Influence Of REV Infection On The Expression Of Apoptosis-related Factors In Immune Organs And CEF Of SPF Chickens

Avian reticuloendotheliosis virus(REV)can induce tumorigenesis and immunosuppression and other representative characteristics of avian reticuloendotheliosis(RE),which is currently a major threat to the poultry industry.Exploring detailed REV pathogenic mechanisms such as immunosuppression helps maintain poultry industry and purify the poultry breeding environment.In this study,1-day-old SPF chickens and chicken embryo fibroblasts(CEF)were used as experimental subjects.The objectives of the experiment were divided into REV infection group and control group random Ly.The chickens in both groups were injected intraperitoneally.The chickens in the infection group were injected with REV infection and the control group were injected with the same amount of avian saline(aseptic).The experiments were carried out on the 1st,3rd,7th,14 th and 21 st day after REV infection.The changes of number of apoptosis in immune organs and CEF cells of chickens were detected by flow cytometry and Anexin V-FITC/PI double staining,and the expression of Caspase-3 and Caspase-8 m RNA in immune organs of chickens infected with REV was detected by RT-PCR technique.The contents of Caspase-3 and Caspase-8 protein were detected by Western Blot.CEF was prepared from 9 embryonic SPF chicken embryos and divided into REV infection group(I)and control group(C).In the REV infection group,CEF was infected with 150 ?L REV solution at 16 h after preparation,and the control group was treated with 150 ?L serum-free DMEM culture solution at 16 h after cell preparation.CEFs were collected at 6,12,24,48,and 72 h after REV infection,and using the same method as the SPF chickens detection index above,the dynamic changes of apoptosis and Caspase-3 and Caspase-8 m RNA expression and protein content were systematically detected,the main results are as follows:(1)On the 1st and 7th day after REV infection of 1 day old SPF chick ens,the percentage of thymocyte lymphocyte apoptosis was extremely significant(P<0.01)higher than control chickens;the percentage of spleen and bursa lymphocyte apoptosis were the significantly higher(P<0.01)than the control chickens after 1-7 days and 1-3 days infection REV respectively;other times were no significant difference(P>0.05).(2)After CEF infection of REV,the apoptosis was significantly higher at 6h,24 h and 72h(P<0.01)than control cells,and other times were no significant difference(P>0.05).(3)After REV infection in 1 day old SPF chickens,the expression of Capase-3 m RNA in thymus was significantly higher at 1-3 days and 14 days(P<0.05)than in control chickens,while Caspase-8 m RNA expression was significantly(P<0.05)or extremely significant(P<0.01)higher than control group at 1-3 days,which was significantly lower(P<0.05)on the 14 th day than the control chickens;the expression of Capase-3 m RNA in the spleen was significant at 1-7 days(P<0.05)or extremely significant(P<0.01)was higher than control chickens,while the expression of Caspase-8 m RNA was significantly increased at 1-3 days(P<0.01);The expression of Capase-3 m RNA in bursa of Fabricius was significantly higher at 1-3 days and 14-21 days(P<0.05 or P<0.01)than in control chickens.Caspase-8 m RNA expression was on day 3 and 14-21 that significant(P<0.05)or extremely significant(P<0.01)increased,and no statistical difference was found at other times(P>0.05).(4)After CEF infection of REV,the expression levels of Caspase-3 and Caspase-8 m RNA in the cells were significantly increased or extremely significant at 12-72 h and 6-72 h,respectively(P<0.05 or P<0.01);other times were no Significant difference found(P>0.05).(5)The content of Caspase-3 and Caspase-8 in thymus of REF infected 1 day old SPF chickens was significantly higher at 3-14 days(P<0.05 or P<0.01)than in control chickens;The content of Caspase-8 protein and Caspase-3 protein in spleen was significantly higher than that of the control chickens at 1-3 days and 3 days(P<0.05 or P<0.01).The protein contents of Caspase-3 and Caspase-8 in bursa of Fabricius were significantly or extremely significant(P<0.05 or P<0.01)higher than control group at day 1?7 and 1-3 days,respectively.There was no statistical difference at other times(P>0.05).(6)The protein content of Caspase-3 and Caspase-8 in the cells after REV infection was significantly higher than that in the control group at 12-48 h and 6-24 h,respectively(P<0.01).There were no statistical differences at other times(P>0.05).In this study,the relationship between apoptosis and REV infection was detected and discussed comprehensively and systematically,and then the immunosuppression caused by REV infection was further expounded,which provided a very important scientific experimental basis for exploring the pathogenesis of REV and the prevention and treatment of RE.