Rivera-Rivas José J, Kisiela Dagmara, Czuprynski Charles J
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA.
Vet Immunol Immunopathol. 2009 Oct 15;131(3-4):167-76. doi: 10.1016/j.vetimm.2009.04.002. Epub 2009 Apr 11.
Respiratory infection of cattle with bovine herpesvirus type 1 (BHV-1) predisposes cattle to secondary pneumonia with Mannheimia haemolytica as part of the bovine respiratory disease complex (BRD). One cell type that has received limited investigation for its role in the inflammation that accompanies BRD is the respiratory epithelial cell. In the present study we investigated mechanisms by which BHV-1 infection of respiratory epithelial cells contributes to the recruitment and activation of bovine polymorphonuclear neutrophils (PMNs) in vitro. Primary cultures of bovine bronchial epithelial (BBE) cells were infected with BHV-1 and assessed for cytokine expression by real-time PCR. We found that BHV-1 infection elicits a rapid IL-1, IL-8 and TNF-alpha mRNA response by BBE cells. Bovine PMNs exhibited greater adherence to BHV-1 infected BBE cells than uninfected cells. The increased adherence was significantly reduced by the addition of an anti-IL-1beta antibody or human soluble TNF-alpha receptor (sTNF-alphaR). Pre-incubation of bovine PMNs with conditioned media from BHV-1 infected BBE cells increased PMN migration, which was inhibited by addition of an anti-IL-1beta antibody, sTNF-alphaR, or an IL-8 peptide inhibitor. Conditioned media from BHV-1 infected BBE cells activated bovine PMNs in vitro as demonstrated by PMN shape change, production of reactive oxygen species and degranulation. PMNs also exhibited increased LFA-1 expression and susceptibility to M. haemolytica LKT following incubation with BHV-1 infected BBE cell conditioned media. Our results suggest that BHV-1 infection of BBE cells triggers cytokine expression that contributes to the recruitment and activation of neutrophils, and amplifies the detrimental effects of M. haemolytica LKT.
牛感染1型牛疱疹病毒（BHV-1）引发的呼吸道感染使牛易患继发性肺炎，溶血曼氏杆菌是牛呼吸道疾病综合征（BRD）的一部分。在BRD伴随的炎症中，呼吸道上皮细胞在其中所起的作用鲜有研究。在本研究中，我们调查了呼吸道上皮细胞感染BHV-1在体外促进牛多形核中性粒细胞（PMN）募集和激活的机制。用BHV-1感染牛支气管上皮（BBE）细胞的原代培养物，并通过实时PCR评估细胞因子表达。我们发现，BHV-1感染引发BBE细胞快速产生白细胞介素-1（IL-1）、白细胞介素-8（IL-8）和肿瘤坏死因子-α（TNF-α）的mRNA反应。与未感染细胞相比，牛PMN对感染BHV-1的BBE细胞的黏附性更强。添加抗IL-1β抗体或人可溶性TNF-α受体（sTNF-αR）可显著降低这种增加的黏附性。用感染BHV-1的BBE细胞的条件培养基预孵育牛PMN可增加PMN迁移，添加抗IL-1β抗体、sTNF-αR或IL-8肽抑制剂可抑制这种迁移。感染BHV-1的BBE细胞的条件培养基在体外激活了牛PMN，表现为PMN形态改变、活性氧生成和脱颗粒。与感染BHV-1的BBE细胞条件培养基孵育后，PMN还表现出淋巴细胞功能相关抗原-1（LFA-1）表达增加以及对溶血曼氏杆菌白细胞毒素（LKT）的敏感性增加。我们的结果表明，BBE细胞感染BHV-1会触发细胞因子表达，这有助于中性粒细胞的募集和激活，并放大溶血曼氏杆菌LKT的有害作用。
