P56. A novel cancer vaccine with nanogel-based antigen transporter and sequence-optimised long peptide antigen

Background The limited success of cancer vaccines in clinical could be owing to their low efficacy that can be largely affected by their formulation. Vaccine formulation usually consists of three components, antigen, delivery system, and adjuvant. Recently, long peptide antigen (LPA) has been attracting interest, because (1) one LPA can provide antigen presenting cells (APCs) with multiple T cell epitopes and (2) it avoids undesired presentation by non-professional APCs that can lead to the exhaustion of antigen-specific T cells. While a LPA can include multiple epitopes, the prerequisite design of junction of epitopes (inter-epitope sequence, IES) for robust immunogenicity is not yet established, and we explored it in this study. On the other hand, accumulating data has been suggesting the importance of delivery system for cancer vaccines. By employing a novel nanogelbased delivery system, we tried to improve the immunogenicity of LPA vaccine.