Induction of proliferation by high molecular weight B cell growth factor or low molecular weight B cell growth factor is associated with increases in intracellular calcium in different subpopulations of human B lymphocytes.
The activation of resting B cells with anti-surface Ig is associated with transient increases in intracellular calcium. In the present study, we demonstrate that stimulation of B cells which have already been activated by Staphylococcus aureus Cowan I (Sac), with high molecular weight B cell growth factor (HMW-BCGF) or low molecular weight B cell growth factor (LMW-BCGF), but not IL-2, IL-4, or interferon-gamma, is associated with an increase in intracellular calcium, which is modest compared to that seen with anti-Ig (approximately 100 nM vs approximately 400 nM). The increases in intracellular calcium induced by HMW-BCGF or LMW-BCGF occur in distinct but overlapping subpopulations of B cells. Thus, increases in intracellular calcium in human B cells occur not only upon activation but also upon the induction of proliferation by certain (but not all) B cell growth factors. Presumably, the effect of increasing intracellular calcium during the induction of proliferation is to modify a different group of intracellular molecules than those induced during activation.
Ambrus
J L
JL
Washington University School of Medicine, Division of Rheumatology, St. Louis, Missouri 63110.
Chesky
L
L
McFarland
P
P
Young
K R
KR
Mostowski
H
H
August
A
A
Chused
T M
TM
D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D015847:Interleukin-4 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008970:Molecular Weight; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013211:Staphylococcus aureus / Q000276:immunology
D007295:Inositol Phosphates; D015375:Receptors, Interleukin-2; D015847:Interleukin-4; D002118:Calcium