The Mechanism of the Effect of a Recombinant CEA-encoding Vaccinia Virus on CEA Positive Tumor

Objective To explore antitumor mechanism of carcinoembryonic antigen-recombinant vaccinia virus(CEA-rV). Methods C57BL/6 mice were immunized three times with rV-CEA. Six weeks later, the macrophages(M Φs) from CEA-rV-immunized donors were adoptively transfered in CEA +-HePa-bearing recipients,meanwhile, the antitumor effects of the donor M Φs and of the recipients splenocytes in vitro were detected. Results The antitumor effect in vitro of the M Φs from CEA-rV-immunized donors was the same as those from contrals statistically. However, the M Φs expressed strong antitumor activity in CEA positive tumor-bearing recipients,the antitumor effect in vitro of the recipients splenocytes was statistically increased. Conclusion It was demonstrated that antitumor activity induced by CEA-rV was essentially mediated by antigen pressent cells such as the M Φs which activated immune T cells by CEA-specific immune response to kill tumor cells.