Tumor-specific cytotoxicity induced by Ehrlich ascites tumor cell vaccine

Aim To study the tumor specific cytotoxicity induced by Ehrlich ascites tumor cell vaccine. Methods Using paraformaldehyde treated Ehrlich ascites tumor cells as the vaccine, an animal model of tumor vaccination was established. The tumor nodules of the immunized Balb/c mice after subcutaneous tumor rechallenge were observed by HE staining. Splenocytes were separated from immunized, tumor bearing and control mice, respectively. The 51Cr release assay was used to examine the cytotoxicities of three kinds of the splenocytes to Ehrlich ascites tumor cells and Sp2/0 cells. Results It was showed that the tumor cells in tumor nodules of immunized mice exhibited almost complete necrosis and simultaneously possessed a large number of lymphocytes infiltration, fibroblasts and small vessels proliferation, while no phenomena mentioned above was found in the control mice. Specific cytotoxic rate of splenocytes from the immunized mice to the Ehrlich ascites tumor was (42.3±3.2)%,significantly higher than that from the other two groups(P∨0.05) and also significantly higher than that to Sp2/0 cells (8.8±0.4)%(P∨0.05). Conclusion Ehrlich ascites tumor cell vaccine can induce significantly tumor specific cytotoxicity in vivo.