Interleukin-17 and its target genes: mechanisms of interleukin-17 function in disease

Serum and ascitic fluid interleukin-17 in spontaneous bacterial peritonitis in Egyptian patients with HCV-related liver cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a potentially lethal complication of ascites. The inflammatory response is very intense in case of SBP despite low concentration of bacteria in the ascitic fluid with IL-17A overproduced by intestinal Paneth cells and may have role in host immune defense and inflammatory response.

AIMS

To study the diagnostic performance of serum and ascitic fluid IL-17A as a marker of SBP and its correlation with renal function.

METHODS

120 cirrhotic patients including 80 patients with HCV-induced cirrhotic ascites but not with SBP and 40 patients with HCV-induced cirrhotic ascites with SBP were recruited. Serum and ascitic fluid IL17A were measured before and after treatment.

RESULTS

The mean serum and ascitic fluid levels of IL-17 in cirrhotic patients with SBP were significantly higher than in patients with cirrhosis without SBP (p < 0.001). Also, we found significant decline in both serum and ascitic fluid IL17 levels with successful treatment of SBP (p < 0.001). The sensitivity and specificity of serum IL17 was 100 % when using 92 pg/mL as cutoff. Meanwhile, sensitivity and specificity of ascitic fluid IL-17were 100 % when using 132 pg/mL as cutoff.

CONCLUSIONS

IL-17 could be used as a possible diagnostic biomarker for SBP especially in culture negative and non-neutrocytic SBP and in monitoring therapeutic response. Also, it was shown to be related to hepatic and renal functions deterioration.

An IL-17F.S65L Knock-In Mouse Reveals Similarities and Differences in IL-17F Function in Oral Candidiasis: A New Tool to Understand IL-17F

Oropharyngeal candidiasis (OPC) is an opportunistic infection of the oral mucosa caused by the commensal fungus Candida albicans IL-17R signaling is essential to prevent OPC in mice and humans, but the individual roles of its ligands, IL-17A, IL-17F, and IL-17AF, are less clear. A homozygous IL-17F deficiency in mice does not cause OPC susceptibility, whereas mice lacking IL-17A are moderately susceptible. In humans, a rare heterozygous mutation in IL-17F (IL-17F.S65L) was identified that causes chronic mucocutaneous candidiasis, suggesting the existence of essential antifungal pathways mediated by IL-17F and/or IL-17AF. To investigate the role of IL-17F and IL-17AF in more detail, we exploited this "experiment of nature" by creating a mouse line bearing the homologous mutation in IL-17F (Ser65Leu) by CRISPR/Cas9. Unlike Il17f^-/- mice that are resistant to OPC, Il17f^S65L/S65L mice showed increased oral fungal burdens similar to Il17a ^-/- mice. In contrast to humans, however, disease was only evident in homozygous, not heterozygous, mutant mice. The mutation was linked to modestly impaired CXC chemokine expression and neutrophil recruitment to the infected tongue but not to alterations in oral antimicrobial peptide expression. These findings suggest mechanisms by which the enigmatic cytokine IL-17F contributes to host defense against fungi. Moreover, because these mice do not phenocopy Il17f^-/- mice, they may provide a valuable tool to interrogate IL-17F and IL-17AF function in vivo in other settings.

Assessment of the Microbiome Role in Skin Protection Against UV Irradiation Via Network Analysis

Introduction: Diverse microbiotas which have some contributions to gene expression reside in human skin. To identify the protective role of the skin microbiome against UV exposure, proteinprotein interaction (PPI) network analysis is used to assessment gene expression alteration. Methods: A microarray dataset, GEO accession number GSE117359, was considered in this respect. Differential expressed genes (DEGs) in the germ-free (GF) and specific pathogen-free (SPF) groups are analyzed by GEO2R. The top significant DEGs were assigned for network analysis via Cytoscape 3.7.2 and its applications. Results: A total of 28 genes were identified as significant DEGs and the centrality analysis of the network indicated that only one of the seven hub-bottlenecks was from queried genes. The gene ontology analysis of Il6, Cxcl2, Cxcl1, TNF, Il10, Cxcl10, and Mmp9 showed that the crucial genes were highly enriched in the immune system. Conclusion: The skin microbiome plays a significant role in the protection of skin against UV irradiation and the role of TNF and IL6 is prominent in this regard.

IL-17D: A Less Studied Cytokine of IL-17 Family

The interleukin-17 (IL-17) family is a relatively new family of cytokines consisting of 6 related factors (IL-17A-IL-17F), while the receptor family consists of 5 members: IL-17RA-IL-17RE. IL-17A is the prototype member of this family, which is also the signature cytokine of T helper 17 (Th17) cells. Th17 cells are involved in the development of autoimmune disease, inflammation, and tumors. Although IL-17D is similar to IL-17A in its ability to induce inflammatory cytokine production, there are fewer studies on IL-17D. Recently, the role of IL-17D in tumors and infections has attracted our attention. Some knowledge of function of IL-17D has been gained by studies using nonmammalian species. In this review, we introduce the structural characteristics, expression patterns, and biological characteristics of IL-17D along with its potential function in the pathogenesis of disease.

In vivo dual RNA-seq reveals that neutrophil recruitment underlies differential tissue tropism of Streptococcus pneumoniae

Streptococcus pneumoniae is a genetically diverse human-adapted pathogen commonly carried asymptomatically in the nasopharynx. We have recently shown that a single nucleotide polymorphism (SNP) in the raffinose pathway regulatory gene rafR accounts for a difference in the capacity of clonally-related strains to cause localised versus systemic infection. Using dual RNA-seq, we show that this SNP affects expression of bacterial genes encoding multiple sugar transporters, and fine-tunes carbohydrate metabolism, along with extensive rewiring of host transcriptional responses to infection, particularly expression of genes encoding cytokine and chemokine ligands and receptors. The data predict a crucial role for differential neutrophil recruitment (confirmed by in vivo neutrophil depletion and IL-17 neutralization) indicating that early detection of bacteria by the host in the lung environment is crucial for effective clearance. Thus, dual RNA-seq provides a powerful tool for understanding complex host-pathogen interactions and reveals how a single bacterial SNP can drive differential disease outcomes.

Minhas, Aprianto et al. apply dual RNA seq to a set of related Streptococcus pneumoniae strains to find that differential neutrophil recruitment explains different tissue tropism of these strains. This study highlights the power of dual RNA-seq in investigating how a single bacterial SNP determines the host’s disease outcomes.

Interleukin-17 in Chronic Inflammatory Neurological Diseases

A critical role for IL-17, a cytokine produced by T helper 17 (Th17) cells, has been indicated in the pathogenesis of chronic inflammatory and autoimmune diseases. A positive effect of blockade of IL-17 secreted by autoreactive T cells has been shown in various inflammatory diseases. Several cytokines, whose production is affected by environmental factors, control Th17 differentiation and its maintenance in tissues during chronic inflammation. The roles of IL-17 in the pathogenesis of chronic neuroinflammatory conditions, multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE), Alzheimer's disease, and ischemic brain injury are reviewed here. The role of environmental stimuli in Th17 differentiation is also summarized, highlighting the role of viral infection in the regulation of pathogenic T helper cells in EAE.

Expression Levels of IL-17A, IL-17F, IL-17RA, and IL-17RC in Prostate Cancer with Taking into Account the Histological Grade according to Gleason Scale in Comparison to Benign Prostatic Hyperplasia: In Search of New Therapeutic Options

Prostate cancer (PCa) is the second most commonly diagnosed malignant tumor and the fifth leading cause of cancer death in men in the world. The most common types of tumors are adenocarcinomas. Prostate cancer is a slow-growing cancer. The incidence increases with age. Evaluation of proinflammatory factors such as IL-17A, IL-17F, IL-17RA, and IL-17RC expression makes it possible to assess the impact of inflammatory process on progression of PCa. The aim of the study was to retrospectively assess the histological material of PCa divided into few groups using the Gleason score. Studies were carried out on archival tissue material in the form of paraffin blocks of 40 men with PCa after radical prostatectomy. The control group was composed of 10 men with benign prostatic hyperplasia (BPH). The material was obtained by the transurethral resection of the prostate (TURP). Immunohistochemistry was performed on prepared material using specific primary antibodies against IL-17A, IL-17F, IL-17RA, and IL-17RC. Expression of the antibody to be examined using light microscopy and the Remmele-Stegner score (IRS) in cancer staining was then evaluated. Expression of IL-17 RA was not shown in a group of patients with PCa and in the control group. In the group of patients with Gleason score 8 and 9 PCa, the expression of IL-17A was higher compared to that of IL-17F. In addition, in PCa with an increased grade of Gleason scale, a decrease in the expression of the study inflammatory parameters was found. The inflammatory process has an impact on PCa. A study on IL-17 may become a starting point for further research on an attempt to use, for example, immunotherapy in PCa.

Selective targeting of PI3Kδ suppresses human IL-17-producing T cells and innate-like lymphocytes and may be therapeutic for IL-17-mediated diseases

The delta isoform of phosphoinositide 3-kinase (PI3Kδ) regulates various lymphocyte functions. Considering the key pro-inflammatory role of IL-17A and IL-17F cytokines in psoriasis and spondyloarthritis (SpA), we investigated the potential of PI3Kδ blockade to suppress IL-17A, IL-17F and associated pro-inflammatory cytokines that could synergize with IL-17A and IL-17F. Using in vitro studies with primary human cells and ex vivo studies with inflamed target tissues, we assessed if seletalisib, a selective PI3Kδ inhibitor, suppresses cytokine production by T cells and innate-like lymphocytes, and if seletalisib modulates the inflammatory responses in stromal cell populations in psoriasis (human dermal fibroblasts (HDF)) and SpA (fibroblast-like synoviocytes (FLS)). In vitro, seletalisib inhibited the production of pro-inflammatory cytokines, including IL-17A and IL-17F, from peripheral blood mononuclear cells (PBMCs), T helper 17 (Th17) cells as well as γδ-T cells and mucosal-associated invariant T cells. This inhibition resulted in decreased inflammatory activation of HDF in co-culture systems. Seletalisib was also efficacious in inhibiting SpA PBMCs and synovial fluid mononuclear cells (SFMCs) from producing pro-inflammatory cytokines. Furthermore, supernatant derived from cultured seletalisib-treated Th17 cells showed reduced potency for activating inflammatory responses from cultured SpA FLS and decreased their osteogenic differentiation capacity. Finally, analysis of inflamed SpA synovial tissue biopsies revealed activation of the PI3K-Akt-mTOR pathway. We observed that ex vivo seletalisib treatment of inflamed synovial tissue reduced IL-17A and IL-17F expression. Collectively, inhibition of PI3Kδ reduces the production of pro-inflammatory cytokines from IL-17-producing adaptive and innate-like lymphocytes and thereby inhibits downstream inflammatory and tissue remodeling responses. PI3Kδ-targeting may therefore represent a novel therapeutic avenue for the treatment of IL-17-mediated chronic inflammatory diseases such as psoriasis and SpA.

Myeloid-Derived Suppressor Cell-Derived Arginase-1 Oppositely Modulates IL-17A and IL-17F Through the ESR/STAT3 Pathway During Colitis in Mice

Myeloid-derived suppressor cells (MDSC) play a crucial role in regulating the intestinal immune response during colitis. We previously revealed an essential role of MDSC in promoting TH17 cell polarization, which was found to be arginase-1 (Arg-1)-dependent; however, the underlying mechanism remains obscure. Here we report that percentage of MDSC decreased in Arg^myeKO mice during DSS-induced colitis. IL-17A levels reduced but IL-17F levels increased significantly in the colorectum of Arg^myeKO mice, leading to severe tissue damage and high risk of mortality rate. Activation of estrogen receptor (ESR) increased pSTAT3 level in MDSC and consequently led to elevated percentage of MDSC and more Arg-1 and inducible nitric oxide synthase expression in MDSC. Increased level of IL-17A and reduced level of IL-17F alleviated colitis in mice consequently. Together, these findings demonstrate a protective role of MDSC-derived Arg-1 during colitis after activates ESR/STAT3 signaling in MDSC. High level of Arg-1 favors accumulation of IL-17A, but reduced IL-17F expression in the colorectum of mice and ultimately leading to relief of colitis, indicating a potential clinical impact of MDSC-derived Arg-1 for controlling inflammatory bowel disease.

Role of interleukins in heart failure with reduced ejection fraction

Heart failure (HF) is the leading cause of morbidity and mortality in developed countries, and it is the primary cause of mortality in the elderly worldwide. The processes of inflammatory response activation, production and release of pro-inflammatory cytokines, activation of the complement system, synthesis of autoantibodies, and overexpression of Class II major histocompatibility complex molecules contribute to the HF development and progression. High levels of circulating cytokines correlate with the severity of HF, measured with the use of New York Heart Association's classification, and prognosis of the disease. In HF, there is an imbalance between pro-inflammatory and anti-inflammatory cytokines. Concentrations of several interleukins are increased in HF, including IL-1β, IL-6, IL-8, IL-9, IL-10, IL-13, IL-17, and IL-18, whereas the levels of IL-5, IL-7, or IL-33 are down-regulated. Concentrations of inflammatory mediators are associated with cardiac function and can be HF markers and predictors of adverse outcomes or mortality. This review presents the role of interleukins, which contribute to the HF initiation and progression, the importance of their pathways in transition from myocardial injury to HF, and the role of interleukins as markers of disease severity and outcome predictors.

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.

A chemokine/chemokine receptor signature potentially predicts clinical outcome in colorectal cancer patients

BACKGROUND

Differential expression of chemokines/chemokine receptors in colorectal cancer (CRC) may enable molecular characterization of patients' tumors for predicting clinical outcome.

OBJECTIVE

To evaluate the prognostic ability of these molecules in a CRC cohort and the CRC TCGA-dataset.

METHODS

Chemokine (CXCL-12α, CXCL-12β, IL-17A, CXCL-8, GM-CSF) and chemokine receptor (CXCR-4, CXCR-7) transcripts were analyzed by RT-qPCR in 76 CRC specimens (normal: 27, tumor: 49; clinical cohort). RNA-Seq data was analyzed from the TCGA-dataset (n= 375). Transcript levels were correlated with outcome; analyses: univariate, multivariable, Kaplan-Meier.

RESULTS

In the clinical cohort, chemokine/chemokine receptor levels were elevated 3-10-fold in CRC specimens (P⩽ 0.004) and were higher in patients who developed metastasis (P= 0.03 - < 0.0001). CXCR-4, CXCR-7, CXCL-12α, CXCL-8, IL-17 and GM-CSF levels predicted metastasis (P⩽ 0.0421) and/or overall survival (OS; P⩽ 0.0373). The CXCR-4+CXCR-7+CXCL-12 marker (CXCR-4/7+CXCL-12 (α/b) signature) stratified patients into risk for metastasis (P= 0.0014; OR, 2.72) and OS (P= 0.0442; OR, 2.7); sensitivity: 86.67%, specificity: 97.06%. In the TCGA-dataset, the CXCR-4/7+CXCL-12 signature predicted metastasis (P= 0.011; OR, 2.72) and OS (P= 0.0006; OR: 4.04). In both datasets, the signature was an independent predictor of clinical outcome.

CONCLUSIONS

Results of 451 specimens from both cohorts reveal that the CXCR-4/7+CXCL-12 signature potentially predicts outcome in CRC patients and may allow earlier intervention.

The role of the interleukin-23/Th17 pathway in cardiometabolic comorbidity associated with psoriasis

Alterations in the innate and adaptive immunity underpin psoriasis pathophysiology, with the Th17 cells subset now recognized as the fundamental cells in the key controlling pathway involved in its pathogenesis. Since psoriasis is a systemic disease with important comorbidity, further knowledge on the interleukin (IL)‐23/Th17 axis led to the hypothesis that there may be shared pathogenic pathways between primary skin disease and comorbidity. Psoriasis has been identified as a risk factor for cardiovascular and metabolic disease, and increasing evidence gives support to this epidemiological observation from the clinical‐pathologically field. As an example, increased levels of IL‐23 and IL‐23R have been found in human atherosclerotic plaque, and levels correlated with symptom duration and mortality. Also, upregulation of IL‐23/IL‐17 seems to play an important role in both myocardial damage and stroke, with interesting reports on deleterious effect neutralization after administration of related anti‐bodies in both associated conditions. In diabetic patients, increased levels of IL‐23/IL‐17 have also been observed and available data support a synergistic role of IL‐23/IL‐17 in β‐cells damage. In obesity, signs of an expansion of Th17 subset in adipose tissue have been reported, as well as elevated concentrations of IL‐23 in obese patients. In non‐alcoholic fatty liver disease, closely related to metabolic syndrome, but also in other mentioned cardiometabolic disorders, a predominance of IL‐23 and other related pro‐inflammatory factors has been identified as participating in their pathogenesis. Thus, the involvement of the IL‐23/Th17 axis in these shared psoriasis‐cardiometabolic pathogenic mechanisms is reviewed and discussed in the light of the existing preclinical and clinical evidence, including that from comorbid psoriasis patients.

Renin Promotes STAT4 Phosphorylation to Induce IL-17 Production in Keratinocytes of Oral Lichen Planus

Interleukin-17 (IL-17) is highly expressed in the epithelial layer of oral lichen planus (OLP), but the underlying mechanism for IL-17 overexpression remains unknown. Here, we identify renin that is induced by NF-κB pathway contributes to the increase of IL-17 in human oral keratinocytes (HOKs). We describe that the release of cellular renin leads to the phosphorylation of Janus kinase 2 (JAK2) protein. The phosphorylated JAK2 recruits and activates the signal transducer and activator of transcription 4 (STAT4) by phosphorylating STAT4's tyrosine residue 693 (Tyr693). The now-activated STAT4 translocates into nucleus and binds to the promoter region of IL-17 gene in HOKs. Genetic interference of renin restores IL-17 levels in OLP cell models. Collectively, our results reveal that renin upregulates IL-17 expression by enhancing STAT4 phosphorylation. This discovery unveils an underpinning by which IL-17 is increased in oral keratinocytes and provides potential targeted therapies for OLP patients.

Transcriptional Regulators of T Helper 17 Cell Differentiation in Health and Autoimmune Diseases

T helper (Th) 17 cells are a subtype of CD4 T lymphocytes characterized by the expression of retinoic acid-receptor (RAR)-related orphan receptor (ROR)γt transcription factor, encoded by gene Rorc. These cells are implicated in the pathology of autoimmune inflammatory disorders as well as in the clearance of extracellular infections. The main function of Th17 cells is the production of cytokine called interleukin (IL)-17A. This review highlights recent advances in mechanisms regulating transcription of IL-17A. In particular, we described the lineage defining transcription factor RORγt and other factors that regulate transcription of Il17a or Rorc by interacting with RORγt or by binding their specific DNA regions, which may positively or negatively influence their expression. Moreover, we reported the eventual involvement of those factors in Th17-related diseases, such as multiple sclerosis, rheumatoid arthritis, psoriasis, and Crohn's disease, characterized by an exaggerated Th17 response. Finally, we discussed the potential new therapeutic approaches for Th17-related diseases targeting these transcription factors. The wide knowledge of transcriptional regulators of Th17 cells is crucial for the better understanding of the pathogenic role of these cells and for development of therapeutic strategies aimed at fighting Th17-related diseases.

Calcium/calmodulin-dependent protein kinase IV signaling pathway is upregulated in experimental necrotizing enterocolitis

PURPOSE

Activation of calcium/calmodulin-dependent protein kinase IV (CaMKIV) has been shown to increase intestinal injury and inhibit epithelial cell proliferation in dextran sulfate sodium (DSS)-induced colitis mice. However, the role of CaMKIV in necrotizing enterocolitis (NEC) is unknown. We aimed to study the expression and activation of CaMKIV in experimental NEC.

METHODS

Following ethical approval, NEC (n = 10) was induced in C57BL/6 mouse pups by hypoxia, gavage hyperosmolar formula feeding and lipopolysaccharide from postnatal days P5 to 9. Breastfed pups served as control (n = 10). Mouse pups were sacrificed on P9 and the terminal ileum was harvested. Gene NEC injury was scored blindly by three independent investigators. CaMKIV, CREM and IL17 gene expression, and CaMKIV and pCaMKIV protein expression were assessed. The data were compared using Mann-Whitney U test. P < 0.05 was considered significant.

RESULTS

Intestinal injury was induced in the NEC mice and confirmed by histological scoring and inflammatory cytokine IL6. CaMKIV and its downstream target genes of CREM and IL17 were significantly elevated in NEC mice relative to control. Similarly, phosphorylated-CaMKIV (pCaMKIV), the active form of CaMKIV, was more notably expressed in the NEC ileal tissue relative to control ileal tissue. Elevated pCaMKIV protein expression was also confirmed by western blot.

CONCLUSION

CaMKIV expression and activation are upregulated in experimental NEC suggesting a potential contributing factor in the pathogenesis of NEC.

CUX1 and IκBζ (NFKBIZ) mediate the synergistic inflammatory response to TNF and IL-17A in stromal fibroblasts

The role of stromal fibroblasts in chronic inflammation is unfolding. In rheumatoid arthritis, leukocyte-derived cytokines TNF and IL-17A work together, activating fibroblasts to become a dominant source of the hallmark cytokine IL-6. However, IL-17A alone has minimal effect on fibroblasts. To identify key mediators of the synergistic response to TNF and IL-17A in human synovial fibroblasts, we performed time series, dose-response, and gene-silencing transcriptomics experiments. Here we show that in combination with TNF, IL-17A selectively induces a specific set of genes mediated by factors including cut-like homeobox 1 (CUX1) and IκBζ (NFKBIZ). In the promoters of CXCL1, CXCL2, and CXCL3, we found a putative CUX1-NF-κB binding motif not found elsewhere in the genome. CUX1 and NF-κB p65 mediate transcription of these genes independent of LIFR, STAT3, STAT4, and ELF3. Transcription of NFKBIZ, encoding the atypical IκB factor IκBζ, is IL-17A dose-dependent, and IκBζ only mediates the transcriptional response to TNF and IL-17A, but not to TNF alone. In fibroblasts, IL-17A response depends on CUX1 and IκBζ to engage the NF-κB complex to produce chemoattractants for neutrophil and monocyte recruitment.

Immunoregulatory Sensory Circuits in Group 3 Innate Lymphoid Cell (ILC3) Function and Tissue Homeostasis

Recent years have seen a revolution in our understanding of how cells of the immune system are modulated and regulated not only via complex interactions with other immune cells, but also through a range of potent inputs derived from diverse and varied biological systems. Within complex tissue environments, such as the gastrointestinal tract and lung, these systems act to orchestrate and temporally align immune responses, regulate cellular function, and ensure tissue homeostasis and protective immunity. Group 3 Innate Lymphoid Cells (ILC3s) are key sentinels of barrier tissue homeostasis and critical regulators of host-commensal mutualism—and respond rapidly to damage, inflammation and infection to restore tissue health. Recent findings place ILC3s as strategic integrators of environmental signals. As a consequence, ILC3s are ideally positioned to detect perturbations in cues derived from the environment—such as the diet and microbiota—as well as signals produced by the host nervous, endocrine and circadian systems. Together these cues act in concert to induce ILC3 effector function, and form critical sensory circuits that continually function to reinforce tissue homeostasis. In this review we will take a holistic, organismal view of ILC3 biology and explore the tissue sensory circuits that regulate ILC3 function and align ILC3 responses with changes within the intestinal environment.

T cell populations in children with autism spectrum disorder and co-morbid gastrointestinal symptoms

Children with ASD are more likely to experience gastrointestinal (GI) symptoms than typically-developed children. Numerous studies have reported immune abnormalities and inflammatory profiles in the majority of individuals with ASD. Immune dysfunction is often hypothesized as a driving factor in many GI diseases and it has been suggested that it is more apparent in children with ASD that exhibit GI symptoms. In this study we sought to characterize peripheral T cell subsets in children with and without GI symptoms, compared to healthy typically-developing children. Peripheral blood mononuclear cells were isolated from participants, who were categorized into three groups: children with ASD who experience GI symptoms (n ​= ​14), children with ASD who do not experience GI symptoms (n ​= ​10) and typically-developing children who do not experience GI symptoms (n ​= ​15). In order to be included in the GI group, GI symptoms such as diarrhea, constipation, and/or pain while defecating, had to be present in the child regularly for the past 6 months; likewise, in order to be placed in the no GI groups, bowel movements could not include the above symptoms present throughout development. Cells were assessed for surface markers and intracellular cytokines to identify T cell populations. Children with ASD and GI symptoms displayed elevated TH17 populations (0.757% ​± ​0.313% compared to 0.297% ​± ​0.197), while children with ASD who did not experience GI symptoms showed increased frequency of TH2 populations (2.02% ​± ​1.08% compared to 1.01% ​± ​0.58%). Both ASD groups showed evidence of reduced gut homing regulatory T cell populations compared to typically developing children (ASDGI:1.93% ​± ​0.75% and ASDNoGI:1.85% ​± ​0.89 compared to 2.93% ​± ​1.16%). Children with ASD may have deficits in immune regulation that lead to differential inflammatory T cell subsets that could be linked to associated co-morbidities.

Oral Candidiasis: A Disease of Opportunity

Oral candidiasis, commonly referred to as “thrush,” is an opportunistic fungal infection that commonly affects the oral mucosa. The main causative agent, Candida albicans, is a highly versatile commensal organism that is well adapted to its human host; however, changes in the host microenvironment can promote the transition from one of commensalism to pathogen. This transition is heavily reliant on an impressive repertoire of virulence factors, most notably cell surface adhesins, proteolytic enzymes, morphologic switching, and the development of drug resistance. In the oral cavity, the co-adhesion of C. albicans with bacteria is crucial for its persistence, and a wide range of synergistic interactions with various oral species were described to enhance colonization in the host. As a frequent colonizer of the oral mucosa, the host immune response in the oral cavity is oriented toward a more tolerogenic state and, therefore, local innate immune defenses play a central role in maintaining Candida in its commensal state. Specifically, in addition to preventing Candida adherence to epithelial cells, saliva is enriched with anti-candidal peptides, considered to be part of the host innate immunity. The T helper 17 (Th17)-type adaptive immune response is mainly involved in mucosal host defenses, controlling initial growth of Candida and inhibiting subsequent tissue invasion. Animal models, most notably the mouse model of oropharyngeal candidiasis and the rat model of denture stomatitis, are instrumental in our understanding of Candida virulence factors and the factors leading to host susceptibility to infections. Given the continuing rise in development of resistance to the limited number of traditional antifungal agents, novel therapeutic strategies are directed toward identifying bioactive compounds that target pathogenic mechanisms to prevent C. albicans transition from harmless commensal to pathogen.

Increased cytokines production and oxidative stress are related with purinergic signaling and cell survival in post-thyroidectomy hypothyroidism

Thyroid hormones have essential roles in regulation of cellular functions, including the immune system. The purinergic signaling, activated through extracellular nucleotides and nucleosides has also strong implications in immune response regulation. Hypothyroidism may involve effects on the immune and purinergic systems. In view of that, we evaluated cytokines levels, their relation with the expression of purinergic enzymes and the effects of this condition on immune system cells from patients with post-thyroidectomy hypothyroidism. Increased IL6, IL10, IL17 and TNF-α levels as well as an increase in CD73 expression in lymphocytes were observed in patients' blood. Moreover, augmented myeloperoxidase activity, lipid peroxidation and thiolgroup production were observed in post-thyroidectomy hypothyroidism. In addition, proliferation and cell death of lymphocytes were enhanced when exposed to patients' serum. This study demonstrates that hypothyroidism is related to changes in the purinergic system, increased cytokines production and oxidative stress, which interfere in the cell life and signaling.

Systemic Exposure to Lipopolysaccharide from Porphyromonas gingivalis Induces Bone Loss-Correlated Alzheimer's Disease-Like Pathologies in Middle-Aged Mice

BACKGROUND

Alzheimer's disease (AD) and bone loss are clinically exacerbated. However, the mechanism of exacerbation remains understood.

OBJECTIVE

We tested our hypothesis that periodontitis is involved in the exacerbation, contributing to AD pathologies.

METHODS

The bone, memory, and inflammation in bone and brain were examined in 12-month-old mice after systemic exposure to lipopolysaccharide from Porphyromonas gingivalis (P gLPS) for 3 consecutive weeks.

RESULTS

Compared with control mice, bone loss in tibia (26% decrease) and memory decline (47% decrease) were induced in mice with a positive correlation after exposure to P gLPS (r = 0.7378, p = 0.0011). The IL-6 and IL-17 expression in tibia was negatively correlated with the bone volume/total tissue volume (r = -0.6619, p = 0.0052; r = -0.7129, p = 0.0019), while that in the cortex was negatively correlated with the memory test latency (r = -0.7198, p = 0.0017; p = 0.0351, r = -0.5291). Furthermore, the IL-17 expression in microglia was positively correlated with Aβ42 accumulation in neurons (r = 0.8635, p < 0.0001). In cultured MG6 microglia, the P gLPS-increased IL-6 expression was inhibited by a PI3K-specific inhibitor (68% decrease), and that of IL-17 was inhibited by IL-6 antibody (41% decrease). In cultured N2a neurons, conditioned medium from P gLPS-stimulated microglia (MCM) but not P gLPS increased the productions of AβPP, CatB, and Aβ42, which were significantly inhibited by pre-treatment with IL-17 antibody (67%, 51%, and 41% decrease).

CONCLUSION

These findings demonstrated that chronic systemic exposure to P gLPS simultaneously induces inflammation-dependent bone loss and AD-like pathologies by elevating IL-6 and IL-17 from middle age, suggesting that periodontal bacteria induce exacerbation of bone loss and memory decline, resulting in AD progression.

Deriving a Boolean dynamics to reveal macrophage activation with in vitro temporal cytokine expression profiles

BACKGROUND

Macrophages show versatile functions in innate immunity, infectious diseases, and progression of cancers and cardiovascular diseases. These versatile functions of macrophages are conducted by different macrophage phenotypes classified as classically activated macrophages and alternatively activated macrophages due to different stimuli in the complex in vivo cytokine environment. Dissecting the regulation of macrophage activations will have a significant impact on disease progression and therapeutic strategy. Mathematical modeling of macrophage activation can improve the understanding of this biological process through quantitative analysis and provide guidance to facilitate future experimental design. However, few results have been reported for a complete model of macrophage activation patterns.

RESULTS

We globally searched and reviewed literature for macrophage activation from PubMed databases and screened the published experimental results. Temporal in vitro macrophage cytokine expression profiles from published results were selected to establish Boolean network models for macrophage activation patterns in response to three different stimuli. A combination of modeling methods including clustering, binarization, linear programming (LP), Boolean function determination, and semi-tensor product was applied to establish Boolean networks to quantify three macrophage activation patterns. The structure of the networks was confirmed based on protein-protein-interaction databases, pathway databases, and published experimental results. Computational predictions of the network evolution were compared against real experimental results to validate the effectiveness of the Boolean network models.

CONCLUSION

Three macrophage activation core evolution maps were established based on the Boolean networks using Matlab. Cytokine signatures of macrophage activation patterns were identified, providing a possible determination of macrophage activations using extracellular cytokine measurements.

Genetic alterations of interleukin-17 and related genes in human prostate cancer

Interleukin-17 (IL-17) has been shown to promote development of hormone-naïve prostate cancer (HNPC) and castration-resistant prostate cancer (CRPC) as well as lymph node metastasis in mouse models. Gene alterations of IL-17 family of cytokines and their downstream genes in human prostate cancer have not been investigated. We studied 7 datasets archived in cBioPortal and queried gene alterations in a total of 1303 cases of human prostate cancers. 35 genes were examined, including IL-17 family of cytokines and receptors, IL-17-downstream genes, and genes related to IL-17-downstream genes. We found that 34/35 (97%) genes had significantly more alterations in metastatic prostate cancer (with alteration rates ranging from 3.42% to 13.01%) than primary prostate cancer (with alteration rates ranging from 0.40% to 2.96%). 15/35 (43%) genes had significantly more alterations in primary CRPC than primary HNPC. 34/35 (97%) genes had significantly more alterations in metastatic CRPC than primary HNPC. Only three genes (S100A7, S100A8, and S100A9) had significantly more alterations in metastatic CRPC than primary CRPC. The gene alterations were mostly gene amplifications (97%), while gene deep deletions, missense mutations, and truncating mutations were very rare. 7/35 (20%) genes had significantly more alterations in primary neuroendocrine prostate cancer (NEPC) than primary adenocarcinoma (AC). 23/35 (66%) genes had significantly more alterations in metastatic NEPC than metastatic AC. Only three genes (S100A7, S100A8, and S100A9) had significantly more alterations in metastatic NEPC than metastatic AC with neuroendocrine features. Most of the gene alterations in metastatic NEPC were gene amplifications (80%), while gene deep deletions, missense mutations, and truncating mutations were very rare. Our findings suggest that gene amplifications of IL-17 and related genes are more frequently found in metastatic CRPC and NEPC than primary hormone-naïve prostate adenocarcinomas, implying that IL-17 and related genes may play important roles in the progression from HNPC to CRPC and from primary location to metastasis as well as in development of metastatic NEPC.

The IL17F His161Arg polymorphism, a potential risk locus for psoriasis, increases serum levels of interleukin-17F in an Asian population

Interleukin 17 (IL-17) plays pivotal role in the pathogenesis of psoriasis. In a previous study, we identified a locus in the IL17F gene that is associated with psoriasis, the IL17F rs763780 (His161Arg) T/C variant. The current study aimed to elucidate the association between this polymorphism and psoriasis, and to determine its effect on serum levels of cytokine. A total of 116 psoriasis patients and 97 healthy volunteers were recruited. Genotyping analysis was performed using quantitative polymerase chain reaction, and serum levels of cytokine were measured using a multiplex immunoassay. The IL17F His161Arg polymorphism was significantly associated with psoriasis based on the genotype and allele analyses. Psoriasis patients harbouring the mutant allele had significantly increased serum levels of IL-17F. Our results suggest that this polymorphism is a potential risk locus for psoriasis and that it results in a direct increase in IL-17F production.

The Use of Pulsed Electromagnetic Field to Modulate Inflammation and Improve Tissue Regeneration: A Review

Pulsed electromagnetic field (PEMF) is emerging as innovative treatment for regulation of inflammation, which could have significant effects on tissue regeneration. PEMF modulates inflammatory processes through the regulation of pro- and anti-inflammatory cytokine secretion during different stages of inflammatory response. Consistent outcomes in studies involving animal and human tissue have shown promise for the use of PEMF as an alternative or complementary treatment to pharmaceutical therapies. Thus, PEMF treatment could provide a novel nonpharmaceutical means of modulating inflammation in injured tissues resulting in enhanced functional recovery. This review examines the effect of PEMF on immunomodulatory cells (e.g., mesenchymal stem/stromal cells [MSCs] and macrophages [MΦ]) to better understand the potential for PEMF therapy to modulate inflammatory signaling pathways and improve tissue regeneration. This review cites published data that support the use of PEMF to improve tissue regeneration. Our studies included herein confirm anti-inflammatory effects of PEMF on MSCs and MΦ.

MicroRNA-181a-5p Regulates Inflammatory Response of Macrophages in Sepsis

The aim of this study was to evaluate the role of miR-181a-5p in sepsis, and to further explore the molecular mechanism. RAW 264.7 cells were stimulated with 1 μg/ml LPS for 4 hours. Firstly, qRT-PCR and ELISA was adopted to evaluate the expression of miR-181a-5p and p ro-inflammatory cytokines in RAW 264.7 macrophages a fter LPS stimulation. Results showed that pro-inflammatory cytokines and miR-181a-5p were significantly increased after LPS treatment. Then, we identified that sirtuin-1 (SIRT1) was a direct target of miR-181a-5p and it was down-regulated in LPS treated RAW264.7 macrophages. Furthermore, the data suggested that the miR-181a-5p inhibitor significantly inhibited LPS enhanced inflammatory cytokines expression and NF-κB pathway activation, and these changes were eliminated by SIRT1 silencing. Moreover, the role of the miR-181a-5p inhibitor on sepsis was studied in vivo. We found that the miR-181a-5p inhibitor significantly decreased the secretion of inflammatory factors, and the levels of creatine (Cr), blood urea nitrogen (BUN), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in a serum for mice with sepsis. However, all the effects were reversed by SIRT1-siRNA. In summary, these results indicated that miR-181a-5p was involved in sepsis through regulating the inflammatory response by targeting SIRT1, suggesting that miR-181a-5p may be a potential target for the treatment of sepsis.

Interleukin-17A and Chronic Stress in Pregnant Women at 24-28 Weeks Gestation

BACKGROUND

Allostatic load (AL) is a biopsychosocial model that suggests chronic psychosocial stress leads to physiological dysregulation and poor outcomes. The purpose of this study was to examine AL in pregnant women operationalized using proinflammatory cytokines and psychosocial indicators and perinatal outcomes.

OBJECTIVES

The aim of the study was to identify relationships between circulating cytokines/chemokines and the Prenatal Distress Questionnaire, the Maternal Antenatal Attachment Scale, the Emotional Quotient Inventory, the Life Experiences Scale, and demographics in pregnant women.

METHODS

A cross-sectional design was used to recruit pregnant women between 24 and 28 weeks of gestation. Blood and stress/emotional indicators were obtained after informed consent. Plasma was abstracted to simultaneously measure 29 cytokines/chemokines using a multiplex array. Cytokine/chemokine levels were compared with continuous variables using Spearman's rho and with categorical variables using Mann-Whitney U.

RESULTS

Twenty-five women with medically high-risk (n = 16) and low-risk (n = 9) pregnancies consented. Most women were White (68%) with a mean age of 29 years (SD = 5.9). Although several cytokines and chemokines showed significant correlations with the stress/emotional indicators, only interleukin-17A (IL-17A) was significantly associated with all of the indicators (Prenatal Distress Questionnaire: rs = .528, p = .012; Maternal Antenatal Attachment Scale: rs = -.439, p = .036; Emotional Quotient Inventory total: rs = -.545, p = .007), Life Experiences Scale (rs = .458, p = .032), birth weight (rs = -.499, p = .013), and race (p = .01).

DISCUSSION

Increased levels of IL-17A, a known cytokine associated with chronic stress and with poor perinatal outcomes, were associated with high prenatal distress, low maternal attachment, and lower emotional intelligence in pregnant women. Increased levels of IL-17A also were associated with lower birth weight and non-White race. Results support the model of AL in pregnant women and highlight IL-17A as a potential biomarker of AL during pregnancy.

Interleukin-17: Potential Target for Chronic Wounds

Chronic wounds exhibit persistent inflammation with markedly delayed healing. The significant burden of chronic wounds, which are often resistant to standard therapy, prompts further research on novel therapies. Since the interleukin-17 family has been implicated as a group of proinflammatory cytokines in immune-mediated diseases in the gut and connective tissue, as well as inflammatory skin conditions, we consider here if it may contribute to the pathogenesis of chronic wounds. In this review, we discuss the interleukin-17 family's signaling pathways and role in tissue repair. A PubMed review of the English literature on interleukin-17, wound healing, chronic wounds, and inflammatory skin conditions was conducted. Interleukin-17 family signaling is reviewed in the context of tissue repair, and preclinical and clinical studies examining its role in the skin and other organ systems are critically reviewed. The published work supports a pathologic role for interleukin-17 family members in chronic wounds, though this needs to be more conclusively proven. Clinical studies using monoclonal interleukin-17 antibodies to improve healing of chronic skin wounds have not yet been performed, and only a few studies have examined interleukin-17 family expression in chronic skin wounds. Furthermore, different interleukin-17 family members could be playing selective roles in the repair process. These studies suggest a therapeutic role for targeting interleukin-17A to promote wound healing; therefore, interleukin-17A may be a target worthy of pursuing in the near future.

Tofacitinib in Pediatric Psoriasis: An Open-Label Trial to Study Its Safety and Efficacy in Children

Introduction: Psoriasis is a chronic, multifactorial, inflammatory disorder, with an estimated prevalence of 0.71% in children. The commonly used therapeutic agents target the underlying inflammation. Tofacitinib has demonstrated efficacy in adult psoriasis. Aim: To study the efficacy, safety, and tolerability of tofacitinib in pediatric patients with moderate to severe chronic plaque psoriasis. Methods: The study included children aged between 8 and 17 years, with moderate to severe psoriasis, given tofacitinib 5 mg orally twice daily for at least 36 weeks. The clinical response was estimated using the Psoriasis Area and Severity Index (PASI) score, Physician’s Global Assessment (PGA), and the Children’s Dermatology Life Quality Index (CDLQI). The incidence and severity of adverse events (AEs) were meticulously recorded in each case. Results: A total of 47 patients, with a median age of 12.3 years, completed the study. At week 12, 55.32% achieved PASI 75, and 70.21% at week 36. PGA of clear or almost clear responses at week 12 were 59.57 and 65.96%, ­respectfully, at week 36. Relatively few and mostly minor ­adverse effects were noted. No severe AEs were reported. ­Conclusion: The treatment with tofacitinib was safe and well tolerated, and led to significant improvement of their disease and quality of life as reflected in CDLQI scores. However, the results need to be validated in larger multicenter trials.

The IL-17 Family of Cytokines in Health and Disease

The interleukin 17 (IL-17) family of cytokines contains 6 structurally related cytokines, IL-17A through IL-17F. IL-17A, the prototypical member of this family, just passed the 25^th anniversary of its discovery. Although less is known about IL-17B-F, IL-17A (commonly known as IL-17) has received much attention for its pro-inflammatory role in autoimmune disease. Over the past decade, however, it has become clear that the functions of IL-17 are far more nuanced than simply turning on inflammation. Accumulating evidence indicates that IL-17 has important context- and tissue-dependent roles in maintaining health during response to injury, physiological stress, and infection. Here, we discuss the functions of the IL-17 family, with a focus on the balance between the pathogenic and protective roles of IL-17 in cancer and autoimmune disease, including results of therapeutic blockade and novel aspects of IL-17 signal transduction regulation.

Transcriptome Profiling Analysis of Bovine Vaginal Epithelial Cell Response to an Isolated Lactobacillus Strain

Bovine bacterial vaginitis causes infertility, abortion, and postpartum uterine diseases, causing serious economic loss to the dairy industry. The large-scale use of antibiotics destroys normal genital tract flora and hinders the defense mechanisms of the host. Recent research suggests that lactobacilli present in the vaginal microflora of healthy cows constitute the primary microbiological barrier to infection by genital pathogens, exerting a protective role on the reproductive tract via specific adherence to the epithelium and the production of inhibitory substances. Our research identified the mechanisms for Lactobacillus adhesion and pathogenic inhibition, providing valuable information for the development of new probiotics and the discovery of novel therapeutic targets for the prevention of infections in dairy cows.

Lactobacillus strain SQ0048 isolated from bovine vagina has been shown to exhibit specific adherence to the epithelium and to produce inhibitory substances; however, the underlying mechanisms remain unclear. We cultured and identified primary bovine vaginal epithelial cells treated with SQ0048 to investigate the pathways involved in host cell responses using transcriptome sequencing (RNA-seq). Transcription profiling showed 296 significantly altered differentially expressed genes (DEGs), of which 170 were upregulated and 126 downregulated. Gene Ontology (GO) enrichment analysis of the DEGs revealed significant enrichment of 424 GO terms throughout the differentiation process (P < 0.05). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEGs were successfully annotated as members of 171 pathways, with 23 significantly enriched KEGG pathways (P < 0.05). A relatively high number of genes were enriched for the endoplasmic reticulum protein processing and interleukin-17 (IL-17) signaling pathways and for antigen processing and presentation. DEGs were verified by quantitative reverse transcription-PCR (RT-qPCR) and determination of which were most enriched for endoplasmic reticulum protein processing pathways, the activation of which might be a major factor underlying Lactobacillus adhesion to cells and pathogenic inhibition.

IMPORTANCE Bovine bacterial vaginitis causes infertility, abortion, and postpartum uterine diseases, causing serious economic loss to the dairy industry. The large-scale use of antibiotics destroys normal genital tract flora and hinders the defense mechanisms of the host. Recent research suggests that lactobacilli present in the vaginal microflora of healthy cows constitute the primary microbiological barrier to infection by genital pathogens, exerting a protective role on the reproductive tract via specific adherence to the epithelium and the production of inhibitory substances. Our research identified the mechanisms for Lactobacillus adhesion and pathogenic inhibition, providing valuable information for the development of new probiotics and the discovery of novel therapeutic targets for the prevention of infections in dairy cows.

Comparative transcriptome analysis to elucidate the therapeutic mechanism of colchicine against atrial fibrillation

In recent years, colchicine has been used to reduce the risk of cardiovascular events; in particular, it has been effectively used for the treatment of atrial fibrillation (AF). We first discovered that colchicine can treat AF in a rat model and that it can reverse the effects of atrial fibrosis. To illustrate the potential therapeutic mechanism of colchicine against AF, we performed comparative transcriptome analyses; our aim was to elucidate the therapeutic effects of colchicine so as to improve treatment and prognoses of AF. Genomics and bioinformatics analyses revealed that the IL-17 signaling pathway, and renin secretion pathway are involved in the mechanism of action of colchicine. Furthermore, there was a significant correlation between overlapping genes in the two groups of differentially expressed genes. The genes encoding Akap4, Pcdha9, Gp2, Cd177, Krt15, Aqp3, Chia, and Bpifb1 were pivotal and possible action sites for the therapeutic mechanisms of colchicine. We conclude that AF involves a multifactorial pathological process. The mechanisms underlying the action of colchicine in the treatment of AF warrant further studies.

Induction of Inflammation and Fibrosis by Semaphorin 4A in Systemic Sclerosis

OBJECTIVE

To analyze the potential role of semaphorin 4A (Sema4A) in inflammatory and fibrotic processes involved in the pathology of systemic sclerosis (SSc).

METHODS

Sema4A levels in the plasma of healthy controls (n = 11) and SSc patients (n = 20) were determined by enzyme-linked immunosorbent assay (ELISA). The expression of Sema4A and its receptors in monocytes and CD4+ T cells from healthy controls and SSc patients (n = 6-7 per group) was determined by ELISA and flow cytometry. Th17 cytokine production by CD4+ T cells (n = 5-7) was analyzed by ELISA and flow cytometry. The production of inflammatory mediators and extracellular matrix (ECM) components by dermal fibroblast cells (n = 6) was analyzed by quantitative polymerase chain reaction, ELISA, Western blotting, confocal microscopy, and ECM deposition assay.

RESULTS

Plasma levels of Sema4A, and Sema4A expression by circulating monocytes and CD4+ T cells, were significantly higher in SSc patients than in healthy controls (P < 0.05). Inflammatory mediators significantly up-regulated the secretion of Sema4A by monocytes and CD4+ T cells from SSc patients (P < 0.05 versus unstimulated SSc cells). Functional assays showed that Sema4A significantly enhanced the expression of Th17 cytokines induced by CD3/CD28 in total CD4+ T cells as well in different CD4+ T cell subsets (P < 0.05 versus unstimulated SSc cells). Finally, Sema4A induced a profibrotic phenotype in dermal fibroblasts from both healthy controls and SSc patients, which was abrogated by blocking or silencing the expression of Sema4A receptors.

CONCLUSION

Our findings indicate that Sema4A plays direct and dual roles in promoting inflammation and fibrosis, 2 main features of SSc, suggesting that Sema4A might be a novel therapeutic target in SSc.

Th17 cells promote tumor growth in an immunocompetent orthotopic mouse model of prostate cancer

Interleukin-17 (IL-17) has been demonstrated to promote development of a variety of cancers including prostate cancer in genetically modified mouse models. IL-17 is the main product secreted by T helper 17 (Th17) cells. A recent study has shown that Th17 cells and related genes are upregulated in human prostate cancers. However, there is no direct experimental evidence to demonstrate Th17's role in prostate cancer. In the present study, we co-implanted mouse prostate cancer MPC3-luc cells with Th17-polarized mouse splenocytes in the prostate of immunocompetent C57BL/6J male mice. We found that Th17-polarized splenocytes promoted orthotopic allograft prostate tumor growth compared to the control splenocytes. The numbers of IL-17-positive lymphocytes and macrophages were higher in the prostate tumors grown from co-implantation of MPC3-luc cells and Th17-polarized splenocytes, compared to the prostate tumors grown from co-implantation of MPC3-luc cells and control splenocytes. Our findings provide the first direct experimental evidence that Th17 cells may promote prostate cancer growth.

Conjunctival Microbiome-Host Responses Are Associated With Impaired Epithelial Cell Health in Both Early and Late Stages of Trachoma

Background: Trachoma, a neglected tropical disease, is the leading infectious cause of blindness and visual impairment worldwide. Host responses to ocular chlamydial infection resulting in chronic inflammation and expansion of non-chlamydial bacteria are hypothesized risk factors for development of active trachoma and conjunctival scarring.

Methods: Ocular swabs from trachoma endemic populations in The Gambia were selected from archived samples for 16S sequencing and host conjunctival gene expression. We recruited children with active trachoma and adults with conjunctival scarring, alongside corresponding matched controls.

Findings: In children, active trachoma was not associated with significant changes in the ocular microbiome. Haemophilus enrichment was associated with antimicrobial responses but not linked to active trachoma. Adults with scarring trachoma had a reduced ocular bacterial diversity compared to controls, with increased relative abundance of Corynebacterium. Increased abundance of Corynebacterium in scarring disease was associated with innate immune responses to the microbiota, dominated by altered mucin expression and increased matrix adhesion.

Interpretation: In the absence of current Chlamydia trachomatis infection, changes in the ocular microbiome associate with differential expression of antimicrobial and inflammatory genes that impair epithelial cell health. In scarring trachoma, expansion of non-pathogenic bacteria such as Corynebacterium and innate responses are coincident, warranting further investigation of this relationship. Comparisons between active and scarring trachoma supported the relative absence of type-2 interferon responses in scarring, whilst highlighting a common suppression of re-epithelialization with altered epithelial and bacterial adhesion, likely contributing to development of scarring pathology.

Immune Response to Mucosal Brucella Infection

Brucellosis is one of the most prevalent bacterial zoonosis of worldwide distribution. The disease is caused by Brucella spp., facultative intracellular pathogens. Brucellosis in animals results in abortion of fetuses, while in humans, it frequently manifests flu-like symptoms and a typical undulant fever, being osteoarthritis a common complication of the chronic infection. The two most common ways to acquire the infection in humans are through the ingestion of contaminated dairy products or by inhalation of contaminated aerosols. Brucella spp. enter the body mainly through the gastrointestinal and respiratory mucosa; however, most studies of immune response to Brucella spp. are performed analyzing models of systemic immunity. It is necessary to better understand the mucosal immune response induced by Brucella infection since this is the main entry site for the bacterium. In this review, some virulence factors and the mechanisms needed for pathogen invasion and persistence are discussed. Furthermore, some aspects of local immune responses induced during Brucella infection will be reviewed. With this knowledge, better vaccines can be designed focused on inducing protective mucosal immune response.

The Role of IL-17 in Papulopustular Rosacea and Future Directions

Rosacea is a chronic, progressive, inflammatory condition phenotypically subtyped into diagnostic features, major features, and minor/secondary features. There is currently no cure for rosacea, and it carries a significant negative psychosocial burden for afflicted patients. While there are a number of treatment modalities at the disposal of the clinician, clinical experience has suggested a need for updated treatments. The pathogenesis of rosacea is multifactorial; however, this paper will focus on the pivotal role of interleukin 17 (IL-17) in the development and progression of the disease. Furthermore, this paper will explore the mechanism of action of standard rosacea treatments and their effect on different stages of the IL-17 pathway. The standard treatments for rosacea are usually effective in controlling the symptoms of the disease in its mild-to-moderate form; however, their efficacy is diminished in the setting of severe and treatment-resistant rosacea. We hypothesize that IL-17 inhibitors, currently used successfully in psoriasis and psoriatic arthritis, could perhaps be used to treat severe and treatment-resistant papulopustular rosacea in the future; however, clinical trials and case reports will be needed to dictate expanded indications of IL-17 inhibitors. Furthermore, the high cost of IL-17 inhibitors presently prevents their use in disease states other than psoriasis or psoriatic arthritis.

Inflammation as a mediator of arterial ageing

NEW FINDINGS

What is the topic of this review? This review summarizes and synthesizes what is known about the contribution of inflammation to age-related arterial dysfunction. What advances does it highlight? This review details observational evidence for the relationship of age-related inflammation and arterial dysfunction, insight from autoimmune inflammatory diseases and their effects on arterial function, interventional evidence linking inflammation and age-related arterial dysfunction, insight into age-related arterial inflammation from preclinical models and interventions to ameliorate age-related inflammation and arterial dysfunction.

ABSTRACT

Advanced age is a primary risk factor for cardiovascular disease, the leading cause of death in the industrialized world. Two major components of arterial ageing are stiffening of the large arteries and impaired endothelium-dependent dilatation in multiple vascular beds. These two alterations are major contributors to the development of overt cardiovascular disease. Increasing inflammation with advanced age is likely to play a role in this arterial dysfunction. The purpose of this review is to synthesize what is known about inflammation and its relationship to age-related arterial dysfunction. This review discusses both the initial observational evidence for the relationship of age-related inflammation and arterial dysfunction and the evidence that inflammatory autoimmune diseases are associated with a premature arterial ageing phenotype. We next discuss interventional and mechanistic evidence linking inflammation and age-related arterial dysfunction in older adults. We also attempt to summarize the relevant evidence from preclinical models. Lastly, we discuss interventions in both humans and animals that have been shown to ameliorate age-related arterial inflammation and dysfunction. The available evidence provides a strong basis for the role of inflammation in both large artery stiffening and impairment of endothelium-dependent dilatation; however, the specific inflammatory mediators, the initiating factors and the relative importance of the endothelium, smooth muscle cells, perivascular adipose tissue and immune cells in arterial inflammation are not well understood. With the expansion of the ageing population, ameliorating age-related arterial inflammation represents an important potential strategy for preserving vascular health in the elderly.

Circulating Th1, Th2, Th17, Treg, and PD-1 Levels in Patients with Brucellosis

Brucella is an intracellular infection bacterium; the pathogenesis of Brucella and chronicity of infection may be related to the immune response of T cells. T lymphocytes mainly participate in cellular immune response. The extent of different T cell subsets imbalanced and their function dysregulated in patients with brucellosis remain not explicit. We grouped patients at different stages (acute, chronic, and convalescent). The frequencies of Th1, Th2, Th17, Treg, and PD-1 (programmed cell death protein 1) in peripheral blood were examined by flow cytometry, and the expressions of T lymphocyte cytokines in serum were detected by cytometric bead array. Th1, Th17, and Treg cell immunity was predominant in the acute stage, while Th2, Th17, and Treg cell immunity was predominant in the chronic stage. The expressions of PD-1 on CD4+ and CD8+ T lymphocytes were significantly different in acute and chronic patients. The percentages of Th1 cells in convalescent patients were still higher than those in healthy controls within one year after withdrawal. The expression of T lymphocyte cytokines in serum was different in patients at different stages. These results indicate that peripheral T lymphocyte immunity was involved in patients with brucellosis and represents a target for the preclinical and clinical assessment of novel immunomodulating therapeutics. The patients' immune function had not completely recovered in a short period of time during convalescence, so long-term follow-up of convalescent patients is needed.

IL-38: A New Player in Inflammatory Autoimmune Disorders

Interleukin (IL)-38, a newly discovered IL-1 family cytokine, is expressed in several tissues and secreted by various cells. IL-38 has recently been reported to exert an anti-inflammatory function by binding to several receptors, including interleukin-36 receptor (IL-36R), interleukin-1 receptor accessory protein-like 1 (IL-1RAPL1), and interleukin-1 receptor 1 (IL-1R1) to block binding with other pro-inflammatory cytokines and inhibit subsequent signaling pathways; thereby regulating the differentiation and function of T cells, peripheral blood mononuclear cells, macrophages, and dendritic cells. Inflammatory autoimmune diseases, which are common immune-mediated inflammatory syndromes, are characterized by an imbalance between T helper cells (Ths), especially Th1s and Th17s, and regulatory T cells (Tregs). Recent findings have shown that abnormal expression of IL-38 in inflammatory autoimmune diseases, such as rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, primary Sjogren's syndrome, psoriasis, inflammatory bowel disease, hidradenitis suppurativa, ankylosing spondylitis, and glaucoma, involves Th1s, Th17s, and Tregs. In this review, the expression, regulation, and biological function of IL-38 are discussed, as are the roles of IL-38 in various inflammatory autoimmune disorders. Current data support that the IL-38/IL-36R and/or IL-38/IL-1RAPL1 axis primarily play an anti-inflammatory role in the development and resolution of inflammatory autoimmune diseases and indicate a possible therapeutic benefit of IL-38 in these diseases.

IL-17 in Renal Immunity and Autoimmunity

The kidney is an organ particularly susceptible to damage caused by infections and autoimmune conditions. Renal inflammation confers protection against microbial infections. However, if unchecked, unresolved inflammation may lead to kidney damage. Although proinflammatory cytokine IL-17 is required for immunity against extracellular pathogens, dysregulated IL-17 response is also linked to autoimmunity. In this review, we will discuss the current knowledge of IL-17 activity in the kidney in context to renal immunity and autoimmunity and raise the intriguing question to what extent neutralization of IL-17 is beneficial or harmful to renal inflammation.

The connection between the Th17 cell related cytokines and cancer stem cells in cancer: Novel therapeutic targets

Cancer Stem Cells (CSCs) are the subpopulation of cells present in the different types of cancers with capabilities of self-renewal, differentiation, and tumorigenicity when transplanted into an animal host. The research work on the CSC has been providing a promising approach for the improvement of cancer therapies in the future. The CSCs have a close connection with the cytokines related with the T helper 17 (Th17) cell and other factors present in the tumor microenvironment, and these play a pivotal role in tumor progression and metastasis. The properties of CSCs are well defined in various type of tumor which is mainly developed by chemically and spontaneously in murine cancer model but in human defined primarily on acute myeloid leukemia, glioma, and breast cancer. The role of Th1, Th2, Natural Killer cells are well described in the cancer biology, but the Th17 cells are the subset which is recently exploited, and lots of research are going on. In this Review, we summarize current findings of the characteristics and functions of the Th17 cell and its signature cytokines in different cancers and their interconnections with cancer stem cells and with their markers. We have also discussed the functional properties of CSCs and how the CSCs markers can be distinguished from normal stem cells markers. We have also talked about the strategies that are efficiently targeting of CSCs and Th17 cells in different cancers.