IL21R hypomethylation as a biomarker for distinguishing benign and malignant breast tumours.

Some benign and malignant breast tumours are similar in pathological morphology, which are difficult to be distinguished in clinical diagnosis. In this study, we intended to explore novel biomarkers for differential diagnosis of benign and malignant breast tumours. Methylation EPIC 850K beadchip and RNA-sequencing were used to analyse 29 tissue samples from patients with early-stage breast cancer (BC) and benign breast tumours for differently methylated and expressed genes. The altered methylation of IL21R was semi-quantitatively validated in an independent study with 566 tissue samples (279 BC vs. 287 benign breast tumours) using mass spectrometry. Binary logistic regression analysis was performed to evaluate the association between IL21R methylation and BC. BC-associated IL21R hypomethylation and overexpression were identified in the discovery round. In the validation round, BC patients presented significant IL21R hypomethylation compared to women with benign breast tumours (ORs ≥1.29 per-10% methylation, p-values ≤ 5.69E-14), and this hypomethylation was even enhanced in BC patients with ER-negative and PR-negative tumours as well as with triple-negative tumours. The methylation of IL21R showed efficient discriminatory power to distinguish benign breast tumours from BC (area under curve (AUC) = 0.88), and especially from ER-negative BC (AUC = 0.95), PR-negative BC (AUC = 0.93) and triple-negative BC (AUC = 0.96). We disclosed significant IL21R hypomethylation in patients with BC compared to women with benign breast tumours, and revealed the somatic change of DNA methylation could be a potential biomarker for molecular pathology of BC.

Deficiency of IL-22-binding protein enhances the ability of the gut microbiota to protect against enteric pathogens.

Interleukin 22 (IL-22) promotes intestinal barrier integrity, stimulating epithelial cells to enact defense mechanisms against enteric infections, including the production of antimicrobial peptides. IL-22 binding protein (IL-22BP) is a soluble decoy encoded by the Il22ra2 gene that decreases IL-22 bioavailability, attenuating IL-22 signaling. The impact of IL-22BP on gut microbiota composition and functioning is poorly understood. We found that Il22ra2-/- mice are better protected against Clostridioides difficile and Citrobacter rodentium infections. This protection relied on IL-22-induced antimicrobial mechanisms before the infection occurred, rather than during the infection itself. Indeed, the gut microbiota of Il22ra2-/- mice mitigated infection of wild-type (WT) mice when transferred via cohousing or by cecal microbiota transplantation. Indicator species analysis of WT and Il22ra2-/- mice with and without cohousing disclosed that IL22BP deficiency yields a gut bacterial composition distinct from that of WT mice. Manipulation of dietary fiber content, measurements of intestinal short-chain fatty acids and oral treatment with acetate disclosed that resistance to C. difficile infection is related to increased production of acetate by Il22ra2-/--associated microbiota. Together, these findings suggest that IL-22BP represents a potential therapeutic target for those at risk for or with already manifest infection with this and perhaps other enteropathogens.

IL20Rb aggravates pulmonary fibrosis through enhancing bone marrow derived profibrotic macrophage activation.

Idiopathic pulmonary fibrosis (IPF) is one of the most fatal chronic interstitial lung diseases with unknown pathogenesis, current treatments cannot truly reverse the progression of the disease. Pulmonary macrophages, especially bone marrow derived pro-fibrotic macrophages, secrete multiple kinds of profibrotic mediators (SPP1, CD206, CD163, IL-10, CCL18…), thus further promote myofibroblast activation and fibrosis procession. IL20Rb is a cell-surface receptor that belongs to IL-20 family. The role of IL20Rb in macrophage activation and pulmonary fibrosis remains unclear. In this study, we established a bleomycin-induced pulmonary fibrosis model, used IL4/13-inducing THP1 cells to induce profibrotic macrophage (M2-like phenotype) polarization models. We found that IL20Rb is upregulated in the progression of pulmonary fibrosis, and its absence can alleviate the progression of pulmonary fibrosis. In addition, we demonstrated that IL20Rb promote the activation of bone marrow derived profibrotic macrophages by regulating the Jak2/Stat3 and Pi3k/Akt signaling pathways. In terms of therapeutic strategy, we used IL20Rb neutralizing antibodies for animal administration, which was found to alleviate the progression of IPF. Our results suggest that IL20Rb plays a profibrotic role by promoting profibrotic macrophage polarization, and IL20Rb may become a potential therapeutic target for IPF. Neutralizing antibodies against IL20Rb may become a potential drug for the clinical treatment of IPF.

Role of IL-27 in Epstein-Barr virus infection revealed by IL-27RA deficiency.

Epstein-Barr virus (EBV) infection can engender severe B cell lymphoproliferative diseases1,2. The primary infection is often asymptomatic or causes infectious mononucleosis (IM), a self-limiting lymphoproliferative disorder3. Selective vulnerability to EBV has been reported in association with inherited mutations impairing T cell immunity to EBV4. Here we report biallelic loss-of-function variants in IL27RA that underlie an acute and severe primary EBV infection with a nevertheless favourable outcome requiring a minimal treatment. One mutant allele (rs201107107) was enriched in the Finnish population (minor allele frequency = 0.0068) and carried a high risk of severe infectious mononucleosis when homozygous. IL27RA encodes the IL-27 receptor alpha subunit5,6. In the absence of IL-27RA, phosphorylation of STAT1 and STAT3 by IL-27 is abolished in T cells. In in vitro studies, IL-27 exerts a synergistic effect on T-cell-receptor-dependent T cell proliferation7 that is deficient in cells from the patients, leading to impaired expansion of potent anti-EBV effector cytotoxic CD8+ T cells. IL-27 is produced by EBV-infected B lymphocytes and an IL-27RA-IL-27 autocrine loop is required for the maintenance of EBV-transformed B cells. This potentially explains the eventual favourable outcome of the EBV-induced viral disease in patients with IL-27RA deficiency. Furthermore, we identified neutralizing anti-IL-27 autoantibodies in most individuals who developed sporadic infectious mononucleosis and chronic EBV infection. These results demonstrate the critical role of IL-27RA-IL-27 in immunity to EBV, but also the hijacking of this defence by EBV to promote the expansion of infected transformed B cells.

Endothelial IL17RD promotes Western diet-induced aortic myeloid cell infiltration.

The Interleukin-17 (IL17) family is a group of cytokines implicated in the etiology of several inflammatory diseases. Interleukin-17 receptor D (IL17RD), also known as Sef (similar expression to fibroblast growth factor) belonging to the family of IL17 receptors, has been shown to modulate IL17A-associated inflammatory phenotypes. The objective of this study was to test the hypothesis that IL17RD promotes endothelial cell activation and consequent leukocyte adhesion. We utilized primary human aortic endothelial cells and demonstrated that RNAi targeting of IL17RD suppressed transcript levels by 83 % compared to non-targeted controls. Further, RNAi knockdown of IL17RD decreased the adhesion of THP-1 monocytic cells onto a monolayer of aortic endothelial cells in response to IL17A. Additionally, we determined that IL17A did not significantly enhance the activation of canonical MAPK and NFκB pathways in endothelial cells, and further did not significantly affect the expression of VCAM-1 and ICAM-1 in aortic endothelial cells, which is contrary to previous findings. We also determined the functional relevance of our findings in vivo by comparing the expression of endothelial VCAM-1 and ICAM-1 and leukocyte infiltration in the aorta in Western diet-fed Il17rd null versus wild-type mice. Our results showed that although Il17rd null mice do not have significant alteration in aortic expression of VCAM-1 and ICAM-1 in endothelial cells, they exhibit decreased accumulation of proinflammatory monocytes and neutrophils, suggesting that endothelial IL17RD induced in vivo myeloid cell accumulation is not dependent on upregulation of VCAM-1 and ICAM-1 expression. We further performed proteomics analysis to identify potential molecular mediators of the IL17A/IL17RD signaling axis. Collectively, our results underscore a critical role for Il17rd in the regulation of aortic myeloid cell infiltration in the context of Western diet feeding.

IL-27 Alleviates Airway Inflammation and Airway Hyperresponsiveness in Asthmatic Mice by Targeting the CD39/ATP Axis of Dendritic Cells.

Interleukin-27 receptor (IL-27R) is expressed in a variety of immune cells and structural cells, including dendritic cells. The mechanism of IL-27 in asthma has not been fully elucidated. This study aimed to examine whether IL-27 regulated the CD39/ATP axis of dendritic cells in asthma. Our results showed that in ovalbumin (OVA)-induced asthma mouse model, IL-27Rα-/- asthmatic mice showed increased airway resistance, increased infiltration of inflammatory cells in lung tissue, proliferation of goblet cells, enhanced expression of Muc5 AC around airway epithelium, increased total number of cells and eosinophils, increased levels of total IgE, OVA-IgE, IL-4, IL-5, IL-13 and IL-17 A, and increased expression of transcription factors GATA-3 and RORγt in lung tissue. The expression of CD39 mRNA and protein in the lung tissue of IL-27Rα-/- asthmatic mice decreased, and the expression of NLRP3, ASC and Caspase-1 in NLRP3 inflammasome components increased. The concentration of ATP was significantly increased compared with WT asthmatic mice. In vitro experiments showed that the expression of CD39 in lung dendritic cells of IL-27Rα-/- asthmatic mice decreased, while the expression of NLRP3 inflammasome components NLRP3, ASC and Caspase-1 increased. These findings indicate that IL-27 directly and indirectly regulates immunoinflammatory responses in asthma by acting on dendritic cells CD39/ATP Axis.

Oncostatin M suppresses IL31RA expression in dorsal root ganglia and interleukin-31-induced itching.

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by intermittent itchy rash. Type 2 inflammatory cytokines such as interleukin (IL)-4, IL-13, and IL-31 are strongly implicated in AD pathogenesis. Stimulation of IL-31 cognate receptors on C-fiber nerve endings is believed to activate neurons in the dorsal root ganglion (DRG), causing itch. The IL-31 receptor is a heterodimer of OSMRß and IL31RA subunits, and OSMRß can also bind oncostatin M (OSM), a pro-inflammatory cytokine released by monocytes/macrophages, dendritic cells, and T lymphocytes. Further, OSM expression is enhanced in the skin lesions of AD and psoriasis vulgaris patients. Objective: The current study aimed to examine the contributions of OSM to AD pathogenesis and symptom expression. Methods: The expression levels of the OSM gene (OSM) and various cytokine receptor genes were measured in human patient skin samples, isolated human monocytes, mouse skin samples, and mouse DRG by RT-qPCR. Itching responses to various pruritogens were measured in mice by counting scratching episodes. Results: We confirmed overexpression of OSM in skin lesions of patients with AD and psoriasis vulgaris. Monocytes isolated from the blood of healthy subjects overexpressed OSM upon stimulation with IL-4 or GM-CSF. Systemic administration of OSM suppressed IL31RA expression in the mouse DRG and IL-31-stimulated scratching behavior. In contrast, systemic administration of OSM increased the expression of IL-4- and IL-13-related receptors in the DRG. Conclusion: These results suggest that OSM is an important cytokine in the regulation of skin monocytes, promoting the actions of IL-4 and IL-13 in the DRG and suppressing the action of IL-31. It is speculated that OSM released from monocytes in skin modulates the sensitivity of DRG neurons to type 2 inflammatory cytokines and thereby the severity of AD-associated skin itch.

Differential expression of interleukin-35 receptor distinguishes different subsets of granulocyte-macrophage-colony-stimulating factor-producing T helper cells in a mouse endometriosis model.

The immune system contributes to the pathophysiology of endometriosis. The role of ThGM cells, which produce granulocyte macrophage-colony-stimulating factor (GM-CSF), in the pathogenesis of endometriosis remains unknown. To analyze the features of ThGM cells in endometriosis, a mouse endometriosis model was established. ThGM cells in the spleen, peritoneal fluid (PF), and endometriotic lesions (EL) were measured by flow cytometry, based on the expression of surface markers and intracellular proteins. Live ThGM cells were sorted according to chemokine receptor expression profiles and their effects on other CD4+ T cell subsets were determined by co-culture assays. An adoptive transfer assay was performed to characterize the effect of ThGM cells on endometriosis. We found that ThGM cells were present in endometriotic PF and EL. Live EL ThGM cells were enriched in CD4+CXCR3-CCR8-CCR4+CCR10+ T cells. EL ThGM cells differentially express interleukin-35 receptor (IL-35R), consisting of an IL-35R+ subset and an IL-35R- subset. The IL-35R+ subset expressed less GM-CSF, interleukin-2 (IL-2), and tumor necrosis factor-alpha (TNF-α) and proliferated slower than the IL-35R- subset. Meanwhile, the IL-35R+ subset was weaker than the IL-35R- subset in promoting the functions of Th1 and Th17 cells. ThGM cell transfer did not influence EL development but significantly alleviated pro-inflammatory cytokines in PF and ELs. Interleukin-35 (IL-35), the ligand of IL-35R, suppressed ThGM cell function and proliferation in an IL-35R-dependent manner. In summary, ThGM cells in the PF and ELs might exacerbate endometriotic inflammation. IL-35 might suppress the function of ThGM cells via IL-35R.

Metaphocytes are IL-22BP-producing cells regulated by ETS transcription factor Spic and essential for zebrafish barrier immunity.

Metaphocytes are tissue-resident macrophage (TRM)/dendritic cell (DC)-like cells of non-hematopoietic origin in zebrafish barrier tissues. One remarkable property of metaphocytes is their ability to capture soluble antigens from the external environment via transepithelial protrusions, a unique function manifested by specialized subpopulations of the TRMs/DCs in mammal barrier tissues. Yet, how metaphocytes acquire myeloid-like cell properties from non-hematopoietic precursors and how they regulate barrier immunity remains unknown. Here, we show that metaphocytes are in situ generated from local progenitors guided by the ETS transcription factor Spic, the deficiency of which results in the absence of metaphocytes. We further document that metaphocytes are the major IL-22BP-producing cells, and the depletion of metaphocytes causes dysregulated barrier immunity that resembles the phenotype of IL-22BP-deficient mice. These findings reveal the ontogeny, development, and function of metaphocytes in zebrafish, which facilitates our understanding of the nature and function of the mammalian TRM/DC counterparts.

Interleukin-38 suppresses abdominal aortic aneurysm formation in mice by regulating macrophages in an IL1RL2-p38 pathway-dependent manner.

Macrophages play crucial roles in abdominal aortic aneurysm (AAA) formation through the inflammatory response and extracellular matrix degradation; therefore, regulating macrophages may suppress AAA formation. Interleukin-38 (IL-38) is a member of the IL-1 family, which binds to IL-36 receptor (IL1RL2) and has an anti-inflammation effect. Because macrophages express IL1RL2, we hypothesized that IL-38 suppresses AAA formation by controlling macrophages. We assessed a C57BL6/J mouse angiotensin II-induced AAA model with or without IL-38 treatment. RAW 264.7 cells were cultured with tumor necrosis factor-α and treated with or without IL-38. Because p38 has important roles in inflammation, we assessed p38 phosphorylation in vitro and in vivo. To clarify whether the IL-38 effect depends on the p38 pathway, we used SB203580 to inhibit p38 phosphorylation. IL1RL2+ macrophage accumulation along with matrix metalloproteinase (MMP)-2 and -9 expression was observed in mouse AAA. IL-38 reduced the incidence of AAA formation along with reduced M1 macrophage accumulation and MMP-2 and -9 expression in the AAA wall. Macrophage activities including inducible nitric oxide, MMP-2, and MMP-9 production and spindle-shaped changes were significantly suppressed by IL-38. Furthermore, we revealed that inhibition of p38 phosphorylation diminished the effects of IL-38 on regulating macrophages to reduce AAA incidence, indicating the protective effects of IL-38 depend on the p38 pathway. IL-38 plays protective roles against AAA formation through regulation of macrophage accumulation in the aortic wall and modulating the inflammatory phenotype. Using IL-38 may be a novel therapy for AAA patients.

TRAM deletion attenuates monocyte exhaustion and alleviates sepsis severity.

Monocyte exhaustion characterized by immune-suppressive features can develop during sepsis and contribute to adverse patient outcomes. However, molecular mechanisms responsible for the establishment of immune-suppressive monocytes with reduced expression of immune-enhancing mediators such as CD86 during sepsis are not well understood. In this study, we identified that the TLR4 intracellular adaptor TRAM plays a key role in mediating the sustained reduction of CD86 expression on exhausted monocytes and generating an immune-suppressive monocyte state. TRAM contributes to the prolonged suppression of CD86 through inducing TAX1BP1 as well as SARM1, collectively inhibiting Akt and NFκB. TRAM deficient mice are protected from cecal slurry-induced experimental sepsis and retain immune-competent monocytes with CD86 expression. Our data reveal a key molecular circuitry responsible for monocyte exhaustion and provide a viable target for rejuvenating functional monocytes and treating sepsis.

Myeloid cell-derived proteases produce a proinflammatory form of IL-37 that signals via IL-36 receptor engagement.

Interleukin-1 (IL-1) family cytokines are key barrier cytokines that are typically expressed as inactive, or partially active, precursors that require proteolysis within their amino termini for activation. IL-37 is an enigmatic member of the IL-1 family that has been proposed to be activated by caspase-1 and to exert anti-inflammatory activity through engagement of the IL-18R and SIGIRR. However, here we show that the longest IL-37 isoform, IL-37b, exhibits robust proinflammatory activity upon amino-terminal proteolysis by neutrophil elastase or cathepsin S. In sharp contrast, caspase-1 failed to process or activate IL-37 at concentrations that robustly activated its canonical substrate, IL-1ß. IL-37 and IL-36 exhibit high structural homology, and, consistent with this, a K53-truncated form of IL-37, mimicking the cathepsin S-processed form of this cytokine, was found to exert its proinflammatory effects via IL-36 receptor engagement and produced an inflammatory signature practically identical to IL-36. Administration of K53-truncated IL-37b intraperitoneally into wild-type mice also elicited an inflammatory response that was attenuated in IL-36R-/- animals. These data demonstrate that, in common with other IL-1 family members, mature IL-37 can also elicit proinflammatory effects upon processing by specific proteases.

The IL-20RB receptor and the IL-20 signaling pathway in regulating host defense in oral mucosal candidiasis.

Pseudomembranous candidiasis (thrush), erythematous candidiasis, and fungal esophagitis are infections of the barrier mucosa of the upper gastrointestinal tract. The majority of these infections are caused by Candida albicans, an opportunistic fungal pathogen that frequently exists as a harmless commensal on mucosal surfaces lining the gastrointestinal tract. Oral infections are initiated in the superficial stratified squamous epithelium, in which keratinocytes are the most abundant host cells and are the initial points of contact with C. albicans present in saliva. Intrinsic features of oral keratinocytes are likely to play important roles in host defense and tissue homeostasis in oral candidiasis. One understudied pathway that may be important for modulating oral candidiasis is the IL-20 cytokine signaling pathway that employs keratinocyte IL-20RB receptors as ligands for IL-19, IL-20, and IL-24. We report that production of human oral keratinocyte il24 mRNA and protein are stimulated during co-culture with C. albicans. To test the role of the IL-20 family signaling pathway in oral candidiasis, Il20rb-/- mice (lacking the IL-20RB receptor) were compared to wild-type mice in a murine model of oropharyngeal candidiasis. Fungal burdens and percent loss in body weight were determined. Despite comparable fungal burdens, the Il20rb-/- mice exhibited less weight loss over the course of their infection compared to the B6 mice, suggestive of reduced overall disease consequences in the mutant mice. Interference with IL-20 family cytokine signaling may be useful for augmenting the ability of the host to defend itself against pathogens.

Induction of a colitogenic phenotype in Th1-like cells depends on interleukin-23 receptor signaling.

Interleukin-23 receptor plays a critical role in inducing inflammation and autoimmunity. Here, we report that Th1-like cells differentiated in vitro with IL-12 + IL-21 showed similar IL-23R expression to that of pathogenic Th17 cells using eGFP reporter mice. Fate mapping established that these cells did not transition through a Th17 cell state prior to becoming Th1-like cells, and we observed their emergence in vivo in the T cell adoptive transfer colitis model. Using IL-23R-deficient Th1-like cells, we demonstrated that IL-23R was required for the development of a highly colitogenic phenotype. Single-cell RNA sequencing analysis of intestinal T cells identified IL-23R-dependent genes in Th1-like cells that differed from those expressed in Th17 cells. The perturbation of one of these regulators (CD160) in Th1-like cells inhibited the induction of colitis. We thus uncouple IL-23R as a purely Th17 cell-specific factor and implicate IL-23R signaling as a pathogenic driver in Th1-like cells inducing tissue inflammation.

IL22RA1/JAK/STAT Signaling Acts As a Cancer Target Through Pan-Cancer Analysis.

Cytokines and cytokine receptors are important mediators in immunity and cancer development. Interleukin 22 (IL22) is one of the most important cytokines which has protumor effect. Given that common and specific roles of cytokines/receptors in multiple cancers, we conducted a pan-cancer study to investigate the role of IL22RA1 in cancer using The Cancer Genome Atlas (TCGA) database. Notably, we found IL22RA1 transcript was upregulated in 11 cancer types compared with their corresponding control. The mRNA expression level of IL22RA1 was highest in the pancreas among tumor tissues. The higher expression of IL22RA1 was associated with worse overall survival rate in patients. A total of 30 IL22RA1-correlated genes (e.g. IL17D, IL22RA2, IL20RB, IL10RA, IL10RB, TSLP and TYK2) are involved in the JAK/STAT pathway which promotes tumor progression. The upregulation of IL22RA1 in tumors was correlated with immune cell infiltration level. Higher expression of IL22RA2, IL20RB, IL10RA, IL10RB, TSLP, TYK2, STAT1 and STAT3 was associated with decreased overall survival rate in patients. IL22RA1 mutation was observed more in uterine cancer and melanoma compared with the other cancer types. Deactivation of IL22RA1 induced a lot of changes in gene expression. IL22RA1 mutants had upregulated DNA damage/repair genes in uterine cancer, whereas downregulated genes in the FoxO signaling pathway. In melanoma, mutation of IL22RA1 can upregulate the HIF signaling pathway but downregulate metabolic pathways. Our study suggests that IL22RA1/JAK/STAT signaling can be an important target for cancer treatment.

Lack of Association of Polymorphisms in IL22 and IL22RA1 Genes with Fibrosis Severity in Patients with Chronic Hepatitis C.

The IL-22 pathway has been shown to play an important role in the pathogenesis of liver fibrosis. However, little is known about the role of single-nucleotide polymorphisms (SNPs) in IL-22-related genes in relation to the severity of liver fibrosis. This study aimed to investigate the association of polymorphisms in IL22 and IL22RA1 genes with the severity of liver fibrosis in patients with chronic hepatitis C. A total of 326 patients (165 with mild fibrosis and 161 with severe fibrosis) were included. Four SNPs in IL22 (rs1179251, rs2227473, rs1012356, and rs2227485) and two in IL22RA1 (rs4648936 and rs3795299) were evaluated by real-time PCR. No significant association was observed between the polymorphisms studied and the severity of liver fibrosis. The SNPs rs1179251, rs2227473, rs1012356, and rs2227485 in IL22 and rs4648936 and rs3795299 in IL22RA1 may not be involved in the pathogenesis of liver fibrosis in patients with chronic hepatitis C.

IL-22 Plays a Dual Role in the Amniotic Cavity: Tissue Injury and Host Defense against Microbes in Preterm Labor.

IL-22 is a multifaceted cytokine with both pro- and anti-inflammatory functions that is implicated in multiple pathologies. However, the role of IL-22 in maternal-fetal immunity in late gestation is poorly understood. In this study, we first showed that IL-22+ T cells coexpressing retinoic acid-related orphan receptor γt (ROR-γt) are enriched at the human maternal-fetal interface of women with preterm labor and birth, which was confirmed by in silico analysis of single-cell RNA sequencing data. T cell activation leading to preterm birth in mice was preceded by a surge in IL-22 in the maternal circulation and amniotic cavity; however, systemic administration of IL-22 in mice did not induce adverse perinatal outcomes. Next, using an ex vivo human system, we showed that IL-22 can cross from the choriodecidua to the intra-amniotic space, where its receptors (Il22ra1, Il10rb, and Il22ra2) are highly expressed by murine gestational and fetal tissues in late pregnancy. Importantly, amniotic fluid concentrations of IL-22 were elevated in women with sterile or microbial intra-amniotic inflammation, suggesting a dual role for this cytokine. The intra-amniotic administration of IL-22 alone shortened gestation and caused neonatal death in mice, with the latter outcome involving lung maturation and inflammation. IL-22 plays a role in host response by participating in the intra-amniotic inflammatory milieu preceding Ureaplasma parvum-induced preterm birth in mice, which was rescued by the deficiency of IL-22. Collectively, these data show that IL-22 alone is capable of causing fetal injury leading to neonatal death and can participate in host defense against microbial invasion of the amniotic cavity leading to preterm labor and birth.

The Roles of IL-22 and Its Receptor in the Regulation of Inflammatory Responses in the Brain.

Interleukin (IL)-22 is a potent mediator of inflammatory responses. The IL-22 receptor consists of the IL-22Rα and IL-10Rß subunits. Previous studies have shown that IL-22Rα expression is restricted to non-hematopoietic cells in the skin, pancreas, intestine, liver, lung, and kidney. Although IL-22 is involved in the development of inflammatory responses, there have been no reports of its role in brain inflammation. Here, we used RT-PCR, Western blotting, flow cytometry, immunohistochemical, and microarray analyses to examine the role of IL-22 and expression of IL-22Rα in the brain, using the microglial cell line, hippocampal neuronal cell line, and inflamed mouse brain tissue. Treatment of BV2 and HT22 cells with recombinant IL-22 increased the expression levels of the pro-inflammatory cytokines IL-6 and TNF-α, as well as cyclooxygenase (COX)-2 and prostaglandin E2. We also found that the JNK and STAT3 signaling pathways play an important role in IL-22-mediated increases in inflammatory mediators. Microarray analyses revealed upregulated expression of inflammation-related genes in IL-22-treated HT22 cells. Finally, we found that IL-22Rα is spontaneously expressed in the brain and is upregulated in inflamed mouse brain. Overall, our results demonstrate that interaction of IL-22 with IL-22Rα plays a role in the development of inflammatory responses in the brain.

Regulating of LncRNA2264/miR-20b-5p/IL17RD axis on hydrogen sulfide exposure-induced inflammation in broiler thymus by activating MYD88/NF-κB pathway.

Hydrogen sulfide (H2S) is an environmental pollutant. Chronic exposure to H2S can damage the immune system of birds, but the detailed mechanisms of H2S-induced thymus toxicity have not been determined. Competitive endogenous RNA (ceRNA) mechanism participates in many pathophysiological processes by regulating gene expression, including environmental pollutant-induced injury. Therefore, we investigate the specific mechanisms of ceRNA in the process of H2S-induced thymic immune damage in broiler chickens. In the current study, 120 one-day-old male Ross 308 broilers were randomly divided into two groups (n = 60 chickens/group), raising in the control chamber (0.5 ± 0.5 ppm) or H2S-exposed chamber (4.0 ± 0.5 ppm at 0-3 weeks of age and 20.0 ± 0.5 ppm at 4-6 weeks of age groups) to replicate the H2S-exposed broilers. NaHS (3 mM or 6 mM) was used to treat chicken macrophages (HD11) to establish an in vitro. Histopathology and ultrastructural changes of thymus were assessed by hematoxylin and eosin (H&E) staining and transmission electron microscopy (TEM). Gene expression profiles were analyzed by using transcriptomics. The underlying mechanisms of thymic injury were further revealed by dual luciferase reporter gene assay, qRT-PCR and Western blotting. Research results showed that H2S exposure induced an inflammatory response in thymus, with the expression of LncRNA2264 was significantly down-regulated. LncRNA2264 could competitively bind to miR-20b-5p and caused downregulation of the IL17RD. H2S could activate inflammatory factors through the LncRNA2264/miR-20b-5p/IL17RD axis. In summary, this study suggested that LncRNA2264 acted as a miR-20b-5p molecular sponge to regulate the expression of IL17RD involved in H2S exposure-induced thymic inflammation, which has positive implications for guiding the prevention and control of H2S gas poisoning in livestock housing and ensuring animal welfare.

TNF Receptor-Associated Factor 5 Limits IL-27 Receptor Signaling in CD4+ T Lymphocytes.

TNF receptor-associated factor 5 (TRAF5) restrains early signaling activity of the IL-6 receptor in naive CD4+ T cells by interacting with the shared gp130 chain, although TRAF5 was initially discovered as a cytoplasmic adaptor protein to activate signaling mediated by TNF receptor family molecules. This leads to the question of whether TRAF5 limits signaling via the receptor for IL-27, which is composed of gp130 and WSX-1. The aim of this study is to clarify the role of TRAF5 in IL-27 receptor signaling and to understand the differential role of TRAF5 on cytokine receptor signaling. We found that Traf5 -/- CD4+ T cells displayed significantly higher levels of phosphorylated STAT1 and STAT-regulated genes Socs3 and Tbx21, as early as 1 h after IL-27 exposure when compared with Traf5 +/+ CD4+ T cells. Upon IL-27 and TCR signals, the Traf5 deficiency significantly increased the induction of IL-10 and promoted the proliferation of CD4+ T cells. Traf5 -/- mice injected with IL-27 displayed significantly enhanced delayed-type hypersensitivity responses, demonstrating that TRAF5 works as a negative regulator for IL-27 receptor signaling. In contrast, IL-2 and proliferation mediated by glucocorticoid-induced TNF receptor-related protein (GITR) and TCR signals were significantly decreased in Traf5 -/- CD4+ T cells, confirming that TRAF5 works as a positive regulator for cosignaling via GITR. Collectively, our results demonstrate that TRAF5 reciprocally controls signals mediated by the IL-27 receptor and GITR in CD4+ T cells and suggest that the regulatory activity of TRAF5 in gp130 is distinct from that in TNF receptor family molecules in a T cell.