Oral epithelial cells as the origin of pemphigus antigen in human saliva

Absorption of pemphigus sera with normal human saliva or with scraped oral epithelial cells abolished the intercellular antibody titres, as revealed by indirect immunofluorescence. No pemphigus antigenic activity was detected on either human or macaque salivary glands, suggesting that the pemphigus antigen in saliva is a product of the epithelial lining of the oral mucosa. Indirect immunofluorescence on primary cultures of normal oral mucosa demonstrated that pemphigus antigen is synthesized by human oral epithelial cells. Salivary pemphigus antigen was isolated by affinity chromatography on Sepharose-linked IgG-fraction from pemphigus sera. Pemphigus antibody-binding material from the isolated fraction was detected in two bands with apparent molecular weights of 30,000 and 12,000 by immuno-blotting of reduced SDS-polyacrylamide gel electrophoretograms.