[The suppression of the experimental autoimmune uveoretinitis with retinal S antigens by intranasal tolerance...

The aim was to investigate the suppression of rat experimental autoimmune uveoretinitis( EAU) by induced immune tolerance via intranasal administration of retinal S antigens.

The bovine S antigen was purified from bovine retina by salt precipitation and ionic exchange chromatography, the female Lewis rats were used to induce immune tolerance by intranasal administration with purified bovine retinal S antigens and then the rats were used to produce the EAU model by retinal S antigens challenge. The rate of EAU occurrence, the clinical and histological scores, the skin delayed-type hypersensitivity and lymphocyte proliferation stimulated by retinal S antigen and concanavalin A were recorded. The adjunct effect of cyclophosphamide on tolerance induction was observed.

After intranasal administration of retinal S antigens, EAU was induced in two of eight ( 25% ) rats in tolerant group, sis of six (100%) rats in control group , the difference of EAU induction rate was significant in tolerant group compared with control (P = 0. 0097) . The average onset time in tolerant group were 16. 5 days, the control group was 10. 3 days, the difference was significant ( F = 26. 32, P = 0. 000; q = 9. 723, P <0. 01). The average clinical scores of EAU in tolerant group were 0. 89, the control group was 3. 94, the difference was significant( F = 12. 48 ,P = 0. 000; q = 7. 904, P < 0. 01 ). The average histological scores of EAU in tolerant group were 1. 21, the control group was 4. 12, the difference was significant( F = 11. 80, P = 0. 000; q = 7. 510,P <0. 01). The histological features in tolerant group were iris blood vessels slightly dilation, few exudates in anterior chamber and vitreous cavity; there were slighter retina swallow and the photoreceptors damages in the tolerant group. The skin delayed-type hypersensitivity and the proliferative responses of lymphocytes stimulated by S antigen and concanavalin A in tolerant group were slighter than that in the control group. Intraperitoneal injection of cyclophosphamide enhanced the effect of immune tolerance slightly. Only intraperitoneal injection of cyclophosphamide did not diminish the severity of the rat EAU.

The intranasal induced tolerance by retinal S antigens can suppress effectively the prevalence of rat experimental autoimmune uveoretinitis induced by retinal S antigens.