Lung epithelial cell differentiation pathways remain unclear. This is due in part to the plasticity of these cells and the lack
of markers which accurately reflect their differentiation status. The aim of this study was to determine 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 electron microscopy. No significant alteration in binding
reactivity of Bauhinia purpurea (BPA), Maclura pomifera (MPA), Concanavalin A, Wheat germ or Helix pomatia lectins
occurred in cultures compared with Clara cells in mouse lung tissue. In contrast, nitrotetrazolium blue reductase activity and
CC10 expression declined in culture. Rat type II cells were cultured for 8 days. Between days 0 and 4, the number of type II
cells identified by electron microscopy 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 reactivity was altered at day 0 and day 4 respectively, compared
with cells in situ. Therefore, the reactivity of lectins analysed here does not reflect 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
