B cells must extract antigens attached to the surface of antigen presenting cells to generate high-affinity antibodies. Antigen extraction requires force, and recent studies have implicated actomyosin-dependent pulling forces generated within the B cell as the major driver of antigen extraction. These actomyosin-dependent pulling forces also serve to test the affinity of the B cell antigen receptor for antigen prior to antigen extraction. Such affinity discrimination is central to the process of antibody affinity maturation. Here we review the evidence that actomyosin-dependent pulling forces generated within the B cell promote affinity discrimination and power antigen extraction. Our take on these critical B cell functions is influenced significantly by the recent identification of formin-generated, myosin-rich, concentric actin arcs in the medial portion of the T cell immune synapse, as B cells appear to contain a similar contractile actomyosin structure.

中文翻译：

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肌动蛋白和肌球蛋白在 B 淋巴细胞提取抗原中的作用。

B 细胞必须提取附着在抗原呈递细胞表面的抗原以产生高亲和力抗体。抗原提取需要力量，最近的研究表明，在 B 细胞内产生的肌动球蛋白依赖性拉力是抗原提取的主要驱动力。这些肌动球蛋白依赖性拉力还用于在提取抗原之前测试 B 细胞抗原受体对抗原的亲和力。这种亲和力区分是抗体亲和力成熟过程的核心。在这里，我们回顾了在 B 细胞内产生的肌动球蛋白依赖性拉力促进亲和力辨别和动力抗原提取的证据。我们对这些关键 B 细胞功能的看法受到最近发现的甲酸生成、富含肌球蛋白的显着影响，