Variations in the number of peptide-MHC class I complexes required to activate cytotoxic T cell responses.
We determined equilibrium constants for the binding of 16 peptides (based on four T cell epitopes) to three MHC class I proteins (A2, Kb, and Ld) on intact cells and estimated the number of accessible peptide-binding sites on these cells. From these results, and the concentrations of peptides required to sensitize target cells for lysis by CD8+ CTL, we conclude that the critical number of peptide-MHC complexes required per target cell for the activation of CTL responses varies with different combinations of peptide-MHC complexes and CTL clones from several thousand complexes to fewer than ten per target cell.
Kageyama
S
S
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139.
Tsomides
T J
TJ
Sykulev
Y
Y
Eisen
H N
HN
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D006183:H-2 Antigens / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology*; D011485:Protein Binding / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D006183:H-2 Antigens; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D010455:Peptides