Bataki E L, Evans G S, Everard M L
Department of Respiratory Medicine, Sheffield Children's Hospital, Sheffield, UK.
Clin Exp Immunol. 2005 Jun;140(3):470-7. doi: 10.1111/j.1365-2249.2005.02780.x.
Respiratory syncytial virus infects almost all children by 2 years of age. Neutrophils are the predominant airway leucocytes in RSV bronchiolitis and they are activated in the presence of infection. However it is not clear whether RSV can directly signal to activate neutrophil cytotoxic function. To investigate this we have used a preparation of RSV washed using a new centrifugal diafiltration method to rapidly remove inflammatory molecules produced by the epithelial cells used to propagate the RSV stock. Human neutrophils were isolated from peripheral blood and activated with either the unwashed crude RSV preparations or the purified intact RSV. Neutrophils were also challenged with purified RSV G-glycoprotein. The effect of challenging human neutrophils with these preparations of intact RSV, or the RSV G-glycoprotein, was assessed by measuring the cell surface expression of CD11b and CD18b, the phagocytic oxidative burst, and intracellular release of calcium pools. Neutrophils challenged with the washed RSV exhibited significantly lower activation of surface marker expression (P < 0.001) and oxidative burst (P < 0.001) than those challenged with unwashed virus or with virus free supernatant. There was no increase in intracellular calcium release on exposure to the washed RSV. Purified G glycoprotein did not stimulate neutrophils, whilst the use of a blocking antibody to the F protein did not prevent unwashed RSV from activating cytotoxic responses. These results suggest that neutrophils have no innate signalling system that recognizes RSV but they are activated at sites of RSV infection as a result of the cytokines and inflammatory molecules released by virally infected cells.
呼吸道合胞病毒在2岁前几乎感染所有儿童。中性粒细胞是呼吸道合胞病毒细支气管炎中主要的气道白细胞，且在感染时被激活。然而，尚不清楚呼吸道合胞病毒是否能直接发出信号激活中性粒细胞的细胞毒性功能。为了研究这一点，我们使用了一种新的离心渗滤法洗涤的呼吸道合胞病毒制剂，以快速去除用于繁殖呼吸道合胞病毒储备的上皮细胞产生的炎症分子。从外周血中分离出人中性粒细胞，并用未洗涤的粗制呼吸道合胞病毒制剂或纯化的完整呼吸道合胞病毒激活。中性粒细胞也用纯化的呼吸道合胞病毒G糖蛋白进行刺激。通过测量CD11b和CD18b的细胞表面表达、吞噬性氧化爆发以及钙池的细胞内释放，评估用这些完整呼吸道合胞病毒制剂或呼吸道合胞病毒G糖蛋白刺激人中性粒细胞的效果。用洗涤后的呼吸道合胞病毒刺激的中性粒细胞，与用未洗涤的病毒或无病毒上清液刺激的中性粒细胞相比，表面标志物表达的激活（P < 0.001）和氧化爆发（P < 0.001）明显更低。暴露于洗涤后的呼吸道合胞病毒时，细胞内钙释放没有增加。纯化的G糖蛋白不刺激中性粒细胞，而使用针对F蛋白的阻断抗体并不能阻止未洗涤的呼吸道合胞病毒激活细胞毒性反应。这些结果表明，中性粒细胞没有识别呼吸道合胞病毒的固有信号系统，但它们在呼吸道合胞病毒感染部位被激活，这是病毒感染细胞释放的细胞因子和炎症分子作用的结果。
