Idris A H, Smith H R, Mason L H, Ortaldo J R, Scalzo A A, Yokoyama W M
Immunobiology Center, Mount Sinai School of Medicine, New York, NY, 10029, USA.
Proc Natl Acad Sci U S A. 1999 May 25;96(11):6330-5. doi: 10.1073/pnas.96.11.6330.
Previously, we established that natural killer (NK) cells from C57BL/6 (B6), but not BALB/c, mice lysed Chinese hamster ovary (CHO) cells, and we mapped the locus that determines this differential CHO-killing capacity to the NK gene complex on chromosome 6. The localization of Chok in the NK gene complex suggested that it may encode either an activating or an inhibitory receptor. Here, results from a lectin-facilitated lysis assay predicted that Chok is an activating B6 NK receptor. Therefore, we immunized BALB/c mice with NK cells from BALB.B6-Cmv1(r) congenic mice and generated a mAb, designated 4E4, that blocked B6-mediated CHO lysis. mAb 4E4 also redirected lysis of Daudi targets, indicating its reactivity with an activating NK cell receptor. Furthermore, only the 4E4(+) B6 NK cell subset mediated CHO killing, and this lysis was abrogated by preincubation with mAb 4E4. Flow cytometric analysis indicated that mAb 4E4 specifically reacts with Ly-49D but not Ly-49A, B, C, E, G, H, or I transfectants. Finally, gene transfer of Ly-49DB6 into BALB/c NK cells conferred cytotoxic capacity against CHO cells, thus establishing that the Ly-49D receptor is sufficient to activate NK cells to lyse this target. Hence, Ly-49D is the Chok gene product and is a mouse NK cell receptor capable of directly triggering natural killing.
此前，我们证实，来自C57BL/6（B6）小鼠而非BALB/c小鼠的自然杀伤（NK）细胞能够裂解中国仓鼠卵巢（CHO）细胞，并且我们将决定这种差异CHO杀伤能力的基因座定位到了6号染色体上的NK基因复合体。Chok在NK基因复合体中的定位表明，它可能编码一种激活型或抑制型受体。在此，凝集素促进裂解试验的结果预测Chok是一种激活型B6 NK受体。因此，我们用来自BALB.B6-Cmv1(r) 同源基因小鼠的NK细胞免疫BALB/c小鼠，并产生了一种名为4E4的单克隆抗体，该抗体可阻断B6介导的CHO裂解。单克隆抗体4E4还能重定向对Daudi靶细胞的裂解，表明其与一种激活型NK细胞受体具有反应性。此外，只有4E4(+) B6 NK细胞亚群介导了对CHO的杀伤，并且这种裂解可通过与单克隆抗体4E4预孵育而被消除。流式细胞术分析表明，单克隆抗体4E4与Ly-49D特异性反应，但不与Ly-49A、B、C、E、G、H或I转染体反应。最后，将Ly-49D B6基因转入BALB/c NK细胞赋予了其对CHO细胞的细胞毒能力，从而证实Ly-49D受体足以激活NK细胞来裂解该靶细胞。因此，Ly-49D是Chok基因产物，并且是一种能够直接触发自然杀伤的小鼠NK细胞受体。
