The absence of H-2 antigens from mouse pancreatic beta-cells demonstrated by immunoferritin labeling.

Abstract

Islets of Langerhans were isolated from mouse pancreases and fixed in periodate-Lys-paraformaldehyde. The fixed islets were then dissociated with trypsin and EDTA to yield cell suspensions that contained mainly 4 cell types; .beta.-cells, capillary endothelial cells, acinar cells and pancreatic duct epithelial cells. The nonislet cells were probably associated with the surface of the isolated islets. The H-2 antigens of the dissociated pancreatic cells were labeled with an immunoferritin technique. Pancreatic duct epithelial cells showed specific ferritin labeling on their lateral cell membranes but not on apical microvillus membranes. Acinar cells were also labeled on lateral membrane and the capillary endothelial cells were labeled with an immunoferritin technique. Pancreatic duct epithelial cells showed specific ferritin labeling on their lateral cell membranes but not on apical microvillus membranes. Acinar cells were also labeled on lateral membranes and the capillary endothelial cells were labeled on both the luminal and abluminal aspects of their surface membranes. Pancreatic .beta.-cells were unlabeled. The number of ferritin molecules per unit length of .beta.-cell membrane was essentially the same on cells from the antigenic strain and the congeneic control strain and was about 200-fold less than on the labeled pancreatic duct epithelial cell lateral membranes. Pancreatic .beta.-cells are 1 of 6 known epithelial cell types on which H-2 antigens can not be detected by immunoferritin labeling. The apparent absence of H-2 antigens from these cells suggests a study of the viability of .beta.-cells in allografts of dissociated islet cells, in which the .beta.-cells would not be in contact with antigenic cells. Such studies might lead to a new approach to the control of diabetes mellitus by transplantation.