Human ciliated epithelial cells from nasal polyps as an experimental model for Mycoplasma pneumoniae infection.

Human ciliated epithelial cells derived from nasal polyps and cultured in a monolayer were studied as an experimental model for Mycoplasma pneumoniae infection. Scanning electron microscopy revealed two types of cultured epithelial cells: one which was covered by microvilli only and another which had microvilli and actively beating cilia. M. pneumoniae adhered to both types of cells, and the adherence followed saturation kinetics as a function of time. Infection of the cells for 20 h resulted in 75% inhibition of their intracellular catalase activity and a 3.5-fold increase in their malonyldialdehyde levels compared with noninfected controls. This indicates the presence of cellular oxidative damage due to M. pneumoniae infection. It is suggested that human nasal ciliated epithelial cells may serve as a representative model for studying M. pneumoniae in relation to its natural host.