Keller R, Keist R, Bazin H, Joller P, Van der Meide P H
Institute for Immunology and Virology, University of Zurich, Switzerland.
Eur J Immunol. 1990 Sep;20(9):2137-40. doi: 10.1002/eji.1830200937.
The ability of resting and activated rat bone marrow-derived mononuclear phagocytes (BMM phi) to bind monomeric rat, mouse, and human IgG was determined by means of flow cytometry. Rat IgG2b bound with high affinity (Kd approximately equal to 3 x 10(-9) M); binding was optimal at 4 degrees C and was only little affected by trypsin treatment. The other IgG bound with only low affinity (rat IgG2a, mouse and human IgG) or not at all to rat BMM phi (rat IgG1, rat IgG2c). The binding of rat IgG2b was not affected by the presence of a surplus of low-affinity binding IgG, and vice versa, indicating that high- and low-affinity IgG bind to different sites. Binding of high- and low-affinity IgG as well as expression of MHC class II molecules and of tumoricidal activity by BMM phi was markedly enhanced by rat interferon-gamma in low concentration (0.1 to 1.0 IU IFN-gamma/ml). On the other hand, heat-killed Corynebacterium parvum organisms, that were equally potent in triggering tumoricidal activity, neither enhanced the binding of IgG nor the expression of MHC class II molecules by BMM phi, suggesting that these abilities are not necessarily closely related phenomena.
通过流式细胞术测定静息和活化的大鼠骨髓来源的单核吞噬细胞（BMM phi）结合单体大鼠、小鼠和人IgG的能力。大鼠IgG2b以高亲和力结合（Kd约等于3×10⁻⁹ M）；在4℃时结合最佳，且仅受胰蛋白酶处理的轻微影响。其他IgG与大鼠BMM phi的结合亲和力较低（大鼠IgG2a、小鼠和人IgG）或根本不结合（大鼠IgG1、大鼠IgG2c）。大鼠IgG2b的结合不受过量低亲和力结合IgG的影响，反之亦然，表明高亲和力和低亲和力IgG结合到不同位点。低浓度（0.1至1.0 IU IFN-γ/ml）的大鼠干扰素-γ显著增强了高亲和力和低亲和力IgG的结合以及BMM phi的MHC II类分子表达和杀肿瘤活性。另一方面，热灭活的微小棒状杆菌在触发杀肿瘤活性方面同样有效，但既不增强BMM phi对IgG的结合，也不增强其MHC II类分子的表达，这表明这些能力不一定是密切相关的现象。
