Superantigens are unconventional antigens which recognise immune receptors outside their usual recognition sites e.g. complementary determining regions (CDRs), to elicit a response within the target cell. T-cell superantigens crosslink T-cell receptors and MHC Class II molecules on antigen-presenting cells, leading to lymphocyte recruitment, induction of cytokine storms and T-cell anergy or apoptosis among many other effects. B-cell superantigens, on the other hand, bind immunoglobulins on B-cells, affecting opsonisation, IgG-mediated phagocytosis, and driving apoptosis. Here, through a review of the structural basis for recognition of immune receptors by superantigens, we show that their binding interfaces share specific physicochemical characteristics when compared with other protein-protein interaction complexes. Given that antibody-binding superantigens have been exploited extensively in industrial antibody purification, these observations could facilitate further protein engineering to optimize the use of superantigens in this and other areas of biotechnology.

超级抗原是非常规抗原，可识别其通常识别位点（例如互补决定区（CDR））之外的免疫受体，以引发靶细胞内的反应。T 细胞超级抗原与抗原呈递细胞上的 T 细胞受体和 MHC II 类分子交联，导致淋巴细胞募集、诱导细胞因子风暴、T 细胞无反应或凋亡等许多效应。另一方面，B 细胞超抗原与 B 细胞上的免疫球蛋白结合，影响调理作用、IgG 介导的吞噬作用并驱动细胞凋亡。在这里，通过回顾超抗原识别免疫受体的结构基础，我们发现与其他蛋白质-蛋白质相互作用复合物相比，它们的结合界面具有特定的物理化学特征。鉴于抗体结合超抗原已在工业抗体纯化中得到广泛利用，这些观察结果可以促进进一步的蛋白质工程，以优化超抗原在该领域和其他生物技术领域的使用。