Universitätsbibliothek

Dendritic cells, first described by STEINMAN and COHN in the mouse spleen and now called lymphoid dendritic cells (LDC), were investigated in the rat pancreas with the monoclonal antibodies 29AI-L. T. and MRC-OX17, which both recognize the la-antigen immunohistochemically and immune electron microscopically. la-positive cells with a dendritic morphology were found in the connective tissue of the cxocrine and endocrine pancreas. Immune e1ectron microscopically, the Ia-antibodies were 10- calized on the cell surface and in sm all vesicles. A small portion of the la-positive cells showed additional acid phosphatase positivity, i. e. were la-positive macrophages. The other la-positive cells were probably LDC, which may be important in the elimination of foreign antigens, e. g. bacteria and vIruses.