PRODUCTION OF VASCULAR ENDOTHELIAL GROWTH-FACTOR BY HUMAN TUMORS INHIBITS THE FUNCTIONAL MATURATION OF DENDRITIC CELLS

Inadequate presentation of tumor antigens by host professional antigen -presenting cells (APCs), including dendritic cells (DCs), is one pote ntial mechanism for the escape of tumors from the host immune system. Here, we show that human cancer cell lines release a soluble factor or factors that dramatically affect DC maturation from precursors withou t affecting the function of relatively mature DCs. One factor responsi ble for these effects was identified as vascular endothelial growth fa ctor (VEGF). Thus, VEGF may play a broader role in the pathogenesis of cancer than was previously thought, and therapeutic blockade of VEGF action may improve prospects for immunotherapy as well as inhibit tumo r neovasculature.