Objective To observe the therapeutic effect of mensenchymal stem cells (MSCs) for experimental autoimmune uveitis (EAU). Methods MSCs were obtained from Wistar rats and selected by plastic adherence. Lewis rats were divided into treatment group and control group, six rats in each group. EAU models were induced by immunization with an emulsion (0.2 ml) containing 30 mu;g interphotoreceptor retinoid-binding protein derived peptide R16 and complete Freundprime;s adjuvant. The clinical manifestations of two groups were observed. Nine to 11 day after modeling, 1 ml MSCs suspension, which contained 5times;106 MSCs, were injected into the rats in treatment group via tail vein, and the rats in control group were given equal volume of phosphate buffer solution. Fifteen day after modeling, the eyes were collected to test the proportion of interferon gamma;, interleukin-17 and Foxp3 positive cells by flow cytometry. The clinical scores were analyzed by mixed linear model and statistical analysis of variance of repeated measurement data. The results of flow cytometry were analyzed using independent-sample t test. Results Six days after immunization, mild dilatation and congestion of iris vascular was observed. Nine days after immunization, mild muddy anterior chamber, myosis and absent pupillary reaction to light were observed. Twelve days after immunization, muddy anterior chamber, occlusion of pupil and dimmed or disappeared red reflex were observed, and then inflammation was slowly reduced. From 11 to 15 days after immunization, the clinical score of treatment group was lower than that in control group, the difference was statistically significant (t=2.42, 2.21, 4.16, 5.24, 4.03; P＜0.05). The results of flow cytometry showed that MSCs treatment could decrease the proportion of CD4＋T cells, Th1 cells and Th17 cells, increase the proportion of Treg cells. Conclusion MSCs treatment can ameliorate EAU, up-regulate the expression of Treg cells and down-regulate the expression of CD4＋T cells, Th1 cells and Th17 cells.
Objective To investigate the impact of bone marrow mesenchymal stem cell transplantation on a rat model of experimental autoimmune uveitis (EAU) and analyze its immune regulatory mechanisms in vivo.Methods Eighteen Lewis rats were randomly divided into three groups: model control group, intervention group and normal control group, six animals in each group. Human retinal S-antigen peptide (HS-AgP35, 1 mg/ml) was mixed and emulsified with complete Freundprime;s adjuvant and injected into hind foot pad of rats on the first and eighth day to establish the animal model of EAU. For bone marrow mesenchymal stem cell transplantation, 1 ml of cell suspension (2times;106 cells/ml) was injected into tail vein of the intervention group rats on the first day when the emulsified S-antigen was injected. EAU manifestation, pathological change and IFN-gamma; level were evaluated and compared among those three groups after two weeks. Results No abnormal signs were found in the eyes of rats in normal control group. The manifestation grading of the intervention group (two rats at grade 0, three rats at grade 0.5, one rat at grade one) was significantly different from the model control group (one rat at grade one, one rat at grade two, three rats at grade three, one rat at grade four) (P=0.015). The retina of rats in normal control group was ordinary under light microscope. The histopathologrical grading of the intervention group (one rat at grade 0, four rats at grade 0.5,one rat at grade one) and the model control group (four rats at grade three, two rats at grade four) was also statistically different (P＜0.01). Furthermore, the IFN-gamma; level in peripheral blood of the intervention group rats declined significantly compared to the model control group (t=9.0574, P=0.01). Conclusions Bone marrow mesenchymal stem cells can inhibit EAU significantly, possibly by lowering the level of IFN－gamma;, thereby reduce the severity of uveitis and improve the condition of uveitis in rats.
ObjectiveTo investigate the expression of costimulatory molecules( B7，CD28, and CTLA-4) of peripheral blood lymphocytes in patients with Behcet′s disease(BD).MethodsLymphocytes were obtained in 24 patients with BD and 20 healthy individuals, and the expression of CD80(B7-1), CD86(B7-2), CD28 and CTLA-4 on T and B cells were detected by direct three-color immunofluorescence flow cytometry.ResultsSignificantly increased expression of CTLA-4 on CD 4+ T cells[(3.18±1.18)%]was found in BD patients compared with that in controls[(1.73±0.66) %](t=－3.722,P＜0.01). The expression of CD86 on CD19+B cells was also significantly increased in BD patients[(4.49±1.73)%]compared with that in controls[(2.40±1.49) %] (t=-2.071,P＜0.05). No significant difference in the expression of the other costimulatory molecules was found.ConclusionsInteraction of B7 and CD28 on peripheral lymphocytes promote the occurrence of uveitis in BD patients. Intervention with these costimulatory signals may lead to a new prevention or treatment for uveitis patients.(Chin J Ocul Fundus Dis, 2003,19:357-359)
Acquired syphilis uveitis, due to lack of the characteristic features, presents with various types. The most common type is posterior uveitis and panuveitis, including chorioretinitis, retinal vasculitis, optic nerve retinitis. The diagnosis and assessment of response to treatment depends mainly on the serological diagnostic tests, including nontreponemal and treponemal test. Acquired syphilis uveitis often presents with manifestations similar to various types of uveitis, especially to autoimmune uveitis and other infectious uveitis, so differential diagnosis is important. The gold standard treatment for active syphilitic uveitis is penicillin G, or doxycycline if patient is allergy to penicillin. Clinically misdiagnosis and delayed treatment may result in irreversible visual impairment and severe systemic and eye complications. However such timely treatment always has a good prognosis.
ObjectiveTo observe the effects of exosomes derived from rat mesenchymal stem cells (MSC-exosomes) on the rat experimental autoimmune uveitis (EAU) model.MethodsTwelve Lewis rats were randomly divided into experimental group and control group by random number table, with 6 rats in each group. Rats in the experimental group were established with EAU model, 100 μl of MSC-exosomes (50 μg) were periocular injected on the 9th day after modeling while the control rats were injected with the same volume of phosphate buffer. At different time points after modeling, the retinal structure was observed by hematoxylin and eosin (HE) staining, and the clinical and pathological manifestations were evaluated. T cells from the two groups were analyzed by flow cytometry. Immunohistochemical staining was used to observe the expression of macrophage surface marker CD68. The effect of MSC-exosomes on T cells was measured by lymphocyte proliferation assays. And flow cytometry was used to detect Th1, Th17 and regulatory T cells Variety. Electroretinogram (ERG) was used to evaluate the retinal function. Data were compared between the two groups using the t test.ResultsHE staining showed that the retina structure of the experimental group was more complete than that of the control group on the 15th day after modeling. Immunohistochemical staining showed that the positive expression of CD68 in the experimental group was significantly less than that in the control group. On the 15th day after modeling, the retinal pathological score of the experimental group was lower than that of the control group. On the 9th to 13th day after modeling, compared to the control group, the average clinical scores of the retina in the experimental group were lower, and the difference was statistically significant (t=3.665, 3.21, 3.181, 4.121, 3.227; P＜0.01). The results of T cell proliferation assay showed that exosomes (1.0, 10.0 μg/ml) inhibited the proliferation of T cells under different concentrations of R16 (1, 10, 30 μg/ml), and the difference was statistically significant (F=11.630, 4.188, 6.011; P＜0.05). The results of flow cytometry showed that the number of Th1, Th17 and Treg cell subsets in the experimental group was decreased compared with the control group, and the difference was statistically significant (t=7.374, 4.525, 6.910; P＜0.01). There was no difference in the proportion of cells in the T cells and lymph nodes (t=1.126, 0.493, 0.178; P=0.286, 0.632, 0.862). The results of ERG showed that, compared with the control group, the amplitudes of 0.01, 3.0 cd/m2 a wave and b wave of the experiment group were all increased on the 15th day after modeling, and the differences were statistically significant (t=3.604, 4.178, 4.551, 2.566, P＜0.05).ConclusionsMSC-exosomes can reduce the clinical and pathological manifestations of EAU, protect retinal function, reduce ocular macrophage infiltration, down-regulate the proportion of inflammatory cells in the eye, and inhibit T cell proliferation.
The etiology of uveitis is complex and the clinical manifestations are varied. Diagnosis and treatment are often very difficult. Detailed medical history, thorough ocular examination and laboratory examination are important basis for diagnosis. In recent years, with the appearance of microincision vitrectomy surgery, it has been applied widely in the diagnosis and treatment of uveitis. It can confirm diagnosis, manage the fundus complications of uveitis, and has certain therapeutic effects. But it is worth emphasizing that the indications of vitrectomy must be strictly controlled. Suitable indications and surgical timing are the key to the effective diagnosis and treatment of uveitis.