IRBP (1-20), human

IRBP (1-20), human is the 1-20 amino acid fragment of the optical interreceptor retinoid binding protein (IRBP). IRBP is a 140 kda glycoprotein found in the photoreceptor matrix between the neural retina and the retinal pigment epithelium. Human IRBP peptides 1-20 contain a major epitope of the H-2b haplotype. IRBP(1-20) immunity induces t cell-mediated experimental autoimmune uveoretinitis (EAU) disease[1,2].

Female C57BL/6J mice induced by IRBP (1-20), human successfully showed eau phenotype[3,5]. The consequences of IRBP deficiency on the T-cell repertoire were also investigated. IRBP+/+, IRBP+/- and IRBP-/- mice on the C57BL/6 background were immunized with IRBP or with a pathogenic epitope, IRBP (1-20), human peptide in adjuvant, and were evaluated for disease severity and immunological responses. C57BL/6 IRBP-/- mice were completely resistant to EAU and EAP, and had enhanced immunological responses to IRBP and to its pathogenic peptide 1-20, as compared to their IRBP+/+ counterparts. IRBP-/- mice exhibited an altered IRBP epitope recognition[4].

References:
[1]. Avichezer D, Chan CC,et,al. Residues 1-20 of IRBP and whole IRBP elicit different uveitogenic and immunological responses in interferon gamma deficient mice. Exp Eye Res. 2000 Aug;71(2):111-8. doi: 10.1006/exer.2000.0860. PMID: 10930316.
[2]. Avichezer D, Silver PB,et,al. Identification of a new epitope of human IRBP that induces autoimmune uveoretinitis in mice of the H-2b haplotype. Invest Ophthalmol Vis Sci. 2000 Jan;41(1):127-31. PMID: 10634611.
[3]. Meng X, Fang S, et,al. Preventive effect of chrysin on experimental autoimmune uveitis triggered by injection of human IRBP peptide 1-20 in mice. Cell Mol Immunol. 2017 Aug;14(8):702-711. doi: 10.1038/cmi.2015.107. Epub 2016 Mar 21. PMID: 26996065; PMCID: PMC5549600.
[4]. Avichezer D, Liou GI, et,al. Interphotoreceptor retinoid-binding protein (IRBP)-deficient C57BL/6 mice have enhanced immunological and immunopathogenic responses to IRBP and an altered recognition of IRBP epitopes. J Autoimmun. 2003 Nov;21(3):185-94. doi: 10.1016/j.jaut.2003.08.004. PMID: 14599843.
[5]. Tajiri N, Kato T, et,al. The protective function of invariant natural killer T cells in the relapse of experimental autoimmune uveoretinitis. Exp Eye Res. 2021 Feb;203:108406. doi: 10.1016/j.exer.2020.108406. Epub 2020 Dec 19. PMID: 33347870.