Suppression of IL-23-mediated psoriasis-like inflammation by regulatory B cells

Psoriasis is an inflammatory cutaneous disease mediated by T-cell dependent immune responses; however, B cells are also considered to play an important role its development. Regulatory B cells (Bregs) regulate immune responses negatively through interleukin-10 (IL-10) production. This study aimed to investigate the role of Bregs in IL-23-mediated psoriasis-like inflammation in mice. Psoriasis-like inflammation was induced in B cell-specific phosphatase and tensin homolog (PTEN)-deficient mice, in which Bregs were significantly expanded, and in their controls, by intradermal injection of 20 μL phosphate-buffered saline (PBS) containing 0.5 μg rmIL-23 into one ear, every other day for 16 days. IL-23-mediated psoriasis-like inflammation was suppressed in B cell-specific PTEN-deficient mice along with decreased ear thickness and epidermal thickness on day 15. Moreover, adoptive transfer of B1 B cells suppressed IL-23-mediated psoriasis-like inflammation. rmIL-23-injected B cell-specific PTEN-deficient mice showed expanded regulatory T cells (Tregs) in the spleen and draining lymph nodes along with increased Bregs. Further, T helper (Th) 17 differentiation in the rmIL-23-injected ear was suppressed in B cell-specific PTEN-deficient mice. Overall, these results indicate that increased Bregs suppress IL-23-mediated psoriasis-like inflammation through Treg expansion and inhibition of Th17 differentiation. Thus, targeting Bregs may be a feasible treatment strategy for psoriasis.

Dietary Indole-3-Carbinol Activates AhR in the Gut, Alters Th17-Microbe Interactions, and Exacerbates Insulitis in NOD Mice

The diet represents one environmental risk factor controlling the progression of type 1 diabetes (T1D) in genetically susceptible individuals. Consequently, understanding which specific nutritional components promote or prevent the development of disease could be used to make dietary recommendations in prediabetic individuals. In the current study, we hypothesized that the immunoregulatory phytochemcial, indole-3-carbinol (I3C) which is found in cruciferous vegetables, will regulate the progression of T1D in nonobese diabetic (NOD) mice. During digestion, I3C is metabolized into ligands for the aryl hydrocarbon receptor (AhR), a transcription factor that when systemically activated prevents T1D. In NOD mice, an I3C-supplemented diet led to strong AhR activation in the small intestine but minimal systemic AhR activity. In the absence of this systemic response, the dietary intervention led to exacerbated insulitis. Consistent with the compartmentalization of AhR activation, dietary I3C did not alter T helper cell differentiation in the spleen or pancreatic draining lymph nodes. Instead, dietary I3C increased the percentage of CD4+RORγt+Foxp3- (Th17 cells) in the lamina propria, intraepithelial layer, and Peyer's patches of the small intestine. The immune modulation in the gut was accompanied by alterations to the intestinal microbiome, with changes in bacterial communities observed within one week of I3C supplementation. A transkingdom network was generated to predict host-microbe interactions that were influenced by dietary I3C. Within the phylum Firmicutes, several genera (Intestinimonas, Ruminiclostridium 9, and unclassified Lachnospiraceae) were negatively regulated by I3C. Using AhR knockout mice, we validated that Intestinimonas is negatively regulated by AhR. I3C-mediated microbial dysbiosis was linked to increases in CD25high Th17 cells. Collectively, these data demonstrate that site of AhR activation and subsequent interactions with the host microbiome are important considerations in developing AhR-targeted interventions for T1D.

A non-clinical comparative study of IL-23 antibodies in psoriasis

Four antibodies that inhibit interleukin (IL)-23 are approved for the treatment of moderate-to-severe plaque psoriasis. Here, we present non-clinical data comparing ustekinumab, guselkumab, tildrakizumab and risankizumab with regard to thermostability, IL-23 binding affinity, inhibitory-binding mode, in vitro potency and in vivo efficacy. Risankizumab and guselkumab exhibited 5-fold higher affinity for IL-23 and showed more potent inhibition of IL-23 signaling than ustekinumab and tildrakizumab. Risankizumab and guselkumab completely blocked the binding of IL-23 to IL-23Rα as expected, whereas tildrakizumab did not. In vitro, risankizumab and guselkumab blocked the terminal differentiation of TH17 cells in a similar manner, while tildrakizumab had minimal impact on TH17 differentiation. In a human IL-23-induced ear-swelling mouse model, risankizumab and guselkumab were more effective than ustekinumab and tildrakizumab at reducing IL-17, IL-22, and keratinocyte gene expression. Our results indicate that the four clinically approved antibodies targeting IL-23 differ in affinity and binding epitope. These attributes contribute to differences in in vitro potency, receptor interaction inhibition mode and in vivo efficacy in preclinical studies as described in this report, and similarly may affect the clinical performance of these drugs.

Reversal of Abnormal CD4+ T Cell Metabolism Alleviates Thyroiditis by Deactivating the mTOR/HIF1a/Glycolysis Pathway

BACKGROUND

Hashimoto's thyroiditis (HT) is an autoimmune disease that features activation of thyroid antigen-specific helper T cells. HT patients have increased Th1 and Th17 T cell subsets. Glycolysis supports chronic activation of Th1 and Th17 T cells, but how this contributes to HT remains unknown.

METHODS

The metabolism of CD4+ T cells from 30 HT patients and 30 healthy controls was evaluated by determining the extracellular acidification rate (ECAR) and the oxygen consumption rate (OCR). Mice in a subacute thyroiditis (SAT) model were treated with 2DG, metformin, or combination. Metrics of mTOR/HIF-1α/HK2/glycolysis were measured by western blot and Seahorse assay methods. The severity of SAT was measured by flow cytometry and HE staining.

RESULTS

CD4+ T cells from HT patients had enhanced ECAR and OCR. Levels of Glut1, HK2, PKM2, and LDHA in cultured HT CD4+ T cells were elevated. The expression of HK2 and PKM2 in cultured SAT CD4+ T cells was elevated compared with the control group. Activation of the mTOR and HIF-1α pathways was significant in SAT mice, and expression of HIF-1α in the 2DG treated group was reduced. Treatment with 2DG and/or metformin significantly decreased the ratio of Th17 and Th1 T cells.

CONCLUSIONS

Thyroiditis results in elevation of the mTOR/HIF-1α/HK2/glycolysis pathway in CD4+ T cells. The activation of this pathway is reduced by treatment with 2DG and metformin, which also reverted imbalances in CD4+ T cell differentiation.

Long-term aspirin intervention can inhibit TIGIT, regulating T cells to reverse damage to intestines

Aspirin is one of the most commonly prescribed medications. Evidence shows that it can even treat and prevent intestinal tumors. However, it has also caused a great deal of controversy due to its intestinal side effects. We therefore explored whether aspirin was beneficial or harmful to the intestines. We used aspirin continuously interfered with C57BL/6 J mice for 48 weeks, examining their intestinal tissues at 13, 26 and 48 weeks to determine the drug's effect on the intestines. In addition, we used flow cytometry (FCM) used to detect T cells and expression of T-cell immunoreceptor with immunoglobulin (Ig)- and tyrosine-based inhibitory motif (ITIM) domain (TIGIT) on their surfaces to determine aspirin's immunomodulatory effects. The results showed that long-term aspirin intervention could reverse damage to the intestines, an effect related to the drug's significant inhibitory effect on TIGIT. The change in TIGIT level could regulate T-cell subsets, so that counts of Cluster of Differentiation 4 (CD4)+/chemokine (C-X3-C motif) receptor 3 (CXCR3)+ T-helper 1 (Th1) cells and CD4+/interleukin-4 (IL-4)+ Th2 cells increased, while those of CD4+/C-C chemokine receptor type 6 (CCR6)+ Th17 cells and CD4+/CD25+ regulatory T cells (Tregs) decreased. In summary, we demonstrated that long-term aspirin intervention could inhibit TIGIT, regulating T cells to reverse damage to the intestines. Furthermore, aspirin is a potential therapy for diseases related to an increase in TIGIT.

Thiomyristoyl ameliorates colitis by blocking the differentiation of Th17 cells and inhibiting SIRT2-induced metabolic reprogramming

BACKGROUND

The pathogenesis of inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC) has not been fully elucidated. However, a strong correlation between IBD and high T helper 17 (Th17) levels has been found. Sirtuin 2 (SIRT2) has recently been found to play an important role in metabolic reprogramming, but its potential anti-inflammatory properties remain unclear.

METHODS

The expression levels of SIRT2 and glucose metabolism-related proteins in peripheral blood mononuclear cells (PBMCs) of IBD patients and healthy volunteers were detected. Human PBMCs were differentiated into Th17 cells in vitro and were treated with TM simultaneously. The ratio of Th17 cells and apoptotic cells and the production of Interleukin (IL)-17A and the expression levels of transcription factors of classical signaling pathway related to Th17 differentiation were determined. The acetylation of LDHA and glucose metabolism was assessed. Subsequently, C57BL/6J colitis mice induced by 2.5% dextran sulfatesodiumsalt (DSS) were treated with or without TM, Disease activity index, T cell subsets in the mice spleen, relevant inflammatory cytokines in serum, specific mRNA, and proteins in mice colon were evaluated respectively.

RESULTS

SIRT2 and glucose metabolism-related proteins in PBMCs of patients were overexpressed. Compared with the positive control group, human PBMCs treated with TM had lower levels of IL-17A, percentage of Th17 cells, levels of phospho-signal transducer and activator of transcription (p-STAT) 3 and phospho-nuclear transcription factor-κB (p-NF-κB), but higher levels of acetylated LDHA. Compared with colitis mice, TM-treated colitis mice had longer colons, reduced weight-losses, and lower disease activity index and histopathologic scores. Interestingly, although the expression levels of interferon (IFN)-γ, IL-17A, and retinoic acid receptor-related orphan receptor (ROR)-γt were inhibited in the colons of TM-treated colitis mice, the expression of forkhead box protein P3 (FOXP3) didn't change. Consistently, relative to the high percentage of splenic Th17 cells in colitis mice, the percentage of splenic Th17 cells in TM-treated colitis mice was as normal as PBS-treated mice, while the percentage of Treg cells was not affected. Additionally, the TM group had reduced levels of IL-23 and hypoxiainduciblefactor-1α (HIF-1α), and an increased level of IL-10 in the colon, compared with the colitis group.

CONCLUSION

Our results indicate that TM reduces UC progression by reducing metabolic reprogramming and T cell differentiation. Specifically, TM prevented Th17 differentiation by reducing the expression of related transcription factors and promoting acetylation of LDHA (weakening glycolysis). SIRT2 may be a potential target for IBD treatment.

Vitamin D Supplementation Modulates ICOS+ and ICOS- Regulatory T Cell in Siblings of Children With Type 1 Diabetes

OBJECTIVES

Vitamin D plays an immunoregulatory activity. The aim of this study was to assess the correlation between blood serum 25(OH)D levels and Th17 and Treg circulating subsets, mainly Treg/inducible costimulatory-positive (ICOS+), which seems to have a protective role in autoimmunity, in children with type 1 diabetes mellitus (T1D) and their healthy siblings (S). The secondary aim was to evaluate the impact of vitamin D supplementation on these subsets.

PATIENTS AND METHODS

22 T1D and 33 S were enrolled. Glucose, hemoglobin A1c, 25 OH vitamin D (25[OH]D), T helper type 17 (Th17; CD4+CCR6+), regulatory T cells (Treg; CD4+CD25+Foxp3+), and Treg/ICOS+ cells were evaluated. According to human leukocyte antigen (HLA) haplotypes, subjects were classified as "at risk" (HLA+), "protective haplotypes" (HLA-; "nested controls"), and "undetermined" (HLAUND). T1D and S subjects were supplemented with cholecalciferol 1000 IU/die and evaluated after 6 months.

RESULTS

Vitamin D insufficiency (74.4%) and deficiency (43%) were frequent. S subjects with 25(OH)D levels <25 nmol/L had Th17, Treg (p < 0.01), and Treg/ICOS+ (P < 0.05) percentages higher than subjects with 25(OH)D >75 nmol/L. Treg/ICOS+ percentages (P < 0.05) were higher in HLA- S subjects compared to percentages observed in S with T1D. At baseline, in S subjects, a decreasing trend in Th17 and Treg/ICOS+ values (P < 0.05) from vitamin D deficiency to sufficiency was observed; 25(OH)D levels were negative predictors of Treg/ICOS+ (R2 = 0.301) and Th17 percentages (R2 = 0.138). After 6 months, supplemented S subjects showed higher 25(OH)D levels (P < 0.0001), and lower Th17 (P < 0.0001) and Treg/ICOS+ (P < 0.05) percentages than at baseline; supplemented T1D patients only had a decrease in Th17 levels (P < 0.05).

CONCLUSION

Serum 25(OH)D levels seem to affect Th17 and Treg cell subsets in S subjects, consistent with its immunomodulating role. HLA role should be investigated in a larger population.

A Novel Selective Sphingosine Kinase 2 Inhibitor, HWG-35D, Ameliorates the Severity of Imiquimod-Induced Psoriasis Model by Blocking Th17 Differentiation of Naïve CD4 T Lymphocytes

Sphingosine kinases (SK) catalyze the phosphorylation of sphingosine to generate sphingosine-1-phosphate. Two isoforms of SK (SK1 and SK2) exist in mammals. Previously, we showed the beneficial effects of SK2 inhibition, using ABC294640, in a psoriasis mouse model. However, ABC294640 also induces the degradation of SK1 and dihydroceramide desaturase 1 (DES1). Considering these additional effects of ABC294640, we re-examined the efficacy of SK2 inhibition in an IMQ-induced psoriasis mouse model using a novel SK2 inhibitor, HWG-35D, which exhibits nM potency and 100-fold selectivity for SK2 over SK1. Topical application of HWG-35D ameliorated IMQ-induced skin lesions and normalized the serum interleukin-17A levels elevated by IMQ. Application of HWG-35D also decreased skin mRNA levels of interleukin-17A, K6 and K16 genes induced by IMQ. Consistent with the previous data using ABC294640, HWG-35D also blocked T helper type 17 differentiation of naïve CD4⁺ T cells with concomitant reduction of SOCS1. Importantly, HWG-35D did not affect SK1 or DES1 expression levels. These results reaffirm an important role of SK2 in the T helper type 17 response and suggest that highly selective and potent SK2 inhibitors such as HWG-35D might be of therapeutic use for the treatment of psoriasis.

Liposome/gold hybrid nanoparticle encoded with CoQ10 (LGNP-CoQ10) suppressed rheumatoid arthritis via STAT3/Th17 targeting

Coenzyme Q10 (CoQ10), also known as ubiquinone, is a fat-soluble antioxidant. Although CoQ10 has not been approved as medication by the Food and Drug Administration, it is widely used in dietary supplements. Some studies have shown that CoQ10 has anti-inflammatory effects on various autoimmune disorders. In this study, we investigated the anti-inflammatory effects of liposome/gold hybrid nanoparticles encoded with CoQ10 (LGNP-CoQ10). Both CoQ10 and LGNP-CoQ10 were administered orally to mice with collagen-induced arthritis (CIA) for 10 weeks. The inflammation pathology of joint tissues of CIA mice was then analyzed using hematoxylin and eosin and Safranin O staining, as well as immunohistochemistry analysis. We obtained immunofluorescence staining images of spleen tissues using confocal microscopy. We found that pro-inflammatory cytokines were significantly decreased in LGNP-CoQ10 injected mice. Th17 cell and phosphorylated STAT3-expressed cell populations were also decreased in LGNP-CoQ10 injected mice. When human peripheral blood mononuclear cells (PBMCs) were treated with CoQ10 and LGNP-CoQ10, the IL-17 expression of PBMCs in the LGNP-CoQ10-treated group was significantly reduced. Together, these results suggest that LGNP-CoQ10 has therapeutic potential for the treatment of rheumatoid arthritis.

Prednisone improves pregnancy outcome in repeated implantation failure by enhance regulatory T cells bias

OBJECTIVE

Repeated implantation failure (RIF) has been shown related to maternal immune imbalance. Many studies suggested that prednisone promoted the Th17/Treg balance shift to the direction of immune tolerance. Our study aimed to evaluate the role of prednisone in Th17/Treg balance and pregnancy outcome in RIF patients.

STUDY DESIGN AND MAIN OUTCOME MEASURES

Peripheral blood of healthy fertile controls and RIF patients were collected at the late proliferation phase. The population of Treg and Th17 cells, the expression of Foxp3 and RORC mRNA and the concentration of IL-17A, IL-23 and IL-10 were detected by flow cytometry, qRT-PCR and enzyme-linked immunosorbent assay. RIF patients were given oral prednisone 10 mg daily from the late proliferation phase of the cycle before FET. After one month of treatment, the above immune indicators were tested, and natural cycle frozen embryo transfer was performed.

RESULTS

The Treg cells proportion and IL-10 concentration in peripheral blood of RIF patients was lower than that of NF group, while the proportion of Th17 cells and concentration of proinflammatory cytokine were significantly higher. After prednisone treatment, the indicators related to immune tolerance increased significantly. Five out of 19 RIF patients were successful pregnancy after FET, in which, one had an early miscarriage and four live births. No pregnancy complications and fetal abnormalities were observed.

CONCLUSIONS

We report the beneficial effect of prednisone on RIF patients. The underlying mechanism may attribute to shift the Treg/Th17 immune balance to a Treg bias, and enhance embryo implantation, ultimately improve pregnancy outcomes.

Standardized Fraction of Turbinaria ornata Alleviates Dextran Sulfate Sodium-Induced Chronic Colitis in C57BL/6 Mice via Upregulation of FOXP3+ Regulatory T Cells

Turbinaria ornata is a tropical brown algae (seaweed) known to have anti-inflammatory properties. In this study, we analyzed T. ornata extract (TOE) using liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF-MS) and nuclear magnetic resonance (NMR) and evaluated the in vivo efficacy of TOE against dextran sulfate sodium-induced chronic colitis in C57BL/6 mice. The bioactive fraction of TOE was administered orally daily for 6 weeks to mice under different treatments normal, colitis, and colitis + conventional drug (5-aminosalicylic acid, 5-ASA). Regarding clinical manifestation, the disease activity index and colon length of the colitis + TOE group were significantly reduced compared to those of the colitis group. The results of myeloperoxidase activity and histopathological examination showed similar results. Western blot analysis of colon tissues revealed that cyclooxygenase-2, tumor necrosis factor alpha (TNF-α), and phosphorylated signal transducer and activator of transcription-3 (p-STAT3) were significantly decreased in the colitis + 5-ASA group, whereas forkhead box P3 (FOXP3) was increased. qPCR results showed changes in T cell subsets; the administration of TOE upregulated regulatory T cell (Treg) expression, although T helper 17 cell (Th17) expression did not change significantly. Interestingly, the colitis + TOE group showed high levels of both Th1 and Th2 transcription factors, but the secreted cytokine interferon (IFN)-γ and interleukin (IL)-4 remained unchanged and somewhat reduced. Additionally, TNF-α gene expression was significantly reduced in the colitis + TOE group. IL-6 mRNA levels were also decreased, although not significantly. Four compounds were structurally elucidated using 1D- and 2D-NMR spectroscopy, and five compounds were fully identified or tentatively characterized using LC-QTOF-MS. In conclusion, TOE could alleviate chronic colitis via upregulation of Foxp3+ Treg cells and production of the anti-inflammatory cytokine IL-10, which directly inhibits macrophages and pro-inflammatory cytokine synthesis, leading to reduced colitis.

Heterogeneity of Treg/Th17 According to Cancer Progression and Modification in Biliary Tract Cancers via Self-Producing Cytokines

BACKGROUND/AIM

We previously demonstrated that inflammatory cytokine interleukin-6 (IL-6) was produced during cancer progression, worked together with transforming growth factor-beta 1 (TGF-β1), and induced the epithelial-mesenchymal transition (EMT) with chemo-resistance against gemcitabine (GR) at the invasion front of biliary tract cancers (BTCs). However, the significance of cytokine-induced T cell accumulation at the tumor microenvironment in biliary tract cancer (BTC) is not well understood. Because these cytokines (IL-6 and TGF-β1) are able to differentiate naïve T cells into Foxp3-expressing T cells (Tregs) and/or IL-17-producing T helper 17 (Th17) cells, we investigated the relationship between heterogeneous, cancer-producing cytokines and T cell differentiation.

METHODS

In total, 127 curative resected specimens from patients with BTCs at Osaka University Hospital between 2000 and 2012 were evaluated for IL-6, TGF-β1, Tregs, and Th17 cells by immunohistochemistry. The ability of BTC-GR cells to undergo T cell differentiation was investigated in vitro.

RESULTS

Tregs accumulated at the tumor center and Th17 cells accumulated at the invasion front during cancer progression and/or metastasis; each signaled poor prognosis. Treg accumulation was related to TGF-β1 expression by cancer cells, and Th17 cell accumulation was related to IL-6 expression by cancer cells, in resected specimens; this was confirmed in vitro. Compared with parent cells, GR cells produced IL-6 but not TGF-β1 in a time-dependent manner, had EMT features, and induced T cell differentiation to Th17 cells but not Tregs.

CONCLUSION

Cytokines produced by cancer cells (IL-6 and TGF-β1) induced heterogeneity of Tregs and Th17 cells in the tumor microenvironment, supporting progression of BTC.

Cytokine storm in aged people with CoV-2: possible role of vitamins as therapy or preventive strategy

BACKGROUND

In December 2019, a novel human-infecting coronavirus, SARS-CoV-2, had emerged. The WHO has classified the epidemic as a "public health emergency of international concern". A dramatic situation has unfolded with thousands of deaths, occurring mainly in the aged and very ill people. Epidemiological studies suggest that immune system function is impaired in elderly individuals and these subjects often present a deficiency in fat-soluble and hydrosoluble vitamins.

METHODS

We searched for reviews describing the characteristics of autoimmune diseases and the available therapeutic protocols for their treatment. We set them as a paradigm with the purpose to uncover common pathogenetic mechanisms between these pathological conditions and SARS-CoV-2 infection. Furthermore, we searched for studies describing the possible efficacy of vitamins A, D, E, and C in improving the immune system function.

RESULTS

SARS-CoV-2 infection induces strong immune system dysfunction characterized by the development of an intense proinflammatory response in the host, and the development of a life-threatening condition defined as cytokine release syndrome (CRS). This leads to acute respiratory syndrome (ARDS), mainly in aged people. High mortality and lethality rates have been observed in elderly subjects with CoV-2-related infection.

CONCLUSIONS

Vitamins may shift the proinflammatory Th17-mediated immune response arising in autoimmune diseases towards a T-cell regulatory phenotype. This review discusses the possible activity of vitamins A, D, E, and C in restoring normal antiviral immune system function and the potential therapeutic role of these micronutrients as part of a therapeutic strategy against SARS-CoV-2 infection.

Maternal vitamin D supplementation inhibits bisphenol A-induced proliferation of Th17 cells in adult offspring

Bisphenol A (BPA) exposure can increase the risk of immune-related diseases in later life. Vitamin D3 (Vit D3) has been shown to have multiple immunomodulatory actions and has been used to treat immune diseases. However, the potential beneficial effects of Vit D3 on BPA-induced adverse effects in the immune system have not explored. We hypothesize that VitD3 may ameliorate BPA-induced side effects in the immune system, even in offspring of VitD3-supplemented mothers. Here, we established our experimental model by exposing pregnant dams with 1000 nM BPA with or without VitD3 (0.25 μg/kg, 1 μg/kg and 4 μg/kg) treatment. We show that mother's exposure to BPA increases proliferation of the spleen T helper 17 (Th17) cells and serum protein level of IL-17 in the offspring; however, VitD3 supplementation in mothers dose-dependently ameliorated these BPA-induced side effects on the immune system in the offspring as evidenced by attenuated upregulation of Th17 proliferation, and RORγt, IL-17, IL-6, and IL-23 expressions in the offspring. Our data provide the first evidence that maternal VitD3 supplementation offers benefits to the offspring by attenuating BPA-induced side effects on the immune system through vitamin D receptor (VDR)-dependent regulation of transcription factors and cytokines, suggesting its translational potential.

Homology Modeling and Optimized Expression of Truncated IK Protein, tIK, as an Anti-Inflammatory Peptide

Rheumatoid arthritis, caused by abnormalities in the autoimmune system, affects about 1% of the population. Rheumatoid arthritis does not yet have a proper treatment, and current treatment has various side effects. Therefore, there is a need for a therapeutic agent that can effectively treat rheumatoid arthritis without side effects. Recently, research on pharmaceutical drugs based on peptides has been actively conducted to reduce negative effects. Because peptide drugs are bio-friendly and bio-specific, they are characterized by no side effects. Truncated-IK (tIK) protein, a fragment of IK protein, has anti-inflammatory effects, including anti-rheumatoid arthritis activity. This study focused on the fact that tIK protein phosphorylates the interleukin 10 receptor. Through homology modeling with interleukin 10, short tIK epitopes were proposed to find the essential region of the sequence for anti-inflammatory activity. T_H17 differentiation experiments were also performed with the proposed epitope. A peptide composed of 18 amino acids with an anti-inflammatory effect was named tIK-18mer. Additionally, a tIK 9-mer and a 14-mer were also found. The procedure for the experimental expression of the proposed tIK series (9-mer, 14-mer, and 18-mer) using bacterial strain is discussed.

Chronic Alcohol Consumption Exacerbates the Severity of Psoriasiform Dermatitis in Mice

BACKGROUND

A relationship between alcohol consumption and psoriasis has been reported, but it is unclear whether alcohol consumption aggravates psoriasis. Here, we studied the effect of chronic ethanol (EtOH) consumption in the murine model of Aldara-induced psoriasiform dermatitis.

METHODS

C57BL/6 mice received 5% EtOH in their drinking water for 10 weeks. Dermatitis was induced from weeks 9 to 10, by applying Aldara to the shaved patch of skin on the back. Inflammation was characterized by histological and transcriptomic analyses.

RESULTS

EtOH consumption aggravated Aldara-induced dermatitis. The scales were more severe, epidermal thickening was more pronounced, and cutaneous expression of Th17-related cytokines was exacerbated. Control mice simply receiving EtOH displayed minimal cutaneous inflammation, characterized by epidermal infiltrates of T lymphocytes and the overexpression of IL-17A and the Th17-recruiting chemokine CCL20. In vitro studies showed that low concentrations of EtOH induce the expression of CCL20 by murine epidermal keratinocytes.

CONCLUSION

Alcohol consumption leads to subliminar skin inflammation, which is revealed by the exacerbation of Aldara-induced experimental psoriasiform dermatitis, likely through Th17-type minimal skin inflammation. These results favor the systematic management of alcohol consumption in psoriatic patients.

Immunomodulatory and Antiviral Activity of Metformin and Its Potential Implications in Treating Coronavirus Disease 2019 and Lung Injury

The pandemic of coronavirus disease 2019 (COVID-19), a disease which causes severe lung injury and multiple organ damage, presents an urgent need for new drugs. The case severity and fatality of COVID-19 are associated with excessive inflammation, namely, a cytokine storm. Metformin, a widely used drug to treat type 2 diabetes (T2D) mellitus and metabolic syndrome, has immunomodulatory activity that reduces the production of proinflammatory cytokines using macrophages and causes the formation of neutrophil extracellular traps (NETs). Metformin also inhibits the cytokine production of pathogenic Th1 and Th17 cells. Importantly, treatment with metformin alleviates various lung injuries in preclinical animal models. In addition, a recent proteomic study revealed that metformin has the potential to directly inhibit SARS-CoV-2 infection. Furthermore, retrospective clinical studies have revealed that metformin treatment reduces the mortality of T2D with COVID-19. Therefore, metformin has the potential to be repurposed to treat patients with COVID-19 at risk of developing severe illness. This review summarizes the immune pathogenesis of SARS-CoV-2 and addresses the effects of metformin on inhibiting cytokine storms and preventing SARS-CoV-2 infection, as well as its side effects.

Increased Th17 activation and gut microbiota diversity are associated with pembrolizumab-triggered tuberculosis

INTRODUCTION

A hypersensitivity response akin to immune reconstitution inflammatory syndrome (IRIS) has been proposed as a mechanism responsible for anti-PD-1 therapy-induced tuberculosis. IRIS is associated with enhanced activation of IL-17A-expressing CD4 + T cells (Th17). Gut microbiota is thought to be linked to pulmonary inflammation through the gut-lung axis.

MATERIALS AND METHODS

We used ImmuCellAI to investigate the T cell population in lung cancer and tuberculosis samples. Then, we applied flow cytometry to monitor the expression levels of the Th17 cell activation marker CD38 in the peripheral blood of a patient experiencing adverse events, including tuberculosis, in response to pembrolizumab. The gut microbiome was examined by 16S rRNA sequencing to examine the alterations caused by pembrolizumab.

RESULTS

The percentage of Th17 cells was increased in both lung cancer and tuberculosis. FACS analysis showed that pembrolizumab induced substantial CD38 expression in Th17 cells. The patient's fecal samples showed that the diversity of the gut microbiota was significantly increased in response to the pembrolizumab cycle. One enriched genus was Prevotella, which has previously been linked to lung inflammation and Th17 immune activation.

DISCUSSION

The observed Th17 activation in our patient was consistent with a role of Th17-mediated IRIS in pembrolizumab-triggered tuberculosis. Pembrolizumab might trigger airway inflammation with a Th17 phenotype through microbiota interactions in the gut-lung axis.

Dibutyl phthalate aggravated asthma-like symptoms through oxidative stress and increasing calcitonin gene-related peptide release

Dibutyl phthalate (DBP) is one of the most ubiquitous phthalate esters found in everyday products, and is receiving increased attention as an immunologic adjuvant. However, information regarding DBP-aggravated allergic asthma is still limited. This study used a mouse model sensitized with ovalbumin (OVA) to determine any adverse effects of DBP on allergic asthma. Our results reveal that allergic asthmatic mice exposed to DBP for an extended period had a significant increase in inflammatory cell infiltration; a significant increase in levels of serum immunoglobulin and T helper 2 cell (Th2) and T helper 17 cell (Th17) cytokines in lung tissue; and significant changes in lung histology and AHR, all of which are typical asthmatic symptoms. The levels of oxidative stress and levels of the neuropeptide, calcitonin gene related peptide (CGRP), were also elevated after DBP exposure. Interestingly, blocking oxidative stress by administering melatonin (MT) not only reduced oxidative stress and CGRP levels, but also ameliorated the asthmatic symptoms. Collectively, these results show that DBP exacerbates asthma-like pathologies by increasing the expression of CGRP mediated by oxidative stress.

Maresin1 ameliorates acute lung injury induced by sepsis through regulating Th17/Treg balance

The disturbance of the immune homeostasis caused by infection is decisive for multiple organ dysfunction caused by sepsis. Both the th17 cell and the regulatory cell(Tregs) are important components of the immune system and play a crucial role in maintaining immune homeostasis. In this study, we explored the effect of Maresin1, an emerging specific pro-inflammatory mediator, on the balance of Th17/Treg in sepsis, and investigated the underlying mechanism. We used the male C57BL/6 mice to establish the model of sepsis-induced lung injury by cecal ligation and puncture to verify the protective effect of Maresin1. Our study showed that Maresin1 could significantly inhibit the excessive inflammatory response and promote the inflammation regression in the process of sepsis-induced acute lung injury, thereby reducing lung damage and improving lung function. These effects were accompanied with the regulation of Maresin1 on the Th17/Treg balance in the early stages of sepsis. We demonstrated that Maresin1 has a certain effect on increasing the number of Treg and decreasing the number of Th17 cells in the early stages of sepsis, which is consistent with its effect on STAT3/RORγt and STAT5/Foxp3 signal pathways. Our study elucidated for the first time the relationship between Maresin1 and Th17/Treg balance in sepsis-induced acute lung injury.

Anti-allergic rhinitis activity of α-lipoic acid via balancing Th17/Treg expression and enhancing Nrf2/HO-1 pathway signaling

An ovalbumin (OVA)-induced allergic rhinitis (AR) mouse model was established to investigate whether α-Lipoic acid (LA) has a protective effect against upper respiratory tract inflammation. BALB/c mice were sensitized by intraperitoneal injection and challenged by intranasal application of OVA. Mice were orally administered various doses of LA once daily (2, 10, 50 mg/kg) and dexamethasone (Dex; 2.5 mg/kg) 1 h before OVA challenge. Allergic nasal symptoms, levels of OVA-specific immunoglobulins, cytokines, and transcription factors were measured. Nasal and lung histopathology were evaluated. LA administration significantly alleviated the nasal symptoms such as rubbing and sneezing, markedly reduced both serum OVA-specific IgE and IgG1 levels. The LA treatment group showed markedly up-regulated levels of the Treg cytokine IL-10 and Treg transcription factor Foxp3. In contrast, it showed down-regulated levels of the Th17 cytokine IL-17 and the Th17 transcription factor STAT3, and RORγ. LA greatly enhanced the nuclear factor erythroid-derived 2/heme oxygenase 1 (Nrf2/HO-1) pathway signaling and inhibited the activation of NF-κB/IκB, markedly suppressed the levels of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, IL-8 and chemokine COX-2. The histologic alterations of nasal and lung tissues of AR mice were effectively ameliorated by LA. Based on these results, we suggest that LA could be a potential therapeutic agent in OVA-induced AR by virtue of its role in controlling the Th17/Treg balance and enhancing Nrf2/HO-1 pathway signaling.

Baicalin regulates Treg/Th17 cell imbalance by inhibiting autophagy in allergic rhinitis

BACKGROUND

Baicalin has many biological properties such as anti-oxidation and anti-allergy. The current study aimed to explore the effect of Baicalin on allergic rhinitis (AR) and its potential mechanism of action.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation. Expression levels of Th17 and Treg cells-related proteins in nasal mucosa and peripheral blood cells were detected by real-time quantitative PCR, flow cytometry and Western blot. The mice were randomly divided into Control, ovalbumin (OVA), l-Baicalin, H-Baicalin, DSGC, 3-MA, and H-Baicalin + Rapa groups. Changes of allergic rhinitis conditions and eosinophil infiltration of the mice were detected and scored by Diff-Quik staining, and histological changes were observed by Hematoxylin & Eosin (H&E) staining and Periodate Schiff (PAS) staining. Serological changes, expression levels of interleukin-17A (IL-17A), interleukin-10 (IL-10), eosinophilic cationic protein (ECP) and anti-OVA-specific antibodies were detected by Enzyme-linked immunosorbent assay (ELISA).

RESULTS

Clinical case analysis found that AR patients had a Th17/Treg imbalance and activated autophagy, however, Baicalin restored Th17/Treg cell balance and inhibited autophagy in vitro. in vivo experiments demonstrated that Baicalin inhibited OVA-induced allergic nasal symptoms and the activation of autophagy pathway, which was the same as the regulation of 3-MA, while Rapa could weaken the effects of H-baicalin. Moreover, Baicalin reduced the infiltration of different inflammatory cells of the nasal lavage fluid, prevented the damages to epithelial cells, and improved nasal mucosal thickness and mucus secretion. In addition, Baicalin regulated the balance of mouse anti-OVA-specific antibody levels and expressions of Th17/Treg-associated cytokines.

CONCLUSION

Our study revealed that Baicalin can be used to treat AR, and the effect is realized through inhibiting autophagy to regulate Th17/Treg cell differentiation.

Combination of LMT-28 and Metformin Improves Beneficial Anti-Inflammatory Effect in Collagen-Induced Arthritis

OBJECTIVES

The interleukin-6 (IL-6)-mediated signaling pathway plays an essential role in the development of rheumatoid arthritis. LMT-28 suppresses the activation of the IL-6-mediated signaling by direct targeting of gp130. Although LMT-28 and metformin both possess anti-inflammatory activity, the beneficial effect of LMT-28 and metformin combination on a collagen-induced arthritis (CIA) model has not yet been investigated. This study aimed to investigate the anti-inflammatory effect and mechanism of a combination of LMT-28 and metformin in a CIA model.

METHODS

In MH7A cells, cell proliferation and the IL-6-mediated signaling pathway following administration of LMT-28 and metformin combination was analyzed through MTT assay and Western blotting. The level of T helper 17 (Th17) cell differentiation from CD4+ T cells was analyzed in mouse splenocytes and human peripheral blood mononuclear cells. Arthritis score, incidence rate, inflammatory cytokine, and T-cell subsets were measured in CIA mice following administration of LMT-28 and metformin combination.

RESULTS

Combination treatment with LMT-28 and metformin diminished proliferation of MH7A cells and IL-6-mediated gp130, STAT3, and ERK signaling more than in individual treatments. Furthermore, the differentiation of CD4+ T cells into Th17 cells was attenuated more by combination treatment with LMT-28 and metformin than individual treatments. The combination of LMT-28 and metformin ameliorated the arthritic score better than individual treatments. The combination significantly reduced tumor necrosis factor and IL-6 levels in the sera and had an anti-inflammatory effect on the distribution of Treg/Th17 cells in the lymph nodes.

CONCLUSION

Combination treatment with LMT-28 and metformin significantly ameliorates arthritic symptoms in CIA by suppressing Th17 differentiation and IL-6 signaling.

Essential oils and its bioactive compounds modulating cytokines: A systematic review on anti-asthmatic and immunomodulatory properties

BACKGROUND

Asthma, the main inflammatory chronic condition affecting the respiratory system, is characterized by hyperresponsiveness and reversible airway obstruction, recruitment of inflammatory cells and excessive production of mucus. Cytokines as biochemical messengers of immune cells, play an important role in the regulation of allergic inflammatory and infectious airway processes. Essential oils of plant origin are complex mixtures of volatile and semi volatile organic compounds that determine the specific aroma of plants and are categorized by their biological activities.

PURPOSE

We reviewed whether essential oils and their bioactive compounds of plant origin could modulate cytokines' immune responses and improve asthma therapy in experimental systems in vitro and in vivo.

METHODS

Electronic and manual search of articles in English available from inception up to November 2018 reporting the immunomodulatory activity of essential oils and their bioactive compounds for the management of asthma. We used PubMed, EMBASE, Scopus and Web of Science. Publications reporting preclinical experiments where cytokines were examined to evaluate the consequence of anti-asthmatic therapy were included.

RESULTS

914 publications were identified and 13 were included in the systematic review. Four articles described the role of essential oils and their bioactive compounds on bronchial asthma using cell lines; nine in vivo studies evaluated the anti-inflammatory efficacy and immunomodulating effects of essential oil and their secondary metabolites on cytokines production and inflammatory responses. The most important immunopharmacological mechanisms reported were the regulation of cytokine production, inhibition of reactive oxygen species accumulation, inactivation of eosinophil migration and remodeling of the airways and lung tissue, modulation of FOXP3 gene expression, regulation of inflammatory cells in the airways and decreasing inflammatory mediator expression levels.

CONCLUSION

Plant derived essential oils and related active compounds have potential therapeutic activity for the treatment of asthma by modulating the release of pro-inflammatory (TNF-α, IL-1β, IL-8), Th17 (IL-17), anti-inflammatory (IL-10), Th1 (IFN-γ, IL-2, IL-12) and Th2 (IL-4, IL-5, IL-6, IL-13) cytokines and the suppression of inflammatory cell accumulation.

Sauchinone attenuates inflammatory responses in dendritic cells via Blimp-1 and ameliorates dextran sulfate sodium (DSS)-induced colitis

Inflammatory bowel disease (IBD) is a complex inflammatory disorder of the digestive tract with dysregulated innate and adaptive immune responses. Dendritic cells (DC), the most important antigen presenting cells, act as bridges connecting the adaptive and innate immune systems, and play a crucial role in the regulation of local homeostasis in the gut and are also essential mediators in the initiation and development of intestinal inflammation. Our recent study found that sauchinone (SAU) was able to ameliorate experimental colitis in mice by restraining Th17 cell differentiation and their pathogenicity. Here, we found that SAU significantly inhibited LPS-induced DC activation. Moreover, SAU suppressed the ability of LPS-primed DC to induce Th1/Th17 cell differentiation, but SAU-treated DC up-regulated their ability to initiate Foxp3⁺ Treg cell generation. Of note, we found that genetical ablation of Blimp-1 in DC markedly abrogated the SAU suppression of pro-inflammatory cytokine or promote immunomodulatory molecule production by DC. Blimp-1 deficiency boosted the ability of DC to polarize naïve CD4⁺ T cells into Th1/Th17 cell lineages. SAU failed to alleviated DSS-induced colitis in mice with Blimp-1-deficient DC. Our results shed new lights on the mechanisms of how SAU regulates DC biology and intestinal inflammation.