Ding A, Wright S D, Nathan C
J Exp Med. 1987 Mar 1;165(3):733-49. doi: 10.1084/jem.165.3.733.
Several features of activation of mouse peritoneal macrophages were elicited by 1-2-d exposure to submicrogram concentrations of anti-Mac-1 (M1/70), a rat monoclonal antibody that reacts with the alpha chain of complement receptor type 3 (Mac-1). The changes induced included enhanced capacity to secrete H2O2 when triggered with PMA, decreased secretion of proteins, increased expression of Ia antigen and decreased phagocytosis of particles. These changes closely resembled those induced by rIFN-gamma in type, extent, and time course. The concentration of M1/70 IgG resulting in 50% of the maximal activation of macrophage H2O2-releasing capacity averaged 0.18 +/- 0.03 micrograms/ml. This activation was not blocked by anti-FcR mAb, and could be reproduced with M18/2, a mAb against beta chain of Mac-1, suggesting that a direct ligation of Mac-1 with mAb was responsible for the activation. Neither depletion of T cells nor addition of neutralizing Abs to IFN-gamma or TNF-alpha prevented M1/70-mediated macrophage activation. Moreover, F(ab')2 of M1/70, or plating of macrophages on C3bi-coated surfaces, inhibited the activation of macrophages by rIFN-gamma. These findings suggest that Mac-1 (CR3) may play an important role in macrophage activation.
将小鼠腹腔巨噬细胞暴露于亚微克浓度的抗Mac-1（M1/70，一种与补体受体3型（Mac-1）的α链反应的大鼠单克隆抗体）1-2天，可引发巨噬细胞激活的若干特征。诱导的变化包括用佛波酯（PMA）触发时分泌过氧化氢（H2O2）的能力增强、蛋白质分泌减少、Ia抗原表达增加以及颗粒吞噬作用降低。这些变化在类型、程度和时间进程上与重组干扰素-γ（rIFN-γ）诱导的变化非常相似。导致巨噬细胞H2O2释放能力最大激活50%的M1/70 IgG浓度平均为0.18±0.03微克/毫升。这种激活不受抗FcR单克隆抗体的阻断，并且可以用抗Mac-1β链的单克隆抗体M18/2重现，这表明单克隆抗体与Mac-1的直接连接是激活的原因。T细胞耗竭或添加针对IFN-γ或TNF-α的中和抗体均不能阻止M1/70介导的巨噬细胞激活。此外，M1/70的F(ab')2片段，或巨噬细胞铺板于C3bi包被的表面，均可抑制rIFN-γ对巨噬细胞的激活。这些发现表明Mac-1（CR3）可能在巨噬细胞激活中起重要作用。
