Shields Robert L, Lai Jadine, Keck Rodney, O'Connell Lori Y, Hong Kyu, Meng Y Gloria, Weikert Stefanie H A, Presta Leonard G
Department of Immunology, Genentech, Inc., 1 South San Francisco, CA 94080, USA.
J Biol Chem. 2002 Jul 26;277(30):26733-40. doi: 10.1074/jbc.M202069200. Epub 2002 May 1.
Lec13 cells, a variant Chinese hamster ovary cell line, were used to produce human IgG1 that were deficient in fucose attached to the Asn(297)-linked carbohydrate but were otherwise similar to that found in IgG1 produced in normal Chinese hamster ovary cell lines and from human serum. Lack of fucose on the IgG1 had no effect on binding to human FcgammaRI, C1q, or the neonatal Fc receptor. Although no change in affinity was found for the His(131) polymorphic form of human FcgammaRIIA, a slight improvement in binding was evident for FcgammaRIIB and the Arg(131) FcgammaRIIA polymorphic form. In contrast, binding of the fucose-deficient IgG1 to human FcgammaRIIIA was improved up to 50-fold. Antibody-dependent cellular cytotoxicity assays using purified peripheral blood monocytes or natural killer cells from several donors showed enhanced cytotoxicity, especially evident at lower antibody concentrations. When combined with an IgG1 Fc protein variant that exhibited enhanced antibody-dependent cellular cytotoxicity, the lack of fucose was synergistic.
Lec13细胞是一种变异的中国仓鼠卵巢细胞系，用于生产与正常中国仓鼠卵巢细胞系及人血清中产生的IgG1相似，但在与天冬酰胺（297）连接的碳水化合物上缺乏岩藻糖的人IgG1。IgG1上缺乏岩藻糖对其与人FcγRI、C1q或新生儿Fc受体的结合没有影响。虽然未发现人FcγRIIA的His（131）多态形式的亲和力有变化，但FcγRIIB和Arg（131）FcγRIIA多态形式的结合有轻微改善。相比之下，缺乏岩藻糖的IgG1与人FcγRIIIA的结合提高了50倍。使用来自多个供体的纯化外周血单核细胞或自然杀伤细胞进行的抗体依赖性细胞毒性试验显示细胞毒性增强，在较低抗体浓度下尤为明显。当与表现出增强的抗体依赖性细胞毒性的IgG1 Fc蛋白变体结合时，缺乏岩藻糖具有协同作用。
