Negative transcriptional regulation in anergic T cells.
Anergy is a mechanism of T-lymphocyte tolerance induced by antigen-receptor stimulation in the absence of costimulation, whereby T cells exhibit a defect in antigen-induced transcription of the interleukin 2 (IL-2) gene. Here we present evidence for a mechanism of negative IL-2 gene regulation in anergic T cells. High amounts of binding activity to the negative regulatory element A (NRE-A) of the IL-2 promotor were detected in nuclear extracts from human T cells shortly after induction of anergy. Rapid induction of this nuclear complex is blocked by cyclosporin A and is found to be independent of protein synthesis. Plasmid DNAs, containing either the human phorbol 12-myristate 13-acetate-responsive element (PRE) or both NRE-A and PRE, were used as template for in vitro transcription assays in the presence of T-cell nuclear extracts. Under these conditions nuclear extracts from both anergic and rested T-cell clones, after crosslinking of CD3 and CD28, induced transcription of plasmids containing only PRE. However, when plasmids containing NRE-A and PRE were used, transcription was only induced by nuclear extracts from rested but not anergic T cells. These findings suggest the functional relevance of transcriptional repression of the IL-2 gene in anergic T cells.
Becker
J C
JC
Scripps Research Institute, Department of Immunology, La Jolla, CA 92037.
Brabletz
T
T
Kirchner
T
T
Conrad
C T
CT
Bröcker
E B
EB
Reisfeld
R A
RA
D015703:Antigens, CD / Q000276:immunology; D001483:Base Sequence; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D002467:Cell Nucleus / Q000378:metabolism / Q000502:physiology; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D017635:Clonal Anergy; D002999:Clone Cells; D017931:DNA Primers; D015972:Gene Expression Regulation, Neoplastic; D007376:Interleukin-2 / Q000096:biosynthesis*; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology*; D008545:Melanoma / Q000276:immunology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology*; D013698:Templates, Genetic; D014158:Transcription, Genetic; D014162:Transfection
D015703:Antigens, CD; D018106:CD28 Antigens; D017252:CD3 Complex; D017931:DNA Primers; D007376:Interleukin-2; D012333:RNA, Messenger; D015500:Chloramphenicol O-Acetyltransferase