Clinic for Poultry, University of Veterinary Medicine Hannover, Bünteweg 17, Hannover, Germany.
Dev Comp Immunol. 2010 May;34(5):518-29. doi: 10.1016/j.dci.2009.12.011. Epub 2010 Jan 4.
The avian Metapneumovirus (aMPV) causes an economically important acute respiratory disease in turkeys (turkey rhinotracheitis, TRT). While antibodies were shown to be insufficient for protection against aMPV-infection, the role of T-lymphocytes in the control of aMPV-infection is not clear. In this study we investigated the role of T-lymphocytes in aMPV-pathogenesis in a T-cell-suppression model in turkeys. T-cell-intact turkeys and turkeys partly depleted of functional CD4(+) and CD8(+) T-lymphocytes by Cyclosporin A (CsA) treatment were inoculated with the virulent aMPV subtype A strain BUT 8544. CsA-treatment resulted in a significant reduction of absolute numbers of circulating CD4(+) and CD8alpha(+) T-lymphocytes by up to 82 and 65%, respectively (P<0.05). Proportions of proliferating T-cells within mitogen-stimulated peripheral blood mononuclear cells were reduced by similar levels in CsA-treated birds compared to untreated controls (P<0.05). CsA-treated turkeys showed delayed recovery from aMPV-induced clinical signs and histopathological lesions and a prolonged detection of aMPV in choanal swabs. The results of this study show that T-lymphocytes play an important role in the control of primary aMPV-infection in turkeys.
禽类传染性支气管炎病毒（aMPV）可引起火鸡的一种具有重要经济意义的急性呼吸道疾病（火鸡传染性鼻炎，TRT）。虽然抗体被证明不足以预防 aMPV 感染，但 T 淋巴细胞在控制 aMPV 感染中的作用尚不清楚。在这项研究中，我们研究了 T 细胞在火鸡 T 细胞抑制模型中 aMPV 发病机制中的作用。用环孢菌素 A（CsA）处理的 T 细胞完整的火鸡和部分耗尽功能 CD4（+）和 CD8（+）T 淋巴细胞的火鸡接种了强毒 aMPV 亚群 A 株 BUT 8544。CsA 处理导致循环 CD4（+）和 CD8α（+）T 淋巴细胞的绝对数量分别减少了高达 82%和 65%（P<0.05）。与未处理的对照相比，CsA 处理的鸟类中刺激物刺激的外周血单个核细胞中增殖 T 细胞的比例降低了类似水平（P<0.05）。CsA 处理的火鸡从 aMPV 诱导的临床症状和组织病理学病变中恢复得更慢，并且在鼻拭子中检测到 aMPV 的时间更长。这项研究的结果表明，T 淋巴细胞在控制火鸡原发性 aMPV 感染中发挥重要作用。
