Aberrant Expression of Novel Cytokine IL-38 and Regulatory T Lymphocytes in Childhood Asthma

• Published in: Molecules (Basel, Switzerland) Vol. 21; no. 7; p. 933
• Main Authors: Chu, Man, Chu, Ida, Yung, Edmund, Lam, Christopher, Leung, Ting, Wong, Gary, Wong, Chun
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 18.07.2016; MDPI AG
• Subjects: Allergens - immunology; Animals; Asthma - drug therapy; Asthma - genetics; Asthma - immunology; Asthma - metabolism; Biomarkers; Child; childhood asthma; cytokines; Female; Gene Expression; Humans; IL-38; Immunoglobulin E - blood; Immunoglobulin E - immunology; Immunophenotyping; Interleukins - blood; Interleukins - genetics; Lymphocyte Activation; Lymphocyte Count; Male; regulatory T lymphocytes; RNA, Messenger - genetics; RNA, Messenger - metabolism; T-Lymphocytes, Regulatory - immunology; T-Lymphocytes, Regulatory - metabolism; IL-38; cytokines; childhood asthma; regulatory T lymphocytes
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules21070933

We investigated the expression of novel anti-inflammatory interleukin (IL)-38 and regulatory T (Treg) lymphocytes in childhood asthma patients. The protein and mRNA expression level of IL-38, periostin, peripheral CD4+CD25+CD134+ T lymphocytes as well as CD4+CD25highFoxP3+ and CD4+CD25highCD127− Treg lymphocytes from 40 asthmatic patients and 20 normal control (NC) subjects were studied using ELISA, qPCR and flow cytometry. Serum and supernatant cytokines/chemokines were determined by multiplex assay. Serum IL-38, IL-5, IL-17, IL-6, interferon-γ, periostin, IL-1β and IL-13 concentrations were significantly higher in asthmatic patients with or without steroid treatment than those in controls (all p < 0.05). The percentages of both CD4+CD25highFoxP3+ and CD4+CD25highCD127− Treg lymphocytes were markedly decreased in asthmatic patients with and without steroid treatment than those in controls (all p < 0.05). The elevated IL-38 concentration negatively correlated with the percentage of Treg lymphocytes in asthmatic patients with high level (>40 ng/mL) of periostin (p < 0.05). Although the comparable mRNA levels of IL-38 and its receptor IL-36R were found between patients and controls, the mRNA level of IL-38 positively correlated with IL-36R and negatively correlated with IL-10 in all asthmatic patients (both p < 0.05). The percentage of CD4+CD25+CD134+ activated T lymphocytes was also significantly higher in asthmatic patients with steroid treatment than those in controls (p < 0.05). This cross-sectional study demonstrated that the overexpression of circulating IL-38 may play a role in the immunopathogenesis in asthma.