Ambrus J L, Jurgensen C H, Brown E J, McFarland P, Fauci A S
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892.
J Immunol. 1988 Aug 1;141(3):861-9.
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.
人B淋巴细胞的增殖受多种不同信号的调控。已描述了多种B细胞生长因子（BCGF），包括一种称为高分子量BCGF（HMW-BCGF）的60 kDa BCGF。在本文中，我们描述了一种单克隆抗体BA5，它可阻断正常活化的人B淋巴细胞对HMW-BCGF的增殖反应，且不影响T细胞对PHA或IL-2的增殖反应。BA5与静止B细胞的结合最少，与活化B细胞的结合显著增强，与静止或活化T细胞基本不结合。BA5识别活化B细胞溶解膜中的一种90 kDa蛋白质。与活化B细胞上其结合位点交联的125I-HMW-BCGF产生一种150 kDa的R蛋白复合物。使用蛋白质印迹法，与活化B细胞上其结合位点交联的未标记HMW-BCGF产生一条150 kDa的条带，该条带可被BA5和BCGF/1/C2（一种针对HMW-BCGF的单克隆抗体）识别。因此，BA5识别一种与HMW-BCGF受体密切相关的分子，该受体包括HMW-BCGF的一个结合位点。BA5可用于探索HMW-BCGF和B细胞增殖在人B细胞生理学各个方面的作用。
