Anti-tumor efficacy of plasmid encoding emm55 in a murine melanoma model.

Anti-tumor efficacy of plasmid encoding emm55 in a murine melanoma model.

Cancer immunology, immunotherapy : CII (2020-06-20)

Brittany L Bunch, Krithika N Kodumudi, Ellen Scott, Jennifer Morse, Amy Mackay Weber, Anders E Berglund, Shari Pilon-Thomas, Joseph Markowitz, Brittany L Bunch, Krithika N Kodumudi, Ellen Scott, Jennifer Morse, Amy Mackay Weber, Anders E Berglund, Shari Pilon-Thomas, Joseph Markowitz

PMID32556443

摘要

Emm55 is a bacterial gene derived from Streptococcus pyogenes (S. pyogenes) that was cloned into a plasmid DNA vaccine (pAc/emm55). In this study, we investigated the anti-tumor efficacy of pAc/emm55 in a B16 murine melanoma model. Intralesional (IL) injections of pAc/emm55 significantly delayed tumor growth compared to the pAc/Empty group. There was a significant increase in the CD8+ T cells infiltrating into the tumors after pAc/emm55 treatment compared to the control group. In addition, we observed that IL injection of pAc/emm55 increased antigen-specific T cell infiltration into tumors. Depletion of CD4+ or CD8+ T cells abrogated the anti-tumor effect of pAc/emm55. Combination treatment of IL injection of pAc/emm55 with anti-PD-1 antibody significantly delayed tumor growth compared to either monotherapy. pAc/emm55 treatment combined with PD-1 blockade enhanced anti-tumor immune response and improved systemic anti-tumor immunity. Together, these strategies may lead to improvements in the treatment of patients with melanoma.