| abstract |
Low concentrations of the protein kinase C activators, bryostatins 1 and 2 synergized with rBSF-1 are useful in triggering differentiation (granule enzyme expression) and CTL development in naive, resting lymph node T-cells. Bryostatin greatly enhances efficiency of rIL-2 in triggering development of in vivo primed CTL during in vitro incubation, thereby providing evidence for the use of lower concentrations of rIL-2 for in vivo tumor rejection. Both bryostatin 1 and 2, trigger cytotoxicity of CTL clones against Ag-non-bearing target cells and inhibit CTL cytotoxicity against Ag-specific target cells. Bryostatin 1 and 2 synergize with Ca⁺⁺ ionophores in triggering the exocytosis of cytolytic granules from CTL at very low concentrations. Because of the lack of tumor promoting activity in the bryostatins, they are useful per se as immunomodulating drugs and as potentiators for rIL-2 in adoptive immunotherapy. |