Objective To observe the interferon-gamma; (IFN-gamma;), interleukin-2 (IL-2) levels of Th1 cytokine and IL-4、IL-10 levels of Th2 cytokine in serum and culture supernatants of splenic cells of the rats in the prevention of experimental autoimmune uveoretinitis（EAU）by oral tolerance. Methods 72 Lewis rats were randomly divided into EAU group，oral tolerance group (which including 10 mu;g、100 mu;g、1 mg、10 mg of S antigen group respectively) and control group，12 rats in each group. The animal model of EAU was induced by immunization with S antigen（50 mu;g）and Freundrsquo;s complete adjuvant. Oral tolerance 10 mu;g、100 mu;g、1 mg and 10 mg group were fed with 1 ml mixture of 10 mu;g、100 mu;g、1 mg、10 mg S antigen and 1 mg trypsin inhibitor respectively by intubation，once the other day，totally 7 times，and then induced EAU according to above methods；control group was fed with 1 ml mixture of phosphate buffered saline and 1 mg trypsin inhibitor，once the other day，totally 7 times，and then induced EAU. The clinical manifestation of EAU in the eye were recorded,the eyeballs were enucleated at the peak of EAU，followed by pathological grading. Meanwhile the serum was colleced; splentic cells were separated and cultured to collect the supernatant. Cytokine levels of IFN-gamma;, IL-2, IL-4 and IL-10 in serum, cultured supernatant of splenic cells were determined by enzyme-linked immunosorbent assay (ELISA). Results Compared with EAU and control group, the levels of IFN-gamma; and IL-2 (Th1 cytokine) in the serum in 100 mu;g and 1 mg group were decreased while the levels of IL4 and IL10 (Th2 cytokine) were increased，the differences were statistically significant（F=51.9, 68.8, 35.7,7.5,P＜0.01). Compared the levels of Th1 and Th2 cytokines in the serum in 10 mu;g, 10 mg group with EAU and control group, the differences were not statistically significant. In 100 mu;g、1 mg group, the levels of IFN-gamma; and IL-2 (Th1 cytokine) in the culture supernatant of splenic cells were decreased while the levels of IL-4 and IL-10 (Th2 cytokine) were increased, compared with EAU and control group, the differences were statistically significant（F=57.1,15.6,33.1,167.7, P＜0.01）. Compared the levels of Th1 and Th2 cytokine in the culture supernatant of splenic cells in 10 mu;g、10 mg groups with EAU and control group, the difference are not statistically significant. Conclusions In the process to prevent EAU by oral intake, the levels of IFN-gamma; and IL-2 (Th1 cytokine ) were decrease while the levels of IL-4 and IL-10 (Th2 cytokine). Oral administration with too high or low dose of the antigen can not prevent EAU as well as the cytokine levels do not change obviously. Cytokines has played an important role in the prevention of EAU.
Objective To observe the efficacy of the anti-tumor necrosis factor-alpha; monoclonal antibody (TNF-alpha; MCAb) in the treatment of experimental autoimmune uveoretinitis (EAU). Methods EAU animal models were induced by interphotoreceptor retinoid-binding protein (IRBP) R16 peptide with immunization. The rats were divided into 2 groups according to the injection times. TNF-alpha; MCAb was administered intravenously on day 6 or 4, 6 and 8 post-immunization respectively, and then to observe the clinical expression by slit-lamp microscope. Meanwhile, take the rats which did not accept TNF-alpha; MCAb as control group. Delayed type hypersensitivity (DTH) responses were measured on day 13 post-immunization of IRBP R16; the rats were killed on day 14 post-immunization of IRBP R16, and then enucleated the eyes for histopathological examination. To detect the cytokine level of IFN-gamma;, IL-4 in serum and IFN-gamma; in aqueous humor by enzyme-liked immunosorbent assay (ELISA) on day 14 post-injection. The hyperplasia responses of antigen specific lymphocyte of draining lymph node cells were detected. Results The TNF-alpha; MCAb group had mitigated ocular inflammation and decreased pathological grades compared with the control group; the IFN-gamma; concentrations in aqueous humor and serum were decreased, IL-4 was increased in serum; DTH responses were decreased; the hyperplasia responses of draining lymphocytes to IRBP R16 peptide were decreased, all the differences were statistically significant (P＜0.01). The rats accepted TNF-alpha; MCAb thrice had much better curative effect than the rats injected once (P＜0.05). Conclusions Injection of TNF-alpha; MCAb can inhibit ocular inflammation and specific immune cells of EAU remarkably and change the Th1/Th2 balance. Many times injections of TNF-alpha; MCAb were more effective than once.