Transcriptional regulation of interleukin-2 gene expression by CD69-generated signals.
The 5' flanking region of the human interleukin (IL)-2 gene was investigated for enhancer activity in response to CD69-generated signals, using a chloramphenicol acetyltransferase (CAT)-driven transient expression system in Jurkat cells. The region extending from -317 to +47 relative to the initiation site of IL-2 gene transcription was shown to contain sequences able to respond to CD69 cross-linking, by enhancing by about 100% a phorbol 12-myristate 13-acetate (PMA)-plus-ionomycin stimulation of CAT activity. A similar increase in CAT activity produced by PMA-plus-anti-CD3 mAb was induced by CD69 cross-linking, while a 200% increase over that obtained by PMA-plus-anti-CD28 mAb stimulation was seen. Analysis of enhancer deletion mutants revealed that proximal AP-1, OCT-1/octamer-associated protein and nuclear factor of activated T cells (NFAT) binding regions were all necessary to allow CD69-mediated enhancement of CAT activity. By gel mobility shift analysis, cyclosporin A-sensitive NFAT-binding induction and enhancement of AP-1 binding activity could be detected in nuclear extracts of both Jurkat and peripheral blood T cells after simultaneous CD69 and protein kinase C stimulation. Finally, CD69-mediated signals could increase NFAT and AP-1 binding activity following PMA and ionomycin stimulation in peripheral blood T cells. Collectively, these data suggest that CD69-generated signals participate in the control of the IL-2 gene expression at the transcriptional level, likely acting through NFAT and AP-1 transcription factor complexes.
D'Ambrosio
D
D
Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, Italy.
Trotta
R
R
Vacca
A
A
Frati
L
L
Santoni
A
A
Gulino
A
A
Testi
R
R
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D001483:Base Sequence; D002460:Cell Line; D003432:Cross-Linking Reagents; D004247:DNA / Q000235:genetics / Q000378:metabolism; D015342:DNA Probes / Q000235:genetics; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics*; D037181:Lectins, C-Type; D008213:Lymphocyte Activation / Q000235:genetics; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D003432:Cross-Linking Reagents; D004247:DNA; D015342:DNA Probes; D007376:Interleukin-2; D037181:Lectins, C-Type; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D000099192:CD69 Antigens