Mason L H
Laboratory of Experimental Immunology, Division of Basic Sciences, National Cancer Institute-FCRDC, Frederick, Maryland 21702-1201, USA.
J Leukoc Biol. 2000 Oct;68(4):583-6.
Upon ligand recognition, members of the murine Ly-49 receptor family can transmit inhibitory or activating signals that regulate NK cell function. Ly-49A, G, and D have been shown to recognize the murine class I molecule H-2Dd as a potential ligand. Recent studies also have demonstrated also that Ly-49D+ NK cells can lyse CHO cells, although the ligand responsible for this recognition was not identified. Because allorecognition by NK cells may be important in bone-marrow transplantation and because of the overlapping class I recognition by these receptors, recognition of CHO cells by Ly-49G and A was investigated. Our data suggest that Ly-49G and probably A transmit inhibitory signals in response to CHO cells. Receptor inhibition was assessed by examining NK lytic function, IFN-gamma secretion, and DAP12 phosphorylation in response to CHO cells by sorted subsets of Ly-49D vs. G B6 NK cells. Our results suggest that CHO cells may express a common ligand(s) that is capable of engaging Ly-49D, G, and possibly A in C576BL/6 NK cells. In addition to our findings that Ly-49 inhibitory receptors also recognize CHO cells, activating receptors other than Ly-49D are present in B6 mice that can lyse CHO cells.
在配体识别后，小鼠Ly-49受体家族成员可传递调节自然杀伤（NK）细胞功能的抑制性或激活性信号。Ly-49A、G和D已被证明可识别小鼠I类分子H-2Dd作为潜在配体。最近的研究还表明，Ly-49D+NK细胞可裂解中国仓鼠卵巢（CHO）细胞，尽管尚未确定负责这种识别的配体。由于NK细胞的同种异体识别在骨髓移植中可能很重要，并且由于这些受体对I类分子的识别存在重叠，因此研究了Ly-49G和A对CHO细胞的识别情况。我们的数据表明，Ly-49G以及可能的Ly-49A在接触CHO细胞时会传递抑制性信号。通过检测Ly-49D与G B6 NK细胞分选亚群对CHO细胞反应时的NK裂解功能、γ干扰素分泌和DAP12磷酸化来评估受体抑制情况。我们的结果表明，CHO细胞可能表达一种共同配体，该配体能够与C576BL/6 NK细胞中的Ly-49D、G以及可能的A结合。除了我们发现Ly-49抑制性受体也能识别CHO细胞外，B6小鼠中还存在除Ly-49D之外的能裂解CHO细胞的激活性受体。
