IL-17 in Chronic Inflammation: From Discovery to Targeting. Trends Mol Med. 2016;22:230-241. [PMID: 26837266 DOI: 10.1016/j.molmed.2016.01.001]

Research progress on Th17 and T regulatory cells and their cytokines in regulating atherosclerosis

Background

Coronary heart disease due to atherosclerosis is the leading cause of death worldwide. Atherosclerosis is considered a chronic inflammatory state in the arterial wall that promotes disease progression and outcome, and immune cells play an important role in the inflammatory process.

Purpose

We review the mechanisms of CD4+ T subsets, i.e., helper T17 (Th17) cells and regulatory T cells (Tregs), in regulating atherosclerosis, focusing on the role of interleukin (IL)-17, IL-10, and other cytokines in this disease and the factors influencing the effects of these cytokines.

Results

IL-17 secreted by Th17 cells can promote atherosclerosis, but few studies have reported that IL-17 can also stabilize atherosclerotic plaques. Tregs play a protective role in atherosclerosis, and Th17/Treg imbalance also plays an important role in atherosclerosis.

Conclusion

The immune response is important in regulating atherosclerosis, and studying the mechanism of action of each immune cell on atherosclerosis presents directions for the treatment of atherosclerosis. Nevertheless, the current studies are insufficient for elucidating the mechanism of action, and further in-depth studies are needed to provide a theoretical basis for clinical drug development.

Pak2-mediated phosphorylation promotes RORγt ubiquitination and inhibits colonic inflammation

Dysregulated interleukin-17 (IL-17) expression and its downstream signaling is strongly linked to inflammatory bowel diseases (IBDs). However, the molecular mechanisms by which the function of RORγt, the transcription factor of IL-17, is regulated remains elusive. By a mass spectrometry-based approach, we identify that Pak2, a serine (S)/threonine (T) kinase, directly associates with RORγt. Pak2 recognizes a conserved KRLS motif within RORγt and phosphorylates the S-316 within this motif. Genetic deletion of Pak2 in Th17 cells reduces RORγt phosphorylation, increases IL-17 expression, and induces severe colitis upon adoptive transfer to Rag1^−/− mice. Similarly, reconstitution of RORγt-S316A mutant in Rorc^−/− Th17 cells enhances IL-17 expression and colitis severity. Mechanistically, we demonstrate that Pak2-mediated phosphorylation causes a conformational change resulting in exposure of the ubiquitin ligase Itch interacting PPLY motif and degradation of RORγt. Thus, we have uncovered a mechanism by which the activity of RORγt is regulated that can be exploited therapeutically.

Kathania et al. show that Pak2, a Ser/Thr kinase, associates with RORγt and phosphorylates Ser-316 of RORγt. Deletion of Pak2 in Th17 cells enhances IL-17 expression and colitis severity. Pak2-mediated phosphorylation causes a conformational change resulting in increased ubiquitination of RORγt by the E3 ubiquitin ligase Itch.

Continuous activation of the IL-17F driven inflammatory pathway in acute and chronic digital dermatitis lesions in dairy cattle

Objectives of the present study were to get a deeper insight into the course of the inflammatory pathways of digital dermatitis lesions in dairy cattle by investigating the gene expression patterns throughout the different clinical stages (M0 to M4.1) of the disease. Normal skin samples (M0) were used as a reference for comparing the gene expression levels in the other M-stages through RNA Seq-technology. Principal component analysis revealed a distinct gene expression pattern associated with digital dermatitis lesions in comparison to healthy skin with a further clustering of the acute M1, M2 and M4.1 stages versus the chronic M3 and M4 stages. The majority of the up-and downregulated genes in the acute and chronic stages can be placed into a common 'core' set of genes involved in inflammation, such as A2ML1, PI3, CCL11 and elafin-like protein, whereas the most downregulated genes included keratins and anti-inflammatory molecules such as SCGB1D and MGC151921. Pathway analysis indicated the activation of the pro-inflammatory IL-17 signaling pathway in all the M stages through the upregulation of IL-17F. These results indicate that digital dermatitis is associated with an excessive inflammatory immune response concomitant with a disrupted skin barrier and impaired wound repair mechanism. Importantly, despite their macroscopically healed appearance, a significant inflammatory response (Padj < 0.05) was still measurable in the M3 and M4 lesions, potentially explaining the frequent re-activation of such lesions.

Insights into the role of neutrophils in neuropsychiatric systemic lupus erythematosus: Current understanding and future directions

Central nervous system (CNS) involvement of systemic lupus erythematosus (SLE), termed neuropsychiatric SLE (NPSLE), is a major and debilitating manifestation of the disease. While patients with SLE mostly complain of common neuropsychological symptoms such headache and mild mood disorders that may not even be technically attributed to SLE, many SLE patients present with life-threatening NPSLE syndromes such as cerebrovascular disease, seizures and psychosis that are equally challenging in terms of early diagnosis and therapy. While we are just beginning to unravel some mysteries behind the immunologic basis of NPSLE, advancements in the mechanistic understanding of the complex pathogenic processes of NPSLE have been emerging through recent murine and human studies. The pathogenic pathways implicated in NPSLE are multifarious and various immune effectors such as cell-mediated inflammation, autoantibodies and cytokines including type I interferons have been found to act in concert with the disruption of the blood-brain barrier (BBB) and other neurovascular interfaces. Beyond antimicrobial functions, neutrophils are emerging as decision-shapers during innate and adaptive immune responses. Activated neutrophils have been recognized to be involved in ischemic and infective processes in the CNS by releasing neutrophil extracellular traps (NETs), matrix metalloproteinase-9 and proinflammatory cytokines. In the context of NPSLE, these mechanisms contribute to BBB disruption, neuroinflammation and externalization of modified proteins on NETs that serve as autoantigens. Neutrophils that sediment within the peripheral blood mononuclear cell fraction after density centrifugation of blood are generally defined as low-density neutrophils (LDNs) or low-density granulocytes. LDNs are a proinflammatory subset of neutrophils that are increased with SLE disease activity and are primed to undergo NETosis and release cytokines such as interferon-α and tumor necrosis factor. This review discusses the immunopathogenesis of NPSLE with a focus on neutrophils as a core mediator of the disease and potential target for translational research in NPSLE.

SnoopLigase Enables Highly Efficient Generation of C-C-Linked Bispecific Nanobodies Targeting TNF-α and IL-17A

Bispecific antibodies (bis-Nbs) have been extensively developed since the concept was devised over the decades. Taking advantage of the superior characteristics of nanobodies, bis-Nbs exhibit an emerging tendency to become the new generation of research and diagnostic tools. Traditional strategies to connect the homo- or heterogeneous monomers are commonly applied, but there are still technical issues to generate the bispecific molecules as efficiently as designed. Here, we utilize SnoopLigase to directly tether the C terminus (C-C) of the tagged nanobodies against tumor necrosis factor-α (TNF-α) and interleukin-17A (IL-17A). Under optimal conditions, the yield of C-C-linked bis-Nbs can reach as high as 70% due to the existence of SnoopLigase. The prepared bis-Nbs possessed similar or even higher affinity as the monomers and significantly inhibited the proliferation and migration of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) induced by TNF-α and IL-17A. This study provides an innovative route for using SnoopLigase to realize a highly efficient generation of C-C-linked bis-Nbs. The approach can be applied to different and multicomponent systems for their potential applications in disease diagnosis and treatment.

Study on the effect and mechanism of quercetin in treating gout arthritis

Quercetin is widely found in natural plants, especially Chinese herbal plants. It has been used to treat arthritis in China for thousands of years. However, the effects and mechanisms of quercetin in the treatment of gout arthritis (GA) remain unclear. We aimed to verify the treatment of GA with quercetin and investigate the underlying mechanism. A combination of network pharmacology and experiments was used to reveal the mechanism of quercetin in the treatment of GA. Potential targets of quercetin and gout were identified. Then, the protein-protein interaction network for the common targets between quercetin and gout was constructed and the core targets were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses for the common targets were performed to elucidate the pharmacological functions and mechanisms associated with quercetin treatment in GA. Finally, a monosodium urate-induced GA rat model was used to validate the predicted mechanisms in network pharmacology. Seventy-two common targets were identified. KEGG analysis revealed that treatment of GA with quercetin predominantly involved the interleukin (IL)-17, tumor necrosis factor (TNF), mitogen-activated protein kinase, and phosphoinositide 3-kinase-Akt signaling pathways. In an experimental validation, quercetin attenuated ankle joint inflammation-induced bone destruction and histological lesions. It also diminished the expression of IL-6, IL-17A, and IL-17F in the IL-17 pathway, and regulated the release of RAR-related orphan receptor gamma t,IL-17E, IL-1β, IL-6, TNF-α, Foxp3, and transforming growth factor-beta 1. The collective findings implicate quercetin as a valuable alternative drug for the treatment of GA.

IL-17A in diabetic kidney disease: protection or damage

The effect of IL-17A in diabetic kidney disease (DKD) has received increasing attention. Interleukin (IL)-17A promotes renal inflammation and the progression of DKD, and IL-17A deficiency improves experimental DKD. However, recent studies have found that the effect of IL-17A on DKD is more complicated than the negative impact. IL-17A alleviates renal inflammation and fibrosis via regulating autophagy or the macrophage phenotype. Moreover, paradoxical expression of IL-17A has been reported in human DKD. This review focuses on how IL-17A affects the progression of DKD and the resulting opportunities and challenges.

FOXO3a Alleviates the Inflammation and Oxidative Stress via Regulating TGF-β and HO-1 in Ankylosing Spondylitis

This study aimed to investigate whether Forkhead box O3a (FOXO3a) modulates inflammation and oxidative stress in ankylosing spondylitis (AS). We applied bioinformatics analysis, quantitative real-time polymerase chain reaction, immunoblotting, enzyme linked immunosorbent assay, chromatin immunoprecipitation, and dual-luciferase reporter assay. Gene overexpression and knockdown of FOXO3a were conducted via lentivirus and small interfering RNA, respectively. Downregulated FOXO3a expression was first confirmed in AS patients. Interleukin-8 (IL-8) and IL-17A were highly expressed and negatively related with FOXO3a in AS. Total antioxidant capacity (T-AOC) were markedly decreased and positively associated with FOXO3a in AS. Overexpression of FOXO3a inhibited the secretion of inflammatory cytokines and promoted the production of antioxidant enzymes in Jurkat cells. Transforming growth factor-β (TGF-β) and heme oxygenase 1 (HO-1), which had binding sites to FOXO3a based on bioinformatics analysis, were abnormally expressed and positively related with FOXO3a. Accordingly, FOXO3a obviously elevated the protein and transcription levels of TGF-β and HO-1 in Jurkat cells. The above results were verified by silencing FOXO3a. Moreover, FOXO3a directly interacted with and promoted the transcription of TGF-β and HO-1. In summary, the modulation of cellular inflammation and oxidative stress via FOXO3a-mediated TGF-β and HO-1 activation is partly involved in the pathogenesis of AS.

Effects of Astragalus membranaceus on systemic lupus erythematosus in a mouse model of pregnancy

BACKGROUND

This study used astragalus membranaceus (AM) to treat systemic lupus erythematosus (SLE) model mice during pregnancy, aiming to explore the role of AM in Helper T cell 17 (Th17) differentiation and SLE during pregnancy.

METHODS

We used lipopolysaccharide to constructed the SLE mouse model. AM decoction given by intragastric administration lasted from the eighth week of the mouse age until the mouse was killed. We estimated the messenger RNA  levels of IL-17a and Rorc, counted the Th17 cell number and examined the levels of cytokines including interleukin (IL)-12, tumor necrosis factor α, interferon gamma, IL-17A in mouse serum. Periodic acid-Schiff staining and renal glomerular/tubulointerstitial (TI) score were used to evaluate the progression of lupus nephritis (LN).

RESULTS

AM treatment improved the conception rate and increased the number and average weight of fetuses in SLE mice. It significantly decreased the urinary albumin/creatinine ratios and reduced the glomerular scores and TI scores in the pregnant SLE mice. AM gavage significantly decreased the weight of spleen, mesenteric lymph node, total splenocytes and T cells, and the expression of proinflammatory factors. Furthermore, AM treatment reduced the ratio of Th17 cells and the expression levels of RORγt and IL-17A.

CONCLUSION

AM significantly improved pregnancy outcomes and inhibited lupus nephritis during pregnancy in SLE mice.

Network Pharmacological Analysis and Experimental Study of the Antipharyngitis Mechanism of the Chaiqin Qingning Capsule

Objective

The study aimed to explore the active composition and mechanism of the Chaiqin Qingning capsule (CQQN) against pharyngitis based on the network pharmacology and through using a pharyngitis rat model.

Methods

The active ingredients and targets of CQQN were queried using the TCMSP database. Disease-related target genes were queried in the DrugBank, GeneCards, OMIM, and DisGeNEt databases using “pharyngitis” as the search term. The STRING database was used to establish a protein-protein interaction (PPI) network. GO function enrichment and KEGG pathway enrichment analyses were performed to identify active components and key targets. Cytoscape software (version 3.7.2) was used to construct an active component/target gene/enrichment pathway network. AutoDock software was used to select the best binding target for molecular docking. The effect of CQQN was verified in the pharyngitis rats.

Results

Network pharmacology showed 30 active compounds in CQQN with 240 targets, including 54 for the treatment of pharyngitis. Potential active ingredients included quercetin, kaempferol, stigmasterol, saikosaponin D, and isorhamnetin. The key targets involved were AKT1, TNF, IL-6, and IL-1β. Signaling pathways included virus infection, TNF, IL-17, and cancer pathways. The molecular docking results showed that the critical components in CQQN had good potential for binding to key target genes. Animal experiments showed that CQQN could significantly reduce the expression of TNF-α, IL-1β, IL-6, and IL-17 in the serum of rats with pharyngitis (P < 0.05). Hematoxylin and eosin staining showed that the inflammatory state of pharyngeal tissue in rats was significantly reduced compared to that in the model group.

Conclusion

CQQN can improve pharyngitis by regulating the TNF and IL-17 signaling pathways. The study makes a positive exploration and provides a new idea for a more comprehensive and in-depth excavation of CQQN with an intervention effect on pharyngitis and other upper respiratory diseases in the future.

Effects of microRNA-101-3p on predicting pediatric acute respiratory distress syndrome and its role in human alveolar epithelial cell

Pediatric acute respiratory distress syndrome (PARDS) is a severe form of respiratory failure associated with high mortality among children. The objective of this study is reported to explore the clinical function and molecular roles of microRNA-101-3p (miR-101-3p) in PARDS. The levels of miR-101-3p and mRNA levels of SRY-related high-mobility group box 9 (Sox9) were measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Additionally, the diagnostic role of miR-101-3p was identified by using the Receiver operating characteristic (ROC) curve. The cell proliferation and apoptosis were examined through Cell Counting Kit-8 (CCK-8) assay and flow cytometry. To detect inflammation in cells, enzyme-linked immunosorbent assays (ELISA) were performed. The target gene of miR-101-3p was confirmed through data obtained from the luciferase activity. In patients with PARDS, miR-101-3p expression was decreased. Moderate and severe PARDS patients had lower levels of miR-101-3p than mild PARDS patients. The inflammatory progression was related to the aberrant expression of miR-101-3p in all PARDS children. MiR-101-3p was highly predictive for the detection of children with PARDS. In addition, miR-101-3p might protect A549 cells from abnormal proliferation, apoptosis, and inflammation caused by lipopolysaccharide (LPS). Sox9 might be a target gene of miR-101-3p and increased mRNA expression of Sox9 in LPS-treated A549 cells was inhibited by overexpression of miR-101-3p. Ultimately, this study suggested that reduced expression of miR-101-3p plays a role in PARDS, providing a novel angle to study the disease.

Remote ischemic conditioning causes CD4 T cells shift towards reduced cell-mediated inflammation

PURPOSE

Necrotizing enterocolitis (NEC) is a gastrointestinal disease in neonates that is associated with immune-mediated intestinal inflammation. Remote ischemic conditioning (RIC) applied to a limb has been shown to be protective against experimental NEC. In this study, we explore the immune cell-mediated response involved in NEC and the immunomodulatory effects of RIC in an experimental mouse model of the disease.

METHODS

NEC was induced in C57BL/6 mice (ethical approval #58119) pups on postnatal day5 (p5) using gavage hyperosmolar formula, lipopolysaccharide, and hypoxia. RIC consisted of 4 cycles of 5 min ischemia followed by 5 min reperfusion of the right hindlimb during NEC induction on p6 and p8. Breastfed mice were used as control. The mice were sacrificed on p9, with ileal tissue evaluated for inflammatory cytokines and by characterization of T-cell populations.

RESULTS

NEC mice had increased number of CD4⁺ cells indicating an accumulation of T-cells in the mesenchyme of the NEC ileum. Compared to control, NEC pups had upregulated expression pro-inflammatory cytokines (GATA3, IFNγ, IL1β, IL6, IL17, IL22, and TNFα) and reduced anti-inflammatory cytokine (TGFβ). In NEC, there was also a shift in the balance of Treg/Th17 cells towards Th17. Compared to NEC alone, RIC during the course of NEC resulted in reduction of pro-inflammatory cytokines (GATA3, IFNγ, IL1β, IL6, IL17, IL22, and TNFα), increase in anti-inflammatory cytokine TGFβ and concomitant shift back of Th17 cells towards Treg cells.

CONCLUSION

In experimental NEC, remote ischemic conditioning reduces the production of pro-inflammatory markers and increases the production of anti-inflammatory markers. In addition, during NEC, RIC reverses the imbalance of Treg/Th17 providing support for its effect on cell-mediated inflammation. RIC is a non-invasive physical maneuver that can have a significant beneficial effect in reducing the inflammation seen in NEC.

Long-term Safety of Secukinumab Over Five Years in Patients with Moderate-to-severe Plaque Psoriasis, Psoriatic Arthritis and Ankylosing Spondylitis: Update on Integrated Pooled Clinical Trial and Post-marketing Surveillance Data

Secukinumab, a selective interleukin (IL)-17A inhibitor, is approved for use in adult and paediatric psoriasis, psoriatic arthritis, ankylosing spondylitis and non-radiographic axial spondyloarthritis. The aim of this study was to report the long-term safety of secukinumab in pooled data from 28 clinical trials and a post-marketing safety surveillance in psoriasis, psoriatic arthritis and ankylosing spondylitis patients. Analyses included 12,637 secukinumab-treated patients, corresponding to 15,063, 5,985 and 3,527 patient-years of exposure in psoriasis, psoriatic arthritis and ankylosing spondylitis patients, respectively. Incidences of serious adverse events were low, with no identifiable patterns across indications. Active tuberculosis or latent tuberculosis infections were rare. The incidence of opportunistic infections was < 0.2/100 patient-years, the incidence of malignancy was ≤ 1/100 patient-years, and the incidence of major adverse cardiovascular events was < 0.7/100 patient-years, with no apparent increases over time. Secukinumab demonstrated a favourable safety profile for up to 5 years of treatment across the 3 indications, and no new safety signals were identified.

The Th17 Pathway in Vascular Inflammation: Culprit or Consort?

The involvement of IL-17A in autoimmune and inflammatory diseases has prompted the development of therapeutic strategies to block the Th17 pathway. Promising results came from their use in psoriasis and in ankylosing spondylitis. IL-17A acts on various cell types and has both local and systemic effects. Considering the premature mortality observed during chronic inflammatory diseases, IL-17A action on vascular cells was studied. Both in vitro and in vivo results suggest that this cytokine favors inflammation, coagulation and thrombosis and promotes the occurrence of cardiovascular events. These observations led to study the role of IL-17A in diseases characterized by vascular inflammation, namely allograft rejection and vasculitis. Increased circulating levels of IL-17A and histological staining reveal that the Th17 pathway is involved in the pathogenesis of these diseases. Vasculitis treatment faces challenges while the use of steroids has many side effects. Regarding results obtained in giant cell arteritis with IL-6 inhibitors, a cytokine involved in Th17 differentiation, the use of anti-IL-17 is a promising strategy. However, lessons from rheumatoid arthritis and multiple sclerosis must be learnt before targeting IL-17 in vasculitis, which may be culprit, consort or both of them.

Liposomal Glutathione Helps to Mitigate Mycobacterium tuberculosis Infection in the Lungs

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), is responsible for causing significant morbidity and mortality, especially among individuals with compromised immune systems. We have previously shown that the supplementation of liposomal glutathione (L-GSH) reduces M. tb viability and enhances a Th-1 cytokine response, promoting granuloma formation in human peripheral blood mononuclear cells in vitro. However, the effects of L-GSH supplementation in modulating the immune responses in the lungs during an active M. tb infection have yet to be explored. In this article, we report the effects of L-GSH supplementation during an active M. tb infection in a mouse model of pulmonary infection. We determine the total GSH levels, malondialdehyde (MDA) levels, cytokine profiles, granuloma formation, and M. tb burden in untreated and L-GSH-treated mice over time. In 40 mM L-GSH-supplemented mice, an increase in the total GSH levels was observed in the lungs. When compared to untreated mice, the treatment of M. tb-infected mice with 40 mM and 80 mM L-GSH resulted in a reduction in MDA levels in the lungs. L-GSH treatment also resulted in a significant increase in the levels of IL-12, IFN-γ, IL-2, IL-17, and TNF-α in the lungs, while down-regulating the production of IL-6, IL-10, and TGF-β in the lungs. A reduction in M. tb survival along with a decrease in granuloma size in the lungs of M. tb-infected mice was observed after L-GSH treatment. Our results show that the supplementation of mice with L-GSH led to increased levels of total GSH, which is associated with reduced oxidative stress, increased levels of granuloma-promoting cytokines, and decreased M. tb burden in the lung. These results illustrate how GSH can help mitigate M. tb infection and provide an insight into future therapeutic interventions.

A Role of IL-17 in Rheumatoid Arthritis Patients Complicated With Atherosclerosis

Rheumatoid arthritis (RA) is mainly caused by joint inflammation. RA significantly increases the probability of cardiovascular disease. Although the progress of RA has been well controlled recently, the mortality of patients with RA complicated with cardiovascular disease is 1.5–3 times higher than that of patients with RA alone. The number of people with atherosclerosis in patients with RA is much higher than that in the general population, and atherosclerotic lesions develop more rapidly in patients with RA, which has become one of the primary factors resulting in the death of patients with RA. The rapid development of atherosclerosis in RA is induced by inflammation-related factors. Recent studies have reported that the expression of IL-17 is significantly upregulated in patients with RA and atherosclerosis. Simultaneously, there is evidence that IL-17 can regulate the proliferation, migration, and apoptosis of vascular endothelial cells and vascular smooth muscle cells through various ways and promote the secretion of several cytokines leading to the occurrence and development of atherosclerosis. Presently, there is no clear prevention or treatment plan for atherosclerosis in patients with RA. Therefore, this paper explores the mechanism of IL-17 in RA complicated with atherosclerosis and shows the reasons for the high incidence of atherosclerosis in patients with RA. It is hoped that the occurrence and development of atherosclerosis in patients with RA can be diagnosed or prevented in time in the early stage of lesions, and the prevention and treatment of cardiovascular complications in patients with RA can be enhanced to reduce mortality.

Th17 cells in the liver: balancing autoimmunity and pathogen defense

In addition to carcinogenesis, T helper 17 (Th17) cells (a subtype of CD4 + T lymphocytes) are involved in the acute, chronic, and cirrhotic phases of liver diseases; however, their role in the development and progression of liver diseases remains unclear. It is difficult to elucidate the role of Th17 cells in liver diseases due to their dichotomous nature, i.e., plasticity in terms of pathogenic or host protective function depending on environmental and time phase factors. Moreover, insufficient depletion of Th17 cells by inhibiting the cytokines and transcription factors involved in their production causes difficulties in analyzing their specific role in vitro and in vivo murine models, partially due to complex interaction. This review summarizes the recent progress in understanding the plasticity and function of hepatic Th17 cells and type 3 cytokines.

Expression and activity of IL-17 receptor subunits in human cutaneous cells as targets for anti-IL-17 therapeutic antibodies

The key players in different chronic inflammatory skin diseases are cytokines belonging to the IL-17 group, IL-17 receptors and a T helper cell population, Th17 cells. Successful therapeutic strategies that target either IL-17 or the major IL-17 receptor IL-17RA have confirmed the immune-pathogenic pathway. To study the IL-17-ligand - receptor axis at the molecular level, a number of cutaneous cell types from healthy human subjects has been cultured and analyzed for the expression of IL-17 receptors. IL-17RA was the most abundantly expressed receptor type in keratinocytes, epidermal stem cells, fibroblasts, mesenchymal stem cells, hemo- and lymphovascular endothelial cells. IL-17RC and IL-17RD showed moderate expression, while the genes for IL-17RB and IL-17RE were poorly expressed. In none of the investigated cell types, IL-17 ligands caused an increased expression level of the five receptor types in time- and dose-dependent experiments. No evidence for IL-17A, -C, -E or -F induced signal transduction cascades could be obtained by a qRT-PCR and western blot analyses. Further studies are necessary to identify relevant co-stimulating factors from IL-17 subtypes under physiological and pathophysiological conditions.

Cruzipain Sulfotopes-Specific Antibodies Generate Cardiac Tissue Abnormalities and Favor Trypanosoma cruzi Infection in the BALB/c Mice Model of Experimental Chagas Disease

Trypanosoma cruzi cruzipain (Cz) bears a C-terminal domain (C-T) that contains sulfated epitopes “sulfotopes” (GlcNAc6S) on its unique N-glycosylation site. The effects of in vivo exposure to GlcNAc6S on heart tissue ultrastructure, immune responses, and along the outcome of infection by T. cruzi, were evaluated in a murine experimental model, BALB/c, using three independent strategies. First, mice were pre-exposed to C-T by immunization. C-T-immunized mice (C-T_IM) showed IgG2a/IgG1 <1, induced the production of cytokines from Th2, Th17, and Th1 profiles with respect to those of dC-T_IM, which only induced IL-10 respect to the control mice. Surprisingly, after sublethal challenge, both C-T_IM and dC-T_IM showed significantly higher parasitemia and mortality than the control group. Second, mice exposed to BSA-GlcNAc6S as immunogen (BSA-GlcNAc6S_IM) showed: severe ultrastructural cardiac alterations while BSA-GlcNAc_IM conserved the regular tissue architecture with slight myofibril changes; a strong highly specific humoral-immune-response reproducing the IgG-isotype-profile obtained with C-T_IM; and a significant memory-T-cell-response demonstrating sulfotope-immunodominance with respect to BSA-GlcNAc_IM. After sublethal challenge, BSA-GlcNAc6S_IM showed exacerbated parasitemias, despite elevated IFN-γ levels were registered. In both cases, the abrogation of ultrastructural alterations when using desulfated immunogens supported the direct involvement of sulfotopes and/or indirect effect through their specific antibodies, in the induction of tissue damage. Finally, a third strategy using a passive transference of sulfotope-specific antibodies (IgG-GlcNAc6S) showed the detrimental activity of IgG-GlcNAc6S on mice cardiac tissue, and mice treated with IgG-GlcNAc6S after a sublethal dose of T. cruzi, surprisingly reached higher parasitemias than control groups. These findings confirmed the indirect role of the sulfotopes, via their IgG-GlcNAc6S, both in the immunopathogenicity as well as favoring T. cruzi infection.

Effect of intrabronchial administration of autologous adipose-derived mesenchymal stem cells on severe equine asthma

BACKGROUND

Severe equine asthma (SEA) is a common chronic respiratory disease and a significant health and well-being problem in horses. Current therapeutic strategies improve pulmonary function and clinical signs in some horses, but in the long-term, return to full athletic function appears to be rare. The aim of this study was to assess the safety and the effect of intrabronchial administration of adipose-derived mesenchymal stem cells (AD-MSC) on pulmonary inflammatory and clinical parameters in horses with SEA.

METHODS

This was a randomized controlled trial. Twenty adult horses diagnosed with SEA were randomly divided into two groups (n = 10), and treated either with a single intrabronchial application of autologous AD-MSC or oral dexamethasone for three weeks. A targeted clinical examination with determination of clinical score, maximal change in pleural pressure during the breathing cycle, and an endoscopic examination of the airways were performed at baseline and three weeks after treatment. Bronchoalveolar lavage fluid was analyzed cytologically, and IL-1β, IL-4, IL-8, IL-17, TNFα and IFNγ mRNA and protein concentrations were measured at baseline and three weeks. The horses were then monitored over one year for recurrence of SEA. A non-inferiority analysis and a linear mixed-effects model were performed to assess differences between treatments.

RESULTS

The non-inferiority of AD-MSC treatment was not established. However, AD-MSC administration significantly ameliorated the clinical score (P = 0.01), decreased the expression of IL-17 mRNA (P = 0.05) and IL-1β (P ≤ 0.001), IL-4 (P ≤ 0.001), TNFα (P = 0.02) protein levels, and had a positive long-term effect on SEA-associated clinical signs (P = 0.02).

CONCLUSIONS

Intrabronchial administration of AD-MSC had limited short-term anti-inflammatory effects but improved the clinical signs of SEA at one year.

Network Pharmacology and Transcriptomics Reveal the Mechanism of GuaLouQuMaiWan in Treatment of Type 2 Diabetes and Its Active Small Molecular Compound

The main pathophysiological abnormalities in type 2 diabetes (T2D) include pancreatic β-cell dysfunction and insulin resistance. Due to hyperglycemia, patients receive long-term treatment. However, side effects and drug tolerance usually lead to treatment failure. GuaLouQuMaiWan (GLQMW), a common traditional Chinese medicine (TCM) prescription, has positive effects on controlling blood sugar and improving quality of life, but the mechanism is still unclear. To decipher their molecular mechanisms, we used a novel computational systems pharmacology-based approach consisting of bioinformatics analysis, network pharmacology, and drug similarity comparison. We divided the participants into nondisease (ND), impaired glucose tolerance (IGT), and type 2 diabetes groups according to the WHO's recommendations for diabetes. By analyzing the gene expression profile of the ND-IGT-T2D (ND to IGT to T2D) process, we found that the function of downregulated genes in the whole process was mainly related to insulin secretion, while the upregulated genes were related to inflammation. Furthermore, other genes in the ND-IGT (ND to IGT) process are mainly related to inflammation and lipid metabolic disorders. We speculate that 17 genes with a consistent trend may play a key role in the process of ND-IGT-T2D. We further performed target prediction for 50 compounds in GLQMW that met the screening criteria and intersected the differentially expressed genes of the T2D process with the compounds of GLQMW; a total of 18 proteins proved potential targets for GLQMW. Among these, RBP4 is considerably related to insulin resistance. GO/KEGG enrichment analyses of the target genes of GLQMW showed enrichment in inflammation- and T2D therapy-related pathways. Based on the RDKit tool and the DrugBank database, we speculate that (-)-taxifolin, dialoside A_qt, spinasterol, isofucosterol, and 11,14-eicosadienoic acid can be used as potential drugs for T2D via molecular docking and drug similarity comparison.

Uncontrolled Asthma Determinants In Overweight And Obese Adults

Relevance of the research — epidemiological and clinical studies in recent years confirmed the existence of a bronchial asthma (BA) phenotype associated with obesity. In the current literature, obesity is considered a possible risk factor for the development of BA. Nonetheless, the factors contributing to the uncontrolled course of BA among overweight patients need to be elucidated. The need for a personalized approach to patient management is reflected in the latest edition of the international consensus document on the asthma treatment – GINA (Global Initiative for Asthma: Global Strategy for Asthma Management and Prevention). Despite substantial number of epidemiological studies on the prevalence of BA in obese patients, the threshold values of major risk factors for the development of uncontrolled BA (vitamin D, IL-17, IL-10, BMI; intake of total fat, carbohydrates and cholesterol) remain unclear. Objective: to identify the risk of developing an uncontrolled course of BA depending on the levels of IL-17, IL-10 and vitamin D; dietary characteristics (intake of total fat, cholesterol and carbohydrates); and body mass index (BMI). Material and methods — The study involved 79 patients with an established diagnosis of BA, 18-69 years old. Patients were split among three groups according to their BMI values. Group I included 27 patients with normal body weight (BMI: 18.5-24.9 kg/m2), 56 (42-61) years of age. Group II comprised 28 overweight patients (BMI: 25-30 kg/m2), 57 (50.5-63.5) years of age; Group III encompassed 24 obese patients (BMI≥30 kg/m2), 58 (54-65) years of age. Results — the risk of developing uncontrolled BA increased by 1.8 times with increase of a total fat intake (95% CI: 1.28-2.72; p=0.001); by 5.7 times with BMI>26.7 kg/m2 (95% CI:2.05-15.92; p<0.001); by 5.2 times with IL-17 level >83.5 pg/mL (95% CI:1.71-15.8; p=0.003); by 8.32 times with vitamin D content <24.5 ng/mL (95% CI: 2.9-23.72; p<0.001). Conclusion — patients with BMI>26.7 kg/m2, vitamin D deficiency (i.e., vitamin D content <24.5 ng/mL), IL-17 content >83.5 pg/mL, as well as excessive consumption of total fat, carbohydrates and cholesterol, could be attributed to the risk group for developing an uncontrolled BA.

Transcriptome sequencing and metabolome analysis reveal the mechanism of Shuanghua Baihe Tablet in the treatment of oral mucositis

Oral mucositis (OM) caused by cancer therapy is the most common adverse reaction in the radiotherapy of head and neck tumors. In severe cases, it can lead to the interruption of treatment, which affects the control of the disease and the quality of life. Shuanghua Baihe Tablet (SBT) is a traditional Chinese medicine (TCM) formula, which is administerd to treat OM in China. It has been clinically effective for more than 30 years, but the underlying mechanism is not completely understood. With the development of multiple omics, it is possible to explore the mechanism of Chinese herbal compound prescriptions. Based on transcriptomics and metabolomics, we explored the underlying mechanism of SBT in the treatment of OM. An OM model of rats was established by 5-FU induction, and SBT was orally administered at dosages of 0.75 and 3 g·kg^-1·d^-1. In order to search for SBT targets and related metabolites, the dysregulated genes and metabolites were detected by transcriptomics and metabolomics. Immune related indicators such as interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were detected by ELISA. Treg cell disorders was analyzed by flow cytometry. Our results showed that SBT significantly alleviated the symptoms of OM rats and the inflammatory infiltration of ulcer tissues. After SBT administration, inflammatory related metabolic pathways including linoleic acid metabolism, valine, leucine and isoleucine biosynthesis were significantly altered. Furthermore, the production of proinflammatory factors like IL-17 and TNF-α, were also dramatically reduced after SBT administration. Besides, the infiltration degree of Treg cells in the spleen of OM modeling rats was significantly improved by SBT administration, thus maintaining the immune balance of the body. The current study demonstrates that SBT regulates inoleic acid metabolism, glycerophospholipid metabolism and amino acid metabolism, and inhibits IL-17/TNF signal transduction to restore Treg and Th17 cell homeostasis in OM rats, thereby alleviating chemotherapy-induced OM.

Biomaterials direct functional B cell response in a material-specific manner

B cells are an adaptive immune target of biomaterials development in vaccine research but, despite their role in wound healing, have not been extensively studied in regenerative medicine. To probe the role of B cells in biomaterial scaffold response, we evaluated the B cell response to biomaterial materials implanted in a muscle wound using a biological extracellular matrix (ECM), as a reference for a naturally derived material, and synthetic polyester polycaprolactone (PCL), as a reference for a synthetic material. In the local muscle tissue, small numbers of B cells are present in response to tissue injury and biomaterial implantation. The ECM materials induced mature B cells in lymph nodes and antigen presentation in the spleen. The synthetic PCL implants resulted in prolonged B cell presence in the wound and induced an antigen-presenting phenotype. In summary, the adaptive B cell immune response to biomaterial induces local, regional, and systemic immunological changes.

Current Evidence for IL-17/23 Blockade for the Treatment of Lupus Nephritis

In the current medical literature, there is increasing evidence for the involvement of the interleukin (IL)-17/23 axis and the potential role of Th17 cells in the pathogenesis of lupus nephritis. Knowledge about the interaction of these immunological pathways in the development of autoimmune diseases has led to the identification of new therapeutic strategies aimed at blocking them. For this reason, the main objective of this review focuses on knowing the recent evidence of the different anti-IL-17/23 treatment strategies in lupus nephritis and their future perspectives. A non-systematic narrative review of the literature was carried out following the objective of having the most representative information on the different anti-IL-17/23 drugs available together with the description of the pathophysiological mechanisms of this pathway involved in systemic lupus erythematosus and lupus nephritis. Despite the great existing theoretical foundation, today few clinical studies support the use of these therapies in both contexts. Nevertheless, the publication of research with a better methodology is expected to approve the indication of some of these drugs in lupus nephritis. However, the clinical response seen with ustekinumab and secukinumab in clinical studies and case reports published to date has been encouraging.

Engineering a variant of IL-17RA with high binding affinity to IL-17A for optimized immunotherapy

Immunotherapy is one of the most recently used treatments for numerous cancer types and also some autoimmune and inflammatory diseases. One of the valuable targets for immunotherapy is Interleukin-17A (IL-17A) or its receptor (IL-17RA) because overexpression of IL-17A as a pro-inflammatory cytokine is associated with several inflammatory, autoimmune and cancer diseases. In this study, the extracellular domain of IL-17RA involved in binding to IL-17A was mutated by using R software to achieve a variant with increased binding affinity to IL-17A. The ∆∆G value of -30.89 kcal/mol was calculated for the best variant (385) with point mutations of R265N, N91T, and W31K using the FoldX module. Also, the KD for its interaction with IL-17A was calculated 0.06 nM by surface plasmon resonance (SPR) technique. Our results indicated that variant 385 could bind to IL-17A with higher binding affinity than wild-type one, so, it can be a good therapeutic candidate for blocking IL-17A.

Anti-Inflammatory Effects of BoNT/A Against Complete Freund's Adjuvant-Induced Arthritis Pain in Rats: Transcriptome Analysis

Arthritis is the most common cause to lead to chronic pain. Botulinum toxin type A (BoNT/A) has been widely used to treat chronic pain. In our previous study, we confirmed the anti-inflammatory and antinociceptive effects of BoNT/A in the Complete Freund’s Adjuvant (CFA)-induced arthritis model, but the underlying anti-inflammatory mechanism was not fully elucidated. The purpose of this study was to investigate the anti-inflammatory effects and mechanisms of BoNT/A on arthritis using transcriptomic analysis. The BoNT/A was injected into the rat ankle joint on day 21 after CFA injection. The von Frey and hot plate tests were applied to assess the pain-related behaviors at different time points. Five days after BoNT/A treatment, gene expression profiling in dorsal root ganglion (DRG) was performed using RNA sequencing (RNA-seq). The differentially expressed genes (DEGs) were analyzed by various tools. The mechanical allodynia and thermal hyperalgesia were significantly reversed after BoNT/A injection. RNA-seq revealed 97 DEGs between the CFA group and Sham group; these DEGs were enriched inflammatory response, IL-17 signaling pathway, etc. There are 71 DEGs between the CFA+BoNT/A group and the CFA group; these DEGs related to response to peptide, PI3K-Akt signaling pathway, ECM–receptor interactions, etc. Three key genes were significantly decreased after CFA-induced arthritis pain, while BoNT/A increased the expression of these genes. The identification of S100A9, S100A8, and MMP8 genes can provide new therapeutic targets for arthritis pain and affect the signaling pathway to play an anti-inflammatory role after the treatment of BoNT/A.

Association between IL-17A, IL-17F and IL-17RA gene polymorphisms and susceptibility to psoriasis and psoriatic arthritis: a meta-analysis

BACKGROUND

Psoriasis (Ps) is a chronic dermatosis characterized by erythematous-squamous plaques derived from an inflammatory response. The effect of polymorphisms in the genes that encode the members of the IL-17 family and their receptors has been studied to find an association with the susceptibility to Ps. However, the findings have not been conclusive.

OBJECTIVES

To describe the association between IL-17A, IL-17F and IL-17RA gene polymorphisms and susceptibility to Ps.

METHOD

A systematic review was conducted using the PubMed and Scopus databases to identify studies that evaluated the association between IL-17A, IL-17F, and IL-17RA gene polymorphisms and Ps susceptibility. This meta-analysis included reports published until June 2021. Heterogeneity was assessed using Cochran's Q-statistic test and I² statistics. The associations between polymorphisms and Ps susceptibility were determined by pooled OR with a 95% CI.

RESULTS

Fifteen studies were included. The frequency of the T allele of the IL-17F rs763780 polymorphism was significantly lower in patients with vulgar Ps (OR = 0.732, p = 0.026). The TT genotype of the IL-17F rs763780 polymorphism was significantly associated with a decreased frequency in individuals with Ps and psoriatic arthritis (PsA) (TT:TC + CC OR = 0.664, p = 0.046). Regarding IL-17RA polymorphisms, the AG genotype of the rs4819554 polymorphism showed a near-significant decrease in psoriasis risk compared to the GG genotype (AG:GG OR = 0.604, p = 0.050). Other polymorphisms in IL-17A, IL-17F and IL-17RA showed no association with Ps.

CONCLUSIONS

The T allele and TT genotype of the IL-17F rs763780 polymorphism may be associated with a decreased risk of psoriasis. Therefore, the implications of this variant on psoriasis pathogenesis and treatment require further investigation.

Enteromorpha prolifera polysaccharide-zinc complex modulates the immune response and alleviates LPS-induced intestinal inflammation via inhibiting the TLR4/NF-κB signaling pathway

Enteromorpha prolifera polysaccharide-zinc (EP-Zn), a kind of polysaccharide-zinc complex, has been shown to improve the immune response and reduce the inflammatory factors in weaned piglets. Yet, the molecular mechanism remains unclear. The present study was conducted to investigate the immunomodulating activity and anti-inflammatory mechanism of EP-Zn in mice. Different doses (350 mg kg^-1, 700 mg kg^-1, 1050 mg kg^-1 and 1400 mg kg^-1) of EP-Zn were administered to C57BL/6J mice for 28 days. The results showed that under physiological conditions, 350 mg kg^-1 EP-Zn stimulated cytokine (TNF-α, IL-1β, IL-6 and IL-10) secrection, regulated the intestinal microbiota, and reduced the levels of short-chain fatty acids (SCFAs) (acetic acid and propionic acid). In addition, in the LPS-induced inflammation model, EP-Zn pretreatment effectively alleviated LPS-induced shortening of colonic length and increased MPO and DAO contents, improved intestinal physical barrier function by modulating mucosal structure, and attenuated intestinal inflammation via inhibiting the TLR4/NF-κB signaling pathway. These findings suggested that EP-Zn exerted immunomodulatory and anti-inflammatory activities under physiological and inflammatory conditions, respectively.

Monocyte Chemotactic Protein-Induced Protein 1 (MCPIP-1): A Key Player of Host Defense and Immune Regulation

Inflammatory response is a host-protective mechanism against tissue injury or infections, but also has the potential to cause extensive immunopathology and tissue damage, as seen in many diseases, such as cardiovascular diseases, neurodegenerative diseases, metabolic syndrome and many other infectious diseases with public health concerns, such as Coronavirus Disease 2019 (COVID-19), if failure to resolve in a timely manner. Recent studies have uncovered a superfamily of endogenous chemical molecules that tend to resolve inflammatory responses and re-establish homeostasis without causing excessive damage to healthy cells and tissues. Among these, the monocyte chemoattractant protein-induced protein (MCPIP) family consisting of four members (MCPIP-1, -2, -3, and -4) has emerged as a group of evolutionarily conserved molecules participating in the resolution of inflammation. The focus of this review highlights the biological functions of MCPIP-1 (also known as Regnase-1), the best-studied member of this family, in the resolution of inflammatory response. As outlined in this review, MCPIP-1 acts on specific signaling pathways, in particular NFκB, to blunt production of inflammatory mediators, while also acts as an endonuclease controlling the stability of mRNA and microRNA (miRNA), leading to the resolution of inflammation, clearance of virus and dead cells, and promotion of tissue regeneration via its pleiotropic effects. Evidence from transgenic and knock-out mouse models revealed an involvement of MCPIP-1 expression in immune functions and in the physiology of the cardiovascular system, indicating that MCPIP-1 is a key endogenous molecule that governs normal resolution of acute inflammation and infection. In this review, we also discuss the current evidence underlying the roles of other members of the MCPIP family in the regulation of inflammatory processes. Further understanding of the proteins from this family will provide new insights into the identification of novel targets for both host effectors and microbial factors and will lead to new therapeutic treatments for infections and other inflammatory diseases.

AZD0284, a Potent, Selective, and Orally Bioavailable Inverse Agonist of Retinoic Acid Receptor-Related Orphan Receptor C2

Inverse agonists of the nuclear receptor RORC2 have been widely pursued as a potential treatment for a variety of autoimmune diseases. We have discovered a novel series of isoindoline-based inverse agonists of the nuclear receptor RORC2, derived from our recently disclosed RORC2 inverse agonist 2. Extensive structure-activity relationship (SAR) studies resulted in AZD0284 (20), which combined potent inhibition of IL-17A secretion from primary human TH17 cells with excellent metabolic stability and good PK in preclinical species. In two preclinical in vivo studies, compound 20 reduced thymocyte numbers in mice and showed dose-dependent reduction of IL-17A containing γδ-T cells and of IL-17A and IL-22 RNA in the imiquimod induced inflammation model. Based on these data and a favorable safety profile, 20 was progressed to phase 1 clinical studies.

Role of Interleukin-17 in Acute Pancreatitis

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

The role of IL-17, IL-23 and IL-31, IL-33 in allergic skin diseases

PURPOSE OF REVIEW

Allergic skin diseases such as urticaria, atopic dermatitis and allergic contact dermatitis are among the most common skin diseases with severe socioeconomic consequences. The pathogenesis of allergic skin diseases is complex. This review provides an overview of cytocines IL-17, IL-23, IL-31 and IL-33.

RECENT FINDINGS

Current research results show a variety of immunological processes in the pathogenesis of the allergic skin diseases, including the role of cytokines. In addition to the Th1 and Th2 immune response, the immune response via Th17 is becoming increasingly important in allergic skin diseases but also the cytokines IL-23, IL-31 and IL-33 have been discussed in the literature recently. Different cytokines promote in a kind of orchestra the different symptoms seen in the different allergic skin diseases, including pruritus, dermatitis, mast cell mediator release and inflammation.

SUMMARY

We are still in the early stages of understanding pathophysiology of allergic skin diseases and the role of various cytokines in the immune system. With the development of targeted antibodies against the proinflammatory cytokines, the variety of normal therapeutic options can be expected to evolve.

Interleukin-17A in Alzheimer's disease: recent advances and controversies

Alzheimer’s disease (AD) is a progressive neurodegenerative disease that mainly affects older adults. Although the global burden of AD is increasing year by year, the causes of AD remain largely unknown. Numerous basic and clinical studies have shown that interleukin-17A (IL-17A) may play a significant role in the pathogenesis of AD. A comprehensive assessment of the role of IL-17A in AD would benefit the diagnosis, understanding of etiology and treatment. However, over the past decade, controversies remain regarding the expression level and role of IL-17A in AD. We have incorporated newly published researches and point out that IL-17A expression levels may vary along with the development of AD, exercising different roles at different stages of AD, although much more work remains to be done to support the potential role of IL-17A in AD-related pathology. Here, it is our intention to review the underlying mechanisms of IL-17A in AD and address the current controversies in an effort to clarify the results of existing research and suggest future studies.

Generation and characterization of a humanized anti-IL-17A rabbit monoclonal antibody

Interleukin-17A (IL-17A) produced by Th17 cells, contributes to the pathogenesis of various autoimmune diseases by stimulating the release of cytokines and chemokines and its regulation. Anti-IL-17A antibody which blocks the function of IL-17A has been proved to be an effective treatment of autoimmune disease. The aim of our study was to generate a potential humanized anti-IL-17A therapeutic monoclonal antibody (mAb) through a comprehensive panel of in vitro and in vivo biological activity studies, as well as physicochemical characterization. HZD37-5, a humanized monoclonal antibody specifically recognizing N78 loci of IL-17A, binds to human and rhesus monkeys, blocks IL-17 induced signal transduction and the release of IL-6, IL-8, CXCL-1 and G-GSF. In an in vivo efficacy mouse model, HZD37-5 significantly inhibited human IL-17A induced-keratinocyte chemoattractant (KC) secretion in a dose-dependent manner. The pharmacokinetics (PK) study result of HZD37-5 in rhesus monkeys indicated that HZD37-5 had favorable PK characteristics with limited distribution (78.0-78.8 ml/kg), slow elimination (5.00-6.45 ml/day/kg), long half-life (9.1-10.7 days) and high bioavailability (103%) following a single IV or SC dose at 1.5 mg/kg. These findings provided a comprehensive preclinical characterization of HZD37-5 and supported that it may be developed as a potential therapeutic for the treatment of autoimmune diseases, including psoriasis, psoriatic arthritis, axial spondyloarthritis, etc.

IL-17 is expressed on beta and alpha cells of donors with type 1 and type 2 diabetes

PURPOSE

IL-17 is an important effector cytokine driving immune-mediated destruction in autoimmune diseases such as psoriasis. Blockade of the IL-17 pathway after the initiation of insulitis was effective in delaying or preventing the onset of type 1 diabetes (T1D) in rodent models. Expression of IL-17 transcripts in islets from a donor with recent-onset T1D has been reported, however, studies regarding IL-17 protein expression are lacking. We aimed to study whether IL-17 is being expressed in the islets of diabetic donors.

METHODS

We stained human pancreatic tissues from non-diabetic (n = 5), auto-antibody positive (aab+) (n = 5), T1D (n = 6) and T2D (n = 5) donors for IL-17, Insulin, and Glucagon, and for CD45 in selected cases. High resolution images were acquired with Zeiss laser scanning confocal microscope LSM780 and analyzed with Zen blue 2.3 software. Cases stained for CD45 were also acquired with widefield slide scanner and analyzed with QuPath software.

RESULTS

We observed a clear cytoplasmic staining for IL-17 in insulin-containing islets of donors with T1D and T2D, accounting for an average of 7.8 ± 8.4% and 14.9 ± 16.8% of total islet area, respectively. Both beta and alpha cells were sources of IL-17, but CD45⁺ cells were not a major source of IL-17 in those donors. Expression of IL-17 was reduced in islets of non-diabetic donors, aab+ donors and in insulin-deficient islets of donors with T1D.

CONCLUSION

Our finding that IL-17 is expressed in islets of donors with T1D or T2D is quite intriguing and warrants further mechanistic studies in human islets to understand the role of IL-17 in the context of metabolic and immune stress in beta cells.

Retinoic acid-related orphan receptor gamma t (RORγt) inverse agonists/antagonists for the treatment of inflammatory diseases - where are we presently?

Introduction: The transcription factor retinoic acid-related orphan receptor gamma t (RORγt) has been identified as the master regulator of T_H17 cell differentiation and IL-17/22 production and is therefore an attractive target for the treatment of inflammatory diseases. Several orally or topically administered small molecule RORγt inverse agonists (RIAs) have progressed up to the end of clinical Phase 2.Areas covered: Based on publications and patent evaluations this review summarizes the evolution of the chemical matter for all 16 pharmaceutical companies, who develop(ed) a clinical-stage RIAs (until March 2021). Structure proposals for some clinical stage RIAs are presented and the outcome of the clinical trials is discussed.Expert opinion: So far, the clinical trials have been plagued with a high attrition rate. Main reasons were lack of efficacy (topical) or safety signals (oral) as well as, amongst other things, thymic lymphomas as seen with BMS-986251 in a preclinical study and liver enzyme elevations in humans with VTP-43742. Possibilities to mitigate these risks could be the use of RIAs with different chemical structures not interfering with thymocytes maturation and no livertox-inducing properties. With new frontrunners (e.g., ABBV-157 (cedirogant), BI 730357 or IMU-935) this is still an exciting time for this treatment approach.

Small molecule approaches to treat autoimmune and inflammatory diseases (Part III): Targeting cytokines and cytokine receptor complexes

Chronic and dysregulated cytokine signaling plays an important role in the pathogenic development of many autoimmune and inflammatory diseases. Despite intrinsic challenges in the disruption of interactions between cytokines and cytokine receptors, many first-in-class small-molecule inhibitors have been discovered over the past few years. The third part of the digest series presents recent progress in identifying such inhibitors and highlights the application of novel research tools in the fields of structural biology, computational analysis, screening methods, biophysical/biochemical assays and medicinal chemistry strategy.

Serum protein signatures differentiate paediatric autoimmune/inflammatory disorders

Because of their rarity, limited awareness among non-specialists, and significant overlaps in their clinical presentation, childhood autoimmune/inflammatory conditions represent a diagnostic and therapeutic challenge. Juvenile idiopathic arthritis (JIA), with its 7 sub-forms, is the most common paediatric "rheumatic" disease. Juvenile-onset systemic lupus erythematosus (jSLE) is a severe autoimmune/inflammatory disease that can affect any organ system and shares clinical features with JIA. To overcome issues around diagnostic approaches in the context of clinical overlap, we aimed at the definition of disease sub-form specific cytokine and chemokine profiles. Serum samples from patients with JIA (n = 77) and jSLE (n = 48), as well as healthy controls (n = 30), were collected. Samples were analysed using the Meso Scale Discovery (MSD) U-PLEX Biomarker Group 1 (hu) panel. Distinct serum protein signatures associate with JIA vs jSLE disease groups. Proteins with high discriminatory ability include IL-23, MIP-1β, MCP-1, M-CSF and MDC. Furthermore, serum IL-18, MIF, MIP-5 and YKL-40 discriminate between systemic JIA and other JIA subtypes. Thus, simultaneous quantification of serum proteins in a panel format may provide an avenue for the diagnosis and monitoring of childhood autoimmune/inflammatory conditions.

From Messengers to Receptors in Psoriasis: The Role of IL-17RA in Disease and Treatment

The paradigm of psoriasis as a Th17-driven disease has evolved in the last years towards a much deeper knowledge of the complex pathways, mechanisms, cells, and messengers involved, highlighting the crucial role played by the IL-17 family of cytokines. All IL-17 isoforms signal through IL-17R. Five subunits of IL-17R have been described to date, which couple to form a homo- or hetero-receptor complex. Characteristically, IL-17RA is a common subunit in all hetero-receptors. IL-17RA has unique structural—containing a SEFIR/TILL domain—and functional—requiring ACT-1 for signaling—properties, enabling Th17 cells to act as a bridge between innate and adaptive immune cells. In psoriasis, IL-17RA plays a key role in pathogenesis based on: (a) IL-17A, IL-17F, and other IL-17 isoforms are involved in disease development; and (b) IL-17RA is essential for signaling of all IL-17 cytokines but IL-17D, whose receptor has not been identified to date. This article reviews current evidence on the biology and role of the IL-17 family of cytokines and receptors, with focus on IL-17RA, in psoriasis and some related comorbidities, and puts them in context with current and upcoming treatments.

Genome-Wide Differential Expression Profiling of Pulmonary circRNAs Associated With Immune Reaction to Pasteurella multocida in Goats

Pasteurella multocida is a highly versatile pathogen that infects a wide range of animals, including goats, causing pneumonia and hemorrhagic septicemia. Circular RNA (circRNA) is a type of non-coding RNA that plays an important role in regulating cellular metabolism. However, whether and how circRNA is involved in regulating immune responses in the goat lung has not been reported. Thus, this study was designed to examine the function of circRNA in goats infected with Pasteurella multocida. Goats were assigned into one of two groups: an uninfected control group (CK) and an infected group challenged with P. multocida. Compared with the CK group, which remained healthy, the infected goats showed clinical signs of infection, including depression, cough, nasal discharge, and dyspnea, along with elevated body temperature and lesions in the lung. Whole-transcriptome sequencing and small RNA sequencing were then performed using lung samples from goats from each group. A total of 138 circRNA, 56 microRNAs (miRNA), and 2,673 messenger RNA (mRNA) molecules were significantly differentially expressed in the P. multocida-infected group compared with the CK group. Randomly selected differentially expressed circRNA, miRNA, and mRNA molecules (n = 5 per group) were then validated by quantitative reverse-transcriptase polymerase chain reaction analysis. Gene ontology (GO) analysis of the source genes indicated that six immune-related terms were enriched among the differentially expressed cirRNA molecules, including inflammatory response, immune effector process, cell activation involved in immune response, cytokine-mediated signaling pathway, response to endogenous stimulus, and immune response. The corresponding circRNA molecules were then selected for construction of a competitive endogenous RNA network to identify networks that may be involved in the immune response to P. multocida infection. The results indicated that P. multocida HN01 may cause pneumonia and stimulate an immune response in goats via regulation of circRNA expression. This study presents the first comprehensive circRNA profile in response to P. multocida infection in goats, thus, providing a basis for understanding the function of circRNA in the host immune response to P. multocida infection.

Dual interleukin-17A/F deficiency protects against acute and chronic response to cigarette smoke exposure in mice

IL-17A and IL-17F are both involved in the pathogenesis of neutrophilic inflammation observed in COPD and severe asthma. To explore this, mice deficient in both Il17a and Il17f and wild type (WT) mice were exposed to cigarette smoke or environmental air for 5 to 28 days and changes in inflammatory cells in bronchoalveolar lavage (BAL) fluid were determined. We also measured the mRNA expression of keratinocyte derived chemokine (Kc), macrophage inflammatory protein-2 (Mip2), granulocyte–macrophage colony stimulating factor (Gmcsf) and matrix metalloproteinase-9 (Mmp9 ) in lung tissue after 8 days, and lung morphometric changes after 24 weeks of exposure to cigarette smoke compared to air-exposed control animals. Macrophage counts in BAL fluid initially peaked at day 8 and again on day 28, while neutrophil counts peaked between day 8 and 12 in WT mice. Mice dual deficient with Il17a and 1l17f showed similar kinetics with macrophages and neutrophils, but cell numbers at day 8 and mRNA expression of Kc, Gmcsf and Mmp9 were significantly reduced. Furthermore, airspaces in WT mice became larger after cigarette smoke exposure for 24 weeks, whereas this was not seen dual Il17a and 1l17f deficient mice. Combined Il17a and Il17f deficiency resulted in significant attenuation of neutrophilic inflammatory response and protection against structural lung changes after long term cigarette smoke exposure compared with WT mice. Dual IL-17A/F signalling plays an important role in pro-inflammatory responses associated with histological changes induced by cigarette smoke exposure.

IL-17A Secreted by Th17 Cells Is Essential for the Host against Streptococcus agalactiae Infections

Streptococcus agalactiae is an important bacterial pathogen and causative agent of diseases including neonatal sepsis and meningitis, as well as infections in healthy adults and pregnant women. Although antibiotic treatments effectively relieve symptoms, the emergence and transmission of multidrug-resistant strains indicate the need for an effective immunotherapy. Effector T helper (Th) 17 cells are a relatively newly discovered subpopulation of helper CD4⁺ T lymphocytes, and which, by expressing interleukin (IL)-17A, play crucial roles in host defenses against a variety of pathogens, including bacteria and viruses. However, whether S. agalactiae infection can induce the differentiation of CD4⁺ T cells into Th17 cells, and whether IL-17A can play an effective role against S. agalactiae infections, are still unclear. In this study, we analyzed the responses of CD4⁺ T cells and their defensive effects after S. agalactiae infection. The results showed that S. agalactiae infection induces not only the formation of Th1 cells expressing interferon (IFN)-γ, but also the differentiation of mouse splenic CD4⁺ T cells into Th17 cells, which highly express IL-17A. In addition, the bacterial load of S. agalactiae was significantly increased and decreased in organs as determined by antibody neutralization and IL-17A addition experiments, respectively. The results confirmed that IL-17A is required by the host to defend against S. agalactiae and that it plays an important role in effectively eliminating S. agalactiae. Our findings therefore prompt us to adopt effective methods to regulate the expression of IL-17A as a potent strategy for the prevention and treatment of S. agalactiae infection.

Implications of VIP and PACAP in Parkinson's Disease: What do we Know So Far?

BACKGROUND

Parkinson's disease is one of the most common neurodegenerative disorders and although its aetiology is not yet fully understood, neuroinflammation has been identified as a key factor in the progression of the disease. Vasoactive intestinal peptide and pituitary adenylate-cyclase activating polypeptide are two neuropeptides that exhibit anti-inflammatory and neuroprotective properties, modulating the production of cytokines and chemokines and the behaviour of immune cells. However, the role of chemokines and cytokines modulated by the endogenous receptors of the peptides varies according to the stage of the disease.

METHODS

We present an overview of the relationship between some cytokines and chemokines with vasoactive intestinal peptide, pituitary adenylate cyclase activating polypeptide and their endogenous receptors in the context of Parkinson's disease neuroinflammation and oxidative stress, as well as the modulation of microglial cells by the peptides in this context.

RESULTS

The two peptides exhibit neuroprotective and anti-inflammatory properties in models of Parkinson's disease, as they ameliorate cognitive functions, decrease the level of neuroinflammation and promote dopaminergic neuronal survival. The peptides have been tested in a variety of in vivo and in vitro models of Parkinson's disease, demonstrating the potential for therapeutic application.

CONCLUSION

More studies are needed to establish the clinical use of vasoactive intestinal peptide and pituitary adenylate cyclase activating polypeptide as safe candidates for treating Parkinson's disease, as the use of the peptides in different stages of the disease could produce different results concerning effectiveness.

The IL23-IL17 Immune Axis in the Treatment of Ulcerative Colitis: Successes, Defeats, and Ongoing Challenges

Ulcerative colitis (UC) is a chronic relapsing disorder of the colonic tract, characterized by a dysregulated innate and adaptive immune response to gut microbiota that contributes to the perpetuation of intestinal inflammatory processes. The Interleukin (IL) 23/IL17 axis has been reported to play a key role in UC pathogenesis promoting Th17 cells and cytokines-related immune response. Recently, the blockade of IL23/IL17 pathways has been raised enormous interest in the treatment o several chronic inflammatory disorders. In this review, we summarize the emerging results from clinical trials that evoked both promise and discouragement in IL23/IL17 axis in the treatment of UC. Targeting IL23 p40 through Ustekinumab results safe and effective to induce and maintain clinical remission, low inflammatory indexes, mucosal healing, and a better quality of life. Studies targeting IL23 p19 through Mirikizumab, Risankizumab, Brazikumab and Guselkumab are still ongoing. To date, no clinical studies targeting IL17 pathway are ongoing in UC. IL-17 targeting is thought to have a context-dependent biological effect, based on whether cytokine is selectively targeted or if its function is dampened by the upstream block of IL23.

Interleukin-17A: Potential mediator and therapeutic target in hypertension

Interleukin-17A (IL-17A) is a proinflammatory cytokine produced by cells of the immune system, predominantly Th17 and γδ lymphocytes. In this paper, we review the role of IL-17A in the pathogenesis of hypertension and in target organ damage. Preclinical studies in mice have shown that systemic adminstration of IL-17A increases blood pressure, probably by acting on multiple levels. Furthermore, IL-17A plasma concentrations are already elevated in patients with mild or moderate hypertension. Many studies in hypertensive mice models have detected IL-17A-producing cells in target organs such as the heart, vessels and kidneys. Patients with hypertensive nephrosclerosis show kidney infiltration by Th17 lymphocytes and γδ lymphocytes that express IL-17A. In addition, in experimental models of hypertension, the blockade of IL-17A by genetic strategies or using neutralizing antibodies, disminished blood pressure, probablyby acting on the small mesenteric arteries as well as in the regulation of tubule sodium transport. Moreover, IL-17A inhibition reduces end-organs damage. As a whole, the data presented in this review suggest that IL-17A participates in the regulation of blood pressure and in the genesis and maintenance of arterial hypertension, and may constitute a therapeutic target of hypertension-related pathologies in the future.

IL-17 drives salivary gland dysfunction via inhibiting TRPC1-mediated calcium movement in Sjögren's syndrome

Objectives

This study aims to determine a role of interleukin‐17A (IL‐17) in salivary gland (SG) dysfunction and therapeutic effects of targeting IL‐17 in SG for treating autoimmune sialadenitis in primary Sjögren’s syndrome (pSS).

Methods

Salivary IL‐17 levels and IL‐17‐secreting cells in labial glands of pSS patients were examined. Kinetic changes of IL‐17‐producing cells in SG from mice with experimental Sjögren’s syndrome (ESS) were analysed. To determine a role of IL‐17 in salivary secretion, IL‐17‐deficient mice and constructed chimeric mice with IL‐17 receptor C (IL‐17RC) deficiency in non‐hematopoietic and hematopoietic cells were examined for saliva flow rates during ESS development. Both human and murine primary SG epithelial cells were treated with IL‐17 for measuring cholinergic activation‐induced calcium movement. Moreover, SG functions were assessed in ESS mice with salivary retrograde cannulation of IL‐17 neutralisation antibodies.

Results

Increased salivary IL‐17 levels were negatively correlated with saliva flow rates in pSS patients. Both IL‐17‐deficient mice and chimeric mice with non‐hematopoietic cell‐restricted IL‐17RC deficiency exhibited no obvious salivary reduction while chimeric mice with hematopoietic cell‐restricted IL‐17RC deficiency showed significantly decreased saliva secretion during ESS development. In SG epithelial cells, IL‐17 inhibited acetylcholine‐induced calcium movement and downregulated the expression of transient receptor potential canonical 1 via promoting Nfkbiz mRNA stabilisation. Moreover, local IL‐17 neutralisation in SG markedly attenuated hyposalivation and ameliorated tissue inflammation in ESS mice.

Conclusion

These findings identify a novel function of IL‐17 in driving salivary dysfunction during pSS development and may provide a new therapeutic strategy for targeting SG dysfunction in pSS patients.

Serum IL-17 levels in patients with rosacea

BACKGROUND

Rosacea is a chronic inflammatory skin disease characterized with increased serum and tissue inflammatory mediators. IL-17 is a well-known inflammatory mediator that plays important roles in pathogenesis of inflammatory skin diseases. Previous studies reported that Th17 pathway is activated in rosacea and IL-17, one of Th17 signature cytokines, is elevated in tissue samples of rosacea patients.

OBJECTIVES

The aim of this study was to investigate serum IL-17 levels in rosacea patients and to study its relationship with disease characteristics.

METHODS

Sixty patients diagnosed with rosacea and 60 healthy controls were included in the study. Serum IL-17 concentrations were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean serum IL-17 level was 8.03 pg/mL (SD = 1.47) in rosacea patients and 7.37 pg/mL (Sd = 1.19) in controls. Serum IL-17 levels were significantly higher in rosacea (p = 0.002). Serum IL-17 levels were similar among patients with erythematotelangiectatic (ET) and papulopustular (PP) rosacea (8.02 vs 8.06, p = 0.83). Serum IL-17 levels did not correlate with rosacea severity (p = 0.59, r = 0.07 in ET rosacea; p = 0.88, r = 0.02 in PP rosacea), age of onset (p = 0.58, r = -0.07), and disease duration (p = 0.37, r = -0.11). Primary features and global assessments did not correlate with serum IL-17 levels (all p > 0.05). Among secondary features, edema showed a significant negative correlation with serum IL-17 concentrations (p = 0.037, r = -0.26).

CONCLUSIONS

Our study showed increased serum IL-17 levels in rosacea patients and a significant correlation between IL-17 concentrations and secondary features of the disease suggesting IL-17 may contribute to pathogenesis of rosacea and may be a new target for rosacea treatment.