Cholera toxin-sensitive and insensitive signaling via surface Ig.
We have observed that a 2-h pretreatment of murine B cells with cholera toxin (CT) renders the B cell incapable of receiving an activation signal via surface Ig as measured by cell volume increase and entry into the S phase of the cell cycle. In contrast, CT pretreatment does not inhibit the delivery of a signal by IL-4, as measured by increase in cell volume. In fact, CT pretreated B cells are able to respond to anti-Ig in the presence of IL-4, as measured by both an increase in cell size and entry into S suggesting that IL-4 overcomes the effects of CT on normal B cell activation. Despite blocking the anti-Ig-mediated entry into the cell cycle, CT was not able to interfere with the induction of nonresponsiveness by anti-Ig in normal B cells or with the delivery of growth-inhibitory signal to the B cell lymphoma WEHI-231. These results suggest that there are two signaling pathways mediated by cross-linking of surface Ig: one pathway sensitive and the other insensitive to modulation by CT.
Warner
G L
GL
Immunology Unit, University of Rochester Cancer Center, NY 14642.
Davies
S
S
Scott
D W
DW
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology*; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007295:Inositol Phosphates / Q000096:biosynthesis; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D015398:Signal Transduction
D000888:Antibodies, Anti-Idiotypic; D000949:Histocompatibility Antigens Class II; D007295:Inositol Phosphates; D007378:Interleukins; D008070:Lipopolysaccharides; D011947:Receptors, Antigen, B-Cell; D015847:Interleukin-4; D002772:Cholera Toxin; D002118:Calcium