Reichenspurner H, Soni V, Nitschke M, Berry G J, Brazelton T, Shorthouse R, Huang X, Boname J, Girgis R, Raitz B A, Mocarski E, Sandford G, Morris R E
Transplantation Immunology, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Calif 94305-5247, USA.
J Heart Lung Transplant. 1998 May;17(5):439-51.
Cytomegalovirus infection has been identified as a significant risk factor for the development of obliterative bronchiolitis in human lung transplant recipients. This study was designed to assess the influence of rat cytomegalovirus (RCMV) on the pathogenesis and development of obliterative bronchiolitis in an experimental model of obliterative airway disease, which occurs after allogenic heterotopic tracheal transplantation in rodents.
Sixty Lewis rats were infected intraperitoneally with 10(7) plaque-forming units of recombinant lac-Z-tagged RCMV expressing the gene for beta-galactosidase. Rats were either infected at the time of surgery (acute infection, n = 30) or 56 days before surgery (chronic infection, n = 30). Tracheae from Brown Norway (allograft) or Lewis (isograft) rats were implanted and wrapped in the greater omentum of infected Lewis rats. RCMV infection was verified in different recipient tissues by in vitro plaque-assays and by direct in situ staining for beta-galactosidase activity. The tracheal grafts were harvested on days 7, 14, and 21 after transplantation and stained with hematoxylin-eosin and Masson's trichrome. The peritracheal cellular inflammation was scored visually. The cellular density of the infiltrating cells and the extent of airway obliteration were analyzed by use of computer-digitized morphometry and compared with uninfected allografts as control.
Both acute and chronic cytomegalovirus infection produced significantly higher mononuclear cell density values on days 7 and 14 compared with noninfected controls, indicating a more intense immune response in the infected allografts. Tracheal allograft obliteration was also more extensive after acute and, in particular, after chronic cytomegalovirus infection (64% narrowing after 21 days compared with 36% in grafts from noninfected control animals).
Our experimental results provide direct evidence that the tracheal grafts were infected with RCMV and that the development of obliterative airway disease was enhanced in the acutely and chronically infected allografts compared with grafts from noninfected control animals.
巨细胞病毒感染已被确认为人类肺移植受者发生闭塞性细支气管炎的一个重要危险因素。本研究旨在评估大鼠巨细胞病毒（RCMV）对闭塞性气道疾病实验模型中闭塞性细支气管炎发病机制和发展的影响，该疾病发生于啮齿动物同种异体异位气管移植后。
60只Lewis大鼠经腹腔注射10⁷个表达β-半乳糖苷酶基因的重组lac-Z标记RCMV的空斑形成单位。大鼠在手术时感染（急性感染，n = 30）或在手术前56天感染（慢性感染，n = 30）。将来自棕色挪威大鼠（同种异体移植）或Lewis大鼠（同基因移植）的气管植入并包裹在感染Lewis大鼠的大网膜中。通过体外空斑试验和β-半乳糖苷酶活性的直接原位染色在不同受体组织中验证RCMV感染。在移植后第7、14和21天收获气管移植物，并用苏木精-伊红和马松三色染色。肉眼对气管周围细胞炎症进行评分。通过计算机数字化形态测量分析浸润细胞的细胞密度和气道闭塞程度，并与未感染的同种异体移植作为对照进行比较。
与未感染的对照组相比，急性和慢性巨细胞病毒感染在第7天和第14天产生的单核细胞密度值显著更高，表明感染的同种异体移植中有更强烈的免疫反应。急性感染后，尤其是慢性巨细胞病毒感染后，气管同种异体移植闭塞也更广泛（21天后狭窄64%，而未感染对照动物的移植物为36%）。
我们的实验结果提供了直接证据，即气管移植物被RCMV感染，并且与未感染对照动物的移植物相比，急性和慢性感染的同种异体移植中闭塞性气道疾病的发展增强。
