Abstract:OBJECTIVE: To study the expression of human β-defensin-3 (hBD-3) induced by lipopolysaccharide (LPS) in human bronchial epithelial (HBE) cells, and explore the role of hBD-3 in respiratary infection. METHODS: HBE cells were stimulated with different concentrations of LPS (0.01, 0.1, 1 and 10 μg/mL). hBD-3 mRNA expression was detected by RT-PCR 2 hrs later. hBD-3 protein expression was detected by Western blot 4 hrs later. RESULTS: hBD-3 mRNA and protein was weakly expressed in normal HBE cells. LPS stimulation resulted in a significant increase of hBD-3 mRNA and protein expression (P<0.01). hBD-3 mRNA and protein expression increased with increasing LPS concentrations. There were significant differences in the hBD-3 mRNA and protein expression in cells stimulated by different concentrations of LPS (P<0.05). CONCLUSIONS: LPS can induce hBD-3 expression in a dose-dependent manner. hBD-3 might play a role in initial defensive reaction against bacterial invasion.[Chin J Contemp Pediatr, 2009, 11 (7):577-580]