Exploration Of Interleukin-17Producing Cells In Peripheral Blood Of Kawasaki Disease Mice

Background: Interleukin-17（IL-17） is a new subtype of cytokines, which differ fromknown families, it Is considered a inflammatory cytokines, secreted by Th17, NK,CD₈⁺lymphocytes, and neutrophils ect in body. IL-17and IL-17-producing cells exertvariousfunctions in host defense and pathological conditions of autoimmune disease.Kawasakidisease is an autoimmune disease, its pathogenesis is not clear. Lactobacillus casei cellwall extract（LCWE） ip into BALB/C mice to establish the animal model of KawasakiDisease. Detect IL-17-producing cells of different subgroup of lymphocytes, neutrophilsby flow cytometry,measure IL-17and INF-γ levels in plasma by ELISA,to make thefunction of IL-17clear in early stage of Kawasaki disease. Methods:There were50mice as experimental group and10mice as control group.LCWE was preparated anddiluted to0.8mg/ml.to inject i.p mice with PBS containing0.7ml LCWE,andmarked.Then collect blood and remove Cardiac tissues of each group before kill themon days18h,3d,5d,10d,28d. Detect IL-17-producing cells of different subgroup oflymphocytes, neutrophils by flow cytometry,measure IL-17and INF-γ levels in plasmaby ELISA.Hematoxylin-eosin（HE） staining under light microscope to observe changesof the Cardiac tissues. Results:1.Pathology: Cardiovascular inflammatory is the mainchanges of experimental group. coronary vascular is particularly serious.There are fewneutrophils infiltration in18h, neutrophils increase in3d,meantime fewlymphocytes,and a large number lymphocytes in5d,but the inflammatory cellsdecreased dramaticly in10d and it disappeared in28d.Meantime,there are inflammatorycells in the endocardial,epicardial and myocardial tissues,the myocardial cell evenswelling and increased eosinophilic staining cytoplasm.Contrast With the control groupdonot have inflammatory cell infiltration.2.Immunological parameters:CD3/Blood,CD₄⁺/CD₃⁺,CD₈⁺/CD₃⁺,CD₄⁺/CD₈⁺,PMN/Blood,CD₃⁺CD₆9⁺/CD₃⁺,IL-17+CD₄⁺,IL-17+CD₈⁺,IL-17+PMN,Il-17,INF-γ in plasma all have some changes in different group,somegroup compared with the control group were statistically significant.3.Statistical:Theplasma levels of IL-17have negatively correlate with CD3/Blood, CD₄⁺/CD₃⁺, CD₈⁺/CD₃⁺,IL-17+/CD₈⁺,P<0.05,have positive correlation with IL-17+CD₄⁺,INF-γ+CD₄⁺,PMN/Blood, P<0.05. IL-17+CD₄⁺with INF-γ+CD₄⁺and IL-17+CD₈⁺withINF-γ+CD₈⁺have positive correlation, P<0.05. IL-17with INF-γ have a positivecorrelation with INF-γ in plasma levels, P>0.05. The plasma levels of IL-17havenegatively correlation with IL-17+PMN, P>0.05.Conclusion:1. Lactobacillus caseicell wall extract（LCWE） can induce coronary arteritis,and this modle is regarded assucessful.The mechanism is super-antigen-induced activation and proliferation oflymphocytes.2.Activated lymphocytes produce large amounts of cytokines such asIL-17and,but there are two inhibite each other. Unbeliveable this phenomenon inducedimmune disorders of mice and coronary arteries impair.3.The expression of IL-17caused a strong expansion of neutrophils and chemotaxis,IL-17can mutual withneutrophils,that as IL-17-producing cells,to increase the host immunity,but if too strongcan led to damage of the body.