An immunohistochemical study of beta 1,4-galactosyltransferase in human skin tissue

An immunohistochemical investigation of beta 1,4-galactosyltransferase (bet a 1,4-GalT) on human skin tissue was performed on formalin-fixed paraffin-e mbedded sections using a monoclonal antibody, MAb8628, which specifically r ecognizes a protein moiety of human beta 1,4-GalT. Distribution of the gala ctose beta 1,4-N-acetylglucosamine (Gal beta 1,4GlcNAc)-R epitope was also detected by staining with Ricinus communis agglutinin (RCA) 120. The beta 1 ,4-GalT was observed to be localized at the perinuclear region of epidermal keratinocytes. The fine localization was also observed at the supranuclear region in the cells of apocrine glands, eccrine ducts and glands. The posi tive staining with RCA 120 was well colocalized with the cells expressing t he beta 1,4-GalT. An electron microscopic study revealed that positive sign als of beta 1,4-GalT definitely reside in the Golgi apparatus. No immunorea ctivity was observed in any other intracellular structure or on the cell su rface. These findings strongly indicated that the beta 1,4-GalT is the majo r enzyme responsible for the Gal beta 1,4GlcNAc-R epitope synthesis in huma n skin tissue. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.