Edible Oxya chinensis sinuosa—Derived Protein as a Potential Nutraceutical for Anticancer Immunity Improvement

Oxya chinensis sinuosa (Ocs) is consumed as representative edible insects in Asia, but its function in various immune systems remains unclear. This study aimed to demonstrate the immunomodulatory effect, particularly on the innate and adaptive immune response, of Ocs protein (Ocs-P) and to investigate its function as a potent anticancer immunostimulant when administered during the progression stage of colon carcinoma in tumor-bearing mice. Our in vitro results demonstrated that Ocs-P treatment induces phenotypic alteration (increased expression of surface molecules and production of T Helper type I-polarizing (Th1-polarizing) cytokines and decreased antigen uptake ability) of dendritic cells (DCs) through the activation of Mitogen-activated protein kinase (MAPK) and nuclear factor kappa B-dependent (NF-κB-dependent) signaling pathways. Additionally, Ocs-P-stimulated DCs initiated differentiation of naive T cells into IFN-γ-producing Th1-type T cells effectively and activated cytotoxic CD8(+) T cell response. In colon carcinoma-bearing mouse models, oral administration of Ocs-P inhibited tumor growth and restored the expression of decreased surface molecules in lineage(-)CD11c(+)MHC-II(+) splenic DCs. Furthermore, Ocs-P administration enhanced the generation of multifunctional CD4(+) and CD8(+) T cells expressing Th1-type cytokines (TNF-α, IFN-γ, and IL-2) and the degranulation marker (CD107a). Collectively, these results suggest that Ocs-P demonstrates an immunostimulatory effect and may induce powerful anticancer immunity.