Study on Human Tracheal Bronchial Epithelial Cells Secreting Cytokines in Vitro by Nontypeable Haemophilus Influenzae

Abstract

Obstrucive To study the interaction of nontypeable haemophilus influenzae strain ATCC49247 with primary human bronchial epithelial cells (HBEC) and the NTHi-induced release and expression of proinflammoraty cytokine in the HBEC. Methods HBEC were isolated by using low temperature protease digestion and cultured in serum-free medium. Confluent epithelial cell cultures were incubated with NTHi, NTHi +erythromycin(0.1mg/L), NTHi + erythromycin(10mg/L), NTHi + gentamicin(100mg/L), NTHi+dexamethasone(100uM)and normal untreated control cells after 24h. Release of IL-8 and TNF-a into the supernatant was assayed by enzyme-linked immunosorbent assay; The expression of ICAM-1 was examined by immunohistochemistry staining. Results (1) Some HBECs were transformed and died after 24h. (2) HBEC: NTHi-induced cells released significantly greater amounts of IL-8 and TNF-a (2172.18±131.83, 7.22±2.17 pg/ml, respectively) than normal untreated cells (1115.76±57.63,2.84±1.04pg/ml)(p Conclusions HBEC can release IL-8 and TNF-a. NTHi may increase significantly release and expression of proinflammatory cytokine. Gentamicin have no anti-inflammatory effects. Erythromycin may have anti-inflammatory effects. Dexamethasone has distinct anti-inflammatory effects.