Function And Molecular Mechanism Of Chicken Adipose Tissue Participating In Secondary Immune Response

The outbreak and epidemic of various diseases have brought serious economic losses to intensive poultry production.The efficacy of secondary immune response of vaccine is the key to determine the long-term ability of poultry to prevent and control diseases,and improving the ability of body secondary immune response is an effective means to improve and solve the level of vaccine prevention and control.In recent years,adipose tissue regulating immune function has become emerging research field.However,the function and mechanism of poultry adipose tissue in response to secondary immune response have not yet carried out.This study focused on the scientific issue of poultry adipose tissue participating in secondary immune response,and selected chicken as the research object to study the function and mechanism of adipose tissue responding to secondary immune response induced by Newcastle disease vaccine using secondary immune response chicken model,RNA-seq,bioinformatics analysis,and qRT-PCR.The results of the study were as follows:Firstly,chicken immunized with Newcastle disease Lasota strain vaccine was used to establish chicken models of primary immunization and secondary immunization.The results of transcriptome sequencing and small RNA sequencing showed that,in the ND immune group,there were 424 differential expression genes and 5 differential expression miRNAs(miR-206,miR-184-3p,miR-1684a-3p,miR-499-5p,and miR-205b)in chicken abdominal adipose tissue between 5 day post primary immunization(D group)and 5 day post secondary immunization(C group),indicating that these genes and miRNAs were closely related to the secondary immune response.In the control group,there were 474 differential expression genes and 6 differential expression miRNAs(miR-122-5p,miR-199 b,miR-122-3p,miR-1434,miR-7b,and miR-1682)in the abdominal adipose tissue between corresponding time point of primary immunization(B group)and corresponding time point of secondary immunization(A group),and the data of the control group could be used to eliminate the influence of the background development of chicken.Secondly,GO and KEGG function enrichment analysis results of RNA-seq data showed that chicken abdominal adipose tissue actively participated in secondary immune response on the fifth day,and the three aspects of DNA replication,cytoskeleton regulation,and lipid metabolism were the concentrated functional expression of adipose tissue in response to secondary immune response.Among them,DNA replication and cytoskeleton regulation,as the regulatory functions of immune activation,had changed significantly.And the weakening of lipid metabolism was an effective strategy for secondary immunization,which was mainly reflected in the functional inhibition as four aspects,including fat biosynthesis and degradation,fatty acid biosynthesis and degradation,cholesterol biosynthesis,and steroid hormone biosynthesis.Finally,PPI analysis screened for nine hub proteins involved in the core function of secondary immune response,including cytoskeleton regulation-related proteins LDB3,MYOZ2,and TNNI2,DNA replication-related proteins MCM2,MCM4,and MCM5,and lipid metabolism-related proteins MSMO1,SQLE,and IDI1.Mi RNA-mRNA integration analysis showed that there was a close interaction network of "miRNA-mRNA" between differentially expression miRNAs and differentially expression genes,in which "miR-206/miR-499-5p-NR4A3/MSMO1" pathway was the possible key molecular regulatory mechanism for adipose tissue participating in secondary immune response.In this study,the functional changes and molecular mechanisms of chicken abdominal adipose tissue participating in secondary immune response were explored at the molecular level,chicken adipose tissue actively responded to secondary immune response by immune activation and lipid metabolism were found for the first time,and the weakening of lipid metabolism was a unique strategy to regulate secondary immune response.In addition,the targeted interaction networks "miRNAs-mRNAs" between differentially expression miRNAs and differentially expression genes were the key mechanisms to regulate secondary immune response of adipose tissue.This study provides new insights for improving the effect of secondary immune response in poultry,and contributes to further study on antiviral strategies.