Bee venom phospholipase A2 (bvPLA2) has been reported to have therapeutic effects such as neuroprotection, anti-inflammation, anti-nociception, anti-cancer properties, caused by increasing regulatory T cells (Tregs). The mechanism of Tregs modulation by bvPLA2 has been demonstrated by binding with the mannose receptor, CD206 in experimental models of several diseases. However, it remains unknown whether this mechanism can also be applied in human blood. In this study, we collected peripheral blood samples from healthy donors and analyzed the percentages of monocyte-derived dendritic cells with CD206 (CD206+ DCs) before expansion, the proportion of Tregs, and the subpopulations after expansion treated with bvPLA2 or PBS using flow cytometry and the correlations among them. The percentage of Tregs tended to be higher in the bvPLA2 group than in the control group. There were significant positive correlations between the CD206 population in hPBMC and the proportions of Tregs treated with bvPLA2, especially in the Treg fold change comparing the increase ratio of Tregs in bvPLA2 and in PBS. These findings indicate that bvPLA2 increased the proportion of Tregs in healthy human peripheral blood and the number of CD206+ DCs could be a predictor of the bvPLA2 response of different individuals.
Keywords: CD206; bee venom phospholipase A2 (bvPLA2); human peripheral blood mononuclear cell (hPBMC); mannose receptor; regulatory T cell (Treg).