Martiniello R, Burton R C, Smart Y C
Discipline of Surgical Science, Faculty of Medicine and Health Science, University of Newcastle, Newcastle, NSW, Australia.
Int J Cancer. 1997 Feb 7;70(4):450-60. doi: 10.1002/(sici)1097-0215(19970207)70:4<450::aid-ijc13>3.0.co;2-j.
Ly-6C+ cells constitute 13 +/- 3% of freshly isolated (CBA x C57BL/6)F1 mouse spleen leukocytes. Three distinct populations were identified: CD3 epsilon +NK-1.1- conventional T cells (6%), CD3 epsilon -NK-1.1- granulocytes (5%) and CD3 epsilon +NK-1.1+ T cells (approximately 2%). The CD3 epsilon +NK-1.1+ cells displayed a predominantly large granular leukocyte morphology and were the only Ly-6C+ cell subset identified by MAb 2B6-F2 to spontaneously lyse the NK-sensitive YAC-1 tumour in vitro. On further phenotypic analysis, these cells co-expressed high levels of TCRV beta 8.1/8.2 and CD11b, moderate levels of CD90 and low levels of CD4 or CD8. The removal of CD4+ and CD8+ cells prior to Ly-6C+ cell sorting showed that it was the CD4-CD8- double-negative (DN) CD3 epsilon +NK-1.1+ T-cell subset which was responsible for killing YAC-1. These results indicate that we have identified a DN Ly-6C+ subset of the recently designated NK-1.1+TCR alpha beta low natural T (NT) cells, which are capable of natural cell-mediated cytotoxicity (NCMC) against the NK-sensitive YAC-I tumour in vitro. Additionally, these cells mediated the in vitro killing of 2 further NK-sensitive tumours, murine B16 melanoma and human Jurkat T lymphoma. YAC-1 and Jurkat expressed Fas and were susceptible to anti-Fas MAb or rhuman Fas ligand (rhFasL)-induced lysis. Furthermore, anti-human Fas MAb M3 was shown to block sorted Ly-6C+ splenocyte in vitro killing of Jurkat. In contrast, B16 did not express cell-surface Fas and was resistant to anti-Fas MAb-induced lysis. Taken together, these results show that not only do Ly-6C+ NT cells kill NK-sensitive tumours in vitro but they mediate this activity via multiple cytotoxic mechanisms including Fas.
Ly-6C+细胞占新鲜分离的（CBA×C57BL/6）F1小鼠脾脏白细胞的13±3%。鉴定出三个不同的群体：CD3ε+NK-1.1-传统T细胞（6%）、CD3ε-NK-1.1-粒细胞（5%）和CD3ε+NK-1.1+T细胞（约2%）。CD3ε+NK-1.1+细胞主要呈现大颗粒白细胞形态，并且是单克隆抗体2B6-F2鉴定出的唯一在体外能自发裂解NK敏感的YAC-1肿瘤的Ly-6C+细胞亚群。进一步的表型分析显示，这些细胞共表达高水平的TCRVβ8.1/8.2和CD11b、中等水平的CD90以及低水平的CD4或CD8。在对Ly-6C+细胞进行分选之前去除CD4+和CD8+细胞表明，负责杀伤YAC-1的是CD4-CD8-双阴性（DN）CD3ε+NK-1.1+T细胞亚群。这些结果表明，我们鉴定出了最近命名的NK-1.1+TCRαβ低天然T（NT）细胞的一个DN Ly-6C+亚群，该亚群在体外能够对NK敏感的YAC-1肿瘤产生天然细胞介导的细胞毒性（NCMC）。此外，这些细胞介导了另外两种NK敏感肿瘤即小鼠B16黑色素瘤和人Jurkat T淋巴瘤在体外的杀伤。YAC-1和Jurkat表达Fas且易受抗Fas单克隆抗体或重组人Fas配体（rhFasL）诱导的裂解作用影响。此外，抗人Fas单克隆抗体M3被证明能阻断分选的Ly-6C+脾细胞在体外对Jurkat的杀伤。相反，B16不表达细胞表面Fas且对抗Fas单克隆抗体诱导的裂解具有抗性。综上所述，这些结果表明，Ly-6C+NT细胞不仅在体外能杀伤NK敏感肿瘤，而且它们通过包括Fas在内的多种细胞毒性机制介导这种活性。
