@article{5d91f5e0ebce11ddbf70000ea68e967b,
title = "The T-cell accessory molecule CD4 recognizes a monomorphic determinant on isolated Ia",
abstract = "The membrane protein CD4 is commonly found on mature T cells specific for antigen in association with class II major histocompatibility complex (MHC; Ia) proteins. This correlation has led to the suggestion that CD4 binds to a monomorphic region of the Ia molecule on the antigen-presenting cell (APC) and functions either by enhancing interaction between the T cell and the APC, or conversely, by transducing negative signals to the T cell. To address this hypothesis, we have made use of sublines from an unusual T hybrid that is class I MHC restricted but also CD4+. By incorporating purified MHC proteins into a planar membrane system, we show that different Ia molecules can greatly enhance the ability of a CD4+ but not a CD4- variant of this class I-restricted T hybrid to respond to isolated class I molecules. T-cell responses can be strongly augmented by the concurrent expression of CD4 on the T cell and any of four different Ia proteins on planar membranes, thus supporting the idea that CD4 binds to a monomorphic region of the Ia molecule and increases the avidity with which the T cell can interact with its target.",
author = "D Gay and S Buus and J Pasternak and J Kappler and P Marrack",
note = "Keywords: Animals; Antigens, Differentiation, T-Lymphocyte; Cell Membrane; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Histocompatibility Antigens Class II; Hybridomas; Ligands; Liposomes; Microspheres; Receptors, Antigen, T-Cell; T-Lymphocytes",
year = "1988",
language = "English",
volume = "85",
pages = "5629--33",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "The National Academy of Sciences of the United States of America",
number = "15",
}