IL-17B is elevated in patients with pneumonia and mediates IL-8 production in bronchial epithelial cells

Identification through machine learning of potential immune- related gene biomarkers associated with immune cell infiltration in myocardial infarction

BACKGROUND

To investigate the potential role of immune-related genes (IRGs) and immune cells in myocardial infarction (MI) and establish a nomogram model for diagnosing myocardial infarction.

METHODS

Raw and processed gene expression profiling datasets were archived from the Gene Expression Omnibus (GEO) database. Differentially expressed immune-related genes (DIRGs), which were screened out by four machine learning algorithms-partial least squares (PLS), random forest model (RF), k-nearest neighbor (KNN), and support vector machine model (SVM) were used in the diagnosis of MI.

RESULTS

The six key DIRGs (PTGER2, LGR6, IL17B, IL13RA1, CCL4, and ADM) were identified by the intersection of the minimal root mean square error (RMSE) of four machine learning algorithms, which were screened out to establish the nomogram model to predict the incidence of MI by using the rms package. The nomogram model exhibited the highest predictive accuracy and better potential clinical utility. The relative distribution of 22 types of immune cells was evaluated using cell type identification, which was done by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm. The distribution of four types of immune cells, such as plasma cells, T cells follicular helper, Mast cells resting, and neutrophils, was significantly upregulated in MI, while five types of immune cell dispersion, T cells CD4 naive, macrophages M1, macrophages M2, dendritic cells resting, and mast cells activated in MI patients, were significantly downregulated in MI.

CONCLUSION

This study demonstrated that IRGs were correlated with MI, suggesting that immune cells may be potential therapeutic targets of immunotherapy in MI.

Contribution of Interleukin-17A to Retinal Degenerative Diseases

Retinal degenerative diseases are a leading cause of vision loss and blindness throughout the world, characterized by chronic and progressive loss of neurons and/or myelin. One of the common features of retinal degenerative diseases and central neurodegenerative diseases is chronic neuroinflammation. Interleukin-17A (IL-17A) is the cytokine most closely related to disease in its family. Accumulating evidence suggests that IL-17A plays a key role in human retinal degenerative diseases, including age-related macular degeneration, diabetic retinopathy and glaucoma. This review aims to provide an overview of the role of IL-17A participating in the pathogenesis of retinal degenerative diseases, which may open new avenues for potential therapeutic interventions.

Host genetic factors of COVID-19 susceptibility and disease severity in a Thai population

Host genetic factors have been shown to play a role in SARs-CoV-2 infection in diverse populations. However, the genetic landscape differs among various ethnicities; therefore, we explored the host genetic factors associated with COVID-19 disease susceptivity and disease severity in a Thai population. We recruited and genotyped 212 unrelated COVID-19 Thai patients and 36 controls using Axiom^TM Human Genotyping SARs-COV-2 array, including 847,384 single nucleotide polymorphisms related to SARs-COV-2 pathogenesis, immune response, and related comorbidity No SNPs passed the genome-wide significance threshold of p value <1 × 10^-8. However, with a threshold of p value <1 × 10^-5, a locus on chromosome 5q32 was found to have a suggestive association with COVID-19 disease susceptibility (p value 6.9 × 10^-6; Q-Q plot λ = 0.805, odds ratio 0.02). Notably, IL17B is a gene located in this linkage disequilibrium block and is previously shown to play a part in inflammation and pneumonia. Additionally, a suggestive locus on chromosome 12q22, harboring EEA1 and LOC643339, was associated with COVID-19 disease severity (p value 1.3 × 10^-6 - 4.4 × 10^-6, Q-Q plot λ = 0.997, odds ratio 0.28-0.31). EEA1 is involved in viral entry into cells, while LOC643339 is a long non-coding RNA. In summary, our study suggested loci on chromosomes 5q32 and 12q22 to be linked to COVID-19 disease susceptibility and disease severity, respectively. The small sample size of this study may lessen the likelihood that the association found is real, but it could still be true. Further study with a larger cohort is required to confirm these findings.

Serum interleukin-17 predicts severity and prognosis in patients with community acquired pneumonia: a prospective cohort study

Background

Some studies previously demonstrated that interleukin-17 (IL-17) involves in pulmonary diseases progression. Nevertheless, the role of IL-17 in community-acquired pneumonia (CAP) remains unknown. This study aims to examine the correlations between serum IL-17 with the severity and prognosis in CAP patients through a prospective cohort study.

Methods

All 239 CAP patients were recruited. Serum IL-17 was detected by enzyme-linked immunosorbent assay (ELISA). The CAP severity was evaluated through CAP severity scores, including CURB-65, CRB-65, PSI, SMART-COP, CURXO and APACHE II.

Results

Serum IL-17 was gradually increased consistent with the severity of CAP. Correlative analysis suggested that serum IL-17 was associated with clinical physiologic indicators among CAP patients. Logistic regression indicated that serum IL-17 was positively related to CAP severity scores. Additionally, the prognostic outcomes were tracked among CAP patients. The levels of IL-17 on admission were significantly increased in CAP patients with ICU admission, mechanical ventilation, vasoactive agent, death and longer hospitalization days. Logistic regression analyses revealed serum higher IL-17 on admission elevated the risks of vasoactive agent usage and longer hospital stays in CAP patients. The cut-off concentrations of serum IL-17 for death, ICU admission, mechanical ventilation and ≥ 14 hospital stays were 86.80 ng/mL, 84.92 ng/mL, 84.92 ng/mL and 60.29 ng/mL respectively.

Conclusions

Serum IL-17 on admission is positively associated with the severity and poor prognosis among CAP patients, revealing that IL-17 may implicate in the pathological process of CAP. Therefore, serum IL-17 may become an effective biomarker for diagnosis, prognosis and therapy for CAP patients.

Much More Than IL-17A: Cytokines of the IL-17 Family Between Microbiota and Cancer

The interleukin-(IL-)17 family of cytokines is composed of six members named IL-17A, IL-17B, IL-17C, IL-17D, IL-17E, and IL-17F. IL-17A is the prototype of this family, and it was the first to be discovered and targeted in the clinic. IL-17A is essential for modulating the interplay between commensal microbes and epithelial cells at our borders (i.e., skin and mucosae), and yet, for protecting us from microbial invaders, thus preserving mucosal and skin integrity. Interactions between the microbiota and cells producing IL-17A have also been implicated in the pathogenesis of immune mediated inflammatory diseases and cancer. While interactions between microbiota and IL-17B-to-F have only partially been investigated, they are by no means less relevant. The cellular source of IL-17B-to-F, their main targets, and their function in homeostasis and disease distinguish IL-17B-to-F from IL-17A. Here, we intentionally overlook IL-17A, and we focus instead on the role of the other cytokines of the IL-17 family in the interplay between microbiota and epithelial cells that may contribute to cancer pathogenesis and immune surveillance. We also underscore differences and similarities between IL-17A and IL-17B-to-F in the microbiota-immunity-cancer axis, and we highlight therapeutic strategies that directly or indirectly target IL-17 cytokines in diseases.

Interleukin-17 and ischaemic stroke

Interleukin-17 (IL-17) is a cytokine family that includes 6 members, IL-17A through IL-17F, most of them are reported to have pro-inflammatory role. Through binding to their receptors (IL-17Rs), IL-17 activates the intracellular signalling pathways to play an important role in autoimmune diseases, including rheumatoid arthritis (RA) and multiple sclerosis (MS). Ischaemic stroke is a complex pathophysiological process mainly caused by regional cerebral ischaemia. Inflammatory factors contribute to the physiological process of stroke that leads to poor prognosis. IL-17 plays a crucial role in promoting inflammatory response and inducing secondary injury in post-stroke. Though immune cells and inflammatory factors have been reported to be involved in the damage of stroke, the functions of IL-17 in this process need to be elucidated. This review focuses on the pathological modulation and the mechanism of IL-17 family in ischaemic stroke and seeking to provide new insights for future therapies.

MicroRNA-382-5p is involved in pulmonary inflammation induced by fine particulate matter exposure

Exposure to atmospheric particulate matter (PM) has been related to the increasing incidence and mortality of pulmonary diseases, where microRNAs (miRNAs) play significant roles in these biological and pathological processes. In the present study, we found that miR-382-5p played an anti-inflammatory role in pulmonary inflammation induced by fine particulate matter (PM_2.5) or diesel exhaust particles (DEPs) in vitro and in vivo. The expression level of miR-382-5p was downregulated, while its target gene, namely CXCL12, was elevated in HBE cells after exposure to PM_2.5 or DEPs. Mechanistically, PM_2.5 or DEPs exposure increased CXCL12/MMP9 expression via miR-382-5p inhibition, subsequently triggered pulmonary inflammation. Furthermore, antagonizing the function of CXCL12 significantly reduced the expression of MMP9 and local inflammation induced by PM_2.5 or DEPs. PM_2.5 or DEPs caused apoptosis and G1 phase arrest could be partially restored by overexpression of miR-382-5p and antagonism of CXCL12. In a murine model, enhanced miR-382-5p expression effectively reduced expression levels of CXCL12, MMP9 and inflammatory cytokines, hereby protected lung tissues against PM_2.5 or DEPs-induced lesions. Collectively, the miR-382-5p/CXCL12/MMP9 pathway may provide a mechanism, which mediates inflammatory response to PM_2.5 or DEPs exposure.

Cytokine levels predict 30-day mortality in octogenarians and nonagenarians with community-acquired pneumonia: a retrospective observational study

To analyze the value of cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, IL-6, IL-8, IL-10) as predictors of mortality at 30 days in octogenarians and nonagenarians hospitalized in an internal medicine unit for community-acquired pneumonia (CAP). An observational, analytical, retrospective cohort study was conducted in the Department of Internal Medicine at Alicante General University Hospital between January 2014 and December 2015. Blood samples were frozen at - 80 °C, and cytokines were measured by ELISA. We included 115 patients, of whom 54% were men, with a mean age of 86.4 (standard deviation 4.5) years. There is a moderate correlation between IL-10 levels and CURB-65 score (p < 0.001) and a weak correlation with creatinine levels (p = 0.012) and urea levels (p = 0.032). Forty-five (39.1%) patients died within 30 days. In a multivariate analysis, the variables associated with mortality at 30 days were the following: age (adjusted odds ratio [ORa] 1.134, 95% confidence interval [CI] 1.02, 1.26), male sex (ORa 2.85, 95% CI 1.14, 7.14), IL-8 of 19 pg/mL or more (ORa 4.09, 95% CI 1.67, 10.01), and IL-10 of 11.29 pg/mL or more (ORa 4.00, 95% CI 1.58, 10.12). High IL-8 and IL-10 levels were shown to predict 30-day mortality in elderly patients with CAP. The inflammatory response in these patients seems to condition their prognosis. Further research in this line would provide more understanding about the physiopathological mechanisms and potential therapeutic targets for improving survival.

CD5L contributes to the pathogenesis of methicillin-resistant Staphylococcus aureus-induced pneumonia

Staphylococcus aureus is a major causative microorganism in community- and healthcare-acquired pneumonia. CD5L is an important protein in the control of immune homeostasis. In this study, we found that patients with S. aureus pneumonia displayed increased levels of circulating CD5L. Likewise, mice with S. aureus pneumonia had elevated CD5L levels in the lungs. Anti-CD5L antibody protected mice from lethal pneumonia induced by methicillin-resistant S. aureus. The survival benefit obtained with antibody against CD5L was associated with an improvement of bacterial clearance and a reduction of pulmonary inflammatory cytokines and chemokines. Conversely, co-injection of recombinant CD5L and S. aureus markedly increased the lethality of S. aureus pneumonia. These findings suggest that CD5L contributed to the immunopathology of S. aureus pneumonia.

IL-34 regulates IL-6 and IL-8 production in human lung fibroblasts via MAPK, PI3K-Akt, JAK and NF-κB signaling pathways

IL-34 plays diverse roles in disease due to its inflammatory and immunosuppressive properties. Elevated IL-34 expression has been observed in lung cancers and pulmonary infections although its role is unclear. We found that IL-34 addition to primary lung fibroblasts significantly promoted IL-6 and IL-8 expression in a dose and time dependent manner. These effects were reversed when JAK, NF-κB, Akt and p38 inhibitors were included before IL-34 addition. Protein phosphorylation in these pathways was also observed through western-blotting. Stimulation of human lung fibroblasts with IL-34 in combination with TNF-α, IL-17A and IL-4 enhanced inflammatory cytokine production. Our data confirmed the inflammatory effect of IL-34 on human lung fibroblasts and suggested that the IL-34/CSF-1R axis may be a novel therapeutic target in pulmonary disease.

A review article on brodalumab in the treatment of moderate-to-severe plaque psoriasis

Psoriasis is a chronic immune-mediated skin disorder affecting approximately 2-3% of the worldwide population. Recent advances in our understanding of the immunopathogenesis of psoriasis have resulted in novel therapeutic agents. IL-17, a pro-inflammatory cytokine, plays a pivotal role in psoriasis. Therapeutic agents targeting this cytokine have shown clinical effectiveness in the treatment of moderate-to-severe plaque psoriasis. Brodalumab, a human antibody against IL-17 receptor A, has been approved by the US FDA in February 2017, by the Japanese Pharmaceuticals and Medical Devices Agency in July 2016 and by the EMA in July 2017 for the treatment of moderate-to-severe psoriasis. This article reviews the published data relating to brodalumab for the treatment of moderate-to-severe plaque psoriasis.

IL-36 induces cytokine IL-6 and chemokine CXCL8 expression in human lung tissue cells: Implications for pulmonary inflammatory responses

IL-36α, IL-36β and IL-36γ are cytokine members of IL-1 family. Although IL-36 expression was observed in human lung during pulmonary infections, it remains unknown whether IL-36 could act directly on lung tissue cells during pulmonary inflammatory responses. In this study, we showed that IL-36 receptor was expressed in human lung fibroblasts and bronchial epithelial cells. Correspondingly, IL-36α, IL-36β or IL-36γ up-regulated gene expression of cytokine IL-6 and chemokine CXCL8 in human lung fibroblasts and bronchial epithelial cells, and promoted IL-6 and CXCL8 release from human lung fibroblasts and bronchial epithelial cells. The production of IL-6 and CXCL8 in these lung tissues cells induced by IL-36α, IL-36β or IL-36γ was regulated by p38MAPK, ERK or Akt signaling pathways. Taken together, the above results suggest that IL-36-mediated IL-6 and CXCL8 production in human lung fibroblasts and bronchial epithelial cells may be involved in pulmonary inflammation especially caused by bacterial or viral infections.

IL-17B: A new area of study in the IL-17 family

The interleukin (IL)-17 superfamily, a relatively new family of cytokines, consists of six ligands (from IL-17A to IL-17F), which bind to five receptor subtypes (from IL-17RA to IL-17RE) and induce downstream signaling. IL-17A, a prototype member of this family, has been reported to be involved in the pathogenesis of allergies, autoimmune diseases, allograft transplantations, and malignancies. Unlike IL-17A, which is mainly produced by T helper 17 cells, IL-17B is widely expressed in various tissues. Recently, the biological function of IL-17B in diseases, particularly tumors, has attracted the attention of researchers. We previously reported that the expression of IL-17RB increased in gastric cancer tissues and demonstrated that IL-17B/IL-17RB signaling plays a critical role in gastric tumor progression. However, studies on IL-17B are scant. In this review, we detail the structural characteristics, expression patterns, and biological activities of IL-17B and its potential role in the pathogenesis of diseases.