Expression and function of CD40 on rat peritoneal mesothelial cells

Objective To determine whether peritoneal mesothelial cells express CD40 and to investigate potential mechanism by which CD40-CD40 ligand(CD40L) interaction may be involved in the inflammation of peritoneal membrane. Methods Rat peritoneal mesothelial cells (MC) were harvested from peritoneal cavity and maintained under defined in vitro conditions. Expression of CD40 on MC under normal culture or stimulation with interferon-γ(IFN-γ), tumor necrosis factor-α(TNF-α), interleukin(IL)-1 was examined by RT-PCR and FACS analysis. After activation with CD40 mAb, the expression of intercellular adhesion molecule-1 (ICAM-1) on MC was analyzed by FCAS. Results MC cultured in vitro expressed CD40 constitutively. The expression of CD40mRNA and CD40 protein up-regulated markedly following the stimulations with IFN-γ, but not with IL-1, TNF-α. The expression of ICAM-1 on MC was significantly increased after activation of CD40 with IFN-γ and CD40mAb. Conclusions MC functionally expresses CD40. The interaction of CD40 on MC and CD40L+ cells in peritoneal cavity may play an important role in peritoneal local defense and may be involved in the inflammation process of peritoneum.