Objective To study the effect of nontypeable Hemophilus influenzae(NTHi) strain ATCC49247 on proinflammatory cytokines expression of human A549 lung epithelial cell line. Methods Confluent A549 cells were co-incubated with NTHi, NTHi+Erythromycin(10 mg/L), NTHi+Gentamicin(100 mg/L), and NTHi+Dexamethasone(100 μmol/L),and nuclear factor kappa B(NF-κB) inhibitor primed cells were co-incubated with NTHi for 24 h. Then levels of interleukin-8（IL-8） and tumor necrosis factor-α(TNF-α) in the supernatant was assayed by enzyme-linked immunosorbent assay(ELISA) and the expression of intercellular adhesion molecule-1(ICAM-1) in cells was detected by immunohistochemistry staining. Results A549 cells were transformed and died after co-intubated with NTHi for 24 h. NTHi induced A549 cells to release significantly greater amounts of IL-8, which was inhibited by NF-κB inhibitor pyrrolidine dithiocarbamate（PDTC）. Incubating of A549 cells with NTHi significantly induced release of IL-8 and the expression of ICAM-1, which was blocked by erythromycin and dexamethasone and not by gentamicin. TNF-α was not detected in all circumstances. Conclusions NTHi can increase significantly the release and expression of proinflammatory cytokines through NF-κB pathway. Antibacterial drug erythromycin also has anti-inflammatory effect.
