Combining DNA vaccine and AIM2 in H1 nanoparticles exert anti-renal carcinoma effects via enhancing tumor-specific multi-functional CD8+ T cell responses

Renal carcinoma presents a rapid progression in patients with high metastasis with no effective therapeutic strategy. In this study, we designed a folate-grafted PEI600-CyD (H1) nanoparticle-mediated DNA vaccine containing an adjuvant of absent in melanoma 2 (AIM2) and a tumor-specific antigen of carbonic anhydrase IX (CAIX) for renal carcinoma therapy. Mice bearing subcutaneous human CAIX (hCAIX)-Renca tumor were intramuscularly immunized with H1-pAIM2/pCAIX, H1-pCAIX, H1-pAIM2, or Mock vaccine, respectively. The tumor growth of hCAIX-Renca was significantly inhibited in H1-pAIM2/pCAIX vaccine group compared with the control group. The vaccine activated CAIX-specific CD8 + T-cell proliferation and CTL responses, and enhanced the induction of multi-functional CD8 + T cells (expressing TNF-α, IL-2, and IFN-γ). CD8 + T-cell depletion resulted in the loss of anti-tumor activity of H1-pAIM2/pCAIX vaccine, suggesting that the efficacy of the vaccine was dependent on CD8 + T-cell responses. Lung metastasis of renal carcinoma was also suppressed by H1-pAIM2/pCAIX vaccine treatment accompanied with the increased percentages of CAIX-specific multi-functional CD8 + T cells in the spleen, tumor, and bronchoalveolar lavage as compared with H1-pCAIX vaccine. Similarly, the vaccine enhanced CAIX-specific CD8 + T-cell proliferation and CTL responses. Therefore, these results indicated that H1-pAIM2/pCAIX vaccine exhibits the therapeutic efficacy of anti-renal carcinoma by enhancing tumor-specific multi-functional CD8 + T-cell responses. This vaccine strategy could be a potential and promising approach for the therapy of primary solid or metastasis tumors.