Evaluation of murine lung epithelial cells (TC-1 JHU-1) line to develop Th2-promoting cytokines IL-25/IL-33/TSLP and genes Tlr2/Tlr4 in Check for response to Aspergillus fumigatus

Objective. - The aims of this study were to determine the role of live and heat-killed Aspergillus fumigatus conidia in releasing interleukin (IL)-25, IL-33 and thymic stromal lymphopoietin (TSLP) and to express Toll-like receptor (Tlr)2 and Tlr4 genes. Materials and methods. - Murine lung epithelial cells were incubated with live and heat-killed A. fumigatus conidia at 37 degrees C for 6, 24 and 48 h. After treatments, ELISA was performed to measure the concentrations of IL-25, IL-33 and TSLP in the supernatants. Quantitative real-time PCR (qPCR) was performed to assess the expression levels of Tlr2 and TIr4 genes. Results. - The concentrations of IL-25 and IL-33 significantly increased after exposure to live and heatkilled conidia for various times when compared with untreated control (P < 0.05). The secretion of TSLP at different concentrations of heat-killed conidia was significantly higher than both live conidia and untreated control (P < 0.05). qRT-PCR results indicated a up-regulation from 1.08 to 3.60-fold for Tlr2 gene expression and 1.20 to 1.80-fold for Tlr4 gene expression exposed to heat-killed conidia. Conclusion. - A. fumigatus has a potential ability to stimulate murine lung epithelial cells to produce IL-25/IL-33/TSLP, as well as to express Tlr2/Tlr4 genes, indicating an important role of lung epithelial cells in innate immune responses to A. fumigatus interaction. (C) 2018 Elsevier Masson SAS. All rights reserved.