Antitumor Responses Induced by Recombinant Vaccinia Viruses Expressing p53 and B7 / 中国肿瘤生物治疗杂志

ABSTRACT

Objective: This study was aimed to explore antitumor responses induced by recombinant vaccinia viruses expressing a point mutant p53 (rVV-p53FL) and enhancive effects of recombinant vaccinia viruses expressing costimulatory molecule B7 (rVV-B7). Methods: A 135 Cys to Tyr point mutant p53 protein was used as the model of tumor associated antigen. rVV-of3FL and rVV-B7 were used as vaccines to test their induction of CTLs and antitumor immunity. Results: Immunization BABL/c mice with rVV-p53FL could elicited specific CD8+ CTLs that could effecively lyse P815-mp53 cells, a transfectant of the murine P815 mastocytoma containing the mutant p53 gene. Treatment with rVV-p53FL could survive a part of mice challenged with 1 ? 106 P815-mp53. Treatment with rVV-p53FL could significantly prolong survival of tumor-bearing force. Admixture at 1 1 ratio of rVV-p53FL and rVV-B7 could enhance therapeutic antitumor effects of rVV-p53FL. ~Conclusion: Mutant P53 over-expressed in tumor cells can render cells targets for specific CTLs generated by immunization with mutant p53 protein based vaccine. Costimulatory molecule H7 can enhance tumor-associated antigen inducing antitumor responses.