ABSTRACT
Objective:To explore the effect of nontypeable Haemophilus influenzaen(NTHi)strain ATCC49247on pri-mary rabbit tracheal epithelial(TE)cells.Methods:TE cells were isolated with low temperature protease digestion and cul-tured on collagen gel-coated membranes at an air-liquid interface in serum-free medium.Under these conditions,TE cells were proliferated and differentiated into a pseudostratified mucociliary epithelium,which were infected by NTHi.Morphologic changes of the cells were examined by scanning electron microscopy(SEM)and transmission electron microscopy(TEM)after 24h.Results:SEM showed that bacteria adhered to non-ciliated cells;death or apoptosis occurred in90%of TE cells and cil-iaries were broken.TEM showed NTHi adhered to the cell surface on which there were many microvillus.Lamellipodia and microvilli surrounded bacteria within vacuoles of airway cells.Conclusion:NTHi can attach to non-ciliated cells,the latter de-vours the bacteria by lamellipodia and microvilli.NTHi is toxic to TE cells,resulting in the death or apoptosis of TE cells.