Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2009
Publication Date: 6/23/2009
Citation: Zunino, S.J., Storms, D.H. 2009. Resveratrol Alters Proliferative Responses and Apoptosis in Human Activated B Lymphocytes In Vitro. Journal of Nutrition. 139: 1603–1608, 2009.
Interpretive Summary: Resveratrol is an antioxidant found in grapes, peanuts, and some berries. We hypothesized that resveratrol would influence the response of B lymphocytes that produce antibodies or immunoglobulins after activation. We collected white blood cells from six healthy human volunteers and treated the cells with pokeweed mitogen that activates B lymphocytes. The activated cells were treated with 0, 2, 5, and 10 uM resveratrol and the cells were analyzed for growth and death responses after 6 days. After 8 days, the cells were analyzed for the presence of antibodies. We found that resveratrol decreased the growth of the B lymphocytes after activation. We also found that resveratrol treatment caused an increase in the expression of the Bcl-2 protein in the cell, which can protect the cell from death. We found no difference in the amount of immunoglobulins produced in the B cells after activation. These data suggest that resveratrol inhibits growth of activated B lymphocytes, but promotes survival by increasing expression of the pro-survival protein Bcl-2.
Technical Abstract: We hypothesized that resveratrol, a polyphenol found in grapes, peanuts, and berries would modulate B lymphocyte proliferation, immunoglobulin synthesis, and apoptosis after activation with T-cell dependent pokeweed mitogen. Peripheral blood mononuclear cells (PBMCs) were isolated from the blood of six healthy human volunteers. Unstained and PKH stained PBMCs were incubated with pokeweed mitogen and resveratrol at final concentrations of 0, 2, 5, and 10 uM. After 6 days of incubation, cells were harvested for analysis of proliferation, Bcl-2, and caspase-3 using flow cytometry. After 8 days, supernatants from the cells were collected and IgM and IgG were measured by ELISA. Resveratrol at a concentration of 10uM inhibited proliferation of the CD19+ B lymphocytes (P<0.05) with a trend for increased proliferation with 2, 5, and 10 uM resveratrol (R2 = 0.01693, P for trend = 0.007). The percent of cells expressing Bcl-2 and the fluorescence intensity of Bcl-2 increased in CD19+ B cells treated with 10 uM resveratrol (P <0.05) compared to pokeweed mitogen alone. Increases in Bcl-2 expression and fluorescence intensity displayed a dose response to resveratrol with R2 values 0.1519 and 0.2106, respectively (P for trend <0.001). Increases in activation and fluorescence intensity of caspase-3 in CD19+ B cells was dose responsive to resveratrol with an R2 value of 0.03959 for % of cells (P for trend = 0.0024) and R2 value of 0.07500 for fluorescence (P for trend = 0.0017). An increase in the percent of cells that were double positive for Bcl-2 and Caspase-3 was dose responsive to resveratrol with an R2 value of 0.08625 (P for trend = 0.0004). No differences were observed for IgM and IgG synthesis between the resveratrol-treated and PWM control cells. These data suggest that resveratrol inhibits the proliferative response of activated B lymphocytes and promotes survival by increasing expression of the anti-apoptotic protein Bcl-2.