IL-17A Receptor Research Articles

Myocardial infarction-induced disruption of blood-brain barrier in hypothalamic paraventricular nucleus is mediated by interleukin-17A signaling in rat

Increased inflammatory cytokines in the circulation act in the brain to promote neuroinflammation and sympathetic excitation in myocardial infarction-induced heart failure (HF). However, the mechanisms by which proinflammatory cytokines interrupt blood-brain barrier (BBB) to reach brain remain unclear. We recently reported that the levels of interleukin (IL)-17A, a key inflammatory mediator of immune responses, are significantly elevated in circulation and the brain in HF. IL-17A has been shown to disrupt the integrity of BBB in in vitro model and in vivo rodent model of experimental autoimmune encephalomyelitis. The present study sought to determine whether BBB in hypothalamic paraventricular nucleus (PVN), a key cardiovascular/autonomic region of the brain within the BBB, was damaged in HF and if so, whether IL-17A contributes to BBB disruption in this disease setting. Adult male Sprague Dawley rats underwent coronary artery ligation to induce HF or sham surgery (Sham). Some HF rats were pretreated with bilateral PVN microinjections of an IL-17 receptor A (IL-17RA) siRNA AAV virus or a scrambled siRNA control. The left ventricular function and infarction size were evaluated by echocardiography. Four weeks after coronary artery ligation, BBB permeability was assessed with fluorescein isothiocyanate (FITC, 10 kDa)-dextran extravasation and molecular measurements of its biomarkers. FITC was injected through left carotid artery at a rate of 300 μl/min (10 mg/ml, 3 ml/kg) and allowed to circulate for 30 min. We found that HF rats displayed noticeable FITC extravasation within the PVN area when compared with brain cortex after injections. FITC extravasation was not observed in the PVN and brain cortex in Sham rats. Compared with Sham rats, HF rats had significantly increased PVN mRNA expression of caveolin-1 (1.05± 0.13 vs 3.30 ± 0.48*, fold changes; *P<0.05), a molecular marker of transcytosis, and decreased PVN mRNA levels of occludin and zonula occludens-1 (1.05± 0.14 vs 0.57 ± 0.13*; 1.05± 0.10 vs 0.54 ± 0.03*, respectively), two important tight junction-associated molecules. However, the mRNA expression of caveolin-1, occludin or zonula occludens-1 did not display significant difference in the brain cortex between HF and Sham rats. Pretreatment with IL-17RA siRNA, substantially reduced FITC extravasation within the PVN and reversed mRNA expression of caveolin-1 (1.08 ± 0.20 vs. 0.51 ± 0.09*), occludin (1.07 ± 0.15 vs. 1.86 ± 0.18*) or zonula occludens-1 (1.02 ± 0.08 vs.1.84 ± 0.24*) in HF rats when compared with HF rats pretreated with a scrambled siRNA control. These data indicated that BBB permeability is increased in the PVN in myocardial infarction-induced HF. The activated IL-17A/IL-17RA signaling in BBB endothelium in the PVN in HF may play an important role in disrupting BBB, probably by a molecular mechanism to augment transcellular transport and reduce tight junction protein expression. Supported by NIH grants R01 HL-139521 & HL-155091 to SGW This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 5226: Exome-wide association study identifies coding variant in IL17RA associated with survival in cancer patients treated with immunotherapy

Abstract Immune checkpoint inhibitors (ICI) targeting PD-1/PD-L1 and CTLA4 are effective treatments in multiple cancer types, but durable responses are seen only in a minority of patients. Resistance to ICI is likely to reflect a combination of tumor-intrinsic, such as tumor mutational burden, and tumor-extrinsic factors, such as systemic immune suppression and host genetics. With the advent of large-scale germline genotyping studies, there is emerging evidence that host-specific genetic factors can substantially modify both disease risk and responsiveness to therapy. There has been limited characterization to date of the interaction between host genetics and response to ICI. Here, we perform harmonized mutation calling in available normal exome sequencing from 668 metastatic cancer patients treated with ICI (derived from n=7 studies, spanning n=3 cancer types and PD-1/PD-L1/CTLA4-directed therapy) and performed exome-wide association studies in European ancestry patients. For each cancer type (melanoma, renal cell carcinoma, urothelial carcinoma), we conducted exome-wide Cox regression (with PC1-4 and sex as covariates) to identify coding single-nucleotide polymorphisms (SNPs) associated with overall survival (OS). On fixed-effect meta-analysis, we identified a single coding variant (rs140221307, C allele, MAF 0.5% in European populations) that met genome-wide significance (p=1.11 × 10−15, HR=4.86, 95% CI 3.30-7.15). This SNP causes a substitution of Trp to Arg at amino acid 320 at the interface between the transmembrane and extracellular domains of interleukin 17 receptor A (IL17RA). While the secretion mechanism is uncharacterized, soluble IL17RA can be readily detected in plasma and the survival-reducing variant is associated with substantially elevated plasma IL17RA (p=1.90 × 10−9, beta=1.01, Sun et al. 2018) as well as reduced monocyte counts in UK Biobank (p=2.20 × 10−308, beta=-0.60). We have established a prime editing strategy to induce this variant in cultured human monocytes to investigate its biochemical and functional consequences, and are performing validation studies in independent patient cohorts. Soluble IL17RA would be expected to function as a decoy receptor to antagonize IL17/IL17RA signaling, and so these data suggest that activation of IL-17 receptor signaling might improve responsiveness to ICI therapy. Citation Format: Sam O. Kleeman, Michael Chan, Matthew Chvasta, Tobias Janowitz. Exome-wide association study identifies coding variant in IL17RA associated with survival in cancer patients treated with immunotherapy. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5226.

Immunogenic Cell Death Associated Molecular Patterns and the Dual Role of IL17RA in Interstitial Cystitis/Bladder Pain Syndrome.

The unclear etiology and pathogenesis of interstitial cystitis/bladder pain syndrome (IC/BPS) are responsible for the lack of effective treatment and the poor patient prognosis. Various studies show that chronic inflammation and immune responses are important factors contributing to the pathogenesis of IC/BPS. The process of immunogenic cell death (ICD) involves both the immune response and inflammatory process, and the involvement of ICD in IC/BPS pathogenesis has not been explored. Two IC/BPS transcriptome datasets collected from the Gene Expression Omnibus (GEO) database were used to identify distinct ICD-associated molecular patterns (IAMPs). IAMPs and IC/BPS subtypes were found to be related. The inflammatory immune microenvironments (IIME) in different IAMPs were studied. The potential mechanism by which the interleukin 17 receptor A (IL17RA) influences IC/BPS was examined using in vitro assays. The expression of ICD-related genes (IRGs) was upregulated in IC/BPS bladders, compared with normal bladders. Disease prediction models, based on differentially expressed IRGs, could accurately predict IC/BPS. The IC/BPS patients had two distinct IAMPs, each with its own subtype and clinical features and association with remodeling IIME. IL17RA, a well-established IC/BPS bladder biomarker, mediates both the inflammatory insult and the protective responses. In summary, the current study identified different IAMPs in IC/BPS, which may be involved in the pathogenesis of IC/BPS by remodeling the IIME. The chronic inflammatory process in IC/BPS may be prolonged by IL17RA, which could mediate both pro- and anti-inflammatory responses. The IL17RA-associated pathway may play a significant role in the development of IC/BPS and can be used as a therapeutic target.

IL-17 Signaling in Keratinocytes Orchestrates the Defense against Staphylococcus aureus Skin Infection

Keratinocytes (KCs) form the outer epithelial barrier of the body, protecting against invading pathogens. Mice lacking the IL-17RA or both IL-17A and IL-17F develop spontaneous Staphylococcusaureus skin infections. We found a marked expansion of T17 cells, comprised of RORγt-expressing γδ T cells and T helper 17 cells in the skin-draining lymph nodes of these mice. Contradictory to previous suggestions, this expansion was not a result of a direct negative feedback loop because we found no expansion of T17 cells in mice lacking IL-17 signaling specifically in T cells. Instead, we found that the T17 expansion depended on the microbiota and was observed only when KCs were deficient for IL-17RA signaling. Indeed, mice that lack IL-17RA only in KCs showed an increased susceptibility to experimental epicutaneous infection with S.aureus together with an accumulation of IL-17A-producing γδ T cells. We conclude that deficiency of IL-17RA on KCs leads to microbiota dysbiosis in the skin, which triggers the expansion of IL-17A-producing T cells. Our data show that KCs are the primary target cells of IL-17A and IL-17F, coordinating the defense against microbial invaders in the skin.

Interleukin-31 Receptor A Expression in the Dorsal Root Ganglion of Mice with Atopic Dermatitis.

Atopic dermatitis (AD) is a common skin disease caused by genetic and environmental factors. However, the mechanisms underlying AD development remain unclear. In this study, we examined the genetic factors contributing to the onset of itch-associated scratching in different strains of mice. Interleukin-31 (IL-31) induces severe scratching and dermatitis in mice. However, the site of action of IL-31 remains unclear. Cutaneous IL-31 and IL-31 receptor A (IL-31RA) mRNAs in the dorsal root ganglion (DRG) are expressed exclusively in the AD model, i.e., NC/Nga mice. Here we evaluated the effects of repeated administration of IL-31 on the scratching behavior in NC/Nga, BALB/c, and C57BL/6 mice. The results showed that repeated administration of IL-31 significantly increased itch-associated scratching (LLS) behavior in the three strains of mice. One hour after an intravenous IL-31 injection, BALB/c mice showed alloknesis-like behavior. Mite infestation and IL-31 administration triggered itchy skin, increased LLS counts and DRG neuronal IL-31RA expression, and eventually caused dermatitis. The dermatitis severity and LLS counts induced by mite infestation and IL-31 administration were in the order NC/Nga > BALB/c > C57BL/6. In conclusion, neuronal IL-31RA expression in the DRG was the most important genetic factor affecting the severity of LLS and dermatitis in mice.

Ropinirole inhibits inflammatory cytokine production in gingival epithelial cells and suppresses alveolar bone loss in an experimental rat model of periodontitis.

The present study explored whether the dopamine 2-like receptor agonist, ropinirole, a drug used for treating Parkinson's disease, suppresses neutrophilic inflammation and alveolar bone loss in an experimental rat model of periodontitis. Periodontitis is a neutrophilic inflammatory disease caused by periodontal pathogens. An excessive T helper (Th)17 immune response is involved in the progression of periodontitis, and interleukin (IL)-17 promotes the exacerbation of inflammation and alveolar bone destruction. Recent evidence has suggested that dopamine signaling plays a key role in Th17 cell differentiation, and that dopamine 2-like receptor agonists suppress cytokine production from Th17 cells. We previously demonstrated that tannic acid, which is a dopamine 2-like receptor agonist, inhibits alveolar bone resorption in an experimental model of periodontitis. The present study used a carrageenan-induced rat model of periodontitis with or without ropinirole. Micro-computed tomography analysis was performed. Cells of the murine gingival epithelial cell line GE1 were stimulated with carrageenan and IL-17A in the presence or absence of ropinirole. The anti-inflammatory effect of ropinirole was analyzed using reverse transcription- quantitative PCR and enzyme-linked immunosorbent assay. Subsequently, in the carrageenan-induced rat model of periodontitis, alveolar bone resorption was observed in the maxillary second molar by micro-computed tomography analysis. Intriguingly, ropinirole suppressed the alveolar bone destruction. The expression levels of C-X-C motif chemokine ligand 1 (CXCL1) and IL-17 receptor A (IL-17RA) in GE1 cells were increased by carrageenan, and CXCL1 expression in GE1 cells was upregulated under IL-17A stimulation. Moreover, ropinirole inhibited CXCL1 and IL-17RA expression in GE1 cells in the presence of IL-17A and carrageenan. Finally, haloperidol promoted CXCL1 expression in GE1 cells in the presence of carrageenan. Overall, these findings suggested that ropinirole suppressed neutrophilic inflammation and alveolar bone destruction in periodontitis by inhibiting CXCL1 expression in gingival epithelial cells through the dopamine 2-like receptor. Thus, ropinirole shows promise as a drug for the treatment of periodontitis.

Dysregulated thrombospondin 1 and miRNA-29a-3p in severe COVID-19.

Although nearly a fifth of symptomatic COVID-19 patients suffers from severe pulmonary inflammation, the mechanism of developing severe illness is not yet fully understood. To identify significantly altered genes in severe COVID-19, we generated messenger RNA and micro-RNA profiling data of peripheral blood mononuclear cells (PBMCs) from five COVID-19 patients (2 severe and 3 mild patients) and three healthy controls (HC). For further evaluation, two publicly available RNA-Seq datasets (GSE157103 and GSE152418) and one single-cell RNA-Seq dataset (GSE174072) were employed. Based on RNA-Seq datasets, thrombospondin 1 (THBS1) and interleukin-17 receptor A (IL17RA) were significantly upregulated in severe COVID-19 patients' blood. From single-cell RNA-sequencing data, IL17RA level is increased in monocytes and neutrophils, whereas THBS1 level is mainly increased in the platelets. Moreover, we identified three differentially expressed microRNAs in severe COVID-19 using micro-RNA sequencings. Intriguingly, hsa-miR-29a-3p significantly downregulated in severe COVID-19 was predicted to bind the 3'-untranslated regions of both IL17RA and THBS1 mRNAs. Further validation analysis of our cohort (8 HC, 7 severe and 8 mild patients) showed that THBS1, but not IL17RA, was significantly upregulated, whereas hsa-miR-29a-3p was downregulated, in PBMCs from severe patients. These findings strongly suggest that dysregulated expression of THBS1, IL17RA, and hsa-miR-29a-3p involves severe COVID-19.

Salidroside attenuates HALI via IL-17A-mediated ferroptosis of alveolar epithelial cells by regulating Act1-TRAF6-p38 MAPK pathway

Background and PurposeHyperoxia-induced acute lung injury (HALI) is a critical life-threatening disorder characterized by severe infiltration immune cells and death of type II alveolar epithelial cells (AECII). However, little is known about the relations between immune cells and AECII in HALI. IL-17A is a pro-inflammatory cytokine mainly secreted by Th17 cells, contributing to the pathogenesis of various inflammatory diseases. The present study investigated the role of IL-17A in cell–cell communication between immune cells and AECII in HALI, and explored the therapeutic effect of salidroside (Sal, a natural anti-inflammatory agents) on HALI.MethodsMice with HALI were induced by exposure to hyperoxia over 90% for 12 h, 24 h, 48 h or 72 h, and the optimal timing was detected by H&E and Masson staining. Ferroptosis was confirmed by detecting the levels of MDA, Fe2+ and GPX4, and the morphological alterations of AECII under transmission electron microscopy. The expression of pro-inflammatory cytokine, including IL-6, TGF-β1, IL-17A and IL-17A receptor (IL-17RA) were measured by Western blotting and immunohistochemical stanning. The ferroptosis-related Act1/TRAF6/p38 MAPK pathway was detected by Western blotting. The role of pro-inflammatory cytokine IL-17A for AECII ferroptosis, and the effect of Sal on HALI were investigated by administration of Y-320 (IL-17 inhibitor) and Sal respectively 3 days before mice exposed to hyperoxia.ResultsMice exposed to hyperoxia for 24 h suffered sufficient HALI with inflammatory cell infiltration and collagen deposition, and exhibited features of ferroptosis under TME. Meanwhile, compared with sham mice, mice exposed to hyperoxia showed down-regulation of GPX4, and up-regulation of IL-6, TGF-β1, IL-17A, IL-17RA, Act1, TRAF6, p38 MAPK and p-p38 MAPK. Moreover, inhibition of IL-17A with Y-320 or administration with Sal could reverse the effect caused by hyperoxia respectively.ConclusionsIL-17A is associated with immune cells infiltration in HALI, and contributes to ferroptosis of AECII that related to Act1/TRAF6/p38 MAPK pathway. Additionally, Sal protects against HALI throughout the whole pathogenic process.AqUYWJK2FhV6CXzbcahkdBVideo

IL-17A promotes lung fibrosis through impairing mitochondrial homeostasis in type II alveolar epithelial cells.

The dysfunction of type II alveolar epithelial cells (AECIIs), mainly manifested by apoptosis, has emerged as a major component of idiopathic pulmonary fibrosis (IPF) pathophysiology. A pivotal mechanism leading to AECIIs apoptosis is mitochondrial dysfunction. Recently, interleukin (IL)-17A has been demonstrated to have a pro-fibrotic role in IPF, though the mechanism is unclear. In this study, we report enhanced expression of IL-17 receptor A (IL-17RA) in AECIIs in lung samples of IPF patients, which may be related to the accumulation of mitochondria in AECIIs of IPF. Next, we investigated this relationship in bleomycin (BLM)-induced PF murine model. We found that IL-17A knockout (IL-17A-/- ) mice exhibited decreased apoptosis levels of AECIIs. This was possibly a result of the recovery of mitochondrial morphology from the improved mitochondrial dynamics of AECIIs, which eventually contributed to alleviating lung fibrosis. Analysis of in vitro data indicates that IL-17A impairs mitochondrial function and mitochondrial dynamics of mouse primary AECIIs, further promoting apoptosis. PTEN-induced putative kinase 1 (PINK1)/Parkin signal-mediated mitophagy is an important aspect of mitochondria homeostasis maintenance. Our data demonstrate that IL-17A inhibits mitophagy and promotes apoptosis of AECIIs by decreasing the expression levels of PINK1. We conclude that IL-17A exerts its pro-fibrotic effects by inducing mitochondrial dysfunction in AECIIs by disturbing mitochondrial dynamics and inhibiting PINK1-mediated mitophagy, thereby leading to apoptosis of AECIIs.

Interleukin-13 Receptor α1-Mediated Signaling Regulates Age-Associated/Autoimmune B Cell Expansion and Lupus Pathogenesis.

Age-associated/autoimmune B cells (ABCs) are an emerging B cell subset with aberrant expansion in systemic lupus erythematosus. ABC generation and differentiation exhibit marked sexual dimorphism, and Toll-like receptor 7 (TLR-7) engagement is a key contributor to these sex differences. ABC generation is also controlled by interleukin-21 (IL-21) and its interplay with interferon-γ and IL-4. This study was undertaken to investigate whether IL-13 receptor α1 (IL-13Rα1), an X-linked receptor that transmits IL-4/IL-13 signals, regulates ABCs and lupus pathogenesis. Mice lacking DEF-6 and switch-associated protein 70 (double-knockout [DKO]), which preferentially develop lupus in females, were crossed with IL-13Rα1-knockout mice. IL-13Rα1-knockout male mice were also crossed with Y chromosome autoimmune accelerator (Yaa) DKO mice, which overexpress TLR-7 and develop severe disease. ABCs were assessed using flow cytometry and RNA-Seq. Lupus pathogenesis was evaluated using serologic and histologic analyses. ABCs expressed higher levels of IL-13Rα1 than follicular B cells. The absence of IL-13Rα1 in either DKO female mice or Yaa DKO male mice decreased the accumulation of ABCs, the differentiation of ABCs into plasmablasts, and autoantibody production. Lack of IL-13Rα1 also prolonged survival and delayed the development of tissue inflammation. IL-13Rα1 deficiency diminished in vitro generation of ABCs, an effect that, surprisingly, could be observed in response to IL-21 alone. RNA-Seq revealed that ABCs lacking IL-13Rα1 down-regulated some histologic characteristics of B cells but up-regulated myeloid markers and proinflammatory mediators. Our findings indicate a novel role for IL-13Rα1 in controlling ABC generation and differentiation, suggesting that IL-13Rα1 contributes to these effects by regulating a subset of IL-21-mediated signaling events. These results also suggest that X-linked genes besides TLR7 participate in the regulation of ABCs in lupus.

Cadherin-26 Amplifies Airway Epithelial IL-4 Receptor Signaling in Asthma.

Activation of IL-4R (IL-4 receptor) signaling in airway epithelial cells leads to airway hyperresponsiveness and mucus overproduction in asthma. CDH26 (cadherin-26), a cadherin implicated in the polarization of airway epithelial cells, is upregulated in asthma. However, the role of CDH26 in asthma remains unknown. In this study, we demonstrated that Cdh26 deficiency significantly reduced airway mucus overproduction, airway hyperresponsiveness, and airway eosinophilia in a murine model of allergic airway disease. Interestingly, allergen-induced Il-4Rα upregulation in airway epithelium was markedly reduced in Cdh26-/- mice. In cultured human bronchial epithelial cells, CDH26 knockdown inhibited IL-13, a ligand for IL-4R; induced IL-4Rα and IL-13Rα1 (IL-13 receptor α1) upregulation; and suppressed downstream Jak1 (Janus kinase 1) and Stat6 (signal transducer and activator of transcription 6) phosphorylation. Moreover, CDH26 knockdown inhibited IL-13-induced MUC5AC and eosinophilic chemokine expression. These results suggest that CDH26 plays a key role in epithelial IL-4R signaling activation and downstream effectors. In contrast, CDH26 overexpression amplified IL-13-activated IL-4R signaling in BEAS-2B cells. In the airway epithelium of patients with asthma, IL-4Rα expression was elevated, and CDH26 was the only cadherin that was upregulated among 11 cadherin family members. CDH26 expression was strongly correlated with epithelial IL-4Rα and MUC5AC expression, sputum eosinophilia, and fractional exhaled nitric oxide in patients with asthma. Taken together, we identified CDH26 as a key regulator of epithelial IL-4R signaling in asthma and a potential therapeutic target for IL-4R-mediated allergic diseases.

Organizing structural principles of the IL-17 ligand–receptor axis

The IL-17 family of cytokines and receptors have central roles in host defence against infection and development of inflammatory diseases1. The compositions and structures of functional IL-17 family ligand–receptor signalling assemblies remain unclear. IL-17E (also known as IL-25) is a key regulator of type 2 immune responses and driver of inflammatory diseases, such as allergic asthma, and requires both IL-17 receptor A (IL-17RA) and IL-17RB to elicit functional responses2. Here we studied IL-25–IL-17RB binary and IL-25–IL-17RB–IL-17RA ternary complexes using a combination of cryo-electron microscopy, single-molecule imaging and cell-based signalling approaches. The IL-25–IL-17RB–IL-17RA ternary signalling assembly is a C2-symmetric complex in which the IL-25–IL-17RB homodimer is flanked by two ‘wing-like’ IL-17RA co-receptors through a ‘tip-to-tip’ geometry that is the key receptor–receptor interaction required for initiation of signal transduction. IL-25 interacts solely with IL-17RB to allosterically promote the formation of the IL-17RB–IL-17RA tip-to-tip interface. The resulting large separation between the receptors at the membrane-proximal level may reflect proximity constraints imposed by the intracellular domains for signalling. Cryo-electron microscopy structures of IL-17A–IL-17RA and IL-17A–IL-17RA–IL-17RC complexes reveal that this tip-to-tip architecture is a key organizing principle of the IL-17 receptor family. Furthermore, these studies reveal dual actions for IL-17RA sharing among IL-17 cytokine complexes, by either directly engaging IL-17 cytokines or alternatively functioning as a co-receptor.

Effect of Mortalin on Scar Formation in Human Dermal Fibroblasts and a Rat Incisional Scar Model.

Wound healing is a complicated cascading process; disequilibrium among reparative processes leads to the formation of pathologic scars. Herein, we explored the role of mortalin in scar formation and its association with the interleukin-1α receptor using in vitro and in vivo models. To investigate the effects of mortalin, we performed an MTT cell viability assay, qRT-PCR, and Western blot analyses, in addition to immunofluorescence and immunoprecipitation studies using cultured fibroblasts. A rat incisional wound model was used to evaluate the effect of a mortalin-specific shRNA (dE1-RGD/GFP/shMot) Ad vector in scar tissue. In vitro, the mortalin-treated human dermal fibroblast displayed a significant increase in proliferation of type I collagen, α-smooth muscle actin, transforming growth factor-β, phospho-Smad2/3-complex, and NF-κB levels. Immunofluorescence staining revealed markedly increased mortalin and interleukin-1α receptor protein in keloid tissue compared to those in normal tissue, suggesting that the association between mortalin and IL-1α receptor was responsible for the fibrogenic effect. In vivo, mortalin-specific shRNA-expressing Ad vectors significantly decreased the scar size and type-I-collagen, α-SMA, and phospho-Smad2/3-complex expression in rat incisional scar tissue. Thus, dE1-RGD/GEP/shMot can inhibit the TGF-β/α-SMA axis and NF-κB signal pathways in scar formation, and blocking endogenous mortalin could be a potential therapeutic target for keloids.

A comprehensive network map of IL-17A signaling pathway.

Interleukin-17A (IL-17A) is one of the member of IL-17 family consisting of other five members (IL-17B to IL-17F). The Gamma delta (γδ) T cells and T helper 17 (Th17) cells are the major producers of IL-17A. Aberrant signaling by IL-17A has been implicated in the pathogenesis of several autoimmune diseases including idiopathic pulmonary fibrosis, acute lung injury, chronic airway diseases, and cancer. Activation of the IL-17A/IL-17 receptor A (IL-17RA) system regulates phosphoinositide 3-kinase/AKT serine/threonine kinase/mammalian target of rapamycin (PI3K/AKT/mTOR), mitogen-activated protein kinases (MAPKs) and activation of nuclear factor-κB (NF-κB) mediated signaling pathways. The IL-17RA activation orchestrates multiple downstream signaling cascades resulting in the release of pro-inflammatory cytokines such as interleukins (IL)-1β, IL-6, and IL-8, chemokines (C-X-C motif) and promotes neutrophil-mediated immune response. Considering the biomedical importance of IL-17A, we developed a pathway resource of signaling events mediated by IL-17A/IL-17RA in this study. The curation of literature data pertaining to the IL-17A system was performed manually by the NetPath criteria. Using data mined from the published literature, we describe an integrated pathway reaction map of IL-17A/IL-17RA consisting of 114 proteins and 68 reactions. That includes detailed information on IL-17A/IL-17RA mediated signaling events of 9 activation/inhibition events, 17 catalysis events, 3 molecular association events, 68 gene regulation events, 109 protein expression events, and 6 protein translocation events. The IL-17A signaling pathway map data is made freely accessible through the WikiPathways Database (https://www.wikipathways.org/index.php/Pathway: WP5242).Supplementary InformationThe online version contains supplementary material available at 10.1007/s12079-022-00686-y.

Tuscany consensus for the treatment of moderate-severe psoriasis: update and focus on practical guidelines for place in therapy of anti-IL-17 and anti-IL-23 biologics.

Psoriasis is a common chronic skin disease characterized by a worldwide distribution and a natural tendency towards progression. According to the many clinical forms, the extension of the disease and the many comorbidities, almost the 20% of the patients require a systemic treatment. Biologics have greatly changed the ongoing of psoriasis and the quality of life of psoriasis patients. After the anti-TNF-alpha, which were the first biologics in use for psoriasis, the improvement in knowledge of the pathogenetic mechanisms underlying the disease has led to the development of a series of more specific therapies for psoriasis. This "second generation" of biologics includes the interleukin (IL)-12/23 inhibitor ustekinumab, IL-17 inhibitors (secukinumab and ixekizumab), the IL-17 receptor A (IL-17RA) antagonist brodalumab, and the IL-23 inhibitors guselkumab, risankizumab and tildrakizumab. This study represents an update of the Tuscany consensus focused on the use of new drugs, such as anti-IL-17 and anti-IL-23 in moderate-to-severe psoriasis and their correct place in therapy according to specific clinical requests and in full respect of the current financial restrictions.

Nemolizumab: First Approval.

Nemolizumab is a subcutaneously administered humanized anti-interleukin-31 (IL-31) receptor A (IL-31RA) monoclonal antibody that is being developed by Chugai Pharmaceutical Co. Ltd, Maruho Co. Ltd and Galderma Pharma S.A. for the treatment of skin diseases, including atopic dermatitis (AD), AD associated pruritus (ADaP), prurigo nodularis (PN), chronic kidney disease associated pruritus (CKDaP) and systemic sclerosis (SSc). IL-31 is a neuroimmune cytokine that induces itch, inflammation, keratinocyte differentiation and fibroblast activation in chronic pruritic skin diseases. Nemolizumab (Mitchga® Syringes) was approved in Japan on 28 March 2022 for use in adults and children over the age of 13 years for the treatment of itch associated with AD (only when existing treatment is insufficiently effective). This article summarizes the milestones in the development of nemolizumab leading to this first approval.

Itch in Hidradenitis Suppurativa/Acne Inversa: A Systematic Review.

Hidradenitis suppurativa/acne inversa (HS) is a chronic inflammatory disease of the pilosebaceous unit leading to formation of painful, inflammatory nodules, abscesses and tunnels in apocrine gland-bearing areas of the skin. Pain and drainage are the most important symptoms associated with reduction of quality of life in HS. On the other hand, an overlooked symptom in quality of life studies is itch, despite the fact that several studies have reported its importance. Various theories have tried to explain the pathogenesis of itch in HS, such as the presence of mast cells in the cell infiltrates and elevated Ig E levels in the lesional skin. Smoking and advanced stage of disease have been found to be associated with increased intensity of itch. A PUBMED search was conducted to perform a systematic literature review using the term “hidradenitis suppurativa” [all fields], the keywords “pruritus”, “itching”, “itch” [all fields] and with “AND” as operator. Mast cells and mTor signaling were found to be raised in both lesional and perilesional skin. Itch as a presenting symptom has been found in 35–82.6% of patients across multiple studies. It often co-presents with pain and may be misinterpreted as burning, stinging, tickling, tweaking, prickling, etc. The presence of itch is associated with reduced quality of life, depression and impairment of social life. Brodalumab, a monoclonal antibody against IL-17A receptor, produced significant improvements in itch, pain, QoL and depression in patients with moderate to severe HS. Statins have shown some reduction in itch intensity score. Further studies are required to gain a better understanding of the etiopathogenesis and optimal therapeutic modalities for itch in HS that will allow clinicians to better address issue and reduce its impact on quality of life.

T Cell-Intrinsic Interleukin 17 Receptor A Signaling Supports the Establishment of Chronic Murine Gammaherpesvirus 68 Infection.

Gammaherpesviruses, such as human Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV68), are species-specific, ubiquitous pathogens that are associated with multiple cancers, including B cell lymphomas. These viruses have a natural tropism for B cells and usurp B cell differentiation to drive a unique and robust polyclonal germinal center response to establish a long-term latent reservoir in memory B cells. The robust polyclonal germinal center response driven by gammaherpesvirus infection increases the risk for B cell transformation. Unsurprisingly, many gammaherpesvirus cancers are derived from germinal center or post-germinal center B cells. The viral and host factors that influence the gammaherpesvirus-driven germinal center response are not clearly defined. We previously showed that host interleukin 17 receptor A (IL-17RA) signaling promotes the establishment of chronic MHV68 infection and the MHV68-driven germinal center response. In this study, we found that T cell-intrinsic IL-17RA signaling recapitulates some proviral aspects of global IL-17RA signaling during MHV68 infection. Specifically, we found that T cell-intrinsic IL-17RA signaling supports the MHV68-driven germinal center response, the establishment of latency in the spleen, and viral reactivation in the spleen and peritoneal cavity. Our study unveils an unexpected finding where the T cell-specific IL-17RA signaling supports the establishment of a latent reservoir of a B cell-tropic gammaherpesvirus. IMPORTANCE Gammaherpesviruses, such as human EBV, establish lifelong infection in >95% of adults and are associated with B cell lymphomas. Gammaherpesviruses usurp the germinal center response to establish latent infection, and the germinal center B cells are thought to be the target of viral transformation. We previously found that global expression of IL-17RA promotes the establishment of chronic MHV68 infection and the MHV68-driven germinal center response. In this study, we showed that T cell-intrinsic IL-17RA signaling is necessary to promote the MHV68-driven germinal center response by supporting CD4+ T follicular helper cell expansion. We also found that T cell-intrinsic IL-17RA signaling contributes to but is not solely responsible for the systemic proviral role of IL-17RA signaling, highlighting the multifaceted function of IL-17RA signaling during MHV68 infection.

Abstract 3530: Microbial-Interleukin 17 receptor A (IL-17RA) signaling axis modulates tumor growth and microenvironment

Abstract Microbiota, both within the gut and the tumors, has emerged as a significant player influencing tumor growth and responses to therapies. Recent evidence links microbiota and pancreatic ductal adenocarcinoma (PDAC), an aggressive cancer surrounded by a highly immuno-suppressive tumor microenvironment which limits efficacy of most available therapies. The immunosuppressive tumor microenvironment of PDAC is partially facilitated by a proinflammatory cytokine Interleukin 17 (IL-17). IL-17 can be stimulated by intestinal commensal bacteria under normal physiological conditions. It is critical for microbial defense as well as immunopathology. Both IL-17 neutralization and antibiotics reduce murine PDAC growth. While the vital role of microbiota in affecting tumor immunity has been identified, there is still a gap of knowledge as to how microbes may regulate pro-tumorigenic IL-17 signaling. We wanted to investigate the systemic and local role of IL-17 in regulating the microbial-tumor immune axis. For this purpose, we genetically deleted the IL-17 receptor A (IL-17RA) in different compartments and evaluated tumor growth. We found that IL-17RA signaling was important for maintaining microbial homeostasis and its disruption resulted in differential tumor growth. Absence of IL-17RA signaling in the gut lead to local inflammation as well as systemic immune effects. Our data suggests that modulation of IL-17 signaling could serve as a therapeutic intervention to alter microbial mediated tumor effects. The significance of these findings may extend to other cancers as well. Citation Format: Vidhi Chandra, Yu Zhang, Olivereen Le Roux, Joseph Petrosino, Jay Kolls, Florencia McAllister. Microbial-Interleukin 17 receptor A (IL-17RA) signaling axis modulates tumor growth and microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3530.

Looking for novel interactors of IL-13 receptor α2 (IL13Rα2) and tyrosine-protein phosphatase non-receptor type 1 (PTPN1/ PTP1B) by using proximity-dependent biotinylation (BioID)

Introduction: IL13Rα2 is a high affinity receptor for IL-13 that is re-expressed in late neoplastic stages. The IL- 13/IL- 13Rα2 axis triggers invasion in colorectal cancer (CRC) and other cancers in a process mediated, among others, by the phosphatase PTPN1 (aka PTP1B), involved in the dephosphorylation of the autoinhibitory Src Tyr416, and further Src activation. PTPN1 takes part in IL13Rα2 internalization and associates with poor outcome in glioblastoma and CRC patients. Inhibition of IL13Rα2 pathway decreases invasion of multiple cancer cell lines (i.e., SKOV-3, PC-3 and KM12SM). To better define the oncogenic properties of IL13Rα2 and PTPN1, we aim to identify novel interactors by using proximity-dependent biotinylation coupled to mass spectrometry. Materials and methods: PTPN1 and IL13Rα2 were cloned into pcDNA.5-pDEST-BirA-Flag-Ct by using LR clonase enzyme, obtaining the desired plasmids containing fusion genes PTPN1-BirA and IL13Rα2-BirA. Flp-In™ T-REx™ cells were co-transfected with pOG44 and pcDNA.5 vectors and selected with hygromycin. Then doxycycline and biotin were added to induce the expression of the fusion gene and proximity labelling. Biotinylated proteins were purified by affinity using streptavidin-sepharose, trypsin-digested and analysed in a Q-Exactive mass spectrometer. Raw data were analysed with MaxQuant, followed by Perseus for statistical analysis and SAINT for probabilistic scoring of protein-protein interaction data, which were subjected to gene ontology (GO) analysis. Results: For IL13Rα2, 735 proteins were identified and 94 were scored as significant interactors by SAINT. GO enrichment analysis showed association with cadherin binding and response to reticulum stress, among others. 1009 proteins were identified and 217 were scored as significant PTPN1 interactors. GO enrichment analysis showed important association with mitotic cell cycle regulation, such as CDK1 (G2/M transition) or PCTN (centrosome component). Among the 19 IL13Rα2 and PTPN1 common interactors stand out those related to SNARE complex (YKT6, SNAP29 and VAMP3), which is involved in regulation of cancer invasion, drug resistance and kinase phosphorylation. Another interesting finding was the presence of VRK2, a kinase involved in MAPK pathway. Conclusions: This study reveals novel individual interactors of IL13Rα2 and PTPN1, but also identifies common interactors of both proteins such as members of the SNARE complex and VRK2, opening new strategies for the inhibition of IL13Rα2 and PTPN1 in cancer metastasis.