The interleukin 2 CD28-responsive complex contains at least three members of the NF kappa B family: c-Rel, p50, and p65.
Optimal activation of T cells requires at least two signals. One signal can be delivered by the antigen-specific T-cell receptor, and the second signal is provided by the costimulatory molecule(s) delivered by the antigen-presenting cell. CD28 is a T-cell surface molecule and stimulation through this protein plays an important role in delivering the second activation signal. In this report, we show that in human peripheral blood T cells, CD28-mediated signal transduction involves the rel family proteins--c-Rel, p50, and p65. Treatment of peripheral blood T cells with phorbol 12-myristate 13-acetate (PMA) and anti-CD28 monoclonal antibody (mAb) results in augmentation of nuclear c-Rel, p50, and p65, and this augmentation can occur in the presence of the immunosuppressant cyclosporin A. It is also shown in this report that, in response to PMA/anti-CD28 mAb or anti-CD3/anti-CD28 mAb, c-Rel, p50, and p65 are associated with CD28-responsive element present in the promoter of the human interleukin 2 gene. The functional significance of c-Rel involvement in the CD28-responsive complex is demonstrated by transient transfection analysis, where cotransfection of c-Rel augments the level of expression of a chloramphenicol acetyltransferase reporter gene linked to the CD28-responsive element.
Ghosh
P
P
Laboratory of Experimental Immunology, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702-1201.
Tan
T H
TH
Rice
N R
NR
Sica
A
A
Young
H A
HA
D015703:Antigens, CD / Q000502:physiology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D001483:Base Sequence; D018106:CD28 Antigens; D004268:DNA-Binding Proteins / Q000502:physiology; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000235:genetics*; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D020569:Proto-Oncogene Proteins c-rel; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D012045:Regulatory Sequences, Nucleic Acid; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018106:CD28 Antigens; D004268:DNA-Binding Proteins; D007376:Interleukin-2; D016328:NF-kappa B; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; D012333:RNA, Messenger; D011994:Recombinant Proteins