Dissociation between Fas expression and induction of apoptosis in human islets of Langerhans

Summary There is increasing evidence that inappropriate induction of apoptosis in pancreatic β‐cells may precede the development of type 1 diabetes in animal models and in man. One mechanism by which this has been proposed to occur involves up‐regulation of the death receptor Fas on β‐cells, resulting in apoptosis of the Fas‐bearing β‐cells upon ligation of the receptor. We have examined this hypothesis in isolated human islets of Langerhans and show that–‐in contrast to data obtained with rodent β‐cells–‐expression of Fas per se is not sufficient to allow induction of apoptosis upon addition of agonistic anti‐Fas serum.