PDF(Pubmed)
Abstract：
Influenza A virus (IAV) infections in swine are usually subclinical, but they can reach high morbidity rates. The mortality rate is normally low. In this study, six vaccinated, spontaneously deceased sows revealed IAV infection and enhanced neutrophilic bronchopneumonia with unexpectedly large numbers of infiltrating eosinophils. The purpose of this study was to characterize these lung lesions with special emphasis on the phenotypes of inflammatory cells, the presence of eosinophilic peroxidase (EPO), and neutrophil extracellular traps (NETs). The number of Sirius red-stained eosinophils was significantly higher in the lungs of IAV-infected sows compared to healthy pigs, indicating a migration of eosinophils from blood vessels into the lung tissue stimulated by IAV infection. The detection of intra- and extracellular EPO in the lungs suggests its contribution to pulmonary damage. The presence of CD3+ T lymphocytes, CD20+ B lymphocytes, and Iba-1+ macrophages indicates the involvement of cell-mediated immune responses in disease progression. Furthermore, high numbers of myeloperoxidase-positive cells were detected. However, DNA-histone-1 complexes were reduced in IAV-infected sows, leading to the hypothesis that NETs are not formed in the IAV-infected sows. In conclusion, our findings in the lungs of IAV-infected vaccinated sows suggest the presence of so far unreported field cases of vaccine-associated enhanced respiratory disease.
摘要：
猪的甲型流感病毒（IAV）感染通常是亚临床的，但是它们可以达到很高的发病率。死亡率通常很低。在这项研究中,六个，接种疫苗自发死亡的母猪发现IAV感染和嗜中性粒细胞支气管肺炎增强，并伴有大量的嗜酸性粒细胞浸润。这项研究的目的是表征这些肺部病变，特别强调炎症细胞的表型，嗜酸性过氧化物酶（EPO）的存在，和中性粒细胞胞外诱捕网(NET)。与健康猪相比，感染IAV的母猪肺部天狼星红染色的嗜酸性粒细胞数量明显增多，表明嗜酸性粒细胞从血管迁移到IAV感染刺激的肺组织。肺内和细胞外EPO的检测表明其对肺损伤的贡献。CD3+T淋巴细胞的存在，CD20+B淋巴细胞，和Iba-1+巨噬细胞表明细胞介导的免疫应答参与疾病进展。此外，检测到大量的髓过氧化物酶阳性细胞.然而,DNA-组蛋白-1复合物在感染IAV的母猪中减少，导致NETs不在感染IAV的母猪中形成的假设。总之,我们在感染IAV的接种疫苗母猪肺部的发现表明,目前还存在未报告的疫苗相关增强呼吸道疾病的现场病例.
