番鸭呼肠孤病毒和H9 亚型禽流感病毒共感染对番鸭胸腺免疫抑制作用

Immunosuppression effect of co-infection with MDRV and H9 AIV on thymus in muscovy ducks

摘要:

摘要:【目的】探讨番鸭呼肠孤病毒(muscovy duck reovirus，MDRV) 和H9 亚型禽流感病毒(H9 avian influenza virus，AIV) 共感染对番鸭胸腺免疫功能的影响。【方法】8 日龄番鸭人工感染MDRV 或/ 和H9 AIV，观察番鸭感染后发生率和死亡率、胸腺形态和显微结构变化，淋巴细胞增殖试验检测胸腺细胞增殖功能，RT-PCR检测MDRV 或H9 AIV 在番鸭胸腺的分布。【结果】H9 AIV 感染后番鸭发病率低，无死亡;不影响胸腺的发育，胸腺病理变化不明显，但能显著抑制胸腺淋巴细胞增殖反应。MDRV 单独感染番鸭生长迟缓，发病率80% ，死亡率50% ;胸腺萎缩，出现局限性坏死灶;对番鸭胸腺细胞增殖反应的有抑制作用，差异显著。共感染组番鸭生长迟缓，发病率90% ，死亡率70% ;胸腺萎缩，淋巴细胞减少，出现局限性坏死灶;对番鸭胸腺细胞增殖反应的有抑制作用，差异极显著。共感染组在病毒检出时间和检出率上均大于单一病毒感染组。【结论】H9AIV 感染对胸腺的免疫抑制作用较弱，MDRV 感染后对胸腺的免疫抑制作用较强，MDRV 与H9AIV 共感染在番鸭免疫反应抑制上有协同作用。

Abstract:

Abstract:［Objective］ To study the immunosuppression effect on the thymus of muscovy ducks after infected with muscovy duck reovirus (MDRV) and H9 influenza virus (AIV)．［Methods］ After 8-day-old birds were infected with MDRV or H9 AIV，or both，the morbidity and mortality were totaled，the morphology and ultra-structure of the thymus were observed，proliferation ability of thymus cell were detected and the virus distrubition were detected by RT-PCR．［Results］After H9 AIV infection，The morbidity was low (10%) and without death． No obvious pathological change was observed on the thymus，whereas the proliferation ability of thymus cell was obviously suppressed． After MDRV infection，The birds grew slow，the morbidity was 80% and mortality was 50% ． Thymus was atrophy appearing local necrosis and proliferation ability of thymus cell was obviously suppressed． After co-infection with MDRV and H9 AIV，the birds grew even slower growth． The morbidity was 90% and mortality was 70% ． The thymus was atrophy appearing the lymphopenia and local necrosis and proliferation ability of thymus cell was also more obviously suppressed than MDRV infection． Virus duration time and detection ratio in co-infection group were more than in AIV and MDRV group． ［Conclusion］H9 AIV could lead to minor immunosuppression and MDRV could cause serious immuno-suppression． H9 AIV could aggravate the immunosuppression of thymus after co-infected with MDRV，so MDRV and H9 AIV infection had synergic effect on immunosuppression of the thymus．