Protein-Rich Extract Induces Maturation of Dendritic Cells and Th1 Polarization: A Potential Immunological Adjuvant for Cancer Vaccine.

, a protein-rich edible insect, is widely used as a traditional medicine in China. Several pharmacological studies have reported the anticancer activity of extracts; however, the capacity of extracts as immune potentiators for increasing the efficacy of cancer immunotherapy is still unverified. In the present study, we investigated the immunomodulatory role of protein-rich extract (BBPE) in bone marrow-derived dendritic cells (BMDCs) and DC vaccine-immunized mice. BBPE-treated BMDCs displayed characteristics of mature immune status, including high expression of surface molecules (CD80, CD86, major histocompatibility complex (MHC)-I, and MHC-II), increased production of proinflammatory cytokines (tumor necrosis factor-α and interleukin-12p70), enhanced antigen-presenting ability, and reduced endocytosis. BBPE-treated BMDCs promoted naive CD4 and CD8 T-cell proliferation and activation. Furthermore, BBPE/ovalbumin (OVA)-pulsed DC-immunized mice showed a stronger OVA-specific multifunctional T-cell response in CD4 and CD8 T cells and a stronger Th1 antibody response than mice receiving differently treated DCs, which showed the enhanced protective effect against tumor growth in E.G7 tumor-bearing mice. Our data demonstrate that BBPE can be a novel immune potentiator for a DC-based vaccine in anticancer therapy.