title: Alloreactive cytotoxic T-cell function, peptide nonspecific.
abstract: The recognition requirements necessary for murine alloreactive cytotoxic T-cells to carry out their effector function has been investigated using target cells that express a unique class I major histocompatibility complex (MHC)-peptide pair. The human cell line T2 and the murine cell line RMA-S are defective in peptide transport components needed to effectively express stable MHC class I molecules at the cell surface. When T2 cells were infected with a vaccinia virus that encoded the Kd gene and provided with a Kd-motif peptide from the nucleoprotein of influenza virus (NPP), these cells could be lysed by polyclonal allo Kd-reactive cytotoxic T-lymphocytes (CTL). Similar results were obtained with the murine RMA-S-Kd cell line, transfected with cDNA able to express some 'empty' Kd that is heat-labile. Adding another Kd-motif peptide from influenza virus haemagglutinin (HAP) stabilized the surface expression of Kd and allowed the RMA-S-Kd cells to be lysed before or after heat shock. At 27 degrees C anti-Kd alloreactive CTL-lysed target cells in the presence and absence of HAP peptide. Alloreactive CTL appear to have a more stringent requirement for a high density of MHC class I on cell surfaces relative to peptide-specific MHC-restricted CTL. We conclude that while Kd-restricted CTL activity is strictly peptide-specific, anti-Kd-specific alloreactivity is MHC allele-specific, but peptide-nonspecific. This conclusion is at odds with the Standard Model of T-cell receptor (TCR) function, but consistent with the predictions of a Competing Model of TCR function.
authors.affiliation: Division of Immunology and Cell Biology, John Curtin School of Medical Research, Australian National University, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Müllbacher
authors.forename: M
authors.initials: M
authors.lastname: Lobigs
authors.forename: F J
authors.initials: FJ
authors.lastname: Kos
authors.forename: R
authors.initials: R
authors.lastname: Langman
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D003602:Cytotoxicity, Immunologic; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D007519:Isoantigens / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D010455:Peptides / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D015395:Histocompatibility Antigens Class I; D007519:Isoantigens; D010455:Peptides