Inhibition of LPS-induced TNFα production by plant-derived murine and viral IL-10. J774 cells were stimulated for 18 h with IL-10 alone, LPS alone, or LPS plus IL-10. The eluate of the purification of wild type leaves (wt) was also included, alone or in combination with commercial IL-10, to exclude the interference of plant proteins with the assay. TNFα secretion in the culture medium (med) was quantified by ELISA and is reported as pg/ml supernatant. Values are the means ± SD of four independent experiments for the murine IL-10 (a) and three independent experiments for the viral IL-10 (b). ** p < 0.001.