New lymphocyte stimulating monocot lectins from family Araceae. II.

Two lectins purified from the tubers of Arisaema consanguineum Schott (ACA) and A. curvatum Kunth (ACmA) belonging to the monocot family Araceae were mitogenic for human peripheral blood mononuclear cells (PBMC) in the [3H]-thymidine uptake assay. ACA and ACmA had an optimum stimulatory concentration of 10-25 micrograms/ml and 50-100 micrograms/ml, respectively, as observed in PBMC from five different individuals. The mitogenic response of PBMC was inhibitable in a dose-dependent manner by asialofetuin. The lectins were T-cell specific, and stimulation kinetic studies using ACA and ACmA showed that they induce maximum thymidine uptake in PBMC at day 4 and 3, respectively.