Following antigen challenge, T cells up-regulate cell surface expression of CD4 in vitro and in vivo.
The low precursor frequency of Ag-specific T cells has raised significant barriers to studying the T cell response in vivo. We demonstrate that T cells up-regulate the cell surface expression of CD4 following Ag recognition, which identifies Ag-specific T cells in vitro and in vivo and allows their characterization. The CD4high cell subpopulation contains the Ag-specific population as indicated by Ag-induced proliferation and limiting dilution analyses. The use of the CD4high marker will allow analysis of the dynamics of the T cell immune response in vivo, the study of the suboptimal T cell response to Ag, and the identification of T cells which are reactive to known and unknown autoantigens.
Department of Medicine, Stanford University School of Medicine, CA 94305, USA.
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W
Ridgway
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M
Fassò
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CG
Fathman
D000818:Animals; D000941:Antigens / Q000008:administration & dosage / Q000276:immunology*; D015704:CD4 Antigens / Q000096:biosynthesis*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D018984:Epitopes, T-Lymphocyte / Q000096:biosynthesis; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D051379:Mice; D008811:Mice, Inbred DBA; D009211:Myoglobin / Q000008:administration & dosage / Q000276:immunology*; D013234:Stem Cells / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology*; D014907:Whales
D000941:Antigens; D015704:CD4 Antigens; D018984:Epitopes, T-Lymphocyte; D009211:Myoglobin