Myers Jesse T, Swanson Joel A
Cellular and Molecular Biology Graduate Program and Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor 48109-0620, USA.
J Leukoc Biol. 2002 Oct;72(4):677-84.
Rises in intracellular-free calcium (Ca(2+)) have been variously associated with Fcgamma receptor (FcR)-mediated phagocytosis in macrophages. We show here that activation of murine bone marrow-derived macrophages increases calcium spiking after FcR ligation. Ratiometric fluorescence microscopy was used to measure Ca(2+) during phagocytosis of immunoglobulin G (IgG)-opsonized erythrocytes. Whereas 13% of nonactivated macrophages increased Ca(2+) in the form of one or more spikes, 56% of those activated with lipopolysaccharides (LPS; 18 h at 100 ng/ml) and interferon-gamma (IFN-gamma; 100 U/ml) and 73% of macrophages activated with LPS, IFN-gamma, interleukin (IL)-6 (5 ng/ml), and anti-IL-10 IgG (5 micro g/ml) spiked calcium during phagocytosis. Calcium spikes were inhibited by thapsigargin (Tg), indicating that they originated from endoplasmic reticulum. The fact that activated macrophages showed a more dramatic response suggested that calcium spikes during phagocytosis mediate or regulate biochemical mechanisms for microbicidal activities. However, lowering Ca(2+) with ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid or inhibiting calcium spikes with Tg did not inhibit phagosome-lysosome fusion or the generation of reactive oxygen or nitrogen species. Thus, the increased calcium spiking in activated macrophages was not directly associated with the mechanism of phagocytosis or the increased antimicrobial activities of activated macrophages.
细胞内游离钙（Ca(2+)）升高与巨噬细胞中Fcγ受体（FcR）介导的吞噬作用存在多种关联。我们在此表明，小鼠骨髓来源巨噬细胞的激活会增加FcR连接后的钙峰发放。在吞噬免疫球蛋白G（IgG）调理的红细胞过程中，采用比率荧光显微镜测量Ca(2+)。未激活的巨噬细胞中有13%以一个或多个钙峰的形式增加Ca(2+)，而用脂多糖（LPS；100 ng/ml处理18小时）和干扰素-γ（IFN-γ；100 U/ml）激活的巨噬细胞中有56%，以及用LPS、IFN-γ、白细胞介素（IL）-6（5 ng/ml）和抗IL-10 IgG（5 μg/ml）激活的巨噬细胞中有73%在吞噬过程中出现钙峰。钙峰被毒胡萝卜素（Tg）抑制，表明它们起源于内质网。激活的巨噬细胞表现出更显著反应这一事实表明，吞噬过程中的钙峰介导或调节了杀菌活性的生化机制。然而，用乙二醇双（β-氨基乙基醚）-N,N'-四乙酸降低Ca(2+)或用Tg抑制钙峰并没有抑制吞噬体-溶酶体融合或活性氧或氮物种的产生。因此，激活的巨噬细胞中增加的钙峰发放与吞噬作用机制或激活的巨噬细胞增强的抗菌活性没有直接关联。
