In vitro induction of tumor-specific immunity by highly purified VSV grown in SV40-transformed cells and tumor glycolipids incorporated into liposomes.
Cytotoxic effector lymphocytes (CL) were induced by in vitro immunization of spleen cells from normal Syrian hamsters to syngeneic tumor cells, either SV40-transformed (EH-SV) or spontaneously transformed (EH-N). The lymphocyte reactivity was measured in a direct 51Cr release cytotoxicity assay performed with EH-SV- and EH-N-labelled targets. A specific cytotoxic effect against tumor cells carrying the sensitizing antigens was observed. Cytotoxic effector lymphocytes were also induced by in vitro immunization of hamster spleen cells to highly purified vesicular stomatitis virus (VSV) grown either in syngeneic SV40-transformed fibroblasts or in "normal" fibroblasts. Purified virus possessing an intact envelope or virus subparticles devoid of their glycoprotein spikes stimulated the cellular immune responses against host tumor antigens present within the viral envelope. Cytotoxicity assays have revealed two tumor-specific antigens (TSA), one induced by SV40 and present in SV40-transformed cell lines and the other present in "normal" cells. CL were also induced by in vitro sensitization of spleen cells from normal hamsters to liposomes containing the polar glycolipid fraction from EH-SV and/or EH-N cells. A specific cytotoxic effect against tumor cells that have supplied the glycolipid extract was observed, suggesting specific recognition of glycolipid antigens characteristic for each tumor line. This study supports the view that surface glycolipids act as tumor-specific antigens implicated in the destruction of SV40-induced tumors in Syrian hamsters.
D000818:Animals; D002472:Cell Transformation, Viral; D006224:Cricetinae; D000939:Epitopes / Q000276:immunology; D006017:Glycolipids / Q000276:immunology*; D007111:Immunity, Cellular; D007114:Immunization; D008081:Liposomes / Q000276:immunology*; D008297:Male; D008647:Mesocricetus; D009374:Neoplasms, Experimental / Q000276:immunology; D013539:Simian virus 40 / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014412:Tumor Virus Infections / Q000276:immunology*; D014721:Vesicular stomatitis Indiana virus / Q000276:immunology* / Q000302:isolation & purification
D000939:Epitopes; D006017:Glycolipids; D008081:Liposomes