Disclosed are methods, compositions of matter, and therapeutic protocols for treatment of cancer by selectively inducing immune responses against blood vessels feeding neoplastic tissue. In one embodiment, placental endothelial cells are stimulated with Phorbol Myristate Acetate (PMA) to induce release of nanoparticles that possess ability to: a) be taken up by antigen presenting； b) presented through direct and indirect presentation to CD4 and CD8 T cells, respectively； and c) utilized to stimulate cytoxic T cellular and humoral responses to selectively inhibit angiogenesis of tumors.
