Consistently nonoverlapping distribution of epidermal growth factor receptors in adult human skin detected by various monoclonal antibodies.

We tested three monoclonal antibodies, Ab1, Ab2 and Ab3, against epidermal growth factor receptors (EGFR) of human A431 epidermal carcinoma cells. EGFR immunoreactive to Ab1 (EGFR1) were localized in basal cells, especially at the epidermal sweat duct ridges, suprabasal cells, the peripheral cell layer of the sudoriferous duct, outer root sheaths of hair follicles, hair bulbs and sebaceous glands in all cases. On the other hand, EGFR immunoreactive to Ab2 (EGFR2) and EGFR immunoreactive to Ab3 (EGFR3) appeared in about half of the cases. They were situated on granular layers of the epidermis, especially in skin covered by hair, endothelial cells and the superficial layer of the sudoriferous duct. These results indicate that EGFR takes multiple forms in normal human skin and in A431 cells and that the form depends on the type of cells in the skin.