The host defensive role of mast cells against airway viral infection.

肥大细胞长期以来被认为在过敏性疾病的发病机制中起着核心作用。此外，最近有报道称肥大细胞还具有宿主防御细菌感染的作用。但肥大细胞抗病毒感染的作用尚未明确。本研究的目的是探讨肥大细胞在宿主防御病毒感染中的作用。我们将病毒双链RNA的类似化合物poly I:C鼻内接种到野生型或肥大细胞缺陷型W/Wv小鼠中。Poly I: C在野生型小鼠中引起肺部炎症，但在肥大细胞缺陷小鼠中炎症减轻，静脉将肥大细胞转移到肥大细胞缺陷小鼠中可恢复炎症。此外，肥大细胞缺陷小鼠的局部各种趋化因子和细胞因子浓度降低。这些结果表明，肥大细胞通过上调局部细胞因子和趋化因子的产生，对病毒感染具有宿主防御作用。这一发现可能有助于阐明病毒诱导的过敏性疾病（包括哮喘）恶化的机制。

Mast cells have long been postulated to have a central role in the pathogenesis of allergic disease. In addition, it has been recently reported that mast cells also have a host defensive role against bacterial infection. But the role of mast cells against virus infection has not been clarified. The aim of the present study is to investigate the role of mast cells in host defense against viral infection. We intranasally inoculated poly I:C, which is an analogue compound of virus double-stranded RNA, into wild type or mast cell deficient W/Wv mice. Poly I : C induced lung inflammation in wild type mice, but the inflammation was diminished in mast cell deficient mice, and intravenous transfer of mast cells into mast cell deficient mice restored the inflammation. In addition, the local concentration of various chemokines and cytokines decreased in mast cell deficient mice. From those results, it was suggested that mast cells have a host-defensive role against viral infection via up-regulation of local cytokine and chemokine generation. This finding might contribute to clarify the mechanism of virus-induced exacerbation of allergic diseases including asthma.