We studied in vivo binding sites of pemphigus antibodies and the expre
ssion of pemphigus and desmosomal antigens by keratinocytes in various
culture periods. Both pemphigus vulgaris (PV) and pemphigus foliaceus
(PF) antibodies mainly bound to the desmosomal areas of the lesional
skin. Desmoglein and PV antigens co-localized on the cultured normal h
uman keratinocytes in both monolayers and stratified areas. PF antigen
s, frequently together with involucrin and suprabasal keratins, were e
xpressed by stratified keratinocytes. The Western blotting study demon
strated two different desmogleins with molecular sizes of 130 and 150
kD. The 130-kD desmoglein bore PV antigenic epitopes. The 150-kD band
increased in volume as cultured keratinocytes stratified. PV antigen e
xpression on the 130-kD desmoglein precedes PF antigen formation occur
ring in keratinocyte differentiation.