interleukin-8 and Carcinoma--Mucoepidermoid

Recently, Achromobacter xylosoxidans has been related to chronic lung diseases in patients suffering from cystic fibrosis (CF), but its involvement has not been elucidated. Some virulence properties of A. xylosoxidans isolated from Brazilian patients with CF were revealed in this work.. This study examined the production of a cytotoxic factor of A. xylosoxidans capable of stimulating the secretion of inflammatory cytokines (IL-6 and IL-8) from lung mucoepidermoid carcinoma cells (NCI-H292). The cytokines were measured using enzyme-linked immunosorbent (ELISA) assays. To investigate whether the cytotoxic factors may be endotoxins, they were treated with polymyxin B.. The culture supernatants of all A. xylosoxidans produced a heat stable, active cytotoxin in NCI-H292 cells capable of leading to intracellular vacuoles and subsequent cell contact loss, chromatin condensation, a picnotic nucleus and cell death. There was a higher concentration of proinflammatory cytokines in the NCI-H292 cells after 24 h of incubation, with the fraction greater than 50 kDa from the culture supernatant. The cytotoxin activity remained even after treatment with polymyxin B, which suggested that the release of IL-6 and IL-8 was not stimulated by lipopolysaccharide (LPS).. The cytotoxic factor produced by A. xylosoxidans may represent an important virulence factor, which when associated with CF chronic lung inflammation, may cause tissue damage and decline of lung function.

Topics: Achromobacter denitrificans; Brazil; Carcinoma, Mucoepidermoid; Cell Line, Tumor; Cell Survival; Culture Media, Conditioned; Cystic Fibrosis; Endotoxins; Gram-Negative Bacterial Infections; Humans; In Vitro Techniques; Interleukin-6; Interleukin-8; Pneumonia; Sputum; Virulence

Respiratory viruses induce and potentiate airway inflammation, which is related to the induction of proinflammatory mediators such as interleukin (IL)-8 and IL-6. Here we report on mechanisms implicated in IL-8 and IL-6 production by airway epithelium-like NCI-H292 cells exposed to parainfluenza virus type 4a (PIV-4). PIV-4 readily infected NCI-H292 cells as reflected by intracellular PIV-4 antigen expression. PIV-4 infection triggered a biphasic IL-8 and IL-6 mRNA response. Transient transfection with truncated and mutated promoter constructs identified NF-kappaB and activator protein (AP)-1, and CCAAT-enhancer binding protein (C/EBP) as the relevant transcription factors for PIV-4-induced IL-8 and IL-6 gene transcription, respectively. An increase of DNA-binding activities for NF-kappaB and C/EBP paralleled the induction of the first and second IL-8 and IL-6 mRNA peaks, whereas the onset of AP-1 paralleled the first IL-8 mRNA peak only. The second mRNA peak, apparently dependent on viral replication, coincided also with a marked reduction of IL-8 and IL-6 mRNA degradation. Importantly, cells at the time of the reduced mRNA degradation displayed an exaggerated IL-8 and IL-6 protein production to a secondary stimulus, as exemplified by steeper dose-response curves to TNF-alpha. Thus PIV-4 infection enhances epithelial IL-8 and IL-6 production by transcriptional and posttranscriptional mechanisms. The previously unrecognized phase of reduced IL-8 and IL-6 mRNA degradation and the concurrent amplified epithelial IL-8 and IL-6 responses may play an important role in virus-induced potentiation of airway inflammation.

Topics: Adenocarcinoma; Antineoplastic Agents; Carcinoma, Mucoepidermoid; CCAAT-Enhancer-Binding Proteins; Cell Line, Tumor; Humans; Interleukin-6; Interleukin-8; Lung Neoplasms; NF-kappa B; Parainfluenza Virus 4, Human; Promoter Regions, Genetic; RNA, Messenger; Rubulavirus Infections; Transcription Factor AP-1; Tumor Necrosis Factor-alpha

Tryptase, a protease unique to the mast cell secretory granule, is released in substantial quantities into the respiratory tract of patients with inflammatory disease of the airways. We have investigated the potential of tryptase to act as a mitogen for bronchial epithelial cells and to stimulate release of IL-8 and expression of ICAM-1. Tryptase was isolated from extracts of human lung tissue using ammonium sulphate precipitation, octyl agarose, and heparin agarose chromatography. Purified tryptase stimulated DNA synthesis in the human epithelial cell line H292, as measured by [3H] thymidine incorporation. Maximal growth was observed after 24 h using 25 mU/ml of tryptase (where 1 micron is defined as that which can hydrolyze 1 mumol of the peptide substrate N-alpha-benzoyl-DL-arginine p-nitroanilide hydrochloride per minute at 25 degrees C), a concentration that is likely to be achieved in vivo. Inhibitors of tryptase activity, including leupeptin and benzamidine hydrochloride, significantly decreased tryptase-induced stimulation of DNA synthesis, indicating the requirement for an active catalytic site. Tryptase stimulated a catalytic site-dependent release of IL-8 from epithelial cells after 24 h, and this was associated with up-regulation of ICAM-1 expression, as revealed by FACS analysis. Tryptase may play a critical role in epithelial repair and in the recruitment of granulocytes following mast cell activation.

Topics: Carcinoma, Mucoepidermoid; Cell Division; Chymases; Electrophoresis, Polyacrylamide Gel; Epithelium; Humans; Intercellular Adhesion Molecule-1; Interleukin-8; Lung Neoplasms; Mast Cells; Mitogens; Serine Endopeptidases; Tryptases; Tumor Cells, Cultured; Up-Regulation