Karin Ulrichs, W. Müller-Buchholtz

• It is the aim of this study to characterize and quantify the cells within isolated rat islets that express MHC class 11 antigens. A set of five monoelonal antibodies and two polyclonal antisera of defined specificlty were used in combination with a newly devised procedure for three·dimensional immunofluorescence evaluation of intact islets. It is shown that in addition to passen· ger cells, such as Iymphocytes, macro· phages, and dendrlticlike cells, vascular endothelial and endocrine cells are also capable of expressing class 11 antigens. ThisIt is the aim of this study to characterize and quantify the cells within isolated rat islets that express MHC class 11 antigens. A set of five monoelonal antibodies and two polyclonal antisera of defined specificlty were used in combination with a newly devised procedure for three·dimensional immunofluorescence evaluation of intact islets. It is shown that in addition to passen· ger cells, such as Iymphocytes, macro· phages, and dendrlticlike cells, vascular endothelial and endocrine cells are also capable of expressing class 11 antigens. This expression Is strongly influenced by in vitro culture. pregnancy, streptozotocin- induced diabetes, transplantation trauma, and alloantigenic stimuli. The pos· sible role of the above cells in antigen presentation related to islet transplantation is discussed.…