After NDV selectively infects tumor cells, the immune response induced by NDV's envelope protein and intracellular factors can effectively kill the tumor without affecting normal cells.
When the tumor reactivity of dominant clonotypic TCRs in each mouse was analyzed, 9 of 13 TCRs induced the secretion of IFNγ in response to, and showed killing of, B16F10 cells <i>in vitro</i>, and 2 of them showed strong antitumor activity <i>in vivo</i> Concerning their antigen specificity, 7 of them reacted to p15E peptide of endogenous murine leukemia virus-derived envelope glycoprotein 70, and the rest reacted to tumor-associated antigens expressed on EL4 lymphoma as well as B16 melanoma cells.
Finally, recombinant viruses that selectively enter cells expressing tumor markers or the HIV envelope protein have been engineered and shown to lyse target cells.
Candidate tumor suppressor HYAL2 is a glycosylphosphatidylinositol (GPI)-anchored cell-surface receptor for jaagsiekte sheep retrovirus, the envelope protein of which mediates oncogenic transformation.