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| 1mg |
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| 10mg |
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| Targets |
IRBP (1-20) targets T-cell receptors on CD4+ T lymphocytes specific for this epitope presented by certain MHC class II molecules. In susceptible strains (e.g., HLA-DR3 transgenic mice), it induces an autoimmune response against retinal photoreceptors, leading to uveitis. The peptide is used to model human autoimmune uveoretinitis.
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| ln Vitro |
In cell-free assays, human IRBP (1-20) peptide binds to MHC class II molecules (e.g., HLA-DR3 or I-A molecules). Binding affinity is measured by competition ELISA or SPR. The Kd is typically in the low micromolar range. The peptide does not possess enzymatic activity; its function is to be recognized by TCRs after MHC presentation.
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| ln Vivo |
Human TFA produces EAU in IRBP (1–20)[2]. 21 days following vaccination, lymph node and spleen cells are harvested, and the appropriate antigen is used to activate them in culture in order to measure proliferative and cytokine responses. The peptide caused human TFA and cells from C57BL/6 and 129/J animals vaccinated with IRBP (1–20) to proliferate[2].
In vitro, the peptide (0.1-10 uM) stimulates proliferation and IFN-gamma/IL-17 production from primed T cells isolated from immunized animals. Using T-cell hybridomas specific for human IRBP (1-20), activation can be measured by IL-2 production (ELISA). The peptide is highly specific; a scrambled control does not induce T-cell responses. The TFA salt form does not interfere with activity. |
| Enzyme Assay |
MHC binding is assessed by a cell-free ELISA. Purified HLA-DR3 (or I-A) molecules are coated onto plates. Increasing concentrations of IRBP (1-20) peptide are added along with a biotinylated reference peptide that binds to the same MHC. After washing, bound biotinylated peptide is detected with streptavidin-HRP. The concentration of IRBP (1-20) that reduces reference binding by 50% (IC50) is calculated.
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| Cell Assay |
Splenocytes or lymph node cells from mice immunized with human IRBP (1-20) in CFA are harvested. Cells are cultured in 96-well plates with the peptide (0.01-10 uM) for 48-72 hours. Proliferation is measured by [3H]-thymidine incorporation. Supernatants are analyzed for cytokines (IFN-gamma, IL-17, IL-2) by ELISA. Flow cytometry is used to detect CD4+ T-cell activation markers (CD25, CD44). Negative controls include no peptide and an irrelevant peptide.
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| Animal Protocol |
Animal/Disease Models: C57BL/6 (H-2b) mice, H-2b (C57BL/6, 129/J ) mice[2]
Doses: 200, 300 μg Route of Administration: Ih; After 21 days Experimental Results: C57BL/6 (H-2b) mice immunized with the human peptide (200-300 μg= 80-120 nmoles) developed EAU. 129/ J mice (H-2b) also developed disease, albeit with a lower average score than C57BL/6. To induce EAU, susceptible mice (e.g., B10.RIII or HLA-DR3 transgenic mice) are immunized subcutaneously with 100-200 ug of IRBP (1-20) peptide emulsified in CFA (with Mycobacterium tuberculosis). Pertussis toxin (0.5-1 ug) is injected intraperitoneally on days 0 and 2. Mice are monitored for clinical uveitis by fundoscopy and histology at day 14-21. The peptide induces retinal inflammation and photoreceptor damage, similar to that seen with the well-characterized IRBP161-180 peptide. |
| ADME/Pharmacokinetics |
IRBP (1-20) peptide has MW ~2200 Da. It is soluble in sterile water or PBS (TFA salt aids solubility). The plasma half-life is short (<1 hour) due to proteolysis; for immunization, it is mixed with CFA to form a depot, providing prolonged antigen exposure. The peptide is stable at -20degC for years. It is not intended for PK studies as free peptide; its role is as an immunogen.
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| Toxicity/Toxicokinetics |
The peptide is non-toxic at immunization doses. No systemic toxicity has been reported. Local injection site reactions (swelling, granuloma) may occur due to CFA, not the peptide. The peptide itself does not cause direct organ damage; the induced autoimmune uveitis is the studied effect. Standard safety precautions (gloves, lab coat) should be followed. Not for human use.
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| References |
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| Additional Infomation |
Human IRBP (1-20) is less commonly used than rodent IRBP fragments (e.g., IRBP161-180) for EAU induction, but it is valuable for studies involving humanized MHC transgenic mice. The peptide allows modeling of human-specific T-cell responses. It is a research tool only, not approved for clinical use. Store lyophilized at -20degC, protected from light and moisture.
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| Molecular Formula |
C103H165F3N24O30S
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| Molecular Weight |
2308.62
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| Related CAS # |
IRBP (1-20), human;298202-25-2
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| Appearance |
Solid powder
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment, avoid exposure to moisture. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
DMSO :~100 mg/mL (~43.32 mM)
H2O :~8.33 mg/mL (~3.61 mM) |
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| Solubility (In Vivo) |
Solubility in Formulation 1: 2.5 mg/mL (1.08 mM) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 0.4332 mL | 2.1658 mL | 4.3316 mL | |
| 5 mM | 0.0866 mL | 0.4332 mL | 0.8663 mL | |
| 10 mM | 0.0433 mL | 0.2166 mL | 0.4332 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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