Muschel R J, Rosen N, Bloom B R
J Exp Med. 1977 Jan 1;145(1):175-86. doi: 10.1084/jem.145.1.175.
We have isolated cloned variants in phagocytosis from a cloned continuous murine macrophage-like cell line, J 774.2. A selection procedure against Fc receptor-mediated phagocytosis was devised using IgG-coated SRBC containing a toxic drug, tubercidin, as the lethal agent. A series of variant clones deficient in Fc receptor-mediated phagocytosis were isolated. Such variants occurred at low frequency (approximately 6 X 10(-5)), were stable, and appeared to possess Fc receptors. The degree to which they were defective in phagocytosis of IgG-coated SRBC varied from clone to clone, yet all clones, were able to phagocytize latex particles. The phagocytic defect in some variants could be corrected by the addition of 8 Br-cAMP, in others, the drug was without effect. It is likely, therefore, that different variants are defective in several distinct steps critical to Fc receptor-mediated phagocytosis.
我们从克隆的连续小鼠巨噬细胞样细胞系J 774.2中分离出了吞噬作用方面的克隆变体。设计了一种针对Fc受体介导的吞噬作用的筛选程序，使用包被有IgG的含有毒性药物杀结核菌素的绵羊红细胞（SRBC）作为致死剂。分离出了一系列缺乏Fc受体介导的吞噬作用的变体克隆。这些变体出现的频率较低（约6×10⁻⁵），是稳定的，并且似乎拥有Fc受体。它们在包被有IgG的SRBC吞噬作用方面的缺陷程度因克隆而异，但所有克隆都能够吞噬乳胶颗粒。在一些变体中，吞噬缺陷可以通过添加8-溴环磷酸腺苷（8 Br-cAMP）来纠正，而在另一些变体中，该药物则没有效果。因此，不同的变体可能在对Fc受体介导的吞噬作用至关重要的几个不同步骤中存在缺陷。
