Purchase this article with an account.
B. Matta, P. Jha, P. S. Bora, N. S. Bora; Intravenous Administration of Melanin Associated Antigen Inhibits Experimental Autoimmune Anterior Uveitis (EAAU). Invest. Ophthalmol. Vis. Sci. 2007;48(13):5210.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To inhibit EAAU by inducing antigen specific tolerance and to investigate the underlying mechanism(s) of suppression.
EAAU was induced in Lewis rats by melanin associated antigen (MAA). Different doses of MAA were administered intravenously (iv), intranasally and orally to induce tolerance. Animals were sacrificed at the peak of EAAU and mixed lymphocytes harvested from the eye and the popliteal lymph nodes were cultured in the presence and the absence of MAA. Supernatant and non-adherent T cells were used in the ELISA and RT-PCR respectively for IFN-γ, TNF-α, IL-2, IL-4 and IL-10. Mixed lymphocytes harvested at the onset of EAAU were stained with anti-CD4 and anti-CD25 for flow cytometry. CFSE stained non adherent T cells from LN were analyzed for in vitro proliferative response. For in vivo proliferation, CFSE stained mixed lymphocytes were injected into naïve Lewis rats and CFSE+ve cells were analyzed with flow cytometry. For adoptive transfer of protection, T cells obtained from the popliteal lymph nodes of tolerized and non-tolerized Lewis rats were injected into naïve syngenic animals 24 h before immunization.
Only intravenous administration of MAA inhibited the induction of EAAU. This inhibition was dose dependent. ELISA and RT-PCR analysis revealed that the expression of IFN-γ, TNF-α and IL-2 were dramatically reduced while IL-4 and IL-10 levels were upregulated in non adherent T cells harvested from tolerized rats compared to non-tolerized animals. CD4+ CD25+ T regulatory cells were increased in the LN of tolerized animals compared to non-tolerized rats. In vivo and in vitro assays revealed that cell proliferation in tolerized animals was significantly lower than that observed in non-tolerized rats. Interestingly, protection was transferred to naïve syngenic animals by the adoptive transfer of tolerized T cells.
Our data demonstrated that multiple mechanisms are involved in tolerance induction in EAAU. Our results further suggested that IL-2 levels are reduced due to CD4+ CD25+ regulatory T cells leading to reduced proliferative T cell response in the tolerized animals.
This PDF is available to Subscribers Only