Study On Cell Apoptosis And Immunological Function Of Muscovy Duck Infected With Muscovy Duck Reovirus

Reovirus disease is acute infectious disease with the main pathological characteristics of a number off-white necrosis dot appeared at liver and spleen. It is commonly known as Muscovy duck disease named "white spot disease," "Flower liver disease." Previous studies have shown that this virus not only can induce Muscovy duck immunosuppression while they are infected, but also can induce apoptosis of its related organ.Our study is about the influence of Hericium erinaceus polysaccharide work at the aspect of cell apoptosis and immunological function of Muscovy duck that infected Muscovy Duck Reovirus.120 healthy young Muscovy ducks were divided into A, B, C, D ,E and F groups (20 ducks per group). These test groups and a blank group were raised in separate rooms. At 1-day-old, the A, B, and C groups were subjected to high, medium, and low doses of Hericium Erinaceus Polysaccharides (HEP), (add volume is 300mg/L,200mg/L,100mg/L);respectively, by adding HEP in their drinking water; group D is the cohabitation group without HEP treatment; group E is the Hericium erinaceus polysaccharide control group ; group F is the control group;. 20 One-day old Muscovy Ducks were infected with Museovy Duck Reovirus by intramuscular injection .After three days,then the entire experimental group ducks were infected by cohabite infective test. Histopathological changes,prevention apoptosis and the expression of death factor Fas-L of infected tissues were studied at 2d,6d,9d and 12d after infeetion,using hispathological methods,in-situ end labeling teehnique and immunohistochemistry methods.the result as follows:Then clinical symptoms changes were monitored over a period of several days after infeetion. Our results show that HEP can significantly delay the disease and reduce mortality.The characteristic pathologic changes of infeeted Muscovy ducks were gray-white spotty necrosis on the surface and parenchyma of liver and spleen,but the HEP groups had not seen the obvious necrosis The histopathological changes showed that various degrees of degeneration,necrosis,hyPeremia,and infiltration by lymphoeytes and maerophages in the fociand Perivaseular regions occurred in many organs;The lymphocytes of immune-organs Such as spleen,bursa of fabricius and thymus appeared necrosis and decreased in number,but the HEP groups were less serious. For instance,the extent of Lymphocyte infiltration around the liver veins of the HEP groups is significantly lesser in comparison to the virus control group. The study results of HEP groups show that the volume of splenic corpuscles is increased and the number of spleen cells are more numerous than the virus control group also. As well the number of lymphocyte is increased.The result of TUNEL staining revealed that a large number of positive cells present in many organ tissues,which showed that Muscovy Duck Reovirus can induced varying degreed apoptosis in the liver, spleen, thymus and bursa of fabricius. Compared with virus group , treatment group Muscovy apoptosis appeared earlier .That is the HEP groups promoted apoptosis in earlier period, refrained apoptosis in advanced stage . The Apoptosis of virus control group showed a certain appearance of dispersed distribution,while the apoptosis of HEP groups showed an appearance of some clusters apoptotic cells. This phenomenon indicates that the pattern of apoptosis may prevent virus from diffusing among cells or even is conducive to eleminate virus.The finding was reported for the first time in China.The result of immunohistochemical staining of death factor Fas-L showed that, the changes of Fas-L expression were highly correlated with the level of apoptotic index. The mechanism of apoptosis induced by Muscovy Duck Reovirus is closely related with Fas-L.The positive cells of Fas-L were observed in liver, spleen, thymus and bursa of fabricius. However, with the virus group, the HEP groups revealed that a smaller number of Fas-L positive cells in later stage. It showed that the HEP groups can prevent liver and immune organs of excessive apoptosis in the in advanced stage. The experiment also used the same method, Draw off blood from the heart of 10 ducks in each group after infection 12 days. Separated the serum,detecting the biochemical indicators of infection Muscovy. The result showed that the HEP groups can improve the immunization levels and antioxidant index. The HEP groups had protective effects on the liver,spleen,thymus and bursa of fabricius.