Residues 1-20 of IRBP and whole IRBP elicit different uveitogenic and immunological responses in interferon gamma deficient mice.

Experimental autoimmune uveoretinitis (EAU) is a T-cell-mediated autoimmune disease induced by immunization with uveitogenic retinal antigens, or by the adoptive transfer of uveitogenic T-cells of the Th-1-like phenotype. We have previously shown that IFN-gamma-deficient mice (GKO) on the C57BL/6 background are equally susceptible to interphotoreceptor retinoid binding protein (IRBP)-induced EAU as the wild type (WT). In the present study, we evaluated EAU induction in GKO mice by the newly described H-2(b)epitope contained in residues 1-20 of human IRBP, and compared it to the response to the whole IRBP molecule. Similarly to previous observations with IRBP-induced EAU, delayed type hypersensitivity (DTH) and lymphocyte proliferation responses were elevated in GKO mice, as was production of IL-5 and TNF-alpha. However, unlike the responses induced by whole IRBP, there was no detectable IL-10 production to the peptide. Histopathology on day 21 after immunization, revealed that both GKO and WT mice developed retinal lesions, including damage to the photoreceptor cell layer, vasculitis and inflammatory cellular infiltration, but disease scores were significantly higher in GKO, and retinal detachment was observed only in GKO mice. In contrast to the wild type, the cellular infiltrate in eyes of GKO mice contained a prominent component of eosinophils, although of lower proportion in peptide-induced than in IRBP-induced EAU. We conclude that the cytokine and inflammatory responses to human peptide 1-20 differ perceptibly from the responses to whole bovine IRBP, and may explain the elevated EAU scores of GKO mice compared to wild type.

Avichezer D ，Chan CC ，Silver PB ，Wiggert B ，Caspi RR ... -  《EXPERIMENTAL EYE RESEARCH》

IFN-gamma-deficient mice develop experimental autoimmune uveitis in the context of a deviant effector response.

Jones LS ，Rizzo LV ，Agarwal RK ，Tarrant TK ，Chan CC ，Wiggert B ，Caspi RR ... -  《JOURNAL OF IMMUNOLOGY》

Identification of a new epitope of human IRBP that induces autoimmune uveoretinitis in mice of the H-2b haplotype.

Avichezer D ，Silver PB ，Chan CC ，Wiggert B ，Caspi RR ... -  《INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE》

Endogenous IL-12 is required for induction and expression of experimental autoimmune uveitis.

Tarrant TK ，Silver PB ，Chan CC ，Wiggert B ，Caspi RR ... -  《JOURNAL OF IMMUNOLOGY》

The requirement for pertussis to induce EAU is strain-dependent: B10.RIII, but not B10.A mice, develop EAU and Th1 responses to IRBP without pertussis treatment.

PURPOSE:Experimental autoimmune uveoretinitis (EAU) in mice is an important model for elucidating basic mechanisms in autoimmune eye disease. The need for pertussis toxin (PTX) as an additional adjuvant to elicit EAU has limited the usefulness of this model in some types of studies by introducing a pleiotropic factor with confounding effects on the immune response. METHODS:In the present study the authors examined the ability of B10.RIII mice, the most susceptible strain known so far, to develop EAU in response to the retinal antigen, interphotoreceptor retinoid-binding protein (IRBP), and to a major uveitogenic epitope of IRBP, peptide (p)161-180, in the absence of PTX treatment. RESULTS:The data indicate that high disease scores in response to IRBP and p161-180 were found in B10.RIII mice, without the need for PTX as part of the immunization protocol. Unlike the B10.A strain in which appreciable disease did not develop without PTX, B10.RIII mice mounted a high IFN-gamma response to IRBP in the absence of PTX treatment. Interestingly, and unlike the effect with IRBP, in vitro recall response to p161-180 was low in IFN-gamma, despite good EAU scores. CONCLUSIONS:The data indicate that an important mechanism through which PTX facilitates induction of cell-mediated autoimmunity is by promoting a Th1 polarization of the immune response. The propensity of B10.RIII mice to mount a more polarized Th1 response to IRBP than other strains may contribute to their ability to develop EAU without pertussis adjuvant. Nevertheless, the induction of EAU by p161-180 in the context of a relatively limited IFN-gamma production indicates that non-Th1- and Th-related mechanisms are likely to act in concert to determine the outcome of disease.

Silver PB ，Chan CC ，Wiggert B ，Caspi RR ... -  《INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE》