Adv Exp Med Biol. 2011;780:45-55. doi: 10.1007/978-1-4419-5632-3_5.
Killer Ig-like receptors (KIRs) are major human NK receptors displaying either inhibitory or activating functions which recognize allotypic determinants of HLA-class I molecules. Surprisingly, NK cell treatment with CpG-ODN (TLR9 ligands) results in selective down-modulation of KIR3DL2, its co-internalization with CpG-ODN and its translocation to TLR9-rich early endosomes. This novel KIR-associated function may offer clues to better understand the possible role of certain KIRs and also emphasizes the involvement of NK cells in the course of microbial infections. NK cells are involved not only in innate immune responses against viruses and tumors but also participate in the complex network of cell-to cell interaction that leads to the development of adaptive immune responses. In this context the interaction of NK cells with DC appears to play a crucial role in the acquisition of CCR7, a chemokine receptor that enables NK cells to migrate towards lymph nodes in response to CCL19 and/or CCL21. Analysis of NK cell clones revealed that KIR-mismatched but not KIR-matched NK cells acquire CCR7. These data have important implications in haploidentical haematopoietic stem cell transplantation (HSCT), in which KIR-mismatched NK cells may acquire the ability to migrate to secondary lymphoid compartments (SLCs), where they can kill recipient's antigen presenting cells (APCs) and T cells thus preventing graft versus host (and host vs. graft) reactions.
杀伤细胞免疫球蛋白样受体（KIRs）是主要的人类 NK 受体，具有抑制或激活功能，可识别 HLA Ⅰ类分子的同种异型决定簇。令人惊讶的是，CpG-ODN（TLR9 配体）处理 NK 细胞会导致 KIR3DL2 的选择性下调，其与 CpG-ODN 共内化，并转移到富含 TLR9 的早期内体。这种新的 KIR 相关功能可能为更好地理解某些 KIR 的可能作用提供线索，也强调了 NK 细胞在微生物感染过程中的参与。NK 细胞不仅参与针对病毒和肿瘤的先天免疫反应，还参与导致适应性免疫反应发展的细胞间相互作用的复杂网络。在这种情况下，NK 细胞与 DC 的相互作用似乎在获得 CCR7 方面起着至关重要的作用，CCR7 是一种趋化因子受体，使 NK 细胞能够在 CCL19 和/或 CCL21 的作用下向淋巴结迁移。对 NK 细胞克隆的分析表明，KIR 错配而不是 KIR 匹配的 NK 细胞获得了 CCR7。这些数据在半相合造血干细胞移植（HSCT）中具有重要意义，在半相合 HSCT 中，KIR 错配的 NK 细胞可能获得迁移到次级淋巴器官（SLC）的能力，在那里它们可以杀死受者的抗原呈递细胞（APC）和 T 细胞，从而防止移植物抗宿主（和宿主抗移植物）反应。
