title: The role of self peptides in the allogeneic cross-reactivity of CTLs.
abstract: This study presents data relevant to understanding the molecular and structural basis for the cross-reactivity of many CTLs on multiple MHC targets. Five anti-H-2Kb alloreactive CTL clones derived from B6.C-H-2bm1 (bm1), B6.C-H-2bm8 (bm8), and B6.C-H-2bm11 (bm11) mice and a Sendai virus-specific H-2Kb-restricted CTL clone were studied. Self peptides extracted from Kb molecules were fractionated by HPLC and tested for their ability to be recognized on RMA/s (H-2b) cells by those clones. For each alloreactive clone, a single dominant peptide peak was found to sensitize target cells. In addition to recognizing peptides presented by the Kb molecule, the five alloreactive clones and the one Sendai virus-specific clone all showed cross-reactivities on a panel of Kbm mutant cells in a peptide-dependent manner. Two CTL clones, one alloreactive and one virus specific, cross-recognized Kbm targets by each responding to a unique self peptide in the context of the mutant MHC molecules. Our data underscore the prevalent idea that TCR-alpha beta have an inherent structural capability to react with several peptide/MHC structural patterns other than the original peptide/MHC pattern that might have been used to select that TCR. The high incidence of cross-reactivity seems to reflect a feature of the mechanism of positive selection in the thymus and the need for T cells in the repertoire to have an expanded capability for responding to a wide variety of foreign Ags.
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA.
authors.forename: K
authors.initials: K
authors.lastname: Kuzushima
authors.forename: R
authors.initials: R
authors.lastname: Sun
authors.forename: G M
authors.initials: GM
authors.lastname: van Bleek
authors.forename: Z
authors.initials: Z
authors.lastname: Vegh
authors.forename: S G
authors.initials: SG
authors.lastname: Nathenson
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology; D002999:Clone Cells; D003429:Cross Reactions / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010222:Parainfluenza Virus 1, Human / Q000276:immunology; D010455:Peptides / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D000939:Epitopes; D006183:H-2 Antigens; D015395:Histocompatibility Antigens Class I; D010455:Peptides