Holtrop S, Rijke-Schilder G P, Koene R A, Tax W J
Department of Medicine, University Hospital Nijmegen, The Netherlands.
Immunology. 1991 Dec;74(4):613-20.
With respect to murine (m)IgG1 anti-CD3 monoclonal antibody (mAb), a polymorphic mitogenic response of peripheral blood mononuclear cells (PBMC) has been described which is caused by polymorphism of monocyte Fc gamma RII, and which defines high responders to mIgG1 (mIgG1-HR, approximately 70% of normal individuals) and low responders (mIgG1-LR). PBMC also exhibit a polymorphic mitogenic response to mIgG2b anti-CD3 mAb. In the present study 18 out of 550 individuals (3%) were mIgG2b-HR. Purified monocytes from mIgG2b-HR were able to support the mitogenic response to mIgG2b anti-CD3 mAb of purified T cells from mIgG2b-LR. Surprisingly, a significant mitogenic response to mIgG2b anti-CD3 mAb remained after vigorous depletion of monocytes from mIgG2b-HR PBMC. Apparently B cells are responsible for this accessory function since Epstein-Barr virus (EBV)-transformed B cells from mIgG2b-HR (but not from mIgG2b-LR) were able to support T-cell proliferation induced by mIgG2b anti-CD3 mAb. Only EBV B cells from mIgG2b-HR were able to form rosettes with human red blood cells (RBC) that had been sensitized with mIgG2b anti-glycophorin A mAb (EA-mIgG2b). These EBV B cells did not express Fc gamma RI or Fc gamma RIII, and could bind some but not all anti-Fc gamma RII mAb. The mitogenic response to mIgG2b anti-CD3 was not inhibited by any of the anti-Fc gamma RII mAb. From these studies we conclude that a polymorphic Fc receptor is expressed on human B cells and monocytes, which cross-reacts with mIgG2b. This receptor is different from Fc gamma RI and Fc gamma RIII, and apparently also from Fc gamma RII.
关于鼠源（m）IgG1抗CD3单克隆抗体（mAb），外周血单个核细胞（PBMC）存在多态性促有丝分裂反应，这是由单核细胞FcγRII的多态性引起的，它定义了对mIgG1的高反应者（mIgG1-HR，约占正常个体的70%）和低反应者（mIgG1-LR）。PBMC对mIgG2b抗CD3 mAb也表现出多态性促有丝分裂反应。在本研究中，550名个体中有18名（3%）是mIgG2b-HR。来自mIgG2b-HR的纯化单核细胞能够支持来自mIgG2b-LR的纯化T细胞对mIgG2b抗CD3 mAb的促有丝分裂反应。令人惊讶的是，从mIgG2b-HR PBMC中大量去除单核细胞后，对mIgG2b抗CD3 mAb仍有显著的促有丝分裂反应。显然B细胞负责这种辅助功能，因为来自mIgG2b-HR（而非mIgG2b-LR）的爱泼斯坦-巴尔病毒（EBV）转化B细胞能够支持由mIgG2b抗CD3 mAb诱导的T细胞增殖。只有来自mIgG2b-HR的EBV B细胞能够与用mIgG2b抗血型糖蛋白A mAb（EA-mIgG2b）致敏的人红细胞（RBC）形成玫瑰花结。这些EBV B细胞不表达FcγRI或FcγRIII，并且能结合部分但不是所有的抗FcγRII mAb。对mIgG2b抗CD3的促有丝分裂反应不受任何抗FcγRII mAb的抑制。从这些研究中我们得出结论，一种多态性Fc受体在人B细胞和单核细胞上表达，它与mIgG2b发生交叉反应。这种受体不同于FcγRI和FcγRIII，显然也不同于FcγRII。
