Abstract A139: Antitumor effects of improved DC vaccine with ALA-PDT induced immunogenic apoptotic cells for skin squamous cell carcinoma in mice

Targeted immunotherapy using dendritic cell (DC) vaccine has been employed for the treatment of solid tumors. Topical 5-aminolevulinic acid mediated photodynamic therapy (ALA-PDT), an established approach for topical cancers, can induce an effective antitumor immune response.We have previously shown that ALA-PDT-induced tumor lysates could considerably enhance antigen-presenting capacity of ex vivo-generated DCs.The current study further demonstrates that ALA-PDT-DC vaccine can induce immune responses against cancers.DC cells pulsed by PDT-treated cutaneous squamous cell carcinoma (cSCC) cells inhibited SCC to a greater extent than tumor lysates treated by PDT alone or DCs pulsed by freeze/thawed treated tumor cells (FT-DC).Immunohistochemistry showed that PDT-DC vaccine could increase the activity of CD4+ and CD8+ T cells in the tumor implantation sites.Flow cytometry assays showed that CD4+ and CD8+ T cells in the spleens of PDT-DC vaccine immunized mice increased significantly.Furthermore, we observed increased amounts of IL-12 and IFN-γ and decreased amounts of IL-10 in the splenocytes and peripheral blood of PDT-DC vaccine immunized mice by ELISA.Taken together, our findings suggest that PDT-DC vaccination is an effective prophylactic therapy for cSCC. Note: This abstract was not presented at the conference. Citation Format: Haiyan Zhang, Guolong Zhang, Zhixia Fan, Xiaojie Wang, Lei Shi, Degang Yang, Cody F. Bahavar, Feifan Zhou, Wei R. Chen, Xiuli Wang. Antitumor effects of improved DC vaccine with ALA-PDT induced immunogenic apoptotic cells for skin squamous cell carcinoma in mice [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A139.