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Expression of Ly49A on T cells alters the threshold for T cell responses
Author(s) -
Öberg Linda,
Eriksson Mikael,
Fahlén Linda,
Sentman Charles L.
Publication year - 2000
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/1521-4141(200010)30:10<2849::aid-immu2849>3.0.co;2-6
Subject(s) - biology , microbiology and biotechnology , expression (computer science) , t cell , immunology , immune system , computer science , programming language
Abstract In this study we investigated the balance between activating and inhibitory signals during T cell activation. We have used transgenic mice in which CD8 + T cells expressed an inhibitory receptor, Ly49A, and a specific activating α β TCR. This TCR recognizes an lymphocytic choriomeningitis virus peptide in combination with H‐2D b . We observed a quantitative influence on cellular responses that depended upon the activating signals received through the TCR and the inhibitory signals received through Ly49A. By varying the peptide concentration given to stimulating cells or target cells, we could adjust the amount of ligand available to trigger the TCR. At low doses of peptide, Ly49A‐expressing T cells were unresponsive on target cells that expressed H‐2D d , but responded against target cells without H‐2D d . However, this inhibition could be overcome by increasing the peptide concentration or by addition of anti‐Ly49A F(ab') 2 fragments. Thus, rather than behaving as simple "off" switches, our data indicate that Ly49 receptors modulate T cell signaling so that higher amounts of activating signals are required for effector‐cell responses.