MORPHOLOGICALLY AND FUNCTIONALLY INTACT DENDRITIC CELLS CAN BE DERIVED FROM THE PERIPHERAL-BLOOD OF AGED INDIVIDUALS

Dendritic cells are antigen-presenting cells (APC), which are crucial for the initiation of an immune response. In spite of the well known d ecline of immune function in old age, no information is yet available on whether dendritic cells are also affected by the ageing process. It was therefore the aim of this study to compare peripheral blood dendr itic cells (DC) from old and young healthy individuals. Using granuloc yte-macrophage colony-stimulating factor (GM-CSF) and IL-4, DC were pr opagated from peripheral blood mononuclear cells (PBMC). The obtained cell populations had a typical dendritic morphology and expressed HLA class I and class II, CD23, CD32, CD40, CD44 and CD54, but not CD3 and CD19. Larger numbers of DC were obtained from old individuals than fr om young ones in spite of a similar expression pattern of surface mole cules. DC from aged persons also survived better under in vitro cultur e conditions. When tested for their antigen-presenting capacity, DC fr om young and old individuals were equally effective in inducing the pr oliferation of tetanus toxoid-specific T cell clones after antigenic s timulation. Peripheral blood DC from aged individuals may thus still f unction as powerful APC. They may represent useful tools for immunothe rapy in the aged.