Antibodies forming a complex with antigen in vivo can dramatically change the antibody response to this antigen. In some situations, the response will be a 100‐fold stronger than in animals immunized with antigen alone, and in other situations, the response will be completely suppressed. IgG is known to suppress the antibody response, for example to erythrocytes, and this is used clinically in Rhesus prophylaxis. The mechanism behind IgG‐mediated immune suppression is still not understood. Here, we will review studies performed in experimental animal models and discuss the various hypotheses put forward to explain the profound suppressive effect of IgG. We conclude that an exclusive role for negative regulation of B cells through FcγRIIB, increased clearance of erythrocytes from the circulation or complement‐mediated lysis is unlikely. Epitope masking, where IgG hides the epitope from B cells, or trogocytosis, where IgG removes the epitope from the erythrocyte, is compatible with many observations. These two mechanisms are not mutually exclusive. Moreover, it cannot be ruled out that clearance, in combination with other mechanisms, plays a role.

中文翻译：

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IgG介导的抗体反应抑制：隐藏或抢夺表位？

在体内与抗原形成复合物的抗体可以显着改变抗体对该抗原的反应。在某些情况下，该反应比仅用抗原免疫的动物要强100倍，而在其他情况下，该反应将被完全抑制。已知IgG可以抑制抗体反应，例如对红细胞的反应，在临床上可用于预防恒河猴。IgG介导的免疫抑制的机制仍不清楚。在这里，我们将回顾在实验动物模型中进行的研究，并讨论为解释IgG的深层抑制作用而提出的各种假设。我们得出结论认为，通过FcγRIIB对B细胞进行负调控，增加红细胞从循环中的清除率或补体介导的裂解的排他性作用是不可能的。抗原表位掩盖（其中IgG将B细胞的表位隐藏起来）或光吞作用（其中IgG从红细胞中去除的表位）与许多观察结果兼容。这两种机制不是互斥的。此外，不能排除清除与其他机制一起发挥作用。