The Effect Of Selenoprotein W On The Immunity Function Of Chickens

Selenium (Se) is recognized as an essential nutritional trace element for organisms. It plays avital part in normal physiology of a wide range of organisms, including birds. There have beenconsiderable evidences suggest that Se plays important roles in many aspects of health. Sedeficiency can to be correlated with the incidence of Keshan desease and Kaschin-Beck disease inhuman and white muscle disease of livertock. It was also found that Se is essential for the normalfunctioning of the immune system.Se is mainly present in several proteins, called selenoproteins.The biological functions of Se are mediated by selenoproteins. Selenoprotein W (SelW) is one kindof small selenoproteins SelW is present in various tissues examined in Se-supplemented animals.The levels are highest in muscle, spleen and brain in mammals.The expression of SelW isinfluenced by Se status and intake. But informations about the characteristics of avian SelW remainunkonwn, In this study, a reliable primary culture of chicken spleen lymphocyte was establishedwith the application of cell culture techniques. And then, chicken model having different level of Seand gene knockdown of SelW were obtained.The chicken immune organs (spleen, thymus, andbursa of Fabricius) and chicken spleen lymphocyte as a model for investigating the effects ofselenium or after gene knockdown of SelW on the expression levels of SelW, iNOS, COX-2,NF-κB, PTGE, BCl-2, Capase-3, Bax, P53, Bak-1, IL-1R, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12β,IL-17, INF-r and TNF-α mRNA in chicken immune organs and lymphocyte by using real timequantitative PCR (qPCR) and TUNEL technology.The results as follows:1. SelW mRNA expression of55d immune organs (spleen, thymus, and bursa of Fabricius)was increased in different level of Se (0.032、0.15、0.601、1.058、1.514、2.427mg/kg). SelW mRNAexpression was decreased in0.032mg/kg Se level. Chicken spleen lymphocyte were cultured fordifferent Se level（10-8、10-7�'�10-6M Se）can effect SelW mRNA expression. Suggest that Se canregulate SelW mRNA expression in immune organs.2. In this study, a high transfection was observed in primary cultured chicken spleenlymphocyte24h after the Stealth RNA (S-RNA) transfection, Suggest that gene knockdown ofSelW for primary cultured chicken spleen lymphocyte model was obtained. Producing thefoundation for further research for SelW3. Lack of Se,the expression of IL-1β, IL-6, IL-12β, IL-17, TNF-α mRNA was increased. IL-2,IL-4, IL-10, INF-r mRNA expression was decreased. After gene knockdown of SelW, IL-1R、IL-6、IL-12β、TNF-αmRNA expression was increased. IL-2、IL-4、IL-10、INF-γmRNA expression wasdecreased. Suggest that SelW can regulate above cytokine mRNA expression,and then effectimmune function.. 4. Lack of Se, Apoptotic cell death was increased, the expression of Bcl-2mRNA level wasdown-regulated. Bak-1、caspase-3、Bax mRNA were up-regulated. After gene knockdown of SelW,the expression of Bcl-2mRNA level were down-regulated. Bak-1、caspase-3、Bax mRNA wereup-regulated. Suggest that SelW can regulate above cytokine mRNA expression,and then suppressimmune function.4. We found that the different level of Se, and chicken spleen lymphocyte were cultured fordifferent time in vitro, and after gene knockdown of SelW, resulted in a markedly increase insensitivity to H2O2-induced apoptotic cell death in AO/EB and TUNEL assays. then effect BCl-2,Capase-3, Bax, P53, Bak-1mRNA expression of immune organs (spleen, thymus, and bursa ofFabricius) and chicken spleen lymphocyte. Suggest that SelW is the ong of mechanisms ofeffection of immune function.5. The different level of Se, and chicken spleen lymphocyte were cultured for different time invitro, and after gene knockdown of SelW, effect iNOS, COX-2, NF-κB, PTGE mRNA expressionof immune organs (spleen, thymus, and bursa of Fabricius) and chicken spleen lymphocyte.Suggest that SelW effect immune function by the way of inflammatory pathway.In all, decreasing the expression of SelW mRNA, the mRNA expression of cytokine can beregulated a, and apoptosis was induced by the pathway of Bcl-2、Bak-1、caspase-3、Bax andP53,and increasing the expression of inflammation gene, induce decreasing of immune function.Suggest that SelW effect the regulation of immune function.