What are peptide-ready MHCs (prMHC)?
Load custom peptides onto an MHC monomer or tetramer in-house with our stabilized, peptide-free MHCs
We have developed a portfolio of peptide-ready MHC (prMHC) proteins which are MHC monomers or tetramers stabilized without an antigenic peptide. These MHCs are peptide-ready meaning they can loaded with your custom neoantigen peptide in-house to generate a custom MHC monomer or tetramer.
Simple & Fast Peptide Loading
Peptide Loading Protocol:
Our prMHCs can be loaded in your laboratory with a quick 3-step loading protocol. The peptide is dissolved in DMSO or PBS, mixed with the prMHC at a molar ratio of 5:1 or 10:1, and then incubated for 5-10 minutes at room temperature.
Advantages:
- Quick loading time
- Easy to operate protocol
- High-throughput compatibility
- Does not use UV or peptide exchange technology
For a more detailed protocol or for scientific support for your application, please contact us.
Product Applications
Generate a custom MHC monomer or tetramer
In neoantigen identification, assessing the immune functionality of the antigenic peptide is critical, which includes evaluating its binding affinity to MHC and its reactivity with TCR. To facilitate this, KACTUS has introduced a range of functional prMHC catalog products. These can serve as a ready-to-use loading system to assist in loading antigen peptides and subsequently form a new, complete MHC peptide complex, thereby significantly aiding your neoantigen research studies by ensuring efficiency and reliability.
Assess MHC/TCR Binding Affinity
Enabling rapid and high-quality creation of custom Class I MHC tetramers, our prMHCs provide a streamlined and user-friendly approach to developing new custom MHC monomers and tetramers in just a few minutes directly in your lab. Generated custom MHC monomers or tetramers can be used to analyze MHC/TCR binding affinity in ELISA, SPR, flow cytometry, etc. This innovative system holds applications across various realms including epitope discovery, neoantigen vaccine research, and verification of T cell staining, among others.
High-throughput peptide screening
prMHCs can be used for functional screening of peptides for MHC class I binding, a critical component in vaccine design and immune monitoring. They provide the distinct ability to discriminate between MHC binding and non-binding peptides, which is particularly pivotal when screening immunogenic peptides derived from infectious agents or cancer neoantigens. Additionally, the fast and simple peptide-loading protocol makes it faster to create peptide-MHCs when screening large numbers of peptides.
Specific Applications Scenarios:
Antigenic Peptide Screening
TCR affinity characterization
MHC Binding Analysis
Antigenic Epitope Analysis & Screening
TCR or Antigen-Reactive T Cell Screening
Custom prMHC
KACTUS supports expression of other MHC alleles including class II alleles and non-human species. Submit our custom MHC form to request an allele not listed above.
Product Validation Data
TCR Binding
Loaded Peptide-ready MHC
Human prMHC monomer (HLA-A*11:01), His-Avi Tag, with KRAS G12D peptide
ka (1/Ms): 1.07E+5
ks (1/s): 1.60E-3
KD (M): 1.49E-8
Single-Chain Trimer MHC
Human single chain trimer MHC monomer (KRAS G12D, HLA-A*11:01), His-Avi Tag
ka (1/Ms): 1.43E+5
ks (1/s): 1.29E-3
KD (M): 9.00E-9
No Peptide
Human prMHC monomer (HLA-A*11:01), His-Avi Tag, with no peptide added
No binding
Figure 1. Surface Plasmon Resonance (SPR) analysis of the interaction between KRAS-G12D specific TCR (JDIa41b1) and human MHC complexes. The analysis was performed using different monomers tagged with His-Avi. The loaded prMHC demonstrates equivalent binding performance as the single chain trimer MHC.
Cell Sorting
Our prMHC tetramers demonstrate robust cell sorting activity, providing a powerful tool for researchers working on immunological studies and therapeutic developments. Understanding and isolating antigen-specific T cells is crucial in various fields such as cancer immunotherapy, infectious disease research, and autoimmune disease investigations. Our prMHC tetramers offer high specificity and sensitivity, enabling precise identification and sorting of T cells that recognize specific antigens.
Figure 2. Flow Cytometry Analysis of Jurkat Cells with Human APC-equivalent prMHC Tetramer (HLA-A*02:01), His Tag. The results demonstrate specific binding of the NY-ESO-1 peptide to the NY-ESO-1 specific TCR, with a significant increase in APC-positive cells in the presence of the NY-ESO-1 peptide.
Batch Consistency
Our prMHCs demonstrate consistent batch to batch binding activity. This consistency is critical for reproducible experimental results and is validated through rigorous quality control measures. If you'd like to learn more about the quality, consistency, or stability of our prMHCs, please contact us.
HLA-A*02:01 Monomer
HLA-A*02:01 Tetramer
Figure 3. ELISA data demonstrating the batch consistency analysis of Human HLA-A02:01&B2M&NY-ESO-1 (SLLMWITQC) monomer or tetramer, His tag. For both the monomer and tetramer, the single chain trimer was compared to three separate batches of prMHC loaded with NY-ESO-1 peptide (SLLMWITQC). Results demonstrate high reproducibility and consistency in binding performance.
Available Products
LEARN MORE
Neoantigen peptides and their role in MHC/TCR interactions
Neoantigens are highly specific targets and ideal targets for immunotherapy. Degraded neoantigen peptides can bind with major histocompatibility complex (MHC) molecules, forming complexes that are subsequently transported to the cell surface. These complexes are recognized by T-cell receptor (TCR), triggering an immune response. MHC polypeptide complexes constitute a category of neoantigen targets, and their distinctive interaction with TCR holds immense importance in the advancement of neoantigen-based immunotherapies, including TCR-T cell therapy, antibody drugs, and tumor vaccines.
Identification of the affinity of peptide loaded MHC with TCR [1].
FAQs
Ordering Information
We have a catalog selection of prMHCs in-stock and available to ship. Contact orders@kactusbio.us to place an order using a PO or pay via credit card on our website. We also offer custom prMHCs by submitting this form or contacting sales@kactusbio.us.
To order a custom prMHC, please submit this form or contact sales@kactusbio.us.
For prMHC catalog products, visit the specific product page to view the lead time. For custom prMHC orders, the lead time is 6 to 8 weeks.
Our products
KACTUS provides catalog and customized prMHC monomers, biotinylated monomers, and fluorescent tetramers.
We analyze prMHC products for molecular weight (Tris-Bis PAGE), purity (Tris-Bis PAGE & SEC-HPLC), endotoxin, and concentration. Our prMHC products have > 95% purity and < 1 EU/µg.
Yes, KACTUS provides custom prMHC-I and prMHC-II for all available MHC alleles. Contact us at sales@kactusbio.us to request a custom MHC.
prMHCs can be stored for at least 12 months at -80°C.
About prMHCs
Peptide-ready MHCs (prMHC) is an MHC that doesn’t contain any pre-loaded peptide and can be loaded with custom peptides for TCR binding and cell staining.
A prMHC monomer consists of an α-chain and β-2 microglobulin. It is a single subunit of prMHC tetramer.
It is a prMHC monomer with biotin at the C-terminal Avi tag.
A fluorescent prMHC tetramer is a complex of four prMHC monomers with fluorophores conjugated to each monomer subunit of the prMHC complex.
Expression of prMHCs
Yes, KACTUS prMHCs are a propriety design based on our SAMS™ Protein Engineering Platform.
Yes, prMHC are a single-chain design of α-chain and β-2 microglobulin developed by our protein engineering team.
Yes, prMHCs are purified from HEK293 cells.
prMHCs are affinity-purified via His tag at the C-terminus with additional size exclusion chromatography steps.
No, prMHC tetramerize in vivo during expression in HEK293, a KACTUS propriety design.
Fluorescent Labeling
We currently offer APC-equivalent, FITC-equivalent and PE conjugation for prMHC tetramers.
APC-equivalent is a 90 kDa protein, with excitation peak at 609 nm and emission peak at 643 nm.
No, APC-equivalent is an in vivo label, part of KACTUS proprietary single chain design for fluorescent prMHC tetramer.
Protocols & Applications
Yes, contact support@kactusbio.us for a protocol.
Yes, KACTUS prMHCs can be used for peptide screening.
Yes, contact support@kactusbio.us for a protocol.
Customize your MHC
Our team can modify parameters on an existing MHC catalog product such as neoantigen peptide, biotinylation, and fluorescent-labeling. Alternatively, submit our custom MHC request form to order an entirely customized MHC construct. We'll work closely with you to make sure the product meets your unique specifications.
Custom MHC Services
Soluble TCR Expression
Custom expression of soluble TCR with TCR/MHC binding analysis via SPR.
MHC Monomers & Tetramers
Browse our catalog selection of peptide-MHC complexes.
HLA-G and LILRs
Learn more about our full portfolio of HLA-G and LILRA/LILRB proteins.
ADDRESS
60 Hickory Drive
Waltham, MA 02451
United States
Monomers & Tetramers Ready-to-Load: Peptide-ready MHCs