Infection and activation of airway epithelial cells by Chlamydia pneumoniae

The activation of primary human airway epithelial cells (HAECs) and of the bronchial epithelial cell line BEAS-2B by Chlamydia pneumoniae, an importan t respiratory pathogen, was characterized. A time-dependent enhanced releas e of interleukin (IL)-8 and prostaglandin-E-2 and an increased expression o f the epithelial adhesion molecule intercellular adhesion molecule-1 (ICAM- 1), followed by subsequent transepithelial migration of polymorphonuclear n eutrophils (PMN), were also demonstrated. The transepithelial PMN migration could be blocked by an anti-ICAM-1 monoclonal antibody (MAb) but not by MA bs against IL-8. In addition, there was an enhanced C. pneumoniae-mediated activation of NF-kappaB within 30-60 min in HAECs and BEAS-2B, which was fo llowed by increases in mRNA synthesis of IL-8, ICAM-1, and cyclooxygenase-2 , with maximal effects occurring 2 h after infection, Thus, C. pneumoniae i nfects and activates HAECs and BEAS-2B and therefore may be able to trigger a cascade of pro- and anti-inflammatory reactions during chlamydial infect ions.