Klebanoff S J, Beatty P G, Schreiber R D, Ochs H D, Waltersdorph A M
J Immunol. 1985 Feb;134(2):1153-9.
Two monoclonal antibodies (Mab), designated 60.3 and 60.1, markedly inhibited the phagocytosis of serum-opsonized zymosan by human polymorphonuclear leukocytes (PMN) as measured by the iodination reaction and by microscopic visualization. These antibodies also inhibited rosette formation with EC3bi without decreasing EC3b rosetting, suggesting that Mab 60.3 and 60.1 inhibit the phagocytosis of opsonized zymosan through reaction with the C3bi receptor (CR3) on the leukocyte surface. In support of this concept is the finding that the PMN of two patients with recurrent infections do not ingest opsonized zymosan, lack C3bi receptor function, and react weakly or not at all with Mab 60.3 and 60.1. At concentrations which completely inhibited ingestion of opsonized zymosan, both Mab partially inhibited iodination with Staphylococcus aureus 502A as the particle, and did not affect iodination when Staphylococcus epidermidis was used. This presumably reflects a variable need among the opsonized particles for CR3 for ingestion. Mab 60.3 also inhibited the phagocytosis of certain unopsonized particles as measured by iodination, indicating that the antigens recognized by the Mab do not influence phagocytosis solely by functioning as a C3bi receptor. Mab 60.3 increased the phagocytosis of unopsonized, heat-killed S. aureus by reaction with the PMN via its antibody-combining site, and with the staphylococcal protein A via its Fc region (reverse opsonization). This process required protein A-containing organisms (S. aureus 502A or Cowan 1 but not S. aureus Wood 46 or S. epidermidis), was inhibited by purified protein A, and was not seen either when the F(ab')2 or Fab fragments of the antibody, or when PMN which lack or have low levels of the antigen were employed. Thus, these studies, using iodination as a convenient method for the measurement of phagocytosis, demonstrated two effects of antibodies directed against PMN cell surface components: inhibition of phagocytosis by reaction with the C3bi receptor, and stimulation of phagocytosis by reverse opsonization.
两种单克隆抗体（Mab），分别命名为60.3和60.1，通过碘化反应和显微镜观察发现，它们能显著抑制人多形核白细胞（PMN）对血清调理酵母聚糖的吞噬作用。这些抗体还能抑制与EC3bi形成的玫瑰花结，但不降低EC3b玫瑰花结的形成，这表明Mab 60.3和60.1通过与白细胞表面的C3bi受体（CR3）反应来抑制调理酵母聚糖的吞噬作用。支持这一观点的是，两名反复感染患者的PMN不摄取调理酵母聚糖，缺乏C3bi受体功能，并且与Mab 60.3和60.1反应微弱或无反应。在完全抑制调理酵母聚糖摄取的浓度下，两种Mab都部分抑制了以金黄色葡萄球菌502A为颗粒的碘化反应，而使用表皮葡萄球菌时则不影响碘化反应。这可能反映了不同的调理颗粒对CR3摄取的需求不同。通过碘化反应测量，Mab 60.3还抑制了某些未调理颗粒的吞噬作用，这表明该Mab识别的抗原并非仅通过作为C3bi受体来影响吞噬作用。Mab 60.3通过其抗体结合位点与PMN反应，并通过其Fc区域与葡萄球菌蛋白A反应，从而增加了未调理、热杀死的金黄色葡萄球菌的吞噬作用（反向调理）。这一过程需要含蛋白A的生物体（金黄色葡萄球菌502A或考恩1株，但不是金黄色葡萄球菌伍德46株或表皮葡萄球菌），被纯化的蛋白A抑制，当使用抗体的F(ab')2或Fab片段时，或者当使用缺乏或低水平表达该抗原的PMN时，均未观察到这种现象。因此，这些使用碘化反应作为测量吞噬作用简便方法的研究，证明了针对PMN细胞表面成分的抗体有两种作用：通过与C3bi受体反应抑制吞噬作用，以及通过反向调理刺激吞噬作用。
