Haridy Mohie, Sasaki Jun, Ikezawa Mitsutaka, Okada Kosuke, Goryo Masanobu
Department of Pathogenetic Veterinary Sciences, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
J Vet Med Sci. 2012 Jun;74(6):757-64. doi: 10.1292/jvms.11-0374. Epub 2012 Jan 30.
Subclinical infection of chicken anemia virus (CAV) at 4 to 6 weeks of age, after maternal antibodies have waned, is implicated in several field problems in broiler flocks. In order to understand the pathogenesis of subclinical infection with CAV, an immunopathological study of CAV-inoculated 4-week-old SPF chickens was performed. Sixty 4-week-old SPF chickens were equally divided into CAV and control groups. The CAV group was inoculated intramuscularly with the MSB1-TK5803 strain of CAV. Neither mortality nor anemia was detected in the CAV and control groups. In the CAV group, no signs were observed, except that some chickens were grossly smaller compared with the control group. Sporadic thymus lobes appeared to be reddening and atrophied. Within the first two weeks p.i. of CAV, there was a mild to moderate depletion of lymphocytes in the thymus cortex and spleen in some chickens. Moreover, lymphoid depletion of the bursa of Fabricius, proventriculus and cecal tonsils was observed. Hyperplastic lymphoid foci were observed in the liver, lungs, kidneys and heart at the 4th week p.i. of CAV. Immunohistochemically, a moderate lymphoid depletion of CD4(+)and CD8(+) T cells in the thymus cortex and spleen was observed in some chickens within two weeks p.i. of CAV. CAV inclusions and antigens were detected infrequently in the thymus cortex and spleen. It could be concluded that the immunosuppression in subclinical infection with CAV occurs as a result of reduction of cellular immunity.
在母源抗体消退后的4至6周龄时，鸡贫血病毒（CAV）的亚临床感染与肉鸡群中的几个实际问题有关。为了了解CAV亚临床感染的发病机制，对接种CAV的4周龄SPF鸡进行了免疫病理学研究。将60只4周龄的SPF鸡平均分为CAV组和对照组。CAV组肌肉注射CAV的MSB1-TK5803株。在CAV组和对照组中均未检测到死亡或贫血。在CAV组中，除了一些鸡与对照组相比明显更小外，未观察到任何体征。散在的胸腺叶似乎发红并萎缩。在接种CAV后的前两周内，一些鸡的胸腺皮质和脾脏中的淋巴细胞出现轻度至中度耗竭。此外，还观察到法氏囊、腺胃和盲肠扁桃体的淋巴组织耗竭。在接种CAV后的第4周，在肝脏、肺、肾和心脏中观察到增生性淋巴滤泡。免疫组织化学分析显示，在接种CAV后的两周内，一些鸡的胸腺皮质和脾脏中CD4(+)和CD8(+) T细胞出现中度淋巴组织耗竭。在胸腺皮质和脾脏中很少检测到CAV包涵体和抗原。可以得出结论，CAV亚临床感染中的免疫抑制是由于细胞免疫降低所致。
