Identification of a receptor for high molecular weight human B cell growth factor.
Regulation of the proliferation of human B lymphocytes is under the control of several different signals. Various B cell growth factors (BCGF) have been described including a 60-kDa BCGF called high m.w. BCGF (HMW-BCGF). In this paper we describe a mAb BA5 that blocks the proliferation of normal activated human B lymphocytes in response to HMW-BCGF and does not affect the proliferation of T cells in response to PHA or IL-2. BA5 shows minimum binding to resting B cells, significantly enhanced binding to resting B cells, significantly enhanced binding to activated B cells and essentially no binding to resting or activated T cells. BA5 recognizes a 90-kDa protein from solubilized membranes of activated B cells. 125I-HMW-BCGF cross-linked to its binding site on activated B cells produces a 150-kDa R-protein complex. Unlabeled HMW-BCGF cross-linked to its binding site on activated B cells produces a 150-kDa band recognized by both BA5 and BCGF/1/C2 (a mAb to HMW-BCGF) using Western blotting. Thus, BA5 recognizes a molecule intimately associated with the receptor for HMW-BCGF which includes a binding site for HMW-BCGF. BA5 can be used to explore the role of HMW-BCGF and B cell proliferation in various aspects of human B cell physiology.
Ambrus
J L
JL
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892.
Jurgensen
C H
CH
Brown
E J
EJ
McFarland
P
P
Fauci
A S
AS
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D005260:Female; D006801:Humans; D007118:Immunoassay; D015847:Interleukin-4; D007378:Interleukins / Q000276:immunology / Q000378:metabolism*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011233:Precipitin Tests; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen / Q000276:immunology / Q000302:isolation & purification*
D000911:Antibodies, Monoclonal; D007378:Interleukins; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen; D015847:Interleukin-4