In photobiophysics, biophoton means a kind of biological energy which enhances most metabolisms of the body. To investigate the immuno-enhancing effects of biophoton energy projector (BEP) producing light energy, pigs were irradiated with BEP for 8 weeks. Swine peripheral blood mononuclear cells (sPBMCs) were isolated from the blood of irradiated pigs. In this study, the antigen uptake and mitochondrial membrane potential of sPBMCs were measured by flow cytometric analysis. The irradiation of BEP increased the antigen uptake of sPBMCs. For functional analysis, the production of Bordetella bronchiseptica-specific IgG, measured using antigen-specific ELISA, was increased during the period of BEP irradiation. Taken together, the results suggest that the irradiation of BEP has immune-enhancing effects on sPBMCs.