Bestatin, a new immunomodulator, augments the release of mitogenic factors from PHA-stimulated human lymphocytes

A new chemically well-defined immunomodulator termed Bestatin was examined for its capacity to interfere with the release of factors from PHA pulsed human peripheral lymphoid cells which are mitogenic for T-cells. The presence of Bestatin, at Concentrations of 0.01-100 microgram/ml, during PHA-pulsing significantly enhanced the subsequent release of mitogenic factors. The highest increase, fourfold, was observed using 10 microgram/ml of Bestatin, Treatment of lymphoid cells with Bestatin alone or pretreatment with this compound before PHA pulsing did not significantly change the subsequent release of these lymphokines.