FUNCTIONAL INVOLVEMENT OF UROKINASE-TYPE PLASMINOGEN-ACTIVATOR RECEPTOR IN PEMPHIGUS ACANTHOLYSIS

Urokinase-type plasminogen activator (uPA) has been well documented in the development of pemphigus acantholysis. The function of its recept or (uPA-R) in pemphigus acantholysis has only recently attracted atten tion. Increased expression of uPA-R has been demonstrated in pemphigus vulgaris. In this study, we have further explored the functional invo lvement of uPA-R in pemphigus acantholysis. Our results show that uPA- R expression is significantly increased in acantholytic foci of pemphi gus vulgaris and pemphigus foliaceus but not in bullous pemphigoid or normal skin specimens; the expression of uPA-R in cultured human kerat inocytes is subjected to regulation by pemphigus vulgaris IgG but not by pemphigoid Ige or normal human IgG; furthermore, anti-uPA-R monoclo nal antibody effectively inhibits pemphigus vulgaris Ige induced acant holysis in skin organ cultures. These data suggest that uPA-R may play an important role in the pathogenesis of pemphigus acantholysis.