UNIT 18.11 Peptide Induction of Surface Expression of Class I MHC

  1. Ted Hansen,
  2. Nancy Myers

Published Online: 1 NOV 2003

DOI: 10.1002/0471142735.im1811s57

Current Protocols in Immunology

Current Protocols in Immunology

How to Cite

Hansen, T. and Myers, N. 2003. Peptide Induction of Surface Expression of Class I MHC. Current Protocols in Immunology. 57:18.11:18.11.1–18.11.8.

Author Information

  1. Washington University School of Medicine, St. Louis, Missouri

Publication History

  1. Published Online: 1 NOV 2003
  2. Published Print: OCT 2003


This unit describes a method for comparing the relative binding of different peptides to the same MHC class I (MHC-I) molecule using live cells. Live cells expressing suboptimally loaded MHC-I proteins are incubated with medium containing diluted amounts of synthetic peptides to be tested for binding to class I. After overnight incubation with peptide, surface class I expression is monitored by flow cytometry using an allele-specific MAb. Relative binding affinity of peptide reliably correlates with the amount of surface induction of the class I molecule to which it specifically binds. The mechanistic basis of this assay is that surface MHC-I molecules become conformationally unstable shortly after peptide dissociation. However, the binding of an exogenous peptide can stabilize the surface class I molecule, prevent conformational instability, and thus increase class I surface expression in an allele-specific manner.