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Prolongation of neutrophil survival by the culture supernatant of Pseudomonas aeruginosa
Author(s) -
NISHIMAKI Katsushi,
OKUYAMA Kaori,
OKADA Shinji,
HATTORI Toshio,
TAKAYANAGI Motoaki,
OHNO Isao
Publication year - 2007
Publication title -
respirology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 85
eISSN - 1440-1843
pISSN - 1323-7799
DOI - 10.1111/j.1440-1843.2007.01131.x
Subject(s) - diffuse panbronchiolitis , pseudomonas aeruginosa , sputum , autocrine signalling , microbiology and biotechnology , medicine , immunology , antibody , granulocyte , receptor , neutrophile , inflammation , biology , bacteria , pathology , erythromycin , antibiotics , tuberculosis , genetics
Background and objectives: The pathogenesis of airway inflammation in diffuse panbronchiolitis (DPB) is unknown. Neutrophil survival‐enhancing activity, partially mediated by granulocyte‐macrophage colony‐stimulating factor (GM‐CSF), has been shown in the sputum from DPB patients. This study investigated the mechanisms of GM‐CSF expression in the airways of DPB patients. This involved examining the effects of mucoid Pseudomonas aeruginosa strains derived from chronically colonized patients with DPB on neutrophil survival and GM‐CSF expression. Methods: Neutrophils from healthy subjects were cultured with the culture supernatants of P. aeruginosa isolated from sputum of DPB patients in the presence or absence of anti‐GM‐CSF and anti‐GM‐CSF receptor (α chain) antibodies, and viable neutrophils were counted daily. GM‐CSF gene expression in neutrophils was evaluated by RT‐PCR. Results: Neutrophils cultured with the culture supernatants showed significantly prolonged survival, compared with neutrophils cultured with the control broth. The neutrophil survival‐enhancing activity in the culture supernatants was lost by heating. The enhanced survival of neutrophils was abolished in the presence of anti‐GM‐CSF and anti‐GM‐CSF receptor (α chain) antibodies. GM‐CSF mRNA was detected in neutrophils cultured with the bacterial supernatants, but not in those with the control broth. Conclusion: P. aeruginosa ‐derived factors (rich in proteins) stimulated neutrophils to synthesize GM‐CSF, which enhanced neutrophil survival in an autocrine/paracrine fashion.