Antitumor Activity of IL-12 in a Mouse Opportunistic Vascular Tumor: Role of Immunocompetent Cells and Cytokines

IL-12 has been reported to have antitumoral activity in different mouse tumors. In this study IL-12 was tested on the in vivo growth of H5V cells, a tumor line obtained by polyoma middle T (PmT) infection of mouse endothelial cells (Garlanda et al., P.N.A.S., 91:7291, 1994). H5V injection in syngeneic hosts causes vascular tumors that may represent an experimental model for human opportunistic vascular tumors. T lymphocytes, mainly CD8, and Th1 cytokines have been shown to play a major role in the in vivo resistance to H5V to H5V tumor; IFNγ and TGFb1 display antitumoral activity, mainly in immunocompetent hosts.