Kuokkanen Elina, Šuštar Vid, Mattila Pieta K
Unit of Pathology, Institute of Biomedicine, University of Turku, Turku, Finland.
Traffic. 2015 Apr;16(4):311-26. doi: 10.1111/tra.12257. Epub 2015 Feb 20.
B cells form an essential part of the adaptive immune system by producing specific antibodies that can neutralize toxins and target infected or malignant cells for destruction. During B cell activation, a fundamental role is played by a specialized intercellular structure called the immunological synapse (IS). The IS serves as a platform for B cell recognition of foreign, often pathogenic, antigens on the surface of antigen-presenting cells (APC). This recognition is elicited by highly specific B cell receptors (BCR) that subsequently trigger carefully orchestrated intracellular signaling cascades that lead to cell activation. Furthermore, antigen internalization, essential for full B cell activation and differentiation into antibody producing effector cells or memory cells, occurs in the IS. Recent developments especially in various imaging-based methods have considerably advanced our understanding of the molecular control of B cell activation. Interestingly, the cellular cytoskeleton is emerging as a key player at several stages of B cell activation, including the initiation of receptor signaling. Here, we discuss the functions and molecular mechanisms of the IS and highlight the multifaceted role of the actin cytoskeleton in several aspects of B cell activation.
B细胞通过产生能够中和毒素并靶向感染或恶性细胞以进行破坏的特异性抗体，构成了适应性免疫系统的重要组成部分。在B细胞活化过程中，一种称为免疫突触（IS）的特殊细胞间结构发挥着重要作用。免疫突触作为B细胞识别抗原呈递细胞（APC）表面外来（通常是致病性）抗原的平台。这种识别由高度特异性的B细胞受体（BCR）引发，随后触发精心编排的细胞内信号级联反应，从而导致细胞活化。此外，抗原内化发生在免疫突触中，这对于B细胞的完全活化以及分化为产生抗体的效应细胞或记忆细胞至关重要。特别是最近基于各种成像方法的进展，极大地推进了我们对B细胞活化分子控制的理解。有趣的是，细胞细胞骨架在B细胞活化的几个阶段正成为关键参与者，包括受体信号传导的启动。在这里，我们讨论免疫突触的功能和分子机制，并强调肌动蛋白细胞骨架在B细胞活化的几个方面所起的多方面作用。
