Description
Background information
Antigen-specific T cells are key mediators of adaptive immunity and central players in the development of various human pathologies such as cancer, infectious diseases, autoimmunity, and cardiovascular conditions. CD8+ cytotoxic T cells and CD4+ helper T cells detect and bind their specific antigen via their T cell receptor (TCR) complex when it is bound and presented on a dedicated major histocompatibility complex (MHC) class I or II molecule, respectively. This highly specific interaction between MHC and TCR can be deployed to stain and sort even very rare antigen-specific T cells by using peptide-loaded MHC (pMHC) tetramers or multimers coupled to a fluorescent molecule.
MHC MACSimers are fully multimerized MHC multimers with optimized TCR avidity and fluorescence brightness. They are directly conjugated to a fluorochrome and are offered in two different product formats: loadable MACSimers (MHC MACSimer FleX Kits) that can be combined with MACSpep single peptides for fast and flexible peptide-loading, or ready-to-use MACSimers (Peptide-loaded MHC MACSimers) with a pre-loaded peptide for maximum standardization. Both formats enable accurate flow cytometry-based enumeration, phenotypic characterization, and targeted isolation of antigen-specific T cells from different origins.
All MHC MACSimer products are offered in different MHC allele variants. In humans, MHC molecules are encoded by the so called HLA (Human Leukocyte Antigen) system, which is the most polymorphic genetic system known in humans. The genetic regions encoding for human MHC class I molecules are classified as HLA-A, HLA-B, and HLA-C alleles. Human MHC class II alleles include HLA-DR, HLA-DQ, and HLA-DP. Due to highly complex co-dominant inheritance of the HLA system, every person has his or her very own specific combination of HLAs with millions of different haplotypes existing in the global human population. One of the most frequent haplotypes in humans include HLA-A*0201, HLA-A*2402, and HLA-B*0702. In other species, such as mice, the genetic MHC system and the associated haplotypes vary, especially with regard to their nomenclature. In example, the most frequently studied MHC allele in mice is H-2Kb.
Every MHC allele is naturally restricted to one or more specific peptide sequences. The affinity of a peptide sequence to a certain MHC allele can be predicted using open-source prediction tools. More information and resources on peptide loading and affinity prediction can be found in the MACSpep application protocol (Preparation of MACSpep single peptides for peptide loading on MHC MACSimers).
Overview
MHC MACSimers have been developed for the reliable detection, characterization, and isolation of antigen-specific T cells using flow cytometry. MHC MACSimer FleX Kits are offered in different allelic variants and are designed for loading of a custom peptide of interest with minimum hands-on-time. Thus, MHC MACSimer FleX Kits provide maximum flexibility for applications such as neoantigen discovery, screening of potential cancer, autoimmune or pathogen-related T cell epitopes, as well as monitoring of antigen-specific T cell responses.
For users seeking deep technical insight, a comprehensive MHC handbook is available, covering relevant scientific details and experimental protocols, along with expert tips and troubleshooting guidance:
MHC multimer technology
