Molecular Characterization,Expression And Functional Analysis Of Chicken STING

The innate immune system,which carried at birth.And the first step to boost innate immune system is for pattern recognition receptor(PRR)to recognize pathogen-associated molecular pattern(PAMP),which represents the body's first line of defense.Ever since 2008,a series of researches regarding STING(Stimulator of interferon genes)also known as MITA?ERIS and MPYS boost the innate immune system in host cell had gained lots of interests.These researches has shown that STING is the adaptor molecular that can sense the viruses' nuclear acid.So far,research of STING is mainly in mammals such as human and mouse,study about STING function in birds is rarely seen.In the current study,we cloned and analyzed the mRNA of STING,function and domainwere compared between chicken STING and other animals' SITNG.Studing the STING gene in 4 varieties of chicken using SNP analysis.Then we profiled the expression pattern of chSTING by qRT-PCR in 11 organs,including heart,liver,lung,spleen,bursa of Fabricius,thymus gland.Then we treated specific pathogen free(SPF)chicken with Newcastle disease virus(NDV)and detected the expression level of chSTING and genes associate with STING pathway.Further more,we treated chicken embryonic fibroblast(CEFs)with NDV?Poly(dA:dT)and Poly(I:C),and detected the expression levels of chSTING and IRF7,IFN?,IFN?.Main results from our experiment are:(1)Full length chSTING gene's transcript is 1341bp,encoding a protein of 379 amino acid.Multi sequence comparation revealed that chSTING has high identity with other mammals and birds(Birds 60%,mammals 40%).(2)ChSTING gene-based SNP analysis in four different varieties of chicken(30 chickens for each variety),the we discovered that high gene polymorphism and degree of breeding in lohmann brown laying hens.(3)ChSTING was expressed in variety of organs and tissues,and the highest level is in immune related organ such as spleen,bursa of fabricius and thymus gland.And lowest level in skeleton muscle such as breast muscle and leg muscle.(4)After infected with NDV,chSTING expression level risen significantly in spleen,bursa of Fabricius and thymus gland.(5)After infected CEF with NDV,expression levels of chSTING?IRF7?IFNa and IFN? risen significantly.And this trend is positively correlate with the MOI of NDV.(6)After transfected CEF with Poly(dA:dT),expression levels of chSTING?IRF7?IFN? and IFN? risen significantly.Expression levels of those gene increased with time at Poly(dA:dT)= 2?g/ml which is the optimum concentration.(7)After transfected CEF with Poly(I:C),expression levels of chSTING?IRF7?IFNa and IFN? risen significantly.When the Poly(I:C)=1?g/ml,expression level of chSTING gene rise significantly in different time points,levels ofgene expression IRF7?IFN? and IFN? had risen firstly then decreased significantly.