Susavion Biosciences, Inc., Tempe, AZ, United States.
Front Immunol. 2019 Dec 11;10:2880. doi: 10.3389/fimmu.2019.02880. eCollection 2019.
Phagocytic cells [dendritic cells (DCs), macrophages, monocytes, neutrophils, and mast cells] utilize C-type (Ca-dependent) lectin-like (CLEC) receptors to identify and internalize pathogens or danger signals. As monitors of environmental imbalances, CLEC receptors are particularly important in the function of DCs. Activation of the immune system requires, in sequence, presentation of antigen to the T cell receptor (TCR) by DCs, interaction of co-stimulatory factors such as CD40/80/86 on DCs with CD40L and CD28 on T cells, and production of IL-12 and/or IFN-α/β to amplify T cell differentiation and expansion. Without this sequence of events within an inflammatory environment, or in a different order, antigen-specific T cells become unresponsive, are deleted or become regulatory T cells. Thus, the mode by which CLEC receptors on DCs are engaged can either elicit activation of T cells to achieve an immune response or induce tolerance. This minireview illustrates these aspects with Dectin-1, DEC205, the mannose receptor and CLEC10A as examples.
吞噬细胞（树突状细胞 (DCs)、巨噬细胞、单核细胞、中性粒细胞和肥大细胞）利用 C 型（Ca 依赖性）凝集素样 (CLEC) 受体来识别和内化病原体或危险信号。作为环境失衡的监测器，CLEC 受体在 DC 的功能中尤为重要。免疫系统的激活需要 DC 依次将抗原呈递给 T 细胞受体 (TCR)，DC 上的共刺激因子（如 CD40/80/86）与 T 细胞上的 CD40L 和 CD28 相互作用，以及产生 IL-12 和/或 IFN-α/β 来扩增 T 细胞分化和扩增。如果在炎症环境中没有发生这一系列事件，或者顺序不同，抗原特异性 T 细胞就会变得无反应、被删除或成为调节性 T 细胞。因此，DC 上的 CLEC 受体被激活的方式可以引发 T 细胞的激活以实现免疫反应，也可以诱导耐受。本文以 Dectin-1、DEC205、甘露糖受体和 CLEC10A 为例说明了这些方面。
