Role of NKG2D signaling in the cytotoxicity of activated and expanded CD8+ T cells
Role of NKG2D signaling in the cytotoxicity of activated and expanded CD8+ T cells
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DOI：
10.1182/blood-2003-06-2125
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发表时间：
2004-04-15
期刊：
影响因子：
20.3
通讯作者：
Negrin, RS
中科院分区：
文献类型：
--
作者：
Verneris, MR;Karami, M;Negrin, RS
使用T细胞受体（TCR）交联抗体和白细胞介素2（IL-2）激活和扩增T细胞产生能够识别广泛的恶性细胞靶（包括自体白血病细胞）的强效细胞毒性效应细胞。靶细胞识别的机制以前是未知的。最近的研究表明，NKG 2D在自然杀伤（NK）细胞上的连接直接诱导细胞毒性，而在T细胞上，它共刺激TCR信号传导。在这里，我们证明了NKG 2D表达在人CD 8（+）T细胞活化和扩增后上调。使用纯化的CD 8（+）T细胞进行的抗体阻断、重定向细胞溶解和小干扰RNA（siRNA）研究表明，对恶性靶细胞的细胞毒性是通过NKG 2D介导的识别和信号传导而不是通过TCR发生的。活化和扩增的CD 8（+）T细胞在培养10至14天后产生细胞毒性，与衔接蛋白DAP 10的表达一致。在低（30 U/mL）和高（300 U/mL）浓度IL-2中活化和扩增的T细胞均同等上调NKG 2D表达，但仅在高剂量IL-2中培养的细胞表达DAP 10且具有细胞毒性。总之，这些结果表明，NKG 2D触发可能通过DAP 10介导的信号传导导致活化和扩增的CD 8（+）T细胞的主要组织相容性复合体（MHC）非限制性细胞毒性的大部分。
Activating and expanding T cells using T-cell receptor (TCR) cross-linking antibodies and interleukin 2 (IL-2) results in potent cytotoxic effector cells capable of recognizing a broad range of malignant cell targets, including autologous leukemic cells. The mechanism of target cell recognition has previously been unknown. Recent studies show that ligation of NKG2D on natural killer (NK) cells directly induces cytotoxicity, whereas on T cells it costimulates TCR signaling. Here we demonstrate that NKG2D expression is up-regulated upon activation and expansion of human CD8(+) T cells. Antibody blocking, redirected cytolysis, and small interfering RNA (siRNA) studies using purified CD8(+) T cells demonstrate that cytotoxicity against malignant target cells occurs through NKG2D-mediated recognition and signaling and not through the TCR. Activated and expanded CD8(+) T cells develop cytotoxicity after 10 to 14 days of culture, coincident with the expression of the adapter protein DAP10. T cells activated and expanded in low (30 U/mL) and high (300 U/mL) concentrations of IL-2 both up-regulated NKG2D expression equally, but only cells cultured in high-dose IL-2 expressed DAP10 and were cytotoxic. Collectively these results establish that NKG2D triggering accounts for the majority of major histocompatibility complex (MHC)-unrestricted cytotoxicity of activated and expanded CD8(+) T cells, likely through DAP10-mediated signaling.