Characterisation of lectin binding patterns of mouse bronchiolar and rat alveolar epithelial cells in culture

Lung epithelial cell differentiation pathways remain unclear. This is due i n part to the plasticity of these cells and the lack of markers which accur ately reflect their differentiation status. The aim of this study was to de termine if lectin binding properties are useful determinants of functional differentiation status in vitro. Mouse Clara cells were cultured for 5 days . During this time, no alteration in differentiation was evident by electro n microscopy. No significant alteration in binding reactivity of Bauhinia p urpurea (BPA), Maclura pomifera (MPA), Concanavalin A, Wheat germ or Helix pomatia lectins occurred in cultures compared with Clara cells in mouse lun g tissue. In contrast, nitrotetrazolium blue reductase activity and CC10 ex pression declined in culture. Rat type II cells were cultured for 8 days. B etween days 0 and 4, the number of type II cells identified by electron mic roscopy was constant at 70-80%, decreasing to 8% by day 6. In contrast, by day 4, only 42% cells retained alkaline phosphatase activity. BPA and MPA r eactivity was altered at day 0 and day 4 respectively, compared with cells in situ. Therefore, the reactivity of lectins analysed here does not reflec t functional differentiation status of cultured mouse Clara cells. However, BPA and MPA reactivity may be a sensitive indicator of alterations in rat type II cell differentiation in vitro.