Changes Of Oxidation-Antioxidation Function In Immune Organs Of SPF Chicks Infected With REV

Reticuloendotheliosis(RE)is an immunosuppressive neoplastic disease caused by Reticuloendotheliosis virus(REV),which threatens the development of poultry industry seriously.In this study,1-day-old SPF chicks were used to detect the contents of hydrogen peroxide(H2O2),malondialdehyde(MDA),total antioxidant capacity(T-AOC),superoxide dismutase(SOD)activity,contents of catalase(CAT),glutathione peroxidase 1(GPx1)and the mRNA expression of CAR and GPx1 in the immune organs(thymus,spleen,bursa of Fabricius)after infected with REV applying indirect ELISA and real-time fluorescence quantitative PCR.The aim of this study was to explain the pathogenesis of REV from the point of view of oxidative and antioxidative function.All of above can provide the basis for the prevention and treatment of RE.The results were as follows:(1)After infected with REV,the contents of H2O2 and MDA in immune organs of SPF chicks were higher than those of control group in various degrees.Among them,The contents of H2O2 in thymus,spleen and bursa of Fabricius were significantly higher than those of control group at 35 th day,28 th day and 21 st day post infection(PI)(P <0.05);The contents of MDA was significantly higher or extremely significant than those of control group at 28 th day,7-28 days and 21 st day PI(P <0.05 or P <0.01).The results indicated that REV could lead to oxidative substances increased in immune organs of chicks,lipid peroxidation response is enhanced,and the body was in the status of oxidative stress.(2)After infected with REV,the T-AOC and SOD activity in immune organs of SPF chicks were lower than those of control group at different levels.Among them,T-AOC of thymus,spleen and bursa of Fabricius were significantly lower or extremely significant than those of control group at 21-35 days,28-35 days and 35 th day PI(P <0.05 or P <0.01);SOD activity were significantly lower or extremely significant than those of control group at 14-28 days,14-21 days and 21-35 days PI(P <0.05 or P <0.01).The results showed that REV could significantly reduce the antioxidant function of immune organs in SPF chicks.(3)After infected with REV,the contents of CAT,GPx1 and gene expression in immune organs of SPF chicks were lower than those of control group in various degrees.Among them,the contents of CAT in thymus,spleen and bursa of Fabricius were significantly lower or extremely significant than those of control group at 14-28 days,28-35 days and 21 st day PI(P <0.05 or P<0.01);the contents of GPx1 in thymus,spleen and bursa of Fabricius were significantly lower or extremely significant than those of control group at 28 th day,14-21 days and 14 th day PI(P <0.05 or P <0.01);the expression of CAT m RNA in thymus and spleen were significantly lower than those of control group at 21-28 days PI(P <0.05);the expression of GPx1 mRNA in above immune organs were significantly lower or extremely significant than those in control group at 28-35 days,35th day and 28 th day PI(P <0.05 or P <0.01).The results indicated that REV could decrease CAT,GPx1 gene and protein expression,which can cause the capcity of remove peroxide activity decreased,the contents of antioxidant enzyme decreased and antioxidant function weakened.(4)After infected with REV,the organ index of thymus,spleen and bursa of Fabricius were significantly lower or extremely significant than those of control group at 28-35 days(P <0.05 or P<0.01).The results indicated that REV could reduce the immune organ index,cause immune organ atrophy and immunosuppression.