Magnetic antigen-specific CD8+ T cell isolation with MHC I Streptamers®
MHC I Streptamers® are designed for fluorescent staining and/or magnetic isolation of antigen-specific cytotoxic CD8+ T cells. The Streptamer® reagents are fully reversible, i.e. they can be completely removed from the labeled target cells so that the cells preserve their full biological function after staining or isolation.
The MHC I Streptamers®, adducts of Strep-tagged MHC I molecules (MHC I-Streps) and Strep-Tactin®, are directed to antigen-specific CD8 T-cell receptors.
1) MHC I-Streps (Strep-tagged MHC I molecules) are multimerized with Strep-Tactin® attached to a magnetic bead to generate multimers with high binding avidity (Fig.1).
Fig.2: Streptamer® Magnetic Nanobeads are recommended when selection of cells is performed with an automated selection machine from Miltenyi (AutoMACS®, CliniMACS®). Cells are mixed with Streptamer® Magnetic Nanobeads and loaded onto a magnet column (Miltenyi). Cells bound to magnetic beads are retarded on the column through a high gradient magnetic field. After elution of the target cells multimerization is reversed by the addition of biotin and the low affinity Fab-Strep molecules dissociate completely from the cell surface.