Inhibitory effect of bestatin on the growth of human lymphocytes

Bestatin at mid to high concentration had inhibitory effect to [3H]thymidine incorporation of human lymphocytes. It also decreased the PHA-P, Con A and PWM-induced mitogenicity of human lymphocytes. On the contrary, bestatin had growth stimulatory effect to murine lymphocytes, and enhanced the Con A, LPS-induced mitogenicity of murine lymphocytes. These growth inhibitory (human) and stimulatory (mouse) effect of bestatin was found to be independent of adherent cells (macrophage and dendritic cell), indicatory directly working to T or B lymphocytes.