Respiratory Syncytial Virus (RSV) infection inhibits lung eosinophilia, but induces profound eosinophil degranulation in allergic mice

呼吸道合胞病毒（RSV）感染抑制肺部嗜酸性粒细胞增多，但引起过敏小鼠严重的嗜酸性粒细胞脱颗粒

• 批准号: 17591805
• 负责人: TAKIZAWA Ryuta
• 金额: $ 2.28万
• 依托单位: Nippon Medical School
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17591805/
• 关键词: Allergy; RSV; Cytokine; Chemokine; Mouse; 好酸球

RSV-induced bronchiolitis in infants is characterized by high concentrations of eosinophil-derived proteins, including ECP, MBP, and EDN, in nasal and tracheal aspirates. However, attempts to demonstrate the presence of eosinophils in airway mucosa or secretions of infants with RSV infections have been unsuccessful.A BALB/c mouse model of lung eosinophilia (OVA-induced) was used. OVA-sensitized, challenged (by repeated OVA nebulization) mice were infected with RSV or sham-inoculated and differential cell counts were performed in cells recovered by bronchoalveolar lavage (BAL) at day 1 after RSV or sham inoculation. Eosinophil peroxidase (EPO) activity in the BAL fluid was measured by a specific colorimetric assay.A significant reduction in the number of BAL eosinophils was observed in RSV-infected OVA-challenged mice (1.3×10^5/ml) compared with sham-infected, OVA-challenged mice (4.0×10^5/m1) (p<0.001). OVA-challenged, sham infected mice had no evidence of eosinophil degranulation, as no detectable EPO activity was present in the BAL fluid. On the other hand, OVA-challenged, RSV-infected mice had high levels of EPO activity in BAL fluid (p<0.01).These findings suggest the existence of a complex interplay between RSV infection and the migratory and activation pathways of eosinophils that may affect the response of atopic as well as non-atopic individuals to respiratory viral infections.

rsv诱导的婴儿毛细支气管炎的特点是鼻腔和气管吸入物中含有高浓度嗜酸性粒细胞衍生蛋白，包括ECP、MBP和EDN。然而，试图证明嗜酸性粒细胞存在于呼吸道粘膜或呼吸道合胞病毒感染婴儿的分泌物中是不成功的。采用ova诱导的BALB/c小鼠肺嗜酸性粒细胞增多症模型。将OVA致敏的小鼠（通过反复雾化OVA）感染RSV或假接种RSV，并在RSV或假接种后第1天通过支气管肺泡灌洗（BAL）恢复的细胞进行细胞计数。用比色法测定BAL液中嗜酸性过氧化物酶（EPO）活性。与假感染的ova攻击小鼠（4.0×10^5/m1）相比，rsv感染的ova攻击小鼠（1.3×10^5/ml）的BAL嗜酸性粒细胞数量显著减少（p<0.001）。ova攻击后，假性感染小鼠没有嗜酸性粒细胞脱颗粒的迹象，因为BAL液中没有可检测到的EPO活性。另一方面，ova攻击、rsv感染小鼠BAL液中EPO活性较高（p<0.01）。这些发现表明，RSV感染与嗜酸性粒细胞的迁移和激活途径之间存在复杂的相互作用，这可能影响特应性和非特应性个体对呼吸道病毒感染的反应。