title: The law of mass action governs antigen-stimulated cytolytic activity of CD8+ cytotoxic T lymphocytes.
abstract: An analysis of the initial antigen-recognition step in the destruction of target cells by CD8+ cytolytic T lymphocytes (CTLs) shows that a relationship in the form of the law of mass action can be used to describe interactions between antigen-specific receptors on T cells (TCRs) and their natural ligands on target cells (peptide-major histocompatibility protein complexes, termed pepMHC complexes), even though these reactants are confined to their respective cell membranes. For a designated level of lysis and receptor affinities below about 5 X 10(6) M-1, the product of the required number of pepMHC complexes per target cell ("epitope density") and TCR affinity for pepMHC complexes is constant; therefore, over this range TCR affinities can be predicted from epitope densities (or vice versa). At higher receptor affinities ("affinity ceiling") the epitope density required for half-maximal lysis reaches a lower limit of less than 10 complexes per target cell.
authors.affiliation: Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Sykulev
authors.forename: R J
authors.initials: RJ
authors.lastname: Cohen
authors.forename: H N
authors.initials: HN
authors.lastname: Eisen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000276:immunology*; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000737:chemistry; D007700:Kinetics; D008285:Major Histocompatibility Complex; D051379:Mice; D018448:Models, Immunological; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000941:Antigens; D000939:Epitopes; D011948:Receptors, Antigen, T-Cell