IRBP (1-20), human

Product Name: IRBP (1-20), human

Sequence One Letter Code: GPTHLFQPSLVLDMAKVLLD

Sequence Three Letter Code: H-Gly-Pro-Thr-His-Leu-Phe-Gln-Pro-Ser-Leu-Val-Leu-Asp-Met-Ala-Lys-Val-Leu-Leu-Asp-OH

Chemical Formula:C101H164N24O28S1

Molecular Weight: 2194.8

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Inflammation and Immunology Research

Source / Species: human

Conjugation: Unconjugated

Code Nacres: NA.26

Application: IRBP (1–20), human is a synthetic peptide corresponding to residues 1–20 of interphotoreceptor retinoid-binding protein, a glycolipoprotein localized in the interphotoreceptor matrix of the retina. This fragment contains a dominant T cell epitope associated with the H-2b haplotype and exhibits strong immunogenicity. Immunization with IRBP (1–20) induces T cell–mediated experimental autoimmune uveoretinitis (EAU), closely recapitulating pathology triggered by the full-length protein. The peptide is widely used in murine models to study retinal autoimmunity, antigen-specific T cell responses, and inflammatory mechanisms underlying autoimmune uveitis. It supports investigations into immune tolerance, cytokine regulation, and therapeutic strategies targeting ocular inflammatory disease.

Current Research: Interphotoreceptor retinoid-binding protein (IRBP) is a large glycolipoprotein localized within the interphotoreceptor matrix of the retina, where it plays a central role in the visual cycle by facilitating the transport of retinoids between photoreceptors and the retinal pigment epithelium. Beyond its physiological importance, IRBP is a well-characterized autoantigen in autoimmune uveitis. Among its immunogenic regions, the N-terminal fragment encompassing residues 1–20—designated IRBP (1–20), human—has emerged as a highly defined peptide epitope for dissecting antigen-specific T cell responses and modeling retinal autoimmunity. IRBP (1–20) corresponds to a dominant T cell epitope associated with the H-2^b haplotype in mice. This short synthetic peptide retains strong immunogenic properties and is sufficient to induce experimental autoimmune uveoretinitis (EAU) following immunization in susceptible strains. EAU is a T cell–mediated inflammatory disease of the posterior segment of the eye and is widely accepted as a robust model for human autoimmune uveitis. Importantly, disease induced by IRBP (1–20) closely recapitulates the histopathological and immunological features observed with full-length IRBP, including retinal infiltration by autoreactive T lymphocytes, photoreceptor damage, vasculitis, and breakdown of the blood–retina barrier. The use of IRBP (1–20) offers several methodological advantages. As a defined minimal epitope, it enables precise interrogation of antigen-specific CD4⁺ T cell activation, clonal expansion, and differentiation. In H-2^b mice, IRBP (1–20)-specific T cells predominantly differentiate into Th1 and Th17 subsets, both of which are implicated in EAU pathogenesis. IFN-γ–producing Th1 cells and IL-17–secreting Th17 cells contribute to retinal inflammation through recruitment of monocytes and neutrophils, amplification of local cytokine networks, and disruption of retinal architecture. This peptide-driven model therefore provides a controlled system to dissect lineage commitment, transcription factor regulation (e.g., T-bet and RORγt), and effector cytokine dynamics during ocular autoimmunity. Recent research has leveraged IRBP (1–20)–induced EAU to explore the balance between pathogenic effector T cells and regulatory T cells (Tregs). Induction of peripheral tolerance through antigen-specific mechanisms—such as mucosal administration of peptide, tolerogenic dendritic cells, or low-dose antigen exposure—has been evaluated using this defined epitope. Because the inciting antigen is precisely known, investigators can monitor IRBP (1–20)-specific T cell frequencies using peptide restimulation assays, MHC class II tetramers, and cytokine profiling. This has facilitated mechanistic studies of immune deviation, anergy, clonal deletion, and Treg-mediated suppression in the context of retinal inflammation. In addition, IRBP (1–20) serves as a valuable tool for examining cytokine regulation and intracellular signaling pathways involved in autoimmune tissue damage. Studies employing gene-deficient mice or pharmacological inhibitors have used IRBP (1–20) immunization to evaluate the roles of IL-6, IL-23, GM-CSF, and co-stimulatory molecules such as CD28 and ICOS in disease progression. The model has also been instrumental in elucidating the contribution of innate immune activation, including Toll-like receptor signaling and inflammasome components, which modulate antigen-presenting cell function and shape downstream T cell responses. From a translational perspective, IRBP (1–20)-driven EAU remains a cornerstone for preclinical evaluation of therapeutic strategies targeting autoimmune uveitis. Small-molecule inhibitors, biologics directed against proinflammatory cytokines, and cell-based therapies are frequently assessed using this peptide-induced model. Because disease onset and severity are reproducible and quantifiable via clinical scoring and histological analysis, IRBP (1–20) enables rigorous evaluation of immunomodulatory efficacy. Moreover, antigen-specific approaches—such as peptide-coupled nanoparticles or tolerogenic vaccination platforms—can be systematically tested for their ability to attenuate IRBP-reactive T cell responses without broad immunosuppression. In summary, IRBP (1–20), human is a synthetic peptide representing a dominant retinal autoantigenic epitope with strong immunogenic capacity in H-2^b mice. Its ability to reproducibly induce T cell–mediated EAU makes it an indispensable reagent for studying antigen-specific immunity, cytokine networks, immune tolerance mechanisms, and therapeutic interventions in ocular inflammatory disease. By providing a reductionist yet pathophysiologically relevant model, IRBP (1–20) continues to advance mechanistic understanding of autoimmune uveitis and supports the development of targeted strategies aimed at preserving retinal integrity and visual function.