Effects Of Glucocorticoid To The Mechanisms Of Central Tolerance In SLE Model Mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. A great quantity of positive antinuclear antibody (ANA) was found in blood serum of the patients. SLE can be induced in some normal mice during a graft-vs-host reaction (GVHR), referred as SLE-like graft-vs-host disease (SLE-like GVHD). However, the exactly pathogenesis of this murine model is still unclear. It is important to reveal the pathogenesis of this autoallergic disease model so that we can extend the range of its application.The research is try to figure out the functions of central immune in GVHD induced SLE murine model and the effects of glucocorticoid to the functions.Part 1 The abnormities of central tolerance in SLE murine modelIn order to find the pathogenesis of SLE, GVHD induced SLE murine model was detected to investigate the central tolerance disorder in SLE murine model.1. The establishment of SLE model miceWe made (Balb/c×C57BL/6) F1 mice by 6-8 weeks-old Balb/c and C57BL/6 mice. With the injection of T cells separated from spleens, thymi and lymph nodes of Balb/c mice to F1 mice, we estiblished the SLE models.2. The abnormity of SLE model mice1) General status changes4 week after inducing, the model group got the phenomena of loosing hairs, particulalyr in snouts, and activity reduced. The phenomena in female mice were more obviously than male mice.2) Changes of urine proteinUrine protein in the model group were ++~+++, in the control group were (-). This result implied that the functional changes had happened in kidney of the model group.3) The detection of ANA in serum The result was that all the model mice's ANA in serum were positive. There were no positive results in the control group and the negative control. The model mice had the affectability of SLE, as they had the production of ANA.4) Detection of immunocomplex in kidneyAll kidney slices of the model group showed various degrees of green fluorescence. There were no positive result in the control group and the negative control. This result demonstrated that the immunocomplex deposited in glomcrulus ana most were IgG.5) Pathological changes in kidneys and salivary glandsGlomcrulus hyperplasia, thickening basilemma and lots of inflammatory cells infiltration were found in the kidney slice of the model group mice. And in the mean time, it showed that there were inflammatory cells infiltrated in salivary glands. However, glomcrulus and salivary glands were normal in the control group. 3. Detection of promiscuous gene expressionThe thymic promiscuous gene expression of CTSL and SP2 declines in the model group. Obvious sialadenitis and general symptoms in SLE model mice may be relevant with this phenomenon.4. Quantity and function changes of CD4~+CD25~+TregThe quantities of CD4~+CD25~+Treg and the ratio of Treg/CD4~+T decrease slightly. Anyway, the model group still has the tendency of descending. This may result from the immature CD4~+CD25~+Treg in thymi.The expression of CTLA-4, GITR and Foxp3 declined in model group, especially Foxp3. It may indicate that the function of CD4~+CD25~+Treg degraded obviously.Part 2 Effects of glucocorticoid therapy to the central tolerance in SLE mice modelIn order to find the mechanism of the glucocorticoid therapy, we tried to find the effects of glucocorticoid to SLE mice,1. SLE model mice with glucocorticoid therapy The F1 mice were divided into two groups randomly, the model group and the therapy group. The therapy group was injected with glucocorticoid. The model group was injected with NS.2. The abnormities of SLE model mice after glucocorticoid injection1) General status changes Less trichomadesis phenomenon was found in therapy group. New hairs were found in trichomadesis mice of the therapy group. However, the model group mice did not improved.2) Changes of urine protein Urine protein of the model group were ++~+++, and the counterpart of the therapy group mice were +~++.3) Detection of ANA in serumThe results were that both groups the ANA levels of serum were positive. The fluorescence intensity in the therapy group mice was less obviously than that in the model group. This is no positive result in the control group and the negative control group. The result is that glucocorticoid depressed the production of autoantibody.4) Detection of immunocomplex in kidneyBoth the model group mice and the therapy group mice had immunocomplex sedimentation. There were no positive results in the control group and the negative control group.5) Pathological changes of kidneys and salivary glandsThe symptoms in therapy group were improved by the application of glucocorticoid.3. Detection of promiscuous gene expressionThe promiscuous gene expression of CTSL and SP2 in the therapy group was higher than that in the model group. The thymic promiscuous gene expression has recovered by the therapy of glucocorticoid. Further researches are needed to get better therapeutic efficacies.4. Quantity and function alteration of CD4~+CD25~+TregThere was increase in the quantity of CD4~+ CD25~+Treg after the therapy. The expression of CTLA-4, GITR and Foxp3 recovered in the therapy group. The results showed that the function of CD4~+CD25~+Treg reinforced obviously. The symptoms of therapy group were controled by the application of glucocorticoid. Therefore glucocorticoid had effects to the function of thymus. According to the study, SLE model mice had central tolerance defects; and the central tolerance defects had relationship with thymic selection. After the therapy of glucocorticoid, the conditions of the mice were improved and there was an increase of thymic promiscuous gene expression in them. However, the dysfunction still exist; therefore, the application research of glucocorticoid is still needed to obtain better therapeutic efficacy.