title: Endogenous Nur77 Is a Specific Indicator of Antigen Receptor Signaling in Human T and B Cells.
abstract: Distinguishing true Ag-stimulated lymphocytes from bystanders activated by the inflammatory milieu has been difficult. Nur77 is an immediate early gene whose expression is rapidly upregulated by TCR signaling in murine T cells and human thymocytes. Nur77-GFP transgenes serve as specific TCR and BCR signaling reporters in murine transgenic models. In this study, we demonstrate that endogenous Nur77 protein expression can serve as a reporter of TCR and BCR specific signaling in human PBMCs. Nur77 protein amounts were assessed by immunofluorescence and flow cytometry in T and B cells isolated from human PBMCs obtained from healthy donors that had been stimulated by their respective Ag receptors. We demonstrate that endogenous Nur77 is a more specific reporter of Ag-specific signaling events than the commonly used CD69 activation marker in both human T and B cells. This is reflective of the disparity in signaling pathways that regulate the expression of Nur77 and CD69. Assessing endogenous Nur77 protein expression has great potential to identify Ag-activated lymphocytes in human disease.
authors.affiliation: The Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Division of Rheumatology, Department of Medicine, and the Howard Hughes Medical Institute at the University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Judith F
authors.initials: JF
authors.lastname: Ashouri
authors.affiliation: The Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Division of Rheumatology, Department of Medicine, and the Howard Hughes Medical Institute at the University of California, San Francisco, San Francisco, CA 94143 Art.Weiss@ucsf.edu.
authors.forename: Arthur
authors.initials: A
authors.lastname: Weiss
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D015153:Blotting, Western; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000276:immunology*; D011946:Receptors, Antigen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: C539821:NR4A1 protein, human; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D011946:Receptors, Antigen