The Role Of IL-33 In Experimental Autoimmune Encephalomyelitis

Background: Interleukin-33(IL-33),a member of the IL1 cytokine family,is mainly associated with the induction of T-helper type 2(Th2)immune response through its receptor,ST2.IL-33 was identified as a nuclear protein highly expressed in high endothelial venules(HEV).Several immune cell types express IL-33,such as macrophages and dendritic cells,as do non-immune cells,such as endothelial cells,epithelial cells,fibroblasts and astrocytes.IL-33 is thought to be released along with the necrosis of these cells.IL-33 can induce different types of inflammation,and this process depends on the type of cells involved in the reaction.ST2 receptors are expressed in many kinds of cells,especially in Th2 cells and mast cells.IL-33 binds to the ST2 receptor on the surface of Th2 cells and then induces secretion of IL-4 and IL-1;Mast cells stimulated by IL-33 secrete IL-4,IL-5 and IL-6.IL-33 involved in the development and progression of many diseases,including asthma,inflammatory bowel disease,rheumatoid arthritis and central nervous system diseases.We mainly study the central nervous system diseases such as Experimental Autoimmune Encephalomyelitis(EAE).In order to gain a better understanding of the role of IL-33/ST2 in EAE,we establishment IL-33-/-and ST2+/-gene knockout mice strains in the first part of the research,and the gene and protein expression of the knockout mice were identified by PCR and sequencing.In the second part of the research,we examined the difference of lymphocytes in the tissues and organs between IL-33-/-and WT mice under the nature condition to understand the differences between the two different genotype mice;In the third part of the research,we examined the differences of the severity during the course of EAE disease disease and the lymphocyte in the tissue between the two different genotype mice.Objective: 1?To establish IL-33-/-and ST2+/-knockout mice strains.2?To examine the differences of lymphocytes in the tissues and organs betweem IL-33-/-and WT mice under the nature condition.3?To examine the difference in severity of disease between the two different genotype mice in the EAE and the distinction of lymphocyte in the tissue.Methods: 1?Identification of gene and protein expression in IL-33-/-knockout mouse by PCR,Gene Sequencing and Western blot;Gene expression of ST2 +/-knockout mice was identified by PCR.2?To understand the differences of lymphocytes in the spleen,lymph nodes,lungs,liver,peripheral blood and bone marrow of IL-33-/-and WT mice with the FCM under the nature condition.3?The spleen,lymph nodes and the central nervous tissue(brain and spinal cord)were examined by flow cytometry at the peak of the disease(day 19)in EAE mouse.Immunohistochemistry was for spinal cord frozen sections.Results: 1?We successfully breed and identified IL-33-/-and ST2 +/-knockout mice strains.2?There are some difference between two gene type of mice,such as the CD3 + CD4 + T lymphocytes and F4/80+ CD80+ cells in spleen,the CD3+CD4+T lymphocytes and F4/80+CD86+cells in lung.3?The severity of EAE disease in IL-33-/-mice was higher than that in WT mice with the characteristic of differences in clinical scores,the demyelination of spinal cord,infiltration of inflammatory cells and the expression of Th1 and Th17 cells in spleen,lymph nodes and central nervous system.