Recent immunotherapies have shown clinical success. In particular, vaccines based on particulate antigen (Ag) are expected to be implemented based on their efficacy. In the current study, we describe a strategy entailing Ag-encapsulating PEG-modified liposomes (PGL-Ag) as antigen protein delivery devices and show that the success of the liposome depends on the antigen-presenting cell (APC) capacity; after administration of PGL-Ag, dendritic cells (DCs) in particular take up the Ag and subsequently prime T cells. For the generation of antitumor T cell responses in the lymphoid tissues, the function of encapsulated Ag-capturing DCs in vivo could be a biomarker. We next designed a prime-boost strategy to enhance the antitumor effects of the PGL-Ag. In the tumor sites, we show that Ag retention in nanoparticle-capturing DCs promotes a robust antitumor response. Thus, this efficient particulate Ag-based host antigen-presenting cell delivery strategy provides a bridge between innate and adaptive immune response and offers a novel therapeutic option against tumor cells.
Keywords: adaptive immunity; dendritic cell; immunotherapy; nanoparticle; tumor microenvironment.
© 2019 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.