Therapeutic monoclonal antibodies (mAbs), particularly of the IgG1 subclass, are capable of effector function activities that may be important for their mechanism of action. One such effector function activity is Antibody Dependent Cellular Phagocytosis (ADCP), which has been shown to be mediated primarily through the activating FcγR, FcγRIIa, on macrophages and neutrophils. The critical quality attributes that are the most impactful and predictive of ADCP activity, and therefore most suitable to monitor during IgG1 antibody manufacturing, are not well established. Primary cell assays for ADCP are often laborious and subject to donor to donor variability, making such assays less desirable for product characterization. By developing and employing an ADCP reporter gene assay, we have been able to determine with high sensitivity the glycan structures that can impact FcγRIIa mediated ADCP across multiple different IgG1 antibodies. Interestingly we observed that some IgG1 antibodies are very potent mediators of ADCP while others do not mediate ADCP even though they possess other effector function activities (ADCC and CDC). Additionally, we find that ADCP by different IgG1 antibodies has markedly different sensitivity to glycan species, with one antibody demonstrating a surprisingly strong influence of β-galactosylation and high mannose levels.

中文翻译：

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治疗性单克隆抗体上不同糖型对抗体依赖性细胞吞噬作用的差异影响。

治疗性单克隆抗体（mAb），尤其是IgG1亚类的单克隆抗体，能够执行可能对其作用机制重要的效应子功能活动。一种这样的效应子功能活性是抗体依赖性细胞吞噬作用（ADCP），其已显示主要通过活化巨噬细胞和嗜中性白细胞的FcγR，FcγRIIa介导。尚未确定最关键的质量属性，这些属性对ADCP活性的影响最大且可预测，因此最适合在IgG1抗体生产过程中进行监控。ADCP的原代细胞测定通常很费力，并且会因供体之间的可变性而异，这使得这种测定对于产品表征不太理想。通过开发和采用ADCP报告基因分析，我们已经能够以高灵敏度确定跨多个不同IgG1抗体影响FcγRIIa介导的ADCP的聚糖结构。有趣的是，我们观察到某些IgG1抗体是ADCP的强效介体，而其他IgG1抗体却不介导ADCP，即使它们具有其他效应功能（ADCC和CDC）也是如此。此外，我们发现不同的IgG1抗体对ADCP的聚糖种类具有明显不同的敏感性，其中一种抗体证明了β-半乳糖基化和高甘露糖水平的惊人强大影响。