Wiener E, Dellow R A, Mawas F, Rodeck C H
Department of Haematology, Imperial College School of Medicine at St Mary's, London, UK.
Transfus Med. 1996 Sep;6(3):235-41. doi: 10.1111/j.1365-3148.1996.tb00074.x.
To test the role of Fc gamma RIIa in IgG anti-RhD-mediated phagocytosis three IgG1 and two IgG3 human monoclonal anti-D antibodies were tested for ability to mediate binding/phagocytosis of cDE/cde and -D-/-D- red cells by Fc gamma RIIa-R131 and Fc gamma RIIa-H131 cDNA-transfected 3T6 fibroblasts. Both IgG3 monoclonal antibodies brought about -D-/-D- cell interaction with IIa-transfected fibroblasts, while only one of them, Og3, mediated binding of cDE/cde targets. Although Fc gamma RIIa expression was three times greater on IIa-R131 than on IIa-H131 fibroblasts, the latter bound significantly more Og3-coated cDE/cde- and IgG3 anti-D-sensitized -D-/-D- cells, respectively, than the former effectors and showed some phagocytosis of the -D-/-D- targets. IgG1 anti-D antibodies were inactive in mediating red cell interaction with the fibroblasts. Moreover, monoclonal anti-Fc gamma RII IV.3 partially inhibited the phagocytosis by adult or fetal monocytes of Og3-sensitized cDE/cde cells. Fc gamma RIIa-H/H131 monocytes exhibited higher phagocytic indices towards these targets than monocytes of other IIa allotypes. The results indicate that Fc gamma RIIa can participate in the phagocytosis of red cells coated with IgG3 anti-D; in this case the allotype of the receptor will modify the extent of red cell destruction.
为了测试FcγRIIa在IgG抗-RhD介导的吞噬作用中的作用，检测了三种IgG1和两种IgG3人源单克隆抗-D抗体介导cDE/cde和-D-/-D-红细胞与FcγRIIa-R131和FcγRIIa-H131 cDNA转染的3T6成纤维细胞结合/吞噬的能力。两种IgG3单克隆抗体均能使-D-/-D-细胞与IIa转染的成纤维细胞发生相互作用，而其中只有一种，即Og3，介导cDE/cde靶标的结合。尽管FcγRIIa在IIa-R131成纤维细胞上的表达量是IIa-H131成纤维细胞上的三倍，但后者分别与前者效应细胞相比，能显著结合更多的Og3包被的cDE/cde细胞和IgG3抗-D致敏的-D-/-D-细胞，并对-D-/-D-靶标表现出一定的吞噬作用。IgG1抗-D抗体在介导红细胞与成纤维细胞的相互作用中无活性。此外，单克隆抗FcγRII IV.3部分抑制了成年或胎儿单核细胞对Og3致敏的cDE/cde细胞的吞噬作用。FcγRIIa-H/H131单核细胞对这些靶标的吞噬指数高于其他IIa同种异型的单核细胞。结果表明，FcγRIIa可参与IgG3抗-D包被红细胞的吞噬作用；在这种情况下，受体的同种异型将改变红细胞破坏的程度。
