Ne did not directly induce significant IFNc secretion by bovine T cells as it did with human T cells. These data suggest that certain polyphenols may exert species-specific effects and that immunomodulatory effects of polyphenols demonstrated in one species may not always be conserved in other species. Thus, analysis of the immunomodulating properties of polyphenols cannot rely solely on animal testing, and a combination of animal and human cell testing is required to identify relevant, conserved responses. A possible explanation for some of the differences observed between human and bovine T cells in these studies could be due to differences in ages, as young calves were used for our bovine studies while adults were used for our human studies. It has been shown that IFNc secretion by T cells can increase with age, correlating with an increase in CD45RO+ T cells [44]. Therefore, future studies could examine the effects of aging on these responses. It is possible that lymphocyte responses to certain polyphenols in young bovine calves are more 4 IBP chemical information reflective of those that might occur in children, suggesting a potential new use for this animal model in the study of the effects of dietary polyphenols on neonatal and adult lymphocytes. A potentially important and conserved response to oenothein B is enhanced IFNc secretion following exposure to suboptimal IL18 concentrations, which was observed in both bovine and human NK cells. The synergistic effect of oenothein B and IL-18 for enhancing IFNc production by NK cells was observed in mixed PBMC cultures, NK cell-depleted PBMCs, as well as sorted NK cells. Our earlier studies demonstrated that oenothein B couldStimulation of Lymphocytes by Oenothein Binduce IL-12 production by 125-65-5 site monocytes [7], which others have found synergizes with IL-18 to produce IFNc [45]. Thus, this could provide an explanation for oenothein B’s ability to enhance IL-18-induced IFNc production in some of our experiments; however, the enhanced production of IFNc observed in sorted NK cell cultures suggests a direct effect on NK cells by oenothein B. Additionally, oenothein B enhanced IFNc secretion in response to an NK cell target cell line, suggesting that the ability of oenothein B to enhance IFNc secretion is not restricted to IL-18, but also occurs upon co-culture with tumor cell targets. 23727046 In conclusion, our results expand upon previous studies suggesting that oenothein B stimulates innate and antitumor immunity, and further characterizes this activity, suggesting that lymphocyte activation and IFNc production may contribute 
to these responses. The production of IFNc by lymphocytes and other cells enhances antitumor immunity by a number of mechanisms, and it will be important to examine whether lymphocytes and/or IFNc play an important role in the antitumor properties of oenothein B in vivo. In addition, IFNc production is a vital step in the host defense against numerous pathogens, including viruses and intracellular bacteria. Therefore, our data also suggest a potential mechanism whereby oenothein B could enhance antiviral and antibacterial immunity in vivo. Thus, it will also be important to examine if oenothein B enhances host defense against various pathogens whose clearance relies on lymphocyte activity and IFNc production. Further work is also necessary to identify the receptors and signaling pathways involved in these immune stimulatory effects of oenothein B. Finally, these studies suggest that oenothein B may be a p.Ne did not directly induce significant IFNc secretion by bovine T cells as it did with human T cells. These data suggest that certain polyphenols may exert species-specific effects and that immunomodulatory effects of polyphenols demonstrated in one species may not always be conserved in other species. Thus, analysis of the immunomodulating properties of polyphenols cannot rely solely on animal testing, and a combination of animal and human cell testing is required to identify relevant, conserved responses. A possible explanation for some of the differences observed between human and bovine T cells in these studies could be due to differences in ages, as young calves were used for our bovine studies while adults were used for our human studies. It has been shown that IFNc secretion by T cells can increase with age, correlating with an increase in CD45RO+ T cells [44]. Therefore, future studies could examine the effects of aging on these responses. It is possible that lymphocyte responses to certain polyphenols in young bovine calves are more reflective of those that might occur in children, suggesting a potential new use for this animal model in the 
study of the effects of dietary polyphenols on neonatal and adult lymphocytes. A potentially important and conserved response to oenothein B is enhanced IFNc secretion following exposure to suboptimal IL18 concentrations, which was observed in both bovine and human NK cells. The synergistic effect of oenothein B and IL-18 for enhancing IFNc production by NK cells was observed in mixed PBMC cultures, NK cell-depleted PBMCs, as well as sorted NK cells. Our earlier studies demonstrated that oenothein B couldStimulation of Lymphocytes by Oenothein Binduce IL-12 production by monocytes [7], which others have found synergizes with IL-18 to produce IFNc [45]. Thus, this could provide an explanation for oenothein B’s ability to enhance IL-18-induced IFNc production in some of our experiments; however, the enhanced production of IFNc observed in sorted NK cell cultures suggests a direct effect on NK cells by oenothein B. Additionally, oenothein B enhanced IFNc secretion in response to an NK cell target cell line, suggesting that the ability of oenothein B to enhance IFNc secretion is not restricted to IL-18, but also occurs upon co-culture with tumor cell targets. 23727046 In conclusion, our results expand upon previous studies suggesting that oenothein B stimulates innate and antitumor immunity, and further characterizes this activity, suggesting that lymphocyte activation and IFNc production may contribute to these responses. The production of IFNc by lymphocytes and other cells enhances antitumor immunity by a number of mechanisms, and it will be important to examine whether lymphocytes and/or IFNc play an important role in the antitumor properties of oenothein B in vivo. In addition, IFNc production is a vital step in the host defense against numerous pathogens, including viruses and intracellular bacteria. Therefore, our data also suggest a potential mechanism whereby oenothein B could enhance antiviral and antibacterial immunity in vivo. Thus, it will also be important to examine if oenothein B enhances host defense against various pathogens whose clearance relies on lymphocyte activity and IFNc production. Further work is also necessary to identify the receptors and signaling pathways involved in these immune stimulatory effects of oenothein B. Finally, these studies suggest that oenothein B may be a p.