Bakács T, Hadley A G, Kumpel B M, Segal D M, Banhidy F
National Institute of Oncology, Budapest, Hungary.
Immunol Lett. 1994 Sep;42(1-2):91-5. doi: 10.1016/0165-2478(94)90041-8.
The functional activity of Fc gamma RIII on human K cells from peripheral blood was compared with that of Fc gamma RIII on peritoneal macrophages (PM) separated from the waste material of patients undergoing peritoneal dialysis. Fc gamma R function was assessed in vitro using human monoclonal IgG1 anti-D (AB5) or a bispecific antibody comprising Fab fragments of AB5 chemically linked to Fab fragments of monoclonal anti-Fc gamma RIII, 3G8 (AB5 x 3G8). In antibody-dependent cell-mediated cytotoxicity (ADCC) assays, K cells mediated the lysis of papainized red cells sensitized with the AB5 x 3G8 bispecific antibody but not with AB5. In contrast, red cell lysis by PM was not promoted by AB5 x 3G8 although AB5 was active. However, this lysis, being inhibited by monomeric IgG, was presumably mediated via Fc gamma RI. AB5 x 3G8 also failed to promote the binding and phagocytosis of both papainized and native red cells by PM although 99% of red cells and over 90% of peritoneal cells bound the bispecific antibody. In marked contrast to K cells therefore, Fc gamma RIII on PM was unable to mediate functional interactions with red cells sensitized with anti-D x anti-Fc gamma RIII bispecific antibody.
将来自外周血的人K细胞上FcγRIII的功能活性与从接受腹膜透析患者的废料中分离出的腹膜巨噬细胞（PM）上FcγRIII的功能活性进行了比较。使用人单克隆IgG1抗-D（AB5）或一种双特异性抗体在体外评估FcγR功能，该双特异性抗体由化学连接至单克隆抗FcγRIII的Fab片段3G8（AB5×3G8）的AB5的Fab片段组成。在抗体依赖性细胞介导的细胞毒性（ADCC）试验中，K细胞介导了用AB5×3G8双特异性抗体而非AB5致敏的木瓜蛋白酶处理的红细胞的裂解。相反，尽管AB5有活性，但AB5×3G8并未促进PM对红细胞的裂解。然而，这种裂解被单体IgG抑制，推测是通过FcγRI介导的。AB5×3G8也未能促进PM对木瓜蛋白酶处理的和天然红细胞的结合及吞噬作用，尽管99%的红细胞和超过90%的腹膜细胞结合了双特异性抗体。因此，与K细胞形成鲜明对比的是，PM上的FcγRIII无法介导与用抗-D×抗FcγRIII双特异性抗体致敏的红细胞的功能相互作用。
