Thymic Hassall's corpuscles-epidermis antigenic relations defined by a common glycoprotein in man (GP 37)

Immunological identification of a common ConA reactive glycoprotein to Hassall's corpuscles (HC) and keratinocytes is reported. By using a gross separation of epidermis into upper and lower layers, we have demonstrated a group of Concanavalin A (ConA) reactive glycoproteins that are characteristic of the upper more differentiated layers of the epidermis. On of them, of 37 Kd MW (GP37), has been immunologically localized within human epidermal granular cells. This limited localization was confirmed by electron microscopy. In thymus, the HC and some medullary epithelial cells were found reactive. This study demonstrated that some thymic epithelial cells from the medulla and the HC shared a defined antigenic specificity common to epidermal granular cells. This immunocytochemical approach and previous ones allow a better understanding of epidermis-thymus interactions.