Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

BY55 is a human cell surface molecule whose expression is restricted to NK cells, a subset of circulating CD8+ T lymphocytes, and all intestinal intraepithelial T lymphocytes. Here, we report that BY55 is a novel NK receptor showing broad specificity for both classical and nonclassical MHC class I molecules, and that optimal binding requires a prior aggregation of MHC class I complexes. Using BY55 transfectants, we have identified functional consequences of MHC class I/ligand interactions for the class I-bearing cell. The triggering of MHC class I molecules on human T cell clones by BY55 delivered a potent proliferative signal in the presence of soluble CD3 mAb. The costimulatory signal provided by MHC class I ligation was only seen in activated, and not resting, peripheral blood T cells. This observation represents an additional and/or alternative pathway to CD28 costimulation and may be of particular relevance in memory T cells lacking CD28, such as intestinal intraepithelial T lymphocytes, which are CD28- but BY55+.

Type

Journal article

Journal

J Immunol

Publication Date

01/02/1999

Volume

162

Pages

1223 - 1226

Keywords

Animals, Antigens, CD, CD28 Antigens, Cell Line, Cricetinae, GPI-Linked Proteins, HLA-A2 Antigen, Histocompatibility Antigens Class I, Humans, Killer Cells, Natural, Ligands, Lymphocyte Activation, Membrane Proteins, Mice, Receptors, Immunologic, Recombinant Proteins, Signal Transduction, Solubility, T-Lymphocytes, Transfection