-X-C motif chemokine 5 (CXCL5), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in aortic endothelial cells. Conclusion: IL-17A-expressing CD4⁺ T cells were heterogeneous in atherosclerotic aortas.

Circulating JNK pathway-associated phosphatase: A novel biomarker correlates with Th17 cells, acute exacerbation risk, and severity in chronic obstructive pulmonary disease patients

Background

JNK pathway‐associated phosphatase (JKAP) involves in the regulation of inflammation, immunity, and lung injury. The current study aimed to investigate correlation of JKAP with Th1, Th17 cells, acute exacerbation risk, and disease severity in chronic obstructive pulmonary disease (COPD) patients.

Methods

Totally, 45 stable COPD (SCOPD) patients, 45 acute exacerbation COPD (AECOPD) patients, and 45 controls were enrolled. Serum was collected for JKAP, interferon‐gamma (IFN‐γ) (Th1 cytokine), and interleukin 17 (IL‐17) (Th17 cytokine) detection. Besides, peripheral blood mononuclear cell from COPD patients was collected for evaluating Th1 and Th17 cells.

Results

JKAP was highest in controls followed by SCOPD patients and lowest in AECOPD patients (median: 105.673 vs. 75.374 vs. 41.807 pg/ml, p < 0.001). Meanwhile, receiver operating characteristic (ROC) curves revealed that JKAP differentiated the AECOPD patients from the controls (area under curve (AUC): 0.910 (95% confidence interval (CI): 0.849–0.970)) and AECOPD patients from SCOPD patients (AUC: 0.726 (95% CI: 0.622–0.830)). Moreover, JKAP positively correlated with FEV₁ (%predicted) in AECOPD patients (r = 0.347 p = 0.019). Additionally, JKAP was negatively correlated with the GOLD stage in AECOPD patients (r = −0.344, p = 0.021) and SCOPD patients (r = −0.357, p = 0.016). Whereas, JKAP was not associated with other clinical features (all p > 0.05). Besides, JKAP was negatively linked with Th17 cells (r = −0.378, p = 0.010), IFN‐γ (r = −0.358, p = 0.016), IL‐17 (r = −0.414, p = 0.005) in AECOPD patients and Th17 cells (r = −0.342, p = 0.022), IL‐17 (r = −0.299, p = 0.046) in SCOPD patients.

Conclusion

Downregulated JKAP correlates with Th17 cells, higher acute exacerbation risk, and severity in COPD patients, indicating its underlying potency as a biomarker for COPD.

RNA-sequencing identifies differentially expressed genes in T helper 17 cells in peritoneal fluid of patients with endometriosis

Innate and adaptive immune factors play significant roles in the pathophysiology of endometriosis. T helper 17 (Th17) cells, a pro-inflammatory T cell subset, were considered to contribute to the progression of endometriosis lesions. However, the regulatory mechanisms of Th17 cells in endometriosis remain unidentified, partially due to the difficulty in recovering live Th17 cells from endometriosis patients. In this study, by flow cytometry analysis of a set of chemokine receptors including CXCR3, CCR4, CCR10, and CCR6, live RORγt-and-IL-17A-expressing Th17 cells were enriched from peritoneal fluid (PF) of patients with different stages of endometriosis for the first time, RNA-sequencing (RNA-Seq) of these PF Th17 cells revealed significantly up-regulated genes and down-regulated genes in stage I-II and stage III-IV endometriosis, compared with their counterparts in normal PF. In conclusion, this study provides a novel method to isolate live Th17 cells from endometriosis patients, unveils an array of differentially expressed genes in endometriosis Th17 cells, and offers valuable gene expression profile information for endometriosis clinical research.

MicroRNA-590-3p inhibits T helper 17 cells and ameliorates inflammation in lupus mice

T helper 17 (Th17) cells have a pathogenic effect in many autoimmune diseases. Inhibition of Th17 cells can alleviate the inflammatory damage in autoimmune diseases. Our previous study found that microRNA-590-3p (miR-590-3p) was involved in the differentiation of Th17 cells in systemic lupus erythematosus (SLE). Here, we demonstrated that an increase in Th17 cells was correlated with low expression of miR-590-3p in patients with SLE and in lupus mice. Upregulation of miR-590-3p reduced the differentiation and promoted apoptosis of Th17 cells. Subsequent experiments demonstrated that miR-590-3p promoted apoptosis in Th17 cells by inhibiting autophagy. Autophagy-related 7 (Atg7) was the direct target of miR-590-3p that blocked the autophagy pathway. Finally, treatment of MRL/lpr mice with miR-590-3p agomir ameliorated lupus nephritis and skin lesions. Our work revealed that miR-590-3p inhibited Th17 cells by suppressing autophagy and that increased miR-590-3p expression was able to ameliorate the clinical symptoms of lupus. Therefore, miR-590-3p may be a promising therapeutic target for SLE and other Th17 cell-dependent autoimmune diseases.

Interleukin-6 receptor alpha and CD27 discriminate intratumoral T helper 17 subpopulations with distinct functional properties in a mouse lung cancer model

BACKGROUND

T helper 17 (Th17) cells actively participate in the tumor immune response in lung cancer. However, the heterogeneity and plasticity of intratumoral Th17 cells in lung cancer remain elusive. In this study, Th17 subpopulations were characterized in a mouse lung cancer model.

METHODS

Urethane was administered to induce lung cancer in interleukin (IL)-17-EGFP transgenic mice. Flow cytometry was used to analyze the phenotypes, signaling status, and functions of Th17 subpopulations either in vivo or in vitro. The adoptive transfer assay and real-time polymerase chain reaction were applied to analyze the plasticity of Th17 subpopulations.

RESULTS

IL-6Rα^high CD27^- Th17 and IL-6Rα^low CD27⁺ Th17 were identified in intratumoral Th17 cells. The two subpopulations expressed equivalent RORγt. However, the former expressed higher T-bet but lower Foxp3, more IL-17A and IFN-γ but less IL-10 than the latter. Furthermore, IL-6Rα^high CD27^- Th17 moderately inhibited the proliferation of lung cancer cells while IL-6Rα^low CD27⁺ Th17 could not. IL-6Rα^high CD27^- Th17 exhibited weaker Jun N-terminal kinases (JNK) signaling but stronger signal transducer and activator of transcription 3 (Stat3) signaling than IL-6Rα^low CD27⁺ Th17. The adoptive transfer assay indicated that both subpopulations downregulated RORγt in recipients' spleens but maintained RORγt in recipients' lungs. Meanwhile, IL-6Rα^high CD27^- Th17 expressed higher T-bet and IFN-γ than IL-6Rα^low CD27⁺ Th17 in the recipients. IL-6Rα^low CD27⁺ Th17 expressed Foxp3 and IL-10 in recipients' spleens but not lungs.

CONCLUSIONS

This study reveals intratumoral Th17 subpopulations with distinct functional properties and signaling patterns, thus offering valuable insight into Th17 heterogeneity and plasticity in lung cancer.

Role of Interleukin-17 in Acute Pancreatitis

Acute pancreatitis (AP) is a leading cause of death and is commonly accompanied by systemic manifestations that are generally associated with a poor prognosis. Many cytokines contribute to pancreatic tissue damage and cause systemic injury. Interleukin-17 (IL-17) is a cytokine that may play a vital role in AP. Specifically, IL-17 has important effects on the immune response and causes interactions between different inflammatory mediators in the AP-related microenvironment. In this literature review, we will discuss the existing academic understanding of IL-17 and the impacts of IL-17 in different cells (especially in acinar cells and immune system cells) in AP pathogenesis. The clinical significance and potential mechanisms of IL-17 on AP deterioration are emphasized. The evidence suggests that inhibiting the IL-17 cytokine family could alleviate the pathogenic process of AP, and we highlight therapeutic strategies that directly or indirectly target IL-17 cytokines in acute pancreatitis.

Perinatal Resveratrol Therapy to Dioxin-Exposed Dams Prevents the Programming of Hypertension in Adult Rat Offspring

Exposure to environmental chemicals during pregnancy and lactation is a contributing factor in gut microbiota dysbiosis and linked to programming of hypertension. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic dioxin, induces toxic effects by mediating aryl hydrocarbon receptor (AHR). Resveratrol, a potent antioxidant with prebiotic properties, can possess high affinity for AHR and protect against TCDD-activated AHR attack. We examined whether perinatal resveratrol therapy prevents offspring hypertension programmed by maternal TCDD exposure and whether its beneficial effects are related to reshaping gut microbiota and antagonizing AHR-mediated T helper 17 (TH17) cells responses using a maternal TCDD exposure rat model. Pregnant Sprague-Dawley rats were given a weekly oral dose of TCDD 200 ng/kg for four doses (T), 50 mg/L of resveratrol in drinking water (CR), TCDD + resveratrol (TR), or vehicle (C) in pregnancy and lactation periods. Male offspring (n = 7–8/group) were sacrificed at the age of 12 weeks. Perinatal TCDD exposure caused elevated blood pressure in adult male offspring, which resveratrol supplementation prevented. Additionally, the TCDD-induced programming of hypertension is coincided with the activation of AHR signaling, TH17-induced renal inflammation, and alterations of gut microbiota compositions. Conversely, TCDD-mediated induction of AHR signaling and TH17 responses were restored by maternal resveratrol supplementation. Furthermore, maternal resveratrol supplementation prevented the programming of hypertension and was related to increased genera Bacteroides, ASF356, and Lachnoclostridium. Taken together, these results suggest that the interplay between gut microbiota, AHR-mediated TH17 responses, and renal inflammation in the gut and kidneys may play an important role in the action of resveratrol against TCDD-induced programming of hypertension.

Labial gland-derived mesenchymal stem cells and their exosomes ameliorate murine Sjögren's syndrome by modulating the balance of Treg and Th17 cells

Background

Sjögren's syndrome (SS) is a chronic, systemic autoimmune disorder characterized by sicca syndrome and/or systemic manifestations. The disease severely affects the health and life of patients, and the treatment of SS has always been a clinical challenge and essentially palliative. Mesenchymal stem cells (MSCs) have been reported to exert immunomodulatory effects and as a potential novel therapeutic strategy for SS. Labial gland-derived MSCs (LGMSCs) are a population of resident stem cells in the labial gland, first isolated by our group. Exosomes released by MSCs contain a large variety of bioactive molecules and considered to function as an extension of MSCs.

Methods

LGMSCs were isolated from patients who were needed surgery to remove the lip mucocele and LGMSCs derived exosomes (LGMSC-Exos) were isolated by ultracentrifugation. The non-obese diabetic (NOD) mice were treated with LGMSCs or LGMSC-Exos by tail vein injection. The saliva flow rate of mice was determined and salivary glands were dissected and stained with hematoxylin and eosin. In vitro, peripheral blood mononuclear cells (PBMCs) from SS patients were cocultured with LGMSCs or LGMSC-Exos. Percentage of T helper 17 (Th17) cells and regulatory T (Treg) cells were determined by flow cytometry. The serum levels of cytokines in NOD mice and in the supernatant of the co-culture system by ELISA.

Results

Treatment with LGMSCs or LGMSC-Exos reduced inflammatory infiltration in the salivary glands, and restored salivary gland secretory function in NOD mice. Importantly, LGMSCs or LGMSC-Exos were demonstrated to inhibit the differentiation of Th17 cells but promote the induction of Treg cells in NOD mice and PBMCs from SS patients in vitro, accompanied by reduced interleukin 17 (IL-17), interferon gamma, and IL-6 levels and enhanced transforming growth factor beta and IL-10 secretion by T cells.

Conclusions

LGMSCs are potential candidates for MSCs-based therapy and LGMSC-Exos might be utilized for establishing a new cell-free therapy against SS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02541-0.

Moderately pathogenic maternal influenza A virus infection disrupts placental integrity but spares the fetal brain

Maternal infection during pregnancy is a known risk factor for offspring mental health disorders. Animal models of maternal immune activation (MIA) have implicated specific cellular and molecular etiologies of psychiatric illness, but most rely on pathogen mimetics. Here, we developed a mouse model of live H3N2 influenza A virus (IAV) infection during pregnancy that induces a robust inflammatory response but is sublethal to both dams and offspring. We observed classic indicators of lung inflammation and severely diminished weight gain in IAV-infected dams. This was accompanied by immune cell infiltration in the placenta and partial breakdown of placental integrity. However, indications of fetal neuroinflammation were absent. Further hallmarks of mimetic-induced MIA, including enhanced circulating maternal IL-17A, were also absent. Respiratory IAV infection did result in an upregulation in intestinal expression of transcription factor RORγt, master regulator of a subset of T lymphocytes, TH17 cells, which are heavily implicated in MIA-induced etiologies. Nonetheless, subsequent augmentation in IL-17A production and concomitant overt intestinal injury was not evident. Our results suggest that mild or moderately pathogenic IAV infection during pregnancy does not inflame the developing fetal brain, and highlight the importance of live pathogen infection models for the study of MIA.

5-Aza-2-deoxycytidine alleviates the progression of primary biliary cholangitis by suppressing the FoxP3 methylation and promoting the Treg/Th17 balance

Primary biliary cholangitis (PBC) is a common autoimmune liver disease manifested by the infiltration of CD4+ T cells, and the subsequent targeted injury of biliary epithelial cells (BECs). As important components of CD4 subsets, the Treg/Th17 axis maintains an immunological balance between self-tolerance and inflammation in the liver microenvironment. However, the role and regulatory mechanism of the Treg/Th17 axis in PBC remain unclear. In this study, we examined the Treg/Th17 axis in PBC patients and found that the Treg/Th17 axis was imbalanced in PBC at both the transcriptional and cellular levels, with Treg being a weak candidate, which correlates with the PBC progression. This imbalanced Treg/Th17 axis was likely to be affected by the FoxP3 hypermethylation, which was related to the increase of DNA methyltransferase. Furthermore, the effect of 5-Aza-2-deoxycytidine (DAC)-mediated FoxP3 demethylation on PBC mice was investigated. We verified that DAC significantly suppressed the FoxP3 methylation and rebuilt the Treg/Th17 balance, resulting in the alleviation of liver lesions and inflammation. Taken together, our data indicate that DAC plays a positive role in alleviating the progression of PBC through the inhibition of DNA methylation of FoxP3 to rebuild the balanced Treg/Th17 axis. DAC could be considered as a potential candidate for the development of new anti-inflammation strategies in the treatment of PBC.

MiR-206 regulates the Th17/Treg ratio during osteoarthritis

BACKGROUND

The present study aimed to determine the functional role of miR-206 in T helper 17 (Th17)/regulatory T (Treg) cell differentiation during the development of osteoarthritis (OA).

METHODS

Patients with OA and healthy controls were recruited for investigating the association between miR-206 and Th17/Treg ratio. Transfection experiments were conducted in CD4⁺ T cells to verify the mechanism of miR-206 on the balance of Treg/Th17. OA model was constructed to detect the clinical score, histopathological changes and Treg/Th17 ratio. OA model was induced in rats to verify the effect of miR-206 inhibition on Th17/Treg immunoregulation.

RESULTS

High expression of miR-206 was positively correlated with peripheral Th17/Treg imbalance in patients with OA. The interactions between miR-206 and the 3' untranslated regions (3'-UTR) of suppressor of cytokine signaling-3 (SOCS3) and fork head transcriptional factor 3 (Foxp3) were confirmed by luciferase reporter assays. MiR-206 disturbed the Th17/Treg balance by targeting SOCS3 and Foxp3. In vivo assay demonstrated that antagomiR directed against miR-206 restored Th17/Treg balance during the development of OA.

CONCLUSION

MiR-206 contributed to the progression of OA by modulating Th17/Treg imbalance, suggesting that miR-206 inhibition might be a promising therapeutic strategy for the treatment of OA.