Regulation of -defensin-2 gene expression by lentinan in human pulmonary epithelial cells

Human -defensin-2 (HBD-2) is considered a crucial endogenous antimicrobial peptide, performing this role with both a broad spectrum and high performance. To investigate the regulation of -defensin-2 gene expression by lentinan (LNT) and the relationship possessed other than a dose or time dependence. We cultured pulmonary glandular epithelial cells line (SPC-A-1) in vitro. Following treatment with LNT at different concentration (0, 12.5, 25, 50, 100 and 200 µg/ml) and time (1st, 2nd, 4th, 8th, 16th, 24th and 48th h). Utilising the reverse transcription polymerase chain reaction (RT-PCR) with primer designed for HBD-2, the total RNA was extracted from SPC-A-1 cells and the RT-PCR was performed with primers for HBD-2. The expression of HBD-2 mRNA treated by varying concentration of LNT was significantly higher than those from blank control groups (P<0.05) in vitro. In addition, the expression of HBD-2 mRNA in the treatment group with a LNT concentration of 100 µg/ml at the time of 8th h was significantly higher (P<0.05) in vitro, demonstrating both a concentration and time dependence. For the first time in vitro, we demonstrated that LNT can induce -defensin-2 mRNA expression and that the amount of induced expression has both the dose and time-dependent relationship with LNT.