Changes in cell surface glycoprotein expression during differentiation of human keratinocytes.

Six cell surface glycoproteins defined by monoclonal antibodies were selected for study on human epidermal cells. In tests on tissue sections, three of the glycoproteins [J143 (gp140/30); T43 (gp85/36); H99 (gp38)] were expressed in the basal cell layer of the epidermis, whereas the other three glycoproteins [T179 (gp140/95); T16 (gp40/50); BT15 (gp80)] were preferentially expressed in maturing keratinocytes above the basal layer. We compared synthesis of these glycoproteins in fresh epidermis and in primary epidermal short term cultures using [35S]methionine for metabolic labeling. Synthesis of J143 was 8- to 20-fold higher and synthesis of T43 was 4- to 10-fold lower in cultured cells compared with fresh epidermis. BT15, an antigen strongly expressed on terminally differentiating keratinocytes, was synthesized at 5- to 15-fold higher levels in fresh epidermis than in cultured cells. Biosynthesis levels of H99, T179, and T16 did not change in cultured epidermal cells. Based on our findings, we propose a model of surface antigenic changes that occur during keratinocyte differentiation in vivo.