哮喘联盟

   摘要

   流感和哮喘是当今两个主要的健康问题。在2009年流感爆发期间，哮喘则是住院患者最为常见的合并疾病。令人意外的是，较非哮喘患者，哮喘患者因罹患流感入院死亡发生率和入住ICU发生率较低。在哮喘合并流感的体内试验中，研究者发现早期接触热带无爪螨提取物（BTE）可以改变机体针对流感的免疫应答，从而使得感染后体重减轻程度减小且恢复期更快。而这一保护性机制则与T细胞数目增加有关，经BTE致敏的流感小鼠肺中，T细胞和IFN-γ数目显著增加。此外，与感染经PBS处理小鼠相比，BTE致敏的感染小鼠肺引流淋巴结中CD11b+树突状细胞（DCs）显著增多。无论在体内还是体外实验中，CD11b+DCs在启动型
   CD8特异性T细胞中功能更佳，而此功能较少见于CD11b+DCs。研究认为在BTE致敏小鼠中交叉抗原提呈改变和更高效的T细胞启动可以导致肺部T细胞数目更早增加进而加速体内病毒的清除并减少流感导致的病理性损伤。这一研究数据提供了一种新的机制解释为什么哮喘患者发生流感其临床症状较轻的现象。

 

（上海交通大学医学院附属瑞金医院呼吸与危重症医学科 周剑平 万欢英 摘译）

（PLoS One. 2018 Jan 2;13(1):e0190063. doi: 10.1371/journal.pone.0190063. eCollection 2018.）

Prior exposure to inhaled allergen enhances anti-viral immunity and T cell priming by dendritic cells.

PLoS One. 2018 Jan 2;13(1):e0190063. doi: 10.1371/journal.pone.0190063. eCollection 2018.

Lee DCP, Tay NQ, Thian M, Prabhu N, Furuhashi K, Kemeny DM.
 
Abstract
Influenza and asthma are two of the major public health concerns in the world today. During the 2009 influenza pandemic asthma was found to be the commonest comorbid illness of patients admitted to hospital. Unexpectedly, it was also observed that asthmatic patients admitted to hospital with influenza infection were less likely to die or require admission to intensive care compared with non-asthmatics. Using an in vivo model of asthma and influenza infection we demonstrate that prior exposure to Blomia tropicalis extract (BTE) leads to an altered immune response to influenza infection, comprised of less severe weight loss and faster recovery following infection. This protection was associated with significant increases in T cell numbers in the lungs of BTE sensitised and infected mice, as well as increased IFN-γ production from these cells. In addition, elevated numbers of CD11b+ dendritic cells (DCs) were found in the lung draining lymph nodes following infection of BTE sensitised mice compared to infected PBS treated mice. These CD11b+ DCs appeared to be better at priming CD8 specific T cells both in vivo and ex vivo, a function not normally attributed to CD11b+ DCs. We propose that this alteration in cross-presentation and more efficient T cell priming seen in BTE sensitised mice, led to the earlier increase in T cells in the lungs and subsequently faster clearance of the virus and reduced influenza induced pathology. We believe this data provides a novel mechanism that explains why asthmatic patients may present with less severe disease when infected with influenza.