Identification of Fc Gamma Receptor Glycoforms That Produce Differential Binding Kinetics for Rituximab
Identification of Fc Gamma Receptor Glycoforms That Produce Differential Binding Kinetics for Rituximab
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DOI：
10.1074/mcp.m117.066944
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发表时间：
2017-10-01
影响因子：
7
通讯作者：
Rudd, Pauline M.
中科院分区：
文献类型：
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作者：
Hayes, Jerrard M.;Frostell, Asa;Rudd, Pauline M.
Fc gamma 受体 (Fc gamma R) 结合抗体的 Fc 区，因此在抗体依赖性细胞免疫反应（例如 ADCC、CDC 和 ADCP）中发挥着重要作用。免疫效应细胞活性与 Fc γ R 的有效分子结合直接相关，其中抗体和受体的蛋白质和聚糖部分都可以影响相互作用，在本研究中，我们重点关注 Fc γ R 聚糖在这种相互作用中的作用。我们完整描述了中国仓鼠卵巢 (CHO) 表达的人 Fc gamma 受体 RI (CD64)、RIIa(Arg131/His131) (CD32a)、RIIb (CD32b) 和 RIIIa(Phe158/Val158) (CD16a) 的聚糖组成，并分析了聚糖在与 IgG 结合机制中的作用。对单克隆抗体利妥昔单抗与每种 Fc gamma R 的相互作用进行了表征，我们讨论了 CHO-Fc gamma RIIIaPhe158/Val158 和 CHO-Fc gamma RI 相互作用，并将它们与人 (HEK293) 和鼠 (NS0) 产生的受体的等效相互作用进行比较。我们的结果揭示了利妥昔单抗结合谱的明显差异，我们在每种情况下将其归因于宿主细胞依赖性 Fc gamma R 糖基化的差异。将 CHO 表达的 Fc γ RI 和 Fc γ RIIIa Phe158/Val158 的聚糖谱与 NS0 和 HEK293 细胞中表达的受体的聚糖谱进行比较，我们发现受体之间的聚糖类型和丰度存在显着差异，并且这些聚糖差异导致观察到各自 Fc γ R 与利妥昔单抗结合模式的差异。寡甘露糖结构在各个来源的 Fc gamma RI 上普遍存在，并且可能通过稳定作用促进高亲和力利妥昔单抗相互作用。在 Fc gamma RI 和 Fc gamma RIIIa 上，大的唾液酸化聚糖对利妥昔单抗结合具有负面影响，可能是通过破坏相互作用来实现的。总之，数据显示 IgG1-Fc gamma R 结合动力学因 Fc gamma R 的糖基化而异，并进一步支持 Fc gamma R 聚糖在抗体结合相互作用中的稳定作用。
Fc gamma receptors (Fc gamma R) bind the Fc region of antibodies and therefore play a prominent role in antibody-dependent cell-based immune responses such as ADCC, CDC and ADCP. The immune effector cell activity is directly linked to a productive molecular engagement of Fc gamma Rs where both the protein and glycan moiety of antibody and receptor can affect the interaction and in the present study we focus on the role of the Fc gamma R glycans in this interaction. We provide a complete description of the glycan composition of Chinese hamster ovary (CHO) expressed human Fc gamma receptors RI (CD64), RIIa(Arg131/ His131) (CD32a), RIIb (CD32b) and RIIIa(Phe158/Val158) (CD16a) and analyze the role of the glycans in the binding mechanism with IgG. The interactions of the monoclonal antibody rituximab with each Fc gamma R were characterized and we discuss the CHO-Fc gamma RIIIaPhe158/Val158 and CHO-Fc gamma RI interactions and compare them to the equivalent interactions with human (HEK293) and murine (NS0) produced receptors. Our results reveal clear differences in the binding profiles of rituximab, which we attribute in each case to the differences in host cell-dependent Fc gamma R glycosylation. The glycan profiles of CHO expressed Fc gamma RI and Fc gamma RIIIa Phe158/Val158 were compared with the glycan profiles of the receptors expressed in NS0 and HEK293 cells and we show that the glycan type and abundance differs significantly between the receptors and that these glycan differences lead to the observed differences in the respective Fc gamma R binding patterns with rituximab. Oligomannose structures are prevalent on Fc gamma RI from each source and likely contribute to the high affinity rituximab interaction through a stabilization effect. On Fc gamma RI and Fc gamma RIIIa large and sialylated glycans have a negative impact on rituximab binding, likely through destabilization of the interaction. In conclusion, the data show that the IgG1-Fc gamma R binding kinetics differ depending on the glycosylation of the Fc gamma R and further support a stabilizing role of Fc gamma R glycans in the antibody binding interaction.