Highly polarized primary epithelial cells from human nasopharynx grown as spheroid-like vesicles.

The value of experimental culture models using epithelial cells often depends on the degree of polarization and other critical features observed in natural tissues, including the formation of tight junctions, desmosomes and membrane interdigitations. However, growth of normal epithelial cells as monolayers on artificial supports also leads to partial loss of the original characteristics of epithelial cells, and the quality of the monolayer is strongly influenced by the physicochemical properties of the support. In addition, not all normal epithelial cell types are able to adhere and to grow well on artificial substrata. In order to circumvent the drawbacks of two-dimensional cultures we established an in vitro model that closely resembles the in vivo situation of the intact epithelium. Human epithelial cells from nasopharynx (HNPEC) were used to prepare multicellular epithelial vesicles consisting of both non-ciliated and ciliated mucosal cells. Electron microscopy investigations showed that the morphological appearance of the epithelial cells was similar to that in situ. HNPEC vesicle cultures maintain a geometrically intact organization of individual cells that is not achieved using conventional culture conditions. HNPEC vesicles are more in vivo-like than two-dimensional cultures and therefore represent a suitable model for a variety of research purposes including studies on the pathogenesis of invasive microorganisms.