We correlated the transcription of TGF-beta(1), connective tissue growth factor (CTGF), IL-4, IL-13 and interferon-gamma (IFN-gamma) with lung function development in progressive fibrosis in idiopathic interstitial pneumonia.
TLR9 in fibroblasts appeared to be increased by profibrotic Th2 cytokines (IL-4 and IL-13) and this was true in fibroblasts cultured from the most severe form of IIP, idiopathic pulmonary fibrosis (IPF) SLBs, in non-specific interstitial pneumonia fibroblast lines, and in normal fibroblasts.
Thus, these data suggest that the abnormal proliferative properties of human lung fibroblasts from certain IIP patient groups can be modulated in a manner that is dependent on the IL-4 and IL-13 receptor subunit expression by these cells.