Immuno-protective effect of tumor cell vaccine on Kunming mice bearing Ehrlich ascites tumor

AIM To evaluate the immunity of chemically modified tumor cell vaccine. METHODS Tumor cell vaccines (TCV) were prepared by incubating the live Ehrlich ascites tumor cells with concanavalin A-mitomycin C (ConA-MMC), mitomycin C (MMC), concanavalin A-glutaraldehyde (ConA-Glu), glutaraldehyde (Glu), or paraformaldehyde (Para), respectively. The whole cell or soluble forms of the vaccines were administered intraperitoneally into Kunming mice once a week for three times prior to the intraperitoneal inoculation of a lethal dose of live tumor cells. A second challenge with live tumor cells was given four weeks later. Survival and antibody production of the mice were analyzed. RESULTS After the first challenge, the mice, received whole TCV of ConA-MMC, MMC (P < 0.01) and Glu (P < 0.05) promoted survival incidence than the controls. All the treated mice had the survival time prolonged. ConA-MMC vaccine treated mice had longer survival days than that of ConA-Glu ones (P < 0.05). For the soluble TCV immunized mice, those treated with vaccines of Para (P < 0.01), ConA-Para and ConA-Glu (P < 0.05) had longer survival periods compared with that of the controls. Following the second challenge, survival incidence of the mice received vaccines of ConA-MMC, MMC, ConA-Glu or Glu was significantly increased (P < 0.01). Moreover, all the treated mice had the survival time prolonged, and ConA-MMC vaccine treated mice had longer survival days than that of Para treated ones (P < 0.05). Antibodies against Ehrlich ascites tumor cells were found to be positive in sera of the mice treated with whole TCV of ConA-MMC. CONCLUSION Ehrlich ascites tumor cells are immunogenic when treated with ConA-MMC, MMC, ConA-Glu, Glu or Para, which might act as safe and effective tumor vaccines with safety and effectiveness.