Evidence that a single peptide-MHC complex on a target cell can elicit a cytolytic T cell response

Immunity. 1996 Jun;4(6):565-71. doi: 10.1016/s1074-7613(00)80483-5.


Using a chemically homogeneous radiolabeled peptide of high specific activity (125I-QLSPYPFDL, 3.5 x 10(18) cpm per mole) we show that at a peptide concentration (5 pM) causing half-maximal lysis of target cells by a cytolytic T lymphocyte (CTL) clone that recognizes the peptide in association with Ld, a class I MHC protein, only 3 peptide molecules on average are bound by Ld per target cell. From the distribution of Ld on the target cells, we suggest that a single peptide-MHC complex per target cell can trigger activation of the T cell cytolytic response.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Clone Cells
  • Cytotoxicity Tests, Immunologic
  • Cytotoxicity, Immunologic* / drug effects
  • Epitopes / chemistry
  • Epitopes / metabolism
  • H-2 Antigens / immunology
  • HLA-A2 Antigen / immunology
  • Histocompatibility Antigens / immunology*
  • Humans
  • Kinetics
  • Mice
  • Molecular Sequence Data
  • Peptide Fragments / immunology*
  • Peptide Fragments / pharmacology
  • Protein Binding / immunology
  • T-Lymphocytes, Cytotoxic / drug effects
  • T-Lymphocytes, Cytotoxic / immunology*


  • Epitopes
  • H-2 Antigens
  • HLA-A2 Antigen
  • Histocompatibility Antigens
  • Peptide Fragments