Cyclosporin A blocks surface IgM-mediated growth inhibition in an immature B lymphoma, BKS-2.
Cyclosporin A (CSA) is an immunosuppressive drug, which blocks selective activation pathways in T and B cells. Antigen receptor-mediated signaling events have been shown to be very sensitive to CSA. Signaling through the surface IgM receptor had been shown to induce growth inhibition in immature B cell lymphoma cells. In this report, we demonstrate that CSA caused significant reversal of growth inhibition induced by an anti-mu antibody in an immature B lymphoma, BKS-2. Time-course experiments indicated that CSA was completely effective when added as late as 4 h after the addition of ligand. CSA was also found to have no direct effect on anti-mu-induced Ca2+ elevation. These results suggest that the likely target for CSA lies downstream from the initial generation of second messengers, such as Ca2+.
Department of Microbiology and Immunology, University of Kentucky, Lexington 40536-0230.
V
V
Udhayakumar
S
S
Muthukkumar
B
B
Subbarao
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002118:Calcium / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology*; D007075:Immunoglobulin M / Q000502:physiology*; D066298:In Vitro Techniques; D016393:Lymphoma, B-Cell / Q000473:pathology; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell; D016572:Cyclosporine; D002118:Calcium