IL-17 cytokine family

IL-17 in wound repair: bridging acute and chronic responses

Chronic wounds, resulting from persistent inflammation, can trigger a cascade of detrimental effects including exacerbating inflammatory cytokines, compromised blood circulation at the wound site, elevation of white blood cell count, increased reactive oxygen species, and the potential risk of bacterial infection. The interleukin-17 (IL-17) signaling pathway, which plays a crucial role in regulating immune responses, has been identified as a promising target for treating inflammatory skin diseases. This review aims to delve deeper into the potential pathological role and molecular mechanisms of the IL-17 family and its pathways in wound repair. The intricate interactions between IL-17 and other cytokines will be discussed in detail, along with the activation of various signaling pathways, to provide a comprehensive understanding of IL-17's involvement in chronic wound inflammation and repair.

IL17RB expression is associated with malignant cancer behaviors and poor prognosis in oral cancer

OBJECTIVES

Previously, we demonstrated that IL17RB plays an essential role in lung cancer progression. This study aimed to determine whether IL17RB correlates with oral cancer and promotes oral cancer progression.

SUBJECTS AND METHODS

IL17RB expression in oral cancer tissues and normal tissues was determined by immunohistochemistry staining, while the association of IL17RB expression with the clinicopathological characteristics of oral squamous cell carcinoma (OSCC) patients was analyzed and its correlation with progression-free survival and response to radiotherapy and chemotherapy in OSCC patients was also explored. Western blotting was performed to investigate the expression of IL17RB in various OSCC cell lines; moreover, transwell assay was performed to evaluate the effect of IL17RB expression on cell migration ability.

RESULTS

In this study, we found that IL17RB was expressed higher in OSCC tissues compared to normal oral mucosa tissues and its expression was positively correlated with tumor size, lymph node metastasis, advanced cancer stage, and poor prognosis. In vitro study showed that IL17RB expression in OSCC cell lines as determined by Western blotting, was positively correlated with their migration ability.

CONCLUSION

Clinical and in vitro studies suggest that IL17RB might serve as an independent risk factor and a therapeutic target for oral cancer.

Tailoring Biomaterials Ameliorate Inflammatory Bone Loss

Inflammatory diseases, such as rheumatoid arthritis, periodontitis, chronic obstructive pulmonary disease, and celiac disease, disrupt the delicate balance between bone resorption and formation, leading to inflammatory bone loss. Conventional approaches to tackle this issue encompass pharmaceutical interventions and surgical procedures. Nevertheless, pharmaceutical interventions exhibit limited efficacy, while surgical treatments impose trauma and significant financial burden upon patients. Biomaterials show outstanding spatiotemporal controllability, possess a remarkable specific surface area, and demonstrate exceptional reactivity. In the present era, the advancement of emerging biomaterials has bestowed upon more efficacious solutions for combatting the detrimental consequences of inflammatory bone loss. In this review, the advances of biomaterials for ameliorating inflammatory bone loss are listed. Additionally, the advantages and disadvantages of various biomaterials-mediated strategies are summarized. Finally, the challenges and perspectives of biomaterials are analyzed. This review aims to provide new possibilities for developing more advanced biomaterials toward inflammatory bone loss.

An elevated level of interleukin-17A in a Senegalese malaria cohort is associated with rs8193038 IL-17A genetic variant

Malaria infection is a multifactorial disease partly modulated by host immuno-genetic factors. Recent evidence has demonstrated the importance of Interleukin-17 family proinflammatory cytokines and their genetic variants in host immunity. However, limited knowledge exists about their role in parasitic infections such as malaria. We aimed to investigate IL-17A serum levels in patients with severe and uncomplicated malaria and gene polymorphism's influence on the IL-17A serum levels. In this research, 125 severe (SM) and uncomplicated (UM) malaria patients and 48 free malaria controls were enrolled. IL-17A serum levels were measured with ELISA. PCR and DNA sequencing were used to assess host genetic polymorphisms in IL-17A. We performed a multivariate regression to estimate the impact of human IL-17A variants on IL-17A serum levels and malaria outcomes. Elevated serum IL-17A levels accompanied by increased parasitemia were found in SM patients compared to UM and controls (P < 0.0001). Also, the IL-17A levels were lower in SM patients who were deceased than in those who survived. In addition, the minor allele frequencies (MAF) of two IL-17A polymorphisms (rs3819024 and rs3748067) were more prevalent in SM patients than UM patients, indicating an essential role in SM. Interestingly, the heterozygous rs8193038 AG genotype was significantly associated with higher levels of IL-17A than the homozygous wild type (AA). According to our results, it can be concluded that the IL-17A gene rs8193038 polymorphism significantly affects IL-17A gene expression. Our results fill a gap in the implication of IL-17A gene polymorphisms on the cytokine level in a malaria cohort. IL-17A gene polymorphisms also may influence cytokine production in response to Plasmodium infections and may contribute to the hyperinflammatory responses during severe malaria outcomes.

Targeting Interleukin-17 as a Novel Treatment Option for Fibrotic Diseases

Fibrosis is the end result of persistent inflammatory responses induced by a variety of stimuli, including chronic infections, autoimmune reactions, and tissue injury. Fibrotic diseases affect all vital organs and are characterized by a high rate of morbidity and mortality in the developed world. Until recently, there were no approved antifibrotic therapies. In recent years, high levels of interleukin-17 (IL-17) have been associated with chronic inflammatory diseases with fibrotic complications that culminate in organ failure. In this review, we provide an update on the role of IL-17 in fibrotic diseases, with particular attention to the most recent lines of research in the therapeutic field represented by the epigenetic mechanisms that control IL-17 levels in fibrosis. A better knowledge of the IL-17 signaling pathway implications in fibrosis could design new strategies for therapeutic benefits.

Association between IL-17F, IL-17RA Gene Polymorphisms and Response to Biological Drugs in Psoriasis and Beyond

Psoriasis is a systemic inflammatory disease that associates with multiple comorbidities. It involves complex interactions between environmental factors and polygenic predisposition. The IL-17 family is one of the main actors in the pathogenesis of psoriasis. Secondary nonresponse is common, especially during the long-term use of TNF-α inhibitors, but it is not uncommon even for newer biologics, such as IL-17 inhibitors. Identification of clinically useful biomarkers of treatment efficacy and safety would enable optimal treatment selection, improve patient quality of life and outcome, and reduce healthcare costs. To our knowledge, this is the first study to evaluate the relationship between genetic polymorphism of IL-17F (rs763780) and IL-17RA (rs4819554) and response to biological treatment and other clinical data in bio-naive and secondary non-responders psoriasis patients in Romania and Southeastern Europe. We performed a prospective, longitudinal, analytical cohort study of 81 patients diagnosed with moderate-to-severe chronic plaque psoriasis who received biological treatments for the first time. Of the 79 patients treated with TNF-α inhibitors, 44 experienced secondary nonresponse. All patients were genotyped for the two SNPs in IL-17F and IL-17RA genes. The rs763780 polymorphism in the IL-17F gene could be an attractive candidate biomarker for predicting which patients will respond to anti-TNF-α therapies. Another emergent association of rs4819554 in IL-17RA with the risk of nail psoriasis and a higher BMI in moderate-to-severe plaque psoriasis patients is described.

A Meta-Analysis of the Association Between Genetic Polymorphisms in IL-12, IL-17, and IL-21 and Risk of Hepatitis B Virus Infection

Cytokine imbalance is an important feature in the occurrence and outcome of hepatitis B virus (HBV). Single nucleotide polymorphisms (SNPs) within cytokine genes may affect the protein expression and eventually contribute to the susceptibility of HBV infection. The association between interleukin (IL)-12, IL-17, or IL-21 and the risk of HBV infection has been extensively studied, but yielding equivocal results. The aim of this meta-analysis was to determine the impact of SNPs in IL-12, IL-17, and IL-21 on the risk of HBV infection. We retrieved studies evaluating whether SNPs in IL-12, IL-17, and IL-21 influenced HBV infection from electronic databases, including PUBMED, Web of Science, EBOCO, OVID, and Embase. Summarized odds ratios (ORs) and confidence intervals (CIs) were calculated using STATA software. Under a homozygous comparison, the IL-12A rs568408 was associated with an increased risk of HBV infection in both overall analysis (OR = 1.68, 95% CI, 1.12-2.53) and Caucasians (OR = 1.80, 95% CI, 1.14-2.84). Under a dominant genetic model, the similarly higher risk was also observed in overall analysis (OR = 3.62, 95% CI, 3.08-4.24), Caucasians (OR = 3.29, 95% CI, 2.67-4.05), high-quality studies (OR = 3.29, 95% CI, 2.61-4.14), and low-quality studies (OR = 3.95, 95% CI, 3.17-4.93). Although no significant association was observed between IL-17A rs2275913 and the risk of HBV infection in overall comparison, subgroup analysis revealed that the IL-17A rs2275913 AA genotype was associated with a reduced risk in Asians (OR = 0.72, 95% CI, 0.57-0.91) and high-quality studies (OR = 0.71, 95% CI, 0.55-0.92). However, no significant association of IL12B rs3212227, IL-17A rs2275913, IL-21 rs2221903, and rs907715 with HBV infection was observed. In conclusion, we provide evidence that IL-12A rs568408 was associated with an increased risk of HBV infection and IL-17A rs2275913 AA genotype was a protective factor against HBV infection in Asians.

Exploring the Role of a Novel Interleukin-17 Homolog from Invertebrate Marine Mussel Mytilus coruscus in Innate Immune Response: Is Negative Regulation by Mc-Novel_miR_145 the Key?

Interleukin-17 (IL-17) represents a class of proinflammatory cytokines involved in chronic inflammatory and degenerative disorders. Prior to this study, it was predicted that an IL-17 homolog could be targeted by Mc-novel_miR_145 to participate in the immune response of Mytilus coruscus. This study employed a variety of molecular and cell biology research methods to explore the association between Mc-novel_miR_145 and IL-17 homolog and their immunomodulatory effects. The bioinformatics prediction confirmed the affiliation of the IL-17 homolog with the mussel IL-17 family, followed by quantitative real-time PCR assays (qPCR) to demonstrate that McIL-17-3 was highly expressed in immune-associated tissues and responded to bacterial challenges. Results from luciferase reporter assays confirmed the potential of McIL-17-3 to activate downstream NF-κb and its targeting by Mc-novel_miR_145 in HEK293 cells. The study also produced McIL-17-3 antiserum and found that Mc-novel_miR_145 negatively regulates McIL-17-3 via western blotting and qPCR assays. Furthermore, flow cytometry analysis indicated that Mc-novel_miR_145 negatively regulated McIL-17-3 to alleviate LPS-induced apoptosis. Collectively, the current results showed that McIL-17-3 played an important role in molluscan immune defense against bacterial attack. Furthermore, McIL-17-3 was negatively regulated by Mc-novel_miR_145 to participate in LPS-induced apoptosis. Our findings provide new insights into noncoding RNA regulation in invertebrate models.

Comparative molecular docking analysis for analyzing the inhibitory effect of Anakinra and Ustekinumab against IL17F

Interleukin 17 F is a member of IL-17 cytokine family with a 50% structural homology to IL-17A and plays a significant role either alone or in combination with IL-17A towards inflammation in Rheumatoid arthritis (RA). A growing number of drugs targeting IL-17 pathway are being tested against population specific disease markers. The major objective of this research was to investigate the anti-inflammatory effect of Anakinra (an IL-1 R1 inhibitor) and Ustekinumab (an IL-12 and IL-23 inhibitor) by targeting IL17F. The three dimensional structures of IL17F was taken from PDB while structures of drugs were taken from PubChem database. Docking was performed using MOE and Schrodinger ligand docking software and binding energies, including s-score using London-dG fitness function and glide score using glide internal energy function, between drug and targets were compared. Furthermore, Protein-Drug complex were subjected to 150 ns Molecular Dynamics (MD) Simulations using Schrodinger's Desmond Module. Docking and MD simulation results suggest anakinra as a more potent IL17F inhibitor and forming a more structurally stable complex.Communicated by Ramaswamy H. Sarma.

Molecular characterizations, immune modulation, and antibacterial activity of interleukin-17A/F1a and interleukin-17A/F1b in common carp Cyprinus carpio

Interleukin-17 (IL-17), as a pro-inflammatory cytokine family, mediates different pro-inflammatory mediators in various cell types (e.g., epithelial cells, macrophages, endothelial cells, and fibroblasts), which play an important role in defending against pathogens. The IL-17A/F1 genes have recently been reported in fish. However, the functions of these genes are still unclear. In this study, we identified two duplicated IL-17A/F1 genes in common carp (Cyprinus carpio L.), namely, CcIL-17A/F1a and CcIL-17A/F1b. Sequence analysis showed that CcIL-17A/F1a and CcIL-17A/F1b proteins had four conserved cysteine residues, which could form two intra-chain disulfide bridges. Homology comparison displayed that the deduced amino acid sequences of CcIL-17A/F1a and CcIL-17A/F1b shared 31.1%-77.3% and 32.5%-75.7% of sequence similarity to IL-17A/F1 homologues from other fish species, respectively. The mRNA expression levels of CcIL-17A/F1a and CcIL-17A/F1b were obviously increased in gill and head-kidney of fish challenged with A. hydrophila. The recombinant protein rCcIL-17A/F1a and rCcIL-17A/F1b could enhance the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IFN-γ, and TNF-α) and chemokines (CXCL8 and CXCL20). The 3 × Flag eukaryotic expression vectors to express protein rCcIL-17A/F1a (or rCcIL-17A/F1b) were constructed and intramuscularly injected in common carp. The rCcIL-17A/F1a (or rCcIL-17A/F1b) could be successfully expressed in vivo. Four immune-related genes, namely, CD4, CD8, TNF-α, and IgM, were also significantly induced to be expressed at higher mRNA levels compared with the control. The pretreatment with CcIL-17A/F1a or CcIL-17A/F1b could markedly increase the survival rate of common carp challenged with A. hydrophila. Our results demonstrated that CcIL-17A/F1a or CcIL-17A/F1b plays an important role in immune responses and immune defense against bacteria. CcIL-17A/F1a or CcIL-17A/F1b could also be potentially used as an immunopotentiator to prevent diseases in common carp.

Molecular cloning, expression analysis of interleukin 17D (cysteine knot cytokine) from Amphiprion clarkii and their functional characterization and NFκB pathway activation using FHM cells

Interleukin 17D (IL-17D), a pro-inflammatory cytokine, is a signature cytokine of T helper 17 (Th17) cells. However, studies characterizing the functions of IL-17D in teleost are scarce. Therefore, we aimed to characterize the properties of IL-17D in Amphiprion clarkii. We performed spatial and temporal expression, AcIL-17D-mediated antibacterial and inflammatory gene expression, NFκB pathway-related gene expression analyses, and bacterial colony counting and cell protection assays. We found that AcIL-17D contains a 630 bp coding sequence and encodes 210 amino acids. The spatial expression analysis of AcIL-17D in 12 tissues showed ubiquitous expression, with the highest expression in the brain, followed by blood and skin. Temporal expression analysis of AcIL-17D in blood showed upregulated expression at 6 and 24 h (polyinosinic: polycytidylic acid and lipopolysaccharide), 12 h (all stimulants), and 48 h (polyinosinic: polycytidylic acid and Vibrio harveyi). AcIL-17D expression in the blood gradually decreased at later hours in response to all the stimulants. After treatment of fathead minnow (FHM) cells with different recombinant AcIL-17D concentrations, the downstream gene expression analysis showed increased expression of antimicrobial genes in the FHM cells, namely [NK-Lysin (NKL), Hepcidin antimicrobial peptide-1 (HAMP-1), Defensin-β (DEFB1)] and some inflammatory genes such as IL-1β, TNF-α, IL-11, and STAT3. Further nuclear factor κB (NFκB) subunits (NFκB1, NFκB2, RelA, and Rel-B) showed upregulated gene expression at 12 and 24 h. The bacterial colony counting assay using FHM cells showed lower bacterial colony counts in rAcIL-17D-treated cells than in control. Furthermore, the Water-Soluble Tetrazolium Salt (WST -1) assay confirmed the ability of rAcIL-17D in the protection of FHM cells from bacterial infection and conducted the Hoechst 33342 staining upon treatment with rAcIL-17D and rMBP. Therefore, our findings provide important insights into the activation of IL-17D pathway genes in FHM cells, the protective role of AcIL-17D against bacterial infection, and host defense mechanisms in teleost.

The receptor CgIL-17R1 expressed in granulocytes mediates the CgIL-17 induced haemocytes proliferation in Crassostrea gigas

Inflammatory cytokine interleukin-17 (IL-17) binds its receptors (IL-17Rs) to activate the downstream immune signals and plays an important role in host defense. In the present study, an IL-17 receptor (designated as CgIL-17R1) was identified from oyster Crassostrea gigas with an open reading frame of 3141 bp encoding 1047 amino acids. The amino acid sequence of CgIL-17R1 with two conserved FN3 domains shared higher similarity with other known IL-17Rs from mollusc species. The recombinant CgIL-17R1 protein (rCgIL-17R1) displayed high binding affinity to the recombinant CgIL-17 protein (rCgIL-17) in vitro. The mRNA transcripts of CgIL-17R1 were significantly higher expressed in haemocytes, especially in granunolyctes, compared with that in other tissues. After the stimulation with Vibrio splendidus or rCgIL17-1 in vivo, the expressions of CgIL-17R1 and cell proliferation related genes (CgRunx-1, CgCDC-6, CgCDC-45, and CgCDK-2) were significantly up-regulated in haemocytes (p < 0.01). When the CgIL-17R1 expression was interfered by specific CgIL-17R1-dsRNA, the expressions of these cell proliferation related genes reduced significantly, and the proliferation rate of haemocytes declined dramatically at 6 h post V. splendidus stimulation (p < 0.01), compared to that of blank group. These results collectively indicated that CgIL-17R1 expressed in granulocytes mediated the CgIL-17 induced haemocytes proliferation during immune response in oyster C. gigas, which provided novel information about the regulation of haemocyte proliferation in invertebrates.

JUN and PDGFRA as Crucial Candidate Genes for Childhood Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder, characterized by marked genetic heterogeneity. In this study, two independent microarray datasets of cerebellum of ASD were integrative analyzed by NetworkAnalyst to screen candidate crucial genes. NetworkAnalyst identified two up-regulated genes, Jun proto-oncogene (JUN) and platelet derived growth factor receptor alpha (PDGFRA), as the most crucial genes in cerebellum of ASD patients. Based on KEGG pathway database, genes associated with JUN in the cerebellum highlight the pathways of Th17 cell differentiation and Th1 and Th2 cell differentiation. Genes associated with PDGFRA in the cerebellum were found enriched in pathways in EGFR tyrosine kinase inhibitor resistance and Rap1 signaling pathway. Analyzing all differentially expressed genes (DEGs) from the two datasets, Gene Set Enrichment Analysis (GSEA) brought out IL17 signaling pathway, which is related to the expression of JUN and PDGFRA. The ImmuCellAI found the elevated expression of JUN and PDGFRA correlating with increased Th17 and monocytes suggests JUN and PDGFRA may regulate Th17 cell activation and monocytes infiltrating. Mice model of maternal immune activation demonstrated that JUN and PDGFRA are up-regulated and related to the ASD-like behaviors that provide insights into the molecular mechanisms underlying the altered IL17 signaling pathway in ASD and may enable novel therapeutic strategies.

Pharmacokinetic/Pharmacodynamic Assessment of Selective Phosphodiesterase Inhibitors in a Mouse Model of Autoimmune Hepatitis

Autoimmune hepatitis (AIH) is a life-threatening disorder currently treated with nonspecific immunosuppressive drugs. It is postulated that phosphodiesterase (PDE) inhibitors, as agents exerting anti-inflammatory and immunomodulatory activities, may constitute a possible treatment of autoimmune disorders. This study develops a pharmacokinetic/pharmacodynamic (PK/PD) model to assess the effects of PDE-selective inhibitors, namely, cilostazol (PDE3), rolipram (PDE4), and BRL-50481 (PDE7), in a mouse model of AIH. The pharmacokinetics of the PDE inhibitors (PDEi) were assessed in male BALB/c mice after intraperitoneal administration. In pharmacodynamic studies, mice received PDEi and AIH was induced in these animals by intravenous injection of concanavalin A (ConA). Serum drug concentrations, tumor necrosis factor α (TNFα), interleukin 17 (IL-17), and aminotransferase activities were quantified. The PK/PD analysis was performed using ADAPT5 software. The PK/PD model assumes inhibition of cAMP hydrolysis in T cells by PDEi, ConA-triggered formation of TNFα and IL-17, suppression of TNFα and IL-17 production by cAMP, and stimulatory effects of TNFα and IL-17 on the hepatic release of aminotransferases. Selective blockage of PDE4 leads to the highest inhibition of cAMP degradation in T cells and amelioration of disease outcomes. However, inhibition of both PDE3 and PDE7 also contribute to this effect. The proposed PK/PD model may be used to assess and predict the activities of novel PDEi and their combinations in ConA-induced hepatitis. A balanced suppression of different types of PDE appears to be a promising treatment option for AIH; however, this hypothesis warrants testing in humans based on translation of the PK/PD model into clinical settings. SIGNIFICANCE STATEMENT: A novel PK/PD model of PDE inhibitor effects in mice with ConA-induced autoimmune hepatitis was developed involving a mechanistic component describing changes in cAMP concentrations in mouse T cells. According to model predictions, inhibition of PDE4 in T cells causes the highest cAMP elevation in T cells, but suppression of PDE3 and PDE7 also contribute to this effect. A balanced inhibition of PDE3, PDE4, and PDE7 appears to be a promising treatment strategy for AIH.

Associations of IL-4, IL-4R, IL-17A, and IL-17F Polymorphisms with Colorectal Cancer Risk: A Meta-Analysis, Meta-Regression, and Trial Sequential Analysis

Both interleukin (IL)-4 and IL-17 polymorphisms may be involved in the pathogenesis and progression of colorectal cancer (CRC). Herein, we designed a meta-analysis to assess the associations between IL-4, IL-4R, IL-17A, and IL-17F polymorphisms and CRC risk. Scopus, Web of Science, Cochrane Library, and PubMed databases were searched to retrieve articles published until October 21, 2021. We used crude odds ratio (OR) and 95% confidence interval assessing the association of the polymorphisms and CRC risk in 5 genetic models. Trial sequential analysis for the primary analyses was used to control random errors. Twenty-three studies (8: IL-4 rs2243250, 4: IL-4R rs1801275, 5: IL-17A rs2275913, and 6: IL-17F rs763780) were involved in the meta-analysis. The pooled OR (P-value) for the association between IL-4 rs2243250 polymorphism and the CRC risk was 1.11 (0.08), 1.27 (0.12), 1.07 (0.37), 1.09 (0.17), and 1.22 (0.12), for IL-4R rs1801275 polymorphism was 0.71 (0.18), 1.05 (0.76), 0.86 (0.37), 0.87 (0.41), and 0.69 (0.39), for IL-17A rs2275913 polymorphism was 1.83 (0.0003), 1.73 (0.06), 1.47 (<0.001), 1.61 (0.001), and 1.42 (0.15), and for IL-17F rs763780 polymorphism was 1.07 (0.48), 5.33 (0.02), 1.08 (0.49), 1.08 (0.47), and 8.42 (0.002) in allelic, homozygous, heterozygous, recessive, and dominant models, respectively. The G allele and GA genotype of IL-17A rs2275913 polymorphism and the CC genotype of IL-17F rs763780 polymorphism had an elevated risk in CRC cases. The ethnicity and genotyping method, sample size, control, and publication year were effective factors on the pooled results.

A TLR5 mono-agonist restores inhibited immune responses to Streptococcus pneumoniae during influenza virus infection in human monocytes

Influenza A virus (IAV) predisposes individuals to often more severe secondary bacterial infections with Streptococcus pneumonia (S. pneumoniae). The outcomes of these infections may be made worse with the increase in antimicrobial resistance and a lack of new treatments to combat this. Th17 responses are crucial in clearing S. pneumoniae from the lung. We previously demonstrated that early IAV infection of human monocytes significantly reduced levels of S. pneumoniae-driven cytokines involved in the Th17 response. Here, we have further identified that IAV targets specific TLRs (TLR2, TLR4, TLR9) involved in sensing S. pneumoniae infection resulting, in a reduction in TLR agonist-induced IL-23 and TGF-β. The effect of IAV is more profound on the TLR2 and TLR9 pathways. We have established that IAV-mediated inhibition of TLR9-induction is related to a downregulation of RORC, a Th17 specific transcription factor. Other studies using mouse models demonstrated that TLR5 agonism improved the efficacy of antibiotics in the treatment of IAV/S. pneumoniae co-infections. Therefore, we investigated if TLR5 agonism could restore inhibited Th17 responses in human monocytes. Levels of pneumococcus-driven cytokines, which had previously been inhibited by IAV were not reduced in the presence of the TLR5 mono-agonist, suggesting that such treatment may overcome IAV inhibition of Th17 responses. The importance of our research is in demonstrating the IAV directly targets S. pneumoniae-associated TLR pathways. Additionally, the IAV-inhibition of Th17 responses can be restored by TLR5 agonism, which indicates that there may be a different Th17 signalling pathway which is not affected by IAV infection.

Influence of IL10 (rs1800896) Polymorphism and TNF-α, IL-10, IL-17A, and IL-17F Serum Levels in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic autoimmune inflammatory disease that mainly affects the axial and sacroiliac joints. Single-nucleotide polymorphisms (SNPs) in genes encoding cytokines have been associated with AS, which can interfere with the production of these cytokines and contribute to the development of AS. In order to contribute to a better understanding of the pathology of AS, our objective was to investigate a possible association of the IL10 −1082 A>G SNP (rs1800896) with AS and to evaluate the serum levels of TNF-α, IL-10, IL-17A, and IL-17F in AS patients and controls comparing them with their respective genotypes (TNF rs1800629, IL10 rs1800896, IL17A rs2275913, and IL17F rs763780). Patients and controls were selected from the Maringá University Hospital and the Maringá Rheumatism Clinic, in Paraná State, Southern Brazil, and they were diagnosed by the ASAS Criteria. In total, 149 patients and 169 controls were genotyped for the IL10 −1082 A>G polymorphism using a polymerase chain reaction with sequence specific primers (PCR-SSP); the measurement of TNF-α serum levels was performed through the immunofluorimetric test and IL-10, IL-17A, and IL-17F using an ELISA test. There was a high frequency of the IL10 −1082 G allele in AS patients compared with controls with an odds ratio of 1.83 and 95% confidence interval of 1.32 to 2.54, and a significant difference in the genotype frequencies of the IL10 −1082 A/G+G/G between patients and healthy controls, with an odds ratio of 3.01 and 95% confidence interval of 1.75 to 5.17. In addition, increased serum levels of IL-10 were observed in AS patients: 2.38 (IQR, 0.91) pg/ml compared with controls 1.72 (IQR 0.93) pg/ml (P = 0.01). Our results also showed an association between IL17F rs763780 C/T+T/T genotypes and increased serum levels of IL-17F in patients with AS and also in controls. We can conclude that patients with the A/G and G/G genotypes for −1082 A>G (rs1800896) in the IL10 gene are three times more likely to develop AS, that the serum level of IL-10 was higher in AS patients and that the IL17F rs763780 polymorphism can affect the levels of IL-17F in the serum of patients and controls in the same way.

Relationships of interleukin-17 polymorphisms with recurrent aphthous ulcer risk in a Han Chinese population

Objective

Interleukin (IL)-17 is a multifunctional cytokine with important roles in inflammatory and autoimmune diseases. This case–control study explored the relationships of IL-17A rs2275913 and IL-17F rs763780 single-nucleotide polymorphisms (SNPs) with recurrent aphthous ulcer (RAU) morbidity and severity.

Methods

IL-17A rs2275913 and IL-17F rs763780 SNPs were measured in 125 patients with RAU and 116 healthy control participants. The genotype distributions, disease risks, and relationships with RAU severity were analyzed.

Results

RAU risk was associated with rs2275913 after adjustment for age, body mass index, sex, smoking status, and drinking status (AA vs. GG: odds ratio [OR], 2.759; 95% confidence interval [CI], 1.381–5.512; A allele vs. G allele: OR, 1.783; 95% CI, 1.242–2.560). TC and CC genotypes in rs763780, and the corresponding C allele, demonstrated greater prevalence among patients with RAU, compared with the TT genotype (TC vs. TT, OR: 1.895; 95% CI: 1.088–3.301; CC vs. TT, OR: 4.080, 95% CI: 1.079–15.425; C allele vs. T allele, OR: 1.969, 95% CI: 1.257–3.083). Serum IL-17 concentrations were also higher in patients with RAU than in control participants. These concentrations were associated with IL-17 polymorphisms.

Conclusions

IL-17 polymorphisms might be associated with greater risk of RAU pathogenesis.

Anti-IL-17 Agents in the Treatment of Axial Spondyloarthritis

Axial spondyloarthritis (axSpA) describes a group of chronic inflammatory rheumatic diseases primarily involving the axial skeleton. IL-17 is involved in the pathogenesis of numerous inflammatory diseases, including inflammatory arthritis. Until a few years ago, the only biological agents licensed for the treatment of axSpA and nr-axSpA were TNF inhibitors. However, as some patients did not respond to TNF inhibition or experienced secondary failure, the introduction of the first two IL-17 inhibitors (secukinumab [SEC] and ixekizumab [IXE]) has extended the treatment options, and there are now three others (bimekizumab, brodalumab and netakimab) in various stages of clinical development. The last ten years have seen the development of a number of therapeutic recommendations that aimed at improving the management of axSpA patients. The aim of this narrative review of the published literature concerning the role of IL-17 in the pathogenesis of SpA, and the role of IL-17 inhibitors in the treatment of axSpA, is to provide a comprehensive picture of the clinical efficacy and safety of the drugs themselves, and the treatment strategies recommended in the international guidelines.

Predicted regulatory SNPs reveal potential drug targets and novel companion diagnostics in psoriasis

Psoriasis is an autoimmune disease associated with interleukins, their receptors, key transcription factors and more recently, antimicrobial peptides (AMPs). Cathelicidin LL-37 is an AMP proposed to play a fundamental role in psoriasis etiology. With our proprietary software SNPClinic v.1.0, we analyzed 203 common SNPs (MAF frequency ​> ​1%) in proximal promoters of 22 genes associated with psoriasis. These include nine genes which protein products are classic drug targets for psoriasis (TNF, IL17A, IL17B, IL17C, IL17F, IL17RA, IL12A, IL12B and IL23A). SNPClinic predictions were run with DNAseI-HUP chromatin accessibility data in eight psoriasis/epithelia-relevant cell lines from ENCODE including keratinocytes (NHEK), T_H1 and T_H17 lymphocytes. Results were ranked quantitatively by transcriptional relevance according to our novel Functional Impact Factor (FIF) parameter. We found six rSNPs in five genes (CAMP/cathelicidin, S100A7/psoriasin, IL17C, IL17RA and TNF) and each was confirmed as true rSNP in at least one public eQTL database including GTEx portal and ENCODE (Phase 3). Predicted regulatory SNPs in cathelicidin, IL17C and IL17RA genes may explain hyperproliferation of keratinocytes. Predicted rSNPs in psoriasin, IL17C and cathelicidin may contribute to activation and polarization of lymphocytes. Predicted rSNPs in TNF gene are concordant with the epithelium-mesenchymal transition. In spite that these results must be validated in vitro and in vivo with a functional genomics approach, we propose FOXP2, RUNX2, NR2F1, ELF1 and HESX1 transcription factors (those with the highest FIF on each gene) as novel drug targets for psoriasis. Furthermore, four out of six rSNPs uncovered by SNPClinic v.1.0 software, could also be validated in the clinic as companion diagnostics/pharmacogenetics assays for psoriasis prescribed drugs that block TNF-α (e.g. Etanercept), IL-17 (e.g. Secukinumab) and IL-17 receptor (Brodalumab).

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We found six putative regulatory SNPs in cathelicidin (LL-37), psoriasin (S100A7), IL17C, IL17RA and TNF genes.

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These rSNPs could be validated also as companion diagnostics/pharmacogenetics assays for most approved psoriasis drugs.

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Regulatory SNPs in TNF gene are concordant with the epithelial-mesenchymal transition.

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Regulatory SNPs in IL17C and IL17RA may partially explain hyperproliferation of keratinocytes.

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Regulatory SNP rs12049559 in psoriasin (S100A7) may contribute to T-cell polarization.

Interleukin 17F gene variations showed no association with BCG osteitis risk after newborn vaccination

AIM

Interleukin-17 (IL-17) family cytokines promote the host defence against mycobacterial infections. We have previously shown an association between IL17A variations and Bacillus Calmette-Guérin (BCG) osteitis. This paper evaluates the association of three IL17F polymorphisms with BCG osteitis after newborn vaccination.

METHODS

IL17F rs763780, rs11465553 and rs7741835 single nucleotide polymorphisms (SNPs) were studied in 132 adults, who presented with BCG osteitis in infancy. The genotypes and minor allele frequencies (MAFs) were compared between cases and Finnish population-based controls (N = 99) from the 1000 Genomes Project, and MAFs were compared between cases and allele data of Finnish subjects from the large Genome Aggregation Database.

RESULTS

There were no significant differences between former BCG osteitis patients and population-based controls in the IL17F rs763780 (wild 84.4% vs 84.8%), rs11465553 (86.4% vs 91.9%) or rs7741835 (65.7% vs 67.7%) genotypes. Homozygous variant genotypes were only present in 1.5%, 0.8% and 3.8% of cases, respectively. Likewise, MAFs of the three IL17F SNPs did not substantially differ from those of 11 252, 11 939 and 1371 Finnish subjects, respectively, from the available Genome Aggregation Database.

CONCLUSION

IL17F rs763780, rs11465553 and rs7741835 variations showed no association with the risk of BCG osteitis after newborn vaccination.

Current, New and Future Therapeutic Targets in Inflammatory Bowel Disease: A Systematic Review

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic relapsing conditions resulting from immune system activity in a genetically predisposed individual. IBD is based on progressive damage to the inflamed gut tissue. As its pathogenesis remains unknown, recent accumulating data have demonstrated that IBD is a complex and multi-factorial disorder correlated with host luminal factors, which lead to an imbalance between pro- and anti-inflammatory signaling. The growing understanding of the molecular mechanisms responsible for IBD has suggested a wide range of potential therapeutic targets to treat this condition. Some patients do not have a satisfactory response to current therapeutic medications such as antitumor necrosis factor (TNF) agents, or their response decreases over time. As a result, IBD therapeutics have been changed recently, with several new agents being evaluated. The identification of various inflammatory cascades has led to forming the idea to have novel medications developed. Medications targeting Janus kinases (JAK), leukocyte trafficking Interleukin (IL) 12/23, and Sphingosine 1 phosphate (S1P) are among these newly developed medications and highlight the role of microbial-host interaction in inflammation as a safe promising strategy. This systematic review aims to summarize different molecular targeting therapeutics, the most potent candidates for IBD treatment in recent studies.

Characterization of the IL-17 and CD4+ Th17 Cells in the Clinical Course of Dengue Virus Infections

The aims of this study were to determine the involvement of interleukin 17 (IL-17) and IL-17-producing cells in dengue pathogenesis. Blood samples from dengue virus (DENV)-infected patients were collected on different days after the onset of symptoms. Patients were classified according to 1997 World Health Organization guidelines. Our study examined 152 blood samples from dengue fever (DF, n = 109) and dengue hemorrhagic fever (DHF, n = 43) patients and 90 blood samples from healthy controls (HC). High serum concentrations of IL-17A and IL-22 were also associated with DHF (IL-17A [DHF vs. DF, p < 0.01; DHF vs. HC, p < 0.0001]; IL-22 [DHF vs. DF, p < 0.05; DHF vs. HC, p < 0.0001]). Moreover, there was a positive correlation between serum levels of IL-17A and IL-23, a key cytokine that promotes IL-17-based immune responses (r = 0.4089, p < 0.0001). Consistent with the IL-17-biased immune response in DHF patients, we performed ex vivo activation of peripheral blood mononuclear cells (PBMCs) from DHF patients and flow cytometry analysis showed a robust IL-17-biased immune response, characterized by a high frequency of CD4+IL-17+ producing cells. Our results suggests IL-17-producing cells and their related cytokines can play a prominent role in this viral disease.

Cytokine profiles in patients with newly diagnosed multiple myeloma: Survival is associated with IL-6 and IL-17A levels

BACKGROUND

Identifying specific risk factors associated with multiple myeloma (MM) remains a significant issue. Different cytokines take part in the pathogenesis, progression, and prognosis of MM. Therefore, this study aimed to investigate the correlations between serum cytokine levels and clinical characteristics and determine their effects on disease progression and survival of MM patients.

METHODS

We retrospectively analyzed the serum levels of 7 cytokines in 105 patients with newly diagnosed MM and in 20 healthy subjects. Interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were quantitatively determined by cytometric bead assay techniques. The concentrations of each cytokine were compared between the MM patients and healthy subjects using the Mann-Whitney U test. The Kaplan-Meier method was used to analyze progression-free survival (PFS) and overall survival (OS).

RESULTS

Serum IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and IFN-γ levels were higher in patients with newly diagnosed MM than in healthy controls. Positively significant correlations were found between IL-6, IL-10, IL-17A, and β2-microglobulin. Significant correlations were also observed between IL-6 and IL-10, and lactate dehydrogenase. The overall response rate of low-IL-6 and IL-17A patients was significantly higher than that of high-IL-10 and IL-17A patients (P < 0.01). Univariate and multivariate analyses revealed that serum IL-6 levels were >3 pg/mL, serum IL-17A levels were >4 pg/mL, and treatment regimens were independent prognostic factors for PFS and OS.

CONCLUSIONS

Cytokine deregulation, especially that of IL-6 and IL-17A, may be a powerful predictor of clinical prognosis for MM patients.

LDGs versus NDGs in patients with oral squamous cell carcinoma (OSCC)

BACKGROUND

The significant role played by neutrophils in cancer biology is indisputable; yet, their subpopulations may exhibit a contrasting role. The phenomenon of polarization of neutrophils and signaling modulators in the course of a neoplastic process has gained increased attention in recent times. The present study's objective was to quantitatively assess low-density neutrophils (LDNs) and normal-density neutrophils (NDNs) populations including IL-17 expression in confrontation with Th17 lymphocytes in patients with oral squamous cell carcinoma (OSCC). The neutrophil to lymphocyte ratio (NLR) biomarker value was determined. Besides, the influence of rhIL-17 on the proliferation level of the squamous cell carcinoma (SCC) malignant line cells was tested.

METHODS

Leukocytes were isolated in the density gradient and the CD16+ population was magnetically sorted. The percentages of neutrophil subpopulations, lymphocyte Th17, and IL-17 expression in the studied cells were determined on a flow cytometer. Squamous cell carcinoma proliferation was assessed with the MTT test.

RESULT

The existence of two populations of human neutrophils was determined: LDNs and NDNs. A higher percentage of LDNs and Th17 was observed with the concomitant lower percentage of NDNs in patients with OSCC as compared with the control group. NLR was elevated in patients with cancer. The highest IL-17 expression was obtained in the LDNs population in these patients. However, no influence of IL-17 on SCC proliferation could be determined.

CONCLUSION

The present study demonstrated a strong relationship between IL-17 concentration and the count of LDNs or Th17 in the course of OSCC, which may serve as a reference point for new therapies. Moreover, the obtained LDNs/NDNs and NLR values in patients with cancer prove their usefulness in diagnostic and prognostic in patients with OSCC.

Effects of Intermittent Mild Cold Stimulation on mRNA Expression of Immunoglobulins, Cytokines, and Toll-Like Receptors in the Small Intestine of Broilers

Simple Summary

Cold stress has been associated with adverse effects on health and welfare of broilers. Whilst several studies have shown that long-term sustained and mild cold stimulation can improve immune function, little is known of the effects of intermittent cold stimulation on immune modulation in broilers. In this study, broilers were submitted to cold stimulation of 3 °C below than the usual rearing temperature during 3 and 6 h every two days during 43 days to explore its effect on the intestinal immunity. The findings confirm that appropriate mild cold stimulation has an overall positive influence on the intestinal immunity of broilers. The mild cold stimulation tested in this study is cost-effective and likely enhances overall health of broilers.

Abstract

Appropriate cold stimulation can improve immune function and stress tolerance in broilers. In order to investigate the effect of intermittent mild cold stimulation on the intestinal immunity of broilers, 240 healthy one-day-old Ross 308 chickens were randomly divided into three groups: the control group (CC) housed in climatic chambers under usual rearing ambient temperature with a gradual 3.5 °C decrease per week; group II (C3) and group III (C6) to which cold stimulation at 3 °C below the temperature used in CC was applied every two days for 3 and 6 h, respectively, from day 15 to 35, and at the same temperature used in CC from day 35 to 43. The mRNA expression levels of immunoglobulins (IgA and IgG), cytokines (IL2, IL6, IL8, IL17, and IFNγ), and Toll-like receptors (TLR2, TLR4, TLR5, TLR7, and TLR21) were investigated in duodenum, jejunum, and ileum tissue samples on days 22, 29, 35, and 43. From day 15 to 35, mRNA expression of IL2 and IFNγ was increased in the intestine of broilers. After one week of cold stimulation on day 43, mRNA levels of immunoglobulins, cytokines, and Toll-like receptors (TLRs) stabilized. Collectively, the findings indicate that cold stimulation at 3 °C below the usual rearing temperature had a positive impact on intestinal immunity of broilers.

Deltex-1 is indispensible for the IL-6 and TGF-β treatment-triggered differentiation of Th17 cells

CSL(CBF1, Su(H) and LAG-1)-dependent Hes-1 signaling plays an important part in regulating Th17 cell differentiation. However, little is known about influence of CSL-independent Deltex-1 signaling on this subset. The current focus is on roles of the Deltex-1 signaling in the Th17 cell differentiation. IL-17-producing CD4⁺ T cell subpopulation could be induced in vitro by treatment of both IL-6 and TGF-β. This could be reversed by knockdown of the deltex-1 gene, following the attenuation of retinoic acid-related orphan receptor γt (RORγt) and its DNA-binding activity in nuclei. Subsequently, Th17-associated cytokines generated by the treated cells were also diminished by the inhibition of Deltex-1 signaling, but the production of IL-10 was enhanced. Contrary to the alteration of RORγt, both zinc-finger transcription factor-3 (GATA3) and transcription factor Forkhead box P3 (Foxp3) were augmented at their mRNA and protein levels as well as DNA-binding activities with the emerging phenotypes of the corresponding cellular subpopulation and T-bet (encoded by TBX21) was not changed. These results reveal for the first time that Deltex-1 is indispensible for the IL-6 and TGF-β treatment-triggered differentiation of Th17 cells, indicating that CSL-independent Deltex-1 signaling favors naïve CD4⁺ T cells to deviate into Th17 cells via the enhancement of RORγt/IL-17A.

Role of IL-17 gene polymorphisms in osteoarthritis: A meta-analysis based on observational studies

BACKGROUND

Osteoarthritis (OA) is a chronic complex multifactorial joint disease, and a major degenerative form of arthritis. Existing studies on the association between polymorphisms of the IL-17 gene and the risk of OA in different populations have yielded conflicting findings.

AIM

To investigate the association between polymorphisms of the IL-17 gene and the risk of OA.

METHODS

We conducted a meta-analysis by systematically searching databases, including PubMed, EMBASE, MEDLINE, Cochrane Library, and Google Scholar to evaluate this association by calculating pooled odds ratios with 95% confidence intervals. Moreover, subgroup analyses stratified by ethnicity and OA type were also conducted.

RESULTS

In a total of 6 citations involving 8 studies (2131 cases and 2299 controls), 4 single nucleotide polymorphisms were identified. Of these 4 polymorphisms, 2 (rs2275913, rs763780) were common in five case-control studies. Together, the pooled results revealed that the A allele and genotype AA/GA of the rs2275913 polymorphism, and the C allele and genotype CC of the rs763780 polymorphism in the IL-17 gene increased the risk of OA. Furthermore, stratification analyses by ethnicity and OA type showed that the rs2275913 polymorphism increased the risk of OA among Asians and in knee/hip OA, respectively. In addition, stratification analyses also revealed that the rs763780 polymorphism increased OA risk among both Asians and Caucasians in knee/hip OA.

CONCLUSION

The rs763780 polymorphism of the IL-17F gene increased the risk of OA, whereas the rs2275913 polymorphism of the IL-17A gene increased the risk of OA only among Asians. Due to the limitations of this study, these findings should be validated in future studies.

Association of Interleukin-17 gene polymorphisms with susceptibility to chronic hepatitis B virus infection and clearance in Iranian population

Hepatitis B virus (HBV) approximately infects 350 million people. Interleukin-17 (IL-17) as a pro-inflammatory cytokine, have been found to modulate the immune system in infectious and inflammatory diseases. Recently, the influence of genetic changes like single nucleotide polymorphisms (SNP) on expression rate and function of cytokine has been widely investigated. This study was performed to determine any possible association between four IL-17 SNPs (rs2397084, rs763780, rs2275913 and rs10484879) and chronic HBV infection. A total of 466 samples were recruited and studied including 199 chronic patients, 172 healthy controls and 95 spontaneous clearance individuals between genotype and allele frequencies. Genomic DNA was extracted from peripheral blood cells and Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) was used to determine the SNPs genotypes. Genotypes frequencies for rs10484879 were 63.8% CC, 31.7% AC, 4.5% AA in chronic group, 54.7% CC, 36.6% AC, 8.7% AA in control and 63.2% CC, 33.7% AC, 5.8% AA in cleared samples. The AC genotype for rs10484879 was significantly associated with a decreased risk of HBV chronicity (Pvalue = 0.031, OR = 2.699, 95%CI: 1.097-6.639). The genotype and allele frequencies of rs2397084, rs763780 and rs2275913 did not show significant difference between chronic HBV patients and healthy controls. Indeed, there is no significant difference between clearance and chronic patient's genotypes in four SNPs. Our results suggest that IL-17A rs10484879 single nucleotide polymorphism genotype is probably associated with susceptibility to HBV chronic infection, while no significant differences in IL-17 rs2397084, rs763780 and rs227591 distribution were found between HBV patients and spontaneous clearance individuals and control participants.

Narrow-Leafed Lupin (Lupinus angustifolius L.) Seeds Gamma-Conglutin is an Anti-Inflammatory Protein Promoting Insulin Resistance Improvement and Oxidative Stress Amelioration in PANC-1 Pancreatic Cell-Line

(1) Background: Inflammation molecular cues and insulin resistance development are some of the main contributors for the development and advance of the pathogenesis of inflammatory-related diseases; (2) Methods: We isolated and purified γ-conglutin protein from narrow-leafed lupin (NLL or blue lupin) mature seeds using affinity-chromatography to evaluate its anti-inflammatory activities at molecular level using both, a bacterial lipopolysaccharide (LPS)-induced inflammation and an insulin resistance pancreatic cell models; (3) Results: NLL γ-conglutin achieved a plethora of functional effects as the strong reduction of cell oxidative stress induced by inflammation through decreasing proteins carbonylation, nitric oxide synthesis and inducible nitric oxide synthase (iNOS) transcriptional levels, and raising glutathione (GSH) levels and modulation of superoxide dismutase (SOD) and catalase enzymes activities. γ-conglutin induced up-regulated transcriptomic and protein levels of insulin signalling pathway IRS-1, Glut-4, and PI3K, improving glucose uptake, while decreasing pro-inflammatory mediators as iNOs, TNFα, IL-1β, INFγ, IL-6, IL-12, IL-17, and IL-27; (4) Conclusion: These results suggest a promising use of NLL γ-conglutin protein in functional foods, which could also be implemented in alternative diagnosis and therapeutic molecular tools helping to prevent and treat inflammatory-related diseases.

Schizophyllum commune induces IL-17-mediated neutrophilic airway inflammation in OVA-induced asthma model mice

Schizophyllum commune is a ubiquitous basidiomycetous fungus typically found across the world, which has been detected in indoor and outdoor air. Some studies indicated that sensitization to S. commune is correlated with asthma severity in patients. Patients with chronic severe or acute fatal asthma have neutrophil-dominant airway inflammation. We hypothesized that S. commune can exacerbate asthma. To test this hypothesis, we evaluated the direct immunomodulatory activities of S. commune in allergic airway inflammation induced by non-fungal sensitization. Ovalbumin (OVA)-induced asthma model mice were generated using wild-type (WT) and Il-17a^-/-Il-17f^-/- mice that were intratracheally exposed to S. commune, then immune responses in the lungs were assessed after 24 h. Intratracheal administration of S. commune in OVA-induced asthma model mice enhanced neutrophilic airway inflammation, increased the mRNA expression of CXCL1 and CXCL2 in the lungs, and provoked IL-17A, and IL-17F production in BAL fluid. In addition, neutrophilic airway inflammation was significantly inhibited in Il-17a^-/-Il-17f^-/- mice compared with those found in WT mice. We demonstrated that S. commune induces neutrophilic airway inflammation in OVA-induced asthma model mice, and IL-17A and IL-17F had central roles in this activity. As S. commune inhabits the general environment, including indoor and outdoor air, our results suggested that S. commune is a causative agent of asthma exacerbation. This study has provided clues regarding the mechanisms behind fungi and asthma exacerbation.

Association of IL-17A-197G/A and IL-17F-7488T/C polymorphisms and osteoarthritis susceptibility: A meta-analysis

AIM

This meta-analysis was conducted with the aim of collecting and synthesizing the existing evidence on the association of interleukin-17A (IL-17A)-197G/A and IL-17F-7488T/C gene polymorphisms and osteoarthritis (OA) susceptibility.

METHODS

Six electronic databases including PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, and Wanfang were systematically searched for potentially relevant studies previous to June 2019. The strengths of association were estimated by summary odds ratios (ORs) and 95% confidence intervals (95%CIs) in a model-free approach. Heterogeneity test and sensitivity analysis were also conducted to guarantee the reliability of this study.

RESULTS

Six eligible case-control studies comprising 1989 OA patients and 2116 healthy controls were obtained for the meta-analysis. Dominant model was confirmed to be the optimal genetic model (MM + Mm vs mm). The pooled estimate supported that IL-17A-197G/A and IL-17F-7488T/C polymorphisms were significantly associated with OA susceptibility in the overall population (IL-17A-197G/A: GG + GA vs AA, OR = 0.69, 95%CI 0.57-0.80; P < .001; IL-17F-7488T/C, TT + TC vs CC, OR = 0.46, 95%CI 0.29-0.71, P < .001). However, subgroup analyses suggested the association only existed in Asians and knee OA.

CONCLUSION

The findings of the present study indicate that IL-17A-197G/A and IL-17F-7488T/C polymorphisms are positively associated to reduced risk of knee OA, especially in Asian populations.

Inflammatory cytokines in bladder cancer

The presence of inflammatory cells and their products in the tumor microenvironment plays a crucial role in the pathogenesis of a tumor. Releasing the cytokines from a host in response to infection and inflammation can inhibit tumor growth and progression. However, tumor cells can also respond to the host cytokines with increasing the growth/invasion/metastasis. Bladder cancer (BC) is one of the most common cancers in the world. The microenvironment of a bladder tumor has been indicated to be rich in growth factors/inflammatory cytokines that can induce the tumor growth/progression and also suppress the immune system. On the contrary, modulate of the cancer progression has been shown following upregulation of the cytokines-related pathways that suggested the cytokines as potential therapeutic targets. In this study, we provide a summary of cytokines that are involved in BC formation/regression with both inflammatory and anti-inflammatory properties. A more accurate understanding of tumor microenvironment creates favorable conditions for cytokines targeting to treat BC.

IL-17 in the immunopathogenesis of spondyloarthritis

Spondyloarthritis (SpA) is a term that refers to a group of inflammatory diseases that includes psoriatic arthritis, axial SpA and nonradiographic axial SpA, reactive arthritis, enteropathic arthritis and undifferentiated SpA. The disease subtypes share clinical and immunological features, including joint inflammation (peripheral and axial skeleton); skin, gut and eye manifestations; and the absence of diagnostic autoantibodies (seronegative). The diseases also share genetic factors. The aetiology of SpA is still the subject of research by many groups worldwide. Evidence from genetic, experimental and clinical studies has accumulated to indicate a clear role for the IL-17 pathway in the pathogenesis of SpA. The IL-17 family consists of IL-17A, IL-17B, IL-17C, IL-17D, IL-17E and IL-17F, of which IL-17A is the best studied. IL-17A is a pro-inflammatory cytokine that also has the capacity to promote angiogenesis and osteoclastogenesis. Of the six family members, IL-17A has the strongest homology with IL-17F. In this Review, we discuss how IL-17A and IL-17F and their cellular sources might contribute to the immunopathology of SpA.

Psoriasis: Association of interleukin-17 gene polymorphisms with severity and response to treatment

Psoriasis is a chronic, inflammatory disease with a complex pathogenesis that is not yet fully understood. Although it is a multifactorial disease, the genetic factor has a major role in the pathogenesis of psoriasis. Genome wide association studies have identified over 50 genetic loci associated with psoriasis risk. Beside TNF-α or IL-23, the IL-17 family is a newer group that has proven implications in the pathogenesis of psoriasis. The most important members of the family, with pro-inflammatory qualities, are IL-17A and IL-17F. These interleukins are produced by a varied number of cells, but by far the most important are Th17 cells. Of the patients 20-30% present moderate-to-severe psoriasis, therefore, systemic medication (phototherapy, methotrexate, cyclosporine, acitretin or biologic agents) is mandatory. The necessity of an individualized treatment plan, for each patient, is imperative in order to establish the best strategy for non-responders to classical treatment or to other biologic treatments. The discovery of Th17 pathway improved the treatment and prognosis of psoriasis. Anti-psoriatic agents against IL-17 or its receptors are a novel group of biologic agents; these include ixekizumab, secukinumab and brodalumab. Polymorphisms of IL-17 family have been correlated with the severity and response to treatment in psoriasis, and also with the risk of inflammatory, infectious, autoimmune or neoplastic pathologies. The significant difference in the presence or absence of susceptibility loci in different population is due to genetic background and environmental factors that have a major impact on disease predisposition. In this study, we reviewed the importance and influence of the IL-17 polymorphisms as predictors of response to treatment and severity of the disease.

Preparation of a novel monoclonal antibody against caprine interleukin-17A and its applications in immunofluorescence and immunohistochemistry assays

BACKGROUND

Interleukin-17 (IL-17), the characteristic cytokine secreted by T helper 17 lymphocytes (Th17 cells), plays a pivotal role in host defense and many inflammatory or autoimmune diseases. The aim of this study was to obtain purified protein caprine IL-17A (cIL-17A) as an antigen for preparing an IL-17A-specific monoclonal antibody (mAb).

RESULTS

The coding sequence (CDS) region of cIL-17A was cloned from the peripheral blood mononuclear cells (PBMCs) of dairy goats and then inserted into the expression vector PET 32a and transformed into competent TransB (DE3) cells. Recombinant fusion protein obtained under optimized conditions was used to immunize BALB/c mice for preparing monoclonal antibodies. Finally, the supernatants of two hybridoma cell lines showing positive reaction with the recombinant fusion protein and negative reaction with fusion tags of PET 32a were collected for western blot, immunofluorescence (IF) and immunohistochemistry (IHC) analysis. Our results showed that the maximum amount of soluble protein could be obtained directly in the supernatant when the recombinant expression cells were induced by isopropyl-β-d-thiogalactoside (IPTG) at a concentration of 0.3 mmol/L at 16 °C for 42 h. Western blot analysis showed that the mAb H8 could recognize the eukaryotically expressed cIL-17A in the supernatant of transfected HEK293T cells. Immunofluorescence and immunohistochemistry assays showed that mAb H8 could strongly recognize both the eukaryotically expressed and natural cIL-17A.

CONCLUSIONS

The monoclonal antibody mAb H8 prepared in this study may be a potential tool for the detection of cIL-17A and beneficial for investigating the pathogenesis of various IL-17-associated diseases.

Interleukin-17 expression in the serum and exfoliated cervical cells of patients infected with high-risk oncogenic human papillomavirus

Persistent infection by high-risk oncogenic human papillomavirus (HR-HPV) is the main cause of cervical cancer and its precursor lesions, and both the systemic and local immunological responses play an important role in eliminating or maintenance this infection. Th17 cells, as well as interleukin (IL)-17, are related to tumor growth and persistence of viral infection. Thus, this study aimed to quantify IL-17 in the serum and exfoliated cervical cells of HR-HPV-infected patients and healthy patients as well as identify CD4⁺IL17⁺ cells and IL-17 production in uterine cervix biopsies to better understand the behavior of this cytokine in HPV infections. IL-17 was quantified (pg/mL) in the serum and exfoliated cervical cells of 26 HR-HPV-infected patients, and in 18 healthy patients, using flow cytometry. Fifteen paraffin-embedded biopsy samples from the uterine cervix were subjected to immunohistochemistry to detect CD4⁺IL-17⁺ and IL-17⁺ cells. There was a significant increase in the concentration of IL-17 in HR-HPV-positive patients' serum when compared to that in samples of exfoliated cervical cells (p < 0.05). Likewise, when compared with that in healthy patients, the IL-17 concentration was still higher in HR-HPV-positive patients sera (p < 0.05). We did not find differences in the amount of CD4⁺IL-17⁺ cells and other IL-17-secreting cells between different histopathological lesions. Our results suggest that HR-HPV infection predominantly stimulates systemic IL-17 production along with less localized expression.

Evolution and function analysis of interleukin-17 gene from Pinctada fucata martensii

Interleukin-17 (IL-17) is a proinflammatory cytokine that plays an important role in immune responses. In this study, we identified 57 IL-17 genes from the genomes of six marine invertebrates, including Pinctada fucata martensii, Crassostrea gigas, Lottia gigantea, Capitella teleta, Mizuhopecten yessoensis, and Mytilus galloprovincialis. Phylogenetic analysis showed that all invertebrate IL-17 genes were clustered into one group, implying that invertebrate IL-17 evolved from one common ancestral gene. From the extron-intron analysis, we found many intronless IL-17 genes in mollusks, which may be caused by retroposition. Tissue and development transcriptomic analysis showed that the expression of PmIL-17 was tissue and developmental stage-specific. Moreover, we cloned the full length of the IL-17-2 gene from P. f. martensii (PmIL-17-2) and explored its function in the immune response. The full-length cDNA of PmIL-17-2 is 719 bp, containing an open reading frame of 564 bp, a 5' -untranslated region (UTR) of 31 bp, and a 3' -UTR of 124 bp with a 30 bp poly (A) tail. PmIL-17-2 had a strong response to lipopolysaccharide (LPS), indicating that the PmIL-17-2 participates in innate immune responses. In situ hybridization of hemocytes showed that PmIL-17-2 was mainly produced by granulosa cells, and the number of the stained granulosa increased after LPS stimulation. These results lay the foundation for the research of IL-17 family in marine invertebrates.

Osteopontin and interleukin-17A genes polymorphisms in Egyptian systemic lupus erythematosus patients: A relation to disease activity and severity

Osteopontin (OPN) is involved in the regulation of the immune response and is accused in the pathogenesis of several autoimmune diseases including systemic lupus erythematosus (SLE). An obvious link between OPN and T cells, particularly T helper 17 cells is reported, where OPN produced by dendritic cells supports interleukin-17 (IL-17) expression, contributing to pathology of autoimmune disorders. The aim of the study was to investigate the association of genotypes and alleles frequencies of OPN 9250 (rs1126616) and IL-17A 197 (rs2275913) genes polymorphisms with their serum levels, susceptibility, disease activity and severity in Egyptian SLE patients. A total of 80 SLE patients and 80 healthy subjects were enrolled. The PCR-RFLP technique was used to detect OPN 9250 C/T and IL-17A 197 G/A genes polymorphisms. Serum OPN and IL- 17 levels were measured by the enzyme-linked immunosorbent assay. OPN TT genotype and T allele were significantly detected in SLE patients more than controls (P = 0.003, P < 0.001 respectively). IL-17A AA genotype showed non-significant higher frequency in SLE patients than in their controls (P = 0.07). While only the A allele of IL-17A polymorphism was significantly elevated in patients (P = 0.048). There was statistical significant association between OPN CT and TT genotypes and both renal and mucocutaneous manifestations. Also IL-17A AG and AA genotypes was significantly associated with renal, mucocutaneous in addition to the hematological manifestations. Serum OPN levels were significantly increased with TT genotype while serum IL-17 levels were significantly increased with AA genotype. Disease activity and severity scores were significantly elevated with both OPN TT and IL-17A AA genotypes. In conclusion, OPN 9250 C/T and IL-17A 197 G/A genes polymorphisms and their serum levels seemed to have a role in pathogenesis of SLE.

IL-17 and colorectal cancer: From carcinogenesis to treatment

Colorectal cancer (CRC) is one of the most common types of cancer in the world. Several factors contribute to the development of this cancer. Tumor formation in colon triggers immune responses such as immune cells proliferation, phenotype alteration, cytokine synthesis and release, which lead to IL-17 producing T cells, the differentiated CD4+ T cells i.e. T helper 17. IL-17 is a pro-inflammatory cytokine, which its level is up regulated in serum and tissues of CRC patients. Several studies have shown that IL-17 has an important role in metastasis and prognosis of CRC. The aim of this review is to summarize the role of this cytokine in tumorigenesis, angiogenesis and metastasis of CRC and discuss its value in diagnosis, prognosis and treatment of CRC.

Correlation between Interleukin-17 gene polymorphism and osteoarthritis susceptibility in Han Chinese population

Background

Interleukin-17 (IL-17), a pleiotropic cytokine, plays a significant role in the inflammatory diseases. By a pilot study with small population, IL-17 polymorphisms (IL-17A rs2275913 and IL-17F rs763780) showed a more potential risk factor in knee osteoarthritis (OA) in our recruited subjects. In the current study, the association between IL-17A rs2275913 and IL-17F rs763780and the risk of OA in a Chinese population is studied.

Methods

The IL-17A rs2275913 and IL-17F rs763780 polymorphisms were determined in 594 knee OA cases and 576 healthy controls, using polymerase chain reaction-restriction fragment length polymorphism assay. The relationship between genotype distribution and disease risk, as well as OA severity was analyzed by Chi-square test and multivariate logistic regression.

Results

The experimental results indicated that the polymorphism in IL-17 gene rs2275913 site were related to knee OA risk after the adjustment of BMI, sex, age, smoking and drinking status (AA vs. GG: odds ratio (OR), 1.411; 95% confidence interval (CI), 1.021–1.950; P = 0.040; A allele vs. G allele: OR, 1.192; P = 0.037; 95% CI, 1.012–1.404;). Similarly, subjects who are bearing the rs763780 variant genotypes (TC and CC) and C allele also had a higher susceptibility to knee OA compared with those who are bearing the TT genotype (TC vs. TT, OR: 1.312; P = 0.039; 95% CI: 1.017–1.692; CC vs. TT, OR: 2.812, P = 0.006, 95% CI: 1.338–5.909; C allele Vs. T allele, OR:1.413, P = 0.002, 95% CI:1.141–1.751). In the meantime, one high-risk haplotypes, AC (OR was 7.22, P < 0.01) was found. Both two polymorphisms do not correlated with OA severity based on Kellgren-Lawrence (K&L) scales. Finally, serum IL-17 levels of knee OA patients were greatly higher than those of controls (P = 0.001).

Conclusions

With the limited size sample, our study shows that IL-17 gene polymorphisms possibly related to the high-risk knee OA occurrence.

Relationship between interleukin-17A and isolated coronary ectasia

The aim of this study was to evaluate serum interleukin (IL)-17A levels in patients with coronary artery ectasia (CAE), the relationship between IL and 17A and CAE, and to determine the relationship between the severity of coronary ectasia and the level of IL-17A. In total, 41 patients (19 female and 22 male) with ischemic symptoms whose non-invasive cardiac tests were positive for myocardial ischemia, and in whom coronary artery ectasia were detected after coronary angiography, and 45 patients (32 female and 13 male) with normal coronary arteries were included in this study. Echocardiographic assessments were performed. Serum IL-17A levels of all patients were evaluated using an enzyme-linked immunosorbent assay. IL-17A levels of the group with isolated coronary artery ectasia were significantly higher compared with the control group (4.86 ± 3.24 and 1.37 ± 1.56 ng/ml, respectively; p < 0.001). There was no correlation between the levels of IL-17A and the extension of the CAE, but IL-17A levels were high in both groups. CAE patients have significantly increased levels of IL-17A, fibrinogen, and RDW compared to patients with normal coronary arteries. It was demonstrated that increased levels of IL-17A were associated with ectasia formation in CAE patients.

Association of interleukin-17a rs2275913 gene polymorphism and asthma risk: a meta-analysis

INTRODUCTION

Interleukin-17A (IL-17A), a pro-inflammatory cytokine, plays an important role in the pathogenesis of asthma. A number of studies have investigated the relationship between IL-17A rs2275913 polymorphism and risk of asthma. However, the results obtained are inconclusive. The aim of this meta-analysis is to clarify the relationship between IL-17A rs2275913 polymorphism and asthma risk.

MATERIAL AND METHODS

Searches were conducted in PubMed, Web of Science, Elsevier, Google Scholar, Wanfang and Chinese National Knowledge Infrastructure (CNKI) databases, and data were extracted from eligible studies by two independent reviewers. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated. Publication bias, heterogeneity and sensitivity analysis were also assessed.

RESULTS

Ten studies with a total of 5016 subjects were included. Overall, the results indicated a significant association between the IL-17A rs2275913 polymorphism and the risk of asthma (G vs. A: OR = 0.866, 95% CI: 0.789-0.951, p = 0.003; GG+GA vs. AA: OR = 0.752, 95% CI: 0.633-0.895, p = 0.001). In subgroup analysis by age and ethnicity, the G allele of rs2275913 in IL-17A was significantly associated with a reduced risk of asthma in children and Asians.

CONCLUSIONS

The results of this meta-analysis indicate that the G allele of rs2275913 in IL-17A is a protective factor for the development of asthma.

Biological Properties and the Role of IL-25 in Disease Pathogenesis

The interleukin- (IL-) 17 superfamily, a T cell-derived cytokine, consists of 6 ligands (IL-17A-IL-17F) and 5 receptors (IL-17RA-IL-17RE). IL-17A, a prototype member of this family, is involved in the pathogenesis of allergies, autoimmune diseases, allograft transplantations, and malignancies. By contrast, IL-17B is reported to be closely related to certain diseases, particularly tumors such as breast cancer, gastric cancer, and pancreatic cancer. Recently, the biological function of IL-17E (also called IL-25) in disease, particularly airway diseases, has attracted the attention of researchers. However, studies on IL-25 are scant. In this review, we detail the structural characteristics, expression patterns, responder cells, biological properties, and role of IL-25 in disease pathogenesis.