Dawson Dominic R, Nydam Daryl V, Price Christopher T, Graham James E, Cynamon Michael H, Divers Thomas J, Felippe Maria Julia B
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Am J Vet Res. 2011 Nov;72(11):1465-75. doi: 10.2460/ajvr.72.11.1465.
To investigate the effect of opsonization of Rhodococcus equi with R. equi-specific antibodies in plasma on bacterial viability and phagocyte activation in a cell culture model of infection.
Neutrophils and monocyte-derived macrophages from 6 healthy 1-week-old foals and 1 adult horse.
Foal and adult horse phagocytes were incubated with either opsonized or nonopsonized bacteria. Opsonization was achieved by use of plasma containing high or low concentrations of R. equi-specific antibodies. Phagocyte oxidative burst activity was measured by use of flow cytometry, and macrophage tumor necrosis factor (TNF)-α production was measured via an ELISA. Extracellular and intracellular bacterial viability was measured with a novel R. equi-luciferase construct that used a luminometer.
Opsonized bacteria increased oxidative burst activity in adult horse phagocytes, and neutrophil activity was dependent on the concentration of specific antibody. Secretion of TNF-α was higher in macrophages infected with opsonized bacteria. Opsonization had no significant effect on bacterial viability in macrophages; however, extracellular bacterial viability was decreased in broth containing plasma with R. equi-specific antibodies, compared with viability in broth alone.
The use of plasma enriched with specific antibodies for the opsonization of R. equi increased the activation of phagocytes and decreased bacterial viability in the extracellular space. Although opsonized R. equi increased TNF-α secretion and oxidative burst in macrophages, additional factors may be necessary for effective intracellular bacterial killing. These data have suggested a possible role of plasma antibody in protection of foals from R. equi pneumonia.
在感染细胞培养模型中，研究血浆中马红球菌特异性抗体调理马红球菌对细菌活力及吞噬细胞活化的影响。
来自6匹健康1周龄马驹和1匹成年马的中性粒细胞及单核细胞衍生巨噬细胞。
将马驹和成年马的吞噬细胞与经调理或未经调理的细菌一起孵育。通过使用含有高浓度或低浓度马红球菌特异性抗体的血浆实现调理作用。使用流式细胞术测量吞噬细胞的氧化爆发活性，并通过酶联免疫吸附测定法测量巨噬细胞肿瘤坏死因子（TNF）-α的产生。使用一种新型的马红球菌荧光素酶构建体通过光度计测量细胞外和细胞内细菌的活力。
经调理的细菌增加了成年马吞噬细胞的氧化爆发活性，中性粒细胞活性取决于特异性抗体的浓度。感染经调理细菌的巨噬细胞中TNF-α的分泌更高。调理作用对巨噬细胞中的细菌活力没有显著影响；然而，与仅在肉汤中的活力相比，在含有马红球菌特异性抗体的血浆的肉汤中细胞外细菌活力降低。
使用富含特异性抗体的血浆对马红球菌进行调理可增加吞噬细胞的活化并降低细胞外空间中的细菌活力。尽管经调理的马红球菌增加了巨噬细胞中TNF-α的分泌和氧化爆发，但可能还需要其他因素来有效杀灭细胞内细菌。这些数据表明血浆抗体在保护马驹免受马红球菌肺炎感染方面可能发挥作用。
