title: Probing T cell membrane organization using dimeric MHC-Ig complexes.
abstract: In this report, we review a novel method for probing the membrane organization of T cells using dimeric major histocompatibility complexes (MHC), MHC-Ig. MHC-Ig complexes are useful reagents for quantitative analysis of binding data since their valency is controlled. These complexes can be easily labeled and loaded with a variety of peptides. A binding assay using these dimers and quantitative analysis of the MHC-Ig dimer-T cell binding curves is described in detail. Using this approach, we show that the organization of TCR on activated T cells is different from TCR organization on nai;ve T cells. The implications of these findings are discussed with regards to current models of T cell recognition. This analysis offers insight into how T cell controls their biological range of responsiveness. Specifically, these findings reveal the biophysical basis of the ability of activated T cells to recognize low amounts of antigen independent of costimulation.
authors.affiliation: Department of Pathology, Division of Immunopathology, Johns Hopkins School of Medicine, 664G Ross Bldg., 720 Rutland Avenue, Baltimore, MD 21205, USA.
authors.forename: Tarek M
authors.initials: TM
authors.lastname: Fahmy
authors.forename: Joan G
authors.initials: JG
authors.lastname: Bieler
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Schneck
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D003599:Cytoskeleton / Q000276:immunology; D019281:Dimerization; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008213:Lymphocyte Activation; D021962:Membrane Microdomains / Q000276:immunology; D018448:Models, Immunological; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015395:Histocompatibility Antigens Class I; D007136:Immunoglobulins; D011993:Recombinant Fusion Proteins