Localization of epidermal-type fatty acid binding protein in alveolar macrophages and some alveolar type II...

Almost all alveolar macrophages in the mouse lung were strongly immunoreactive for epidermal-type fatty acid binding protein. At the electron microscope level, the immunoreactive material was localized diffusely in the cytoplasm but not within the nucleus. A certain number of alveolar type II epithelial cells were also immunoreactive for the protein with variable immunointensity, while a substantial number of the type II cells were immunonegative. No immunoreactive interstitial fibroblasts were encountered. Based on the present findings, possible roles of epidermal-type fatty acid binding protein in the host-defence mechanism played by alveolar macrophages are suggested.