Ethanol influences class I and class II MHC antigen expression on human fetal islet-like cell clusters

Several autoimmune diseases have been linked to an aberrant expression of major histocompatibility complex (MHC) products Ethanol enhances Class I and Class II products on a variety of cell types, and there is evidence for an autoimmune etiology in numerous pathologies associated with alcoholism. We examined whether ethanol alters the expression of Class I and Class II MHC products on human fetal islet-like cell clusters. Incubation of islet-like clusters for 48 hr in ethanol at a starting concentration of 1.5% increased the percentage of single cells expressing Class I. The percentage of cells expressing Class II did not change, but their relative mean fluorescence increased significantly. These findings suggest that alcohol ingestion could alter MHC expression on pancreatic islet cells in vivo perhaps affecting the development of diabetes in genetically predisposed individuals. These findings also support the hypothesis that the rising incidence of type 1 diabetes seen in areas of the world where the per capita consumption of alcohol is also increasing may be a consequence of the immunological effects of alcohol intake.