Analysis of major histocompatibility complex (MHC) class I antigen in the rat salivary gland

This antigen was examined in rats of different ages (new-born, 3, 5, 7, 10, 12 and 14 days after birth and adult) by immunofluorescence and immunoelectron microscopy. Changes in each kind of salivary gland when graft versus host disease was induced in recipient rats were also investigated. Monoclonal antibodies (HAM 2 or OX 18) specific to rat MHC class I antigen were used and these were detected by FITC-conjugated anti-mouse immunoglobulin. With HAM 2, MHC class I antigen in the submandibular gland was mostly located in the secretory duct cells; this expression was first found 10 days after birth. The antigen was found on the cell surfaces of the secretory duct cells by immunoelectron microscopy. With OX 18, MHC class I antigen was mainly found in the secretory duct cells, but weak expression was also found in the acinar cells. Localization of the antigen, by HAM 2 and OX 18 was less evident in the secretory duct cells of parotid and sublingual glands. When graft versus host disease was induced, MHC class I antigen (HAM 2) was observed in both acinar and secretory duct cells of the submandibular gland.