NK细胞的发育、分化与识别机制  

Development,differentiation and immune recognition of natural killer cells

作　　者：田志刚[1] 陈永艳[1] 

机构地区：[1]中国科学技术大学免疫学研究所,合肥230027

出　　处：《中国免疫学杂志》2009年第1期31-34,共4页Chinese Journal of Immunology

摘　　要：NK细胞由NK前体细胞(NK cell precursors,NKPs)发育分化而来。骨髓造血干细胞可发育分化为NKPs,胸腺早期淋巴样前体细胞(Early lymphoid precursors,ELPs)亦能够发育分化为NKPs。肝脏、淋巴结、脾脏亦存在NKPs,提示这些组织器官均可能是NK细胞发育分化的场所。骨髓来源的NKPs能够迁移至胸腺、淋巴结、肝脏、脾脏等部位;胸腺来源的NKPs能够迁移至淋巴结而进一步发育分化。NKPs进一步发育分化为不成熟NK细胞(iNKs),进而经过一系列的"education"后成为成熟NK细胞(mNKs)。在iNKs向mNKs发育分化中"自身MHCⅠ类分子"的"education"使mNKs至少表达一种抑制性受体,或者不经过"自身MHCⅠ分子"的"education"但也表达NK细胞特异性受体。NK细胞可表达一系列活化性受体及抑制性受体,两者间的平衡是控制NK细胞是否被激活的重要机制。除了经典的杀伤性NK细胞外,可依据NK细胞的免疫调节功能的不同将NK细胞分为辅助性NK细胞(NK1,NK2,NK3),调节性NK细胞(NKreg)和抗原提呈NK细胞(NKDC)等。NK细胞在体内的分布频率是lung>liver>blood>spleen>bone marrow>lymph node>thymus。何种机制导致NK细胞在某些组织器官(如肺脏、肝脏)的"优势"分布尚不清楚,可能与NK细胞的招募、归巢,亚群分布,或者不同组织局部的进一步发育分化有关。Natural killer（NK） cells come from NK cell precursors（NKPs）.The heamatopoietic stem cells of bone marrow may develop into NKPs.The early lymphoid precursors（ELPs） in thymus may also differentiate into NKPs.NKPs are found in liver,lymph node and spleen,indicating these tissue or organs may supply the microenvironment for NKPs differentiation.NKPs from bone marrow may migrate into thymus,lymph node,liver and spleen.NKPs in thymus can move to lymph nodes for further differentiation.NKPs need to differentiate into immature NK cells（iNKs）,which then become mature NK cells（mNKs）,followed by a series of ＂education＂.During differentiation of iNKs into mNKs,the mNKs acquire at least one kind of inhibitory receptor via ＂self-MHC-I education＂,or express other immune receptors without ＂self-MHC-I education＂.The array and balance of inhibitory receptors and triggering receptors on mNKs determine the final activation and function of mNKs.In addition to the classic killing function of NK cells,the NK subsets may divide into helper NK cells（NK1,NK2,NK3）,regulatory NK cells（NKreg） and Ag-presenting NK cells（NKDC）,based on the roles of NK cells in immune response.The distribution of NK cells is as followed：lung〉liver〉blood〉spleen〉bone marrow〉lymph node 〉thymus.It is not clear why and how these distribution exist,which is possibly correlated to recruitment,homing,subset,and microenvironment of NK cells in each tissue or organ.

关 键 词：NK细胞 发育 分化 识别机制 

分 类 号：R392.11[医药卫生—免疫学]