番鸭呼肠孤病毒诱导免疫抑制机制的初步研究

以5日龄健康番鸭为研究对象,人工感染番鸭呼肠孤病毒(MDRV),采用组织化学和免疫学技术检测外周血淋巴细胞转化率,T淋巴细胞ANAE阳性率,IL-2和IL-6含量,脾和腔上囊中浆细胞数量的变化.结果显示,MDRV感染组番鸭外周血淋巴细胞转化率和T淋巴细胞ANAE阳性率均极显著低于对照组(P<0.01),腔上囊和脾中浆细胞数量在攻毒后第10～20 d显著或极显著低于对照组(P<0.05或P<0.01),血清中IL-2和IL-6含量在攻毒后第10 d均极显著低于对照组(P<0.01).结果表明,MDRV感染能较快且持久地降低机体细胞的免疫功能,破坏免疫器官中的浆细胞,影响体液免疫功能,还影响免疫分子IL-2和IL-6的形成,进一步干扰机体免疫功能的发挥,从而容易诱发继发感染,增加死亡率.

Mechanism of immunosuppression induced by Muscovy duck reovirus

Five day-old healthy Muscovy ducklings were infected experimentally with Muscovy duck reovirus(MDRV) dilution in experimental group and 0. 2 mL normal saline in control group by intramuscu-lar injection on leg, respectively, and the transformation rate of lymphocytes in peripheral bipod of the ducklings were detected by MTT, the T-cell positive rate was detected by α-naphthyl acetate esterase (ANAE) staining,the quantity of plasma cells in bursa of Fabricius and spleen was detected by the histo-chemical test,and the content of interleukin 2(IL-2) and IL-6 in the serum was detected by the radiation immunization method. The results showed that the lymphocytes transformation rate and T cells ANAE positive rate of the ducklings was significantly less than that of the control group(P<0. 01). The quantity of plasma cells in bursa of Fabricius and spleen in the experimental group was significantly or very signifi-cantly less than that of the control group(P<0. 05 or P<0. 01) on day 10 to 20 post-infection. And the concentration of IL-2 and IL-6 in the peripheral blood of ducklings in the experimental group was signifi-cantly less than that of the control group on day 10 after infection (P<0. 01). The results revealed that MDRV infection could degrade quickly cellular immunity function for a long time,damage the plasma cells in the bursa of Fabricius and spleen,and affect the humoral immunity function and the forming of IL-2 and IL-6,so the immunity function further reduced and ducks were easy to die by secondary infection.