MHC Class II Tetramers
MHC II Tetramers are fluorescent conjugates containing four copies of Major Histocompatibility Complex class II (MHC II) proteins that can be bound by synthetic peptides. MHC IIs are cell surface proteins responsible for presenting antigen, in form of peptides, of self and non-self origin to helper T-cells (CD4+ T-cells). Many genetic variations of MHC II, called Human Leukocyte Antigen (HLA) types are found in humans. HLA types differ in peptide binding specificities and therefore have capacity to present different sets of peptides to the CD4+ T-cells. Each peptide-MHC II combination will be recognized by a unique set of CD4+ T-cells.
Researchers at Benaroya Research Institute (BRI) have developed a method to express MHC II proteins in cell culture, form tetramers, and bind them with synthetic peptides. The peptide sequences and the HLA types can be customized based on researcher’s needs. MHC II tetramers are fluorescently tagged, such that the T cells that recognize a unique MHC II:antigen complex will also be fluorescently tagged. This allows detection and isolation of the CD4+ T cells based on the T-cell receptor specificity using flow cytometry.
MHC II tetramers are novel tool used to detect and isolate CD4+ T-cells based on antigen-specificity of the T-cell receptors. Tetramers have been an excellent tool for T cell receptor epitope mapping and antigen specific T-cell studies of autoimmune diseases such as Type 1 diabetes and allergies, as well as viral infections. BRI offers the largest library of MHC II types, representing over 90% of HLA types found in the world.
MHC II tetramers with large diversity of HLA types are available from BRI for research purpose. HLA types as well as peptides bound to MHC II can be customized to meet research needs. Peptide-free MHC II tetramers are also available. Additional information and publications are available on the Tetramer Core Laboratory page.