The ability to quantitate a T-cell response is an important piece of information for better understanding of various questions such as efficacy of new vaccines/therapies, evaluating disease progression or clearance, and many other questions. T cell antigen receptors (TCR) recognize peptides that are expressed on antigen presenting cells. Antigen specific T cell responses can be analyzed by using MHC tetramer molecules, where each monomer is bound with a specific peptide. This method provides more robust T cell information compared to only using antibodies because the MHC tetramers will only bind to T cells that recognize the peptide sequence. Using this method, it is certain that any signal that is observed is due to a specific T cell response and not due to an overall increase in T cell presence.
MHC tetramers are composed of four monomers, each with a specific peptide. The monomers are biotinylated and held together using fluorescently-labeled streptavidin. Some researchers have found using MHC multimers with more than 4 monomers result in non-specific binding. By using MHC tetramers, binding affinity of the peptide and TCR remains high, while reducing/avoiding low non-specific binding.
MBL International offers many alleles and sequence combinations for human and mouse MHC tetramers. If you do not see your product of choice, please contact us for custom tetramer production.