Inductive and differentiative signals delivered by C8-substituted guanine ribonucleosides

Goodman, Michael

doi:10.1016/0167-5699(84)90125-7

Cited by 7 publications

References 38 publications

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Suppression of B cell activation by cyclosporin A, FK506 and rapamycin

et al. 1990

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The effects of the immunosuppressants cyclosporin A (CsA), FK506 and rapamycin have been compared using murine B cells activated with a variety of mitogens. FK506 is a macrolide antibiotic that has been recently shown to inhibit T cell activation by a mechanism that appears similar to that of CsA. Rapamycin is a macrolide structurally related to FK506 whose mechanism of T cell suppression appears to be distinct from that of FK506 and CsA. While CsA and FK506 were found to preferentially inhibit B cell activation caused by stimuli which induce a rise in intracellular calcium, rapamycin partially inhibited activation by all stimuli tested, including those which are not associated with a calcium flux. All three compounds were found to inhibit cell cycle progression within the G1 phase; however, the rapamycin-sensitive event within G1 was completed earlier than the G1 events inhibited by CsA and FK506. In addition, inhibition of anti-IgM-activated B cells with CsA and FK506, but not with rapamycin, resulted in cell death. These data suggest that although CsA, FK506 and rapamycin are all inhibitors of B cell activation, the inhibitory activity of rapamycin can be clearly distinguished from that of CsA and FK506. Although the suppressive effects of CsA and FK506 on B cell proliferation were nearly identical in this study, their biological activities were distinguishable since FK506, but not CsA, could antagonize rapamycin-mediated suppression.

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