Expression of a type 2 pneumocyte-specific antigen by a cell strain from normal adult mouse lung

The mouse lung epithelial cell strain NAL 1A has been confirmed as type 2 pneumocyte-related by immunostaining with a type 2 pneumocyte-specific antiserum. Cytoplasmic immunoreactivity with the antiserum paralleled the appearance of phospholipid-containing osmiophilic cytoplasmic inclusions, which were much more abundant in confluent cell cultures at low passage number than in exponentially growing cultures. However, phospholipid analysis indicated that NAL 1A cells were impoverished in phosphatidylglycerol as compared to lung type 2 pneumocytes. Confluent cultures of the neoplastic cell lines NAL 1AM and NUL 1 did not reveal any reactivity with the specific antiserum.