Herberman R B, Bartram S, Haskill J S, Nunn M, Holden H T, West W H
J Immunol. 1977 Jul;119(1):322-6.
Mouse effector cells mediating natural cytotoxicity against tumor cells have been previously thought to be lymphocytes that lack any detectable cell surface markers. The present study presents evidence for receptors for the Fc portion of IgG on these cells. By adsorption of cytotoxic spleen cells on monolayers of sheep erythrocytes (E) plus IgG antibodies to sheep erythrocytes (EA), 50 to 96% of the total cytotoxic reactivity could be removed. Parallel adsorption of cells on E monolayers or on EA monolayers coated with protein A, to block the Fc portion of IgG, resulted in little or no depletion of cytotoxic activity. The presence of Fc receptors on the NK cells was confirmed by combining EA rosette formation with velocity sedimentation at unit gravity. Peak cytotoxicity occurred at the same sedimentation velocity as the peak of Fc-positive cells. After EA rosette formation, there was a shift to a higher sedimentation velocity in the Fc-positive cells and in the natural cytotoxic activity. The increase in sedimentation velocity of NK activity that was observed in these experiments indicated that most of the cells had only bound a small number (three or four) of antibody-coated erythrocytes. Together, these data indicate that cells with Fc receptors account for most of the total lytic activity of normal mouse spleen cells.
以前一直认为，介导对肿瘤细胞天然细胞毒性的小鼠效应细胞是缺乏任何可检测到的细胞表面标志物的淋巴细胞。本研究提供了这些细胞上存在IgG Fc部分受体的证据。通过将细胞毒性脾细胞吸附在绵羊红细胞（E）单层加上抗绵羊红细胞IgG抗体（EA）上，可以去除50%至96%的总细胞毒性反应性。将细胞平行吸附在E单层或涂有蛋白A的EA单层上，以阻断IgG的Fc部分，导致细胞毒性活性几乎没有或没有消耗。通过将EA花环形成与单位重力下的速度沉降相结合，证实了NK细胞上存在Fc受体。峰值细胞毒性出现在与Fc阳性细胞峰值相同的沉降速度处。在形成EA花环后，Fc阳性细胞和天然细胞毒性活性的沉降速度都转移到了更高的值。在这些实验中观察到的NK活性沉降速度的增加表明，大多数细胞仅结合了少量（三或四个）抗体包被的红细胞。总之，这些数据表明，具有Fc受体的细胞占正常小鼠脾细胞总裂解活性的大部分。
