The Function And Mechanism Of Costimulatory Molecules OX40/OX40L Expression In Immunological Pathogenesis Of B6. MRL-Fas^lpr/J Lupus Mice

Systemic Lupus Erythematosus is a comprehensive systemic autoimmune diseases,The characteristic is produce large amounts of autoantibodies to form immune complexes depositedin various tissues and organs to cause serious injury, accompanied by chronic inflammation,but the pathogenic mechanism is not clear. B6. MRL-Fas^lpr/J lupus mice is^lpr genemutation leading to Fas molecular defects, and thus give rise to the proliferation ofabnormal T cells, lymph node hyperplasia, splenomegaly, a large number of anti-DNAantibodies and glomerulonephritis characterized animal models of SLE, because of theonset of symptoms are similar with human SLE, B6. Fas lupus mice are widely used inthe research of SLE pathogenesis and progression of the disease.OX40/OX40L is a pair of important costimulatory molecules belonging to theTNFR/TNF superfamily, OX40mainly expressed on activated CD4⁺T cells and CD8⁺T cells, OX40L expressed on activated antigen-presenting cells, such as dendritic cells（DC）, B cells, the signal in T cell activation, proliferation and inhibition of apoptosisplays a crucial role. In recent years, the study found that the expression of OX40onCD4⁺T cells in the peripheral blood of patients with SLE significantly higher thanhealthy people, and found a large number of OX40L expression in kidney biopsies ofpatients with lupus nephritis detection, but the exactly mechanism is worth furtherexploration. Suggesting that OX40/OX40L play a important role of the occurrence anddevelopment of SLE.In this study, we set B6. Fas lupus mice as a SLE model, and analyzed theexpression of OX40/OX40L in the spleen T cells and antigen-presenting cells by flowcytometry, to explore the role of OX40signal in the pathogenesis of SLE with animaldisease models. PART â… : The expression of OX40/OX40L in the spleen of B6. MRL-Fas^lpr/Jlupus mice in different pathological stageObjective: To detect the expression of OX40/OX40L on CD4⁺and CD8⁺T cellsand OX40L on the CD11b⁺monocytes and CD19⁺B cells in the spleen of B6. Fas lupusmice, then analyze the correlation between the expression of OX40/OX40L and SLEonset.Methods: The experimental group is12B6. Fas lupus mice were divided intothree groups （12weeks,20weeks,28weeks） by weeks of age; the control group is12C57BL/6J mice, divided into three groups （12weeks,20weeks,28weeks） by the sameweeks of age. The expression of the OX40/OX40L on the T cells and antigen-presentingcells of B6. Fas lupus mice was detected by FACS. Proteinuria was evaluated byAlbustix dipstick. Kidney damage was detected by HE staining. IgG deposition byfluorescence staining. In addition, the use of immunohistochemistry in mouse kidneytissue expression of OX40and OX40L. Quantitative data were processed with statisticalsoftware SPSS13.0.Charts and graph were drawn with GraphPad Prism5.0. Thestatistical significance between groups was assessed by T test. The level of statisticalsignificance was established at p<0.05.Results:（1） In the experimental group, protein concentration of uria wereabnormally elevated with age increasing, while the mice in the control group always hadno proteinuria.（2）12week old mice in experimental group almost had no deposition ofIgG, the perivascular also no significant infiltration of lymphocytes, as the age increasedIgG deposition more obvious, and gradually increasing the number of infiltratinglymphocytes,28week old mice had largest deposition IgG, and the most seriouslymphocytic infiltration in the kidney perivascular, reached3level.（3） Compared withthe control group, the expression levels of OX40and OX40L on T cells and B cells in12week old lupus mice both had no significant change. The expression ofOX40/OX40L on CD4⁺T cells in20week old and28week old lupus mice weresignificantly upregulated, while the expression of OX40L on CD8⁺T cells alsoabnormol upregualted, but OX40on CD8⁺T cells had no significant change inexpression level. The expression of OX40and OX40L in the28week old lupus micewere higher than the20week old lupus mice.（4） Compared with the control group, theexpression levels of OX40and OX40L on APCs in12week old lupus mice both had no significant change. The expression of OX40L on APCs in20week old and28week oldlupus mice were significantly upregulated. The expression of OX40L in the28week oldlupus mice were higher than the20week old lupus mice.（5）There was noOX40/OX40L expression on control group and12-week-old lupus mice, whereas20-week-old B6. Fas Lupus mice kidney tissue showed significant expression of OX40and OX40L,28-week-old lupus mice expression even higher, and almost all of OX40and OX40L expressed in glomeruli and around the infiltrating lymphocytes.Conclusion: The age increased, the more kidney damage in lupus mice, OX40andOX40L were abnormally expressed on T cells and APCs in spleen, Show that level ofOX40/OX40L expression is closely related to the severity of the disease lupus,especially with kidney damage. Thus prompt OX40/OX40L co-stimulatory signals maybe involved in the process of SLE disease immune pathology, B cells and CD11b⁺cellsas antigen-presenting cells and T cells interact to pass OX40positive signal, andpromote abnormal T-cell activation, proliferation, and referral guide its long-termsurvival, an important part of the continuous activation of T cells is the SLE diseaseprogression; Further, B cells OX40L may pass reverse signal, resulting in B cellfunction hyperfunction abnormal activation, while in the activated T cell helpersecretion large number of autoantibodies, leading to the occurrence of lupusdevelopment. Therefore, targeting OX40/OX40L may provide new ideas for thediagnosis and treatment of SLEPART â…¡: The biological characteristics of OX40/OX40L expression in CD4⁺Tcells of B6. MRL-Fas^lpr/J lupus miceObjective: To detect the expression of CD25, PD-1ICOS and CXCR5on CD4⁺Tcells, and the expression of CD44and CD62L on CD4⁺T cells, Identification of thebiological characteristics of expression of OX40and OX40L CD4⁺T cell, preliminaryto explore the funtion and mechanism of OX40/OX40L expression in immunologicalpathogenesis of B6. MRL-Fas^lpr/J lupus mice.Method: B6. MRL-Fas^lpr/J lupus mice were selected as objects, the expression ofCD25、PD-1and ICOS on CD4⁺OX40⁺OX40L⁺、CD4⁺OX40⁺OX40L^－、CD4⁺OX40^－OX40L⁺、CD4⁺OX40^－OX40L^－four groups of cells were detected by FACS, and theexpression of CD44and CD62L on CD4⁺OX40⁺OX40L⁺, CD4⁺OX40⁺OX40L^－, CD4⁺OX40^－OX40L⁺four groups of cells were also detected by FACS. The association between OX40/OX40L expression changes and the clinical statistics were analyzedthrough statistical methods.Result:（1） Compared with other T cell subsets, on CD4⁺OX40⁺OX40L⁺andCD4⁺OX40⁺OX40L^－two groups of cells, CD25, PD-1and ICOS was high expression.（2） CD4⁺OX40⁺OX40L⁺and CD4⁺OX40⁺OX40L^－two cell groups is CD44highCD62Llow, CD4⁺OX40^－OX40L⁺is CD44high62Lhigh.（3）Compared with T cell that didnot express OX40and OX40L, the expression of IFN-gamma, IL-17onCD4⁺OX40⁺OX40L⁺,CD4⁺OX40⁺OX40L^－and CD4⁺OX40^－OX40L⁺three groupscells was decreased, especial on CD4⁺OX40⁺OX40L⁺and CD4⁺OX40⁺OX40L^－. IL-4was expressed at high levels, no significant downward.Conclusion: CD25was high expressed on CD4⁺T cells which only expressOX40⁺and co-express OX40and OX40L, indicating that these two groups of T cellsshowed abnormal activation state, while the expression of PD-1, ICOS and CXCR5, andit was CXCR5^highPD-1^highICOS^high, these two groups of T cells may be Tfh. These twogroup cells show effector memory T-cell phenotype, like Tfh phenotype characteristics.Then the CD4⁺T cells which only express OX40L show central memory T cellphenotype, these groups of cells may be different ways to participate in the pathologicalprocess of SLE. In addition, CD4⁺T cells only express OX40⁺and co-express OX40and OX40L show that decreased expression of IFN-gamma and IL-17, but IL-4wasexpressed at high levels, no significant downward, that match the cytokine secretioncharacteristics of Tfh. OX40and OX40L expression in Tfh may help to continue togrow, thereby contributing to the abnormal B cells secrete antibodies, play an importantrole in the pathogenesis of SLE immune.