Activation of human monocytes occurs on cross-linking monocytic antigens to an Fc receptor.
Activation of human monocytes occurs on cross-linking monocytic antigens to an Fc receptor.
复制标题
人类单核细胞的激活发生在单核细胞抗原与 Fc 受体交联时。
作者：
E. Macintyre;P. Roberts;M. Jones;C. E. van der Schoot;E. J. Favalaro;N. Tidman;D. Linch
针对 CD13、CD14 和 II 类 MHC 的鼠科单克隆抗体能够动员正常人单核细胞中的钙并增强已启动细胞中超氧化物的产生。 CD35 (CR1) 抗体也会在某些个体中引起轻微的钙反应。 CD11a、CD11b、CD11c、CD15、CD17、CD18 和 CD45 的抗体不会激活单核细胞。 mAb 引起单核细胞活化的能力不仅取决于与其反应的 Ag，还取决于抗体的同种型以及获得单核细胞的个体。结果表明，这是因为激活单核细胞的 mAb 通过形成 Ag-抗体-FcR 复合物来实现这一目的。因此，即使与 F(ab')2 抗小鼠 Ig 交联，CD13 和 CD14 mAb 的 F(ab')2 片段也不会激活单核细胞，但与完整的抗小鼠 Ig 交联时会激活单核细胞。这些数据表明，通过 FcR 激活需要扰动该受体，但不一定需要一个 FcR 与另一个 FcR 交联。抗体包被的颗粒或细胞能够与单核细胞上除FcR之外的细胞表面受体结合，从而增强FcR介导的激活。
Murine mAb to CD13, CD14, and class II MHC, are able to mobilize calcium in normal human monocytes and enhance superoxide production in primed cells. Antibodies to CD35 (CR1) also cause a minor calcium response in some individuals. Antibodies to CD11a, CD11b, CD11c, CD15, CD17, CD18, and CD45 do not activate monocytes. The ability of mAb to cause monocyte activation is not only dependent on the Ag with which they react but also on the isotype of the antibodies and the individual from whom the monocytes were obtained. It is shown that this is because the mAb that activate monocytes do so by formation of Ag-antibody-FcR complexes. F(ab')2 fragments of mAb to CD13 and CD14 do not therefore activate monocytes even when cross-linked with F(ab')2 anti-mouse Ig but do so when cross-linked with intact anti-mouse Ig. These data indicate that activation via the FcR requires perturbation of this receptor but does not necessarily require cross-linking of one FcR to another. Antibody-coated particles or cells able to bind to cell surface receptors on monocytes other than the FcR would thus augment FcR-mediated activation.