151
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Wan YY, DeGregori J. The survival of antigen-stimulated T cells requires NFkappaB-mediated inhibition of p73 expression. Immunity 2003; 18:331-42. [PMID: 12648451 DOI: 10.1016/s1074-7613(03)00053-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have explored the interactions between the NFkappaB and Cdk-Rb-E2F pathways in controlling T cell fate following antigen stimulation. The inhibition of NFkappaB in antigen-stimulated T cells results in apoptosis but does not inhibit E2F activation and S phase entry. IkappaB-induced apoptosis coincides with the superinduction of p73 expression and activity. G1 Cdk activity is required for IkappaB-induced apoptosis and the induction of p73. Importantly, p73 deficiency rescues activated T cells from the apoptosis resulting from the inhibition of NFkappaB. Thus, Cdk2 activation sends signals for both cell cycle progression and apoptosis, the latter of which must be blocked by NFkappaB to allow for proliferation.
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Affiliation(s)
- Yisong Y Wan
- Program in Molecular Biology, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA
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152
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Iwashima M. Kinetic perspectives of T cell antigen receptor signaling. A two-tier model for T cell full activation. Immunol Rev 2003; 191:196-210. [PMID: 12614361 DOI: 10.1034/j.1600-065x.2003.00024.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
T-cell activation consists of multiple layers of signaling events. Interleukin-2 production is of interest for many, since its expression determines a critical difference between partial and full T-cell activation. To achieve full activation of T cells, it is necessary for the T-cell antigen receptor (TCR) to be engaged for an extended period of time. However, why extended stimulation is required for full T-cell activation is not understood at the molecular level. In this review, orchestrated events of TCR signal transduction will be analyzed in a kinetic manner and connected toward the understanding of the mechanism of T-cell activation. Based on recent results, a model of the mechanism that dictates the threshold between partial and full T-cell activation is proposed.
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Affiliation(s)
- Makio Iwashima
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA 30912-2600, USA.
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153
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Bardos T, Czipri M, Vermes C, Finnegan A, Mikecz K, Zhang J. CD4+CD25+ immunoregulatory T cells may not be involved in controlling autoimmune arthritis. Arthritis Res Ther 2003; 5:R106-13. [PMID: 12718754 PMCID: PMC165034 DOI: 10.1186/ar624] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2002] [Revised: 11/25/2002] [Accepted: 12/17/2002] [Indexed: 01/07/2023] Open
Abstract
Accumulating evidence suggests that regulatory T cells play a crucial role in preventing autoimmunity. Recently, a naturally occurring CD4+CD25+ T-cell subset that is anergic and also suppressive has been shown to suppress autoimmunity in several animal models. We used proteoglycan-induced arthritis (PGIA) as a study model to investigate the role of the CD4+CD25+ regulatory T cells in autoimmune arthritis. There was no significant change in the percentage of CD4+CD25+ T cells during the immunization period when proteoglycan- or ovalbumin-immunized BALB/c and C57BL/6 mice were compared. An adoptive transfer study showed that the CD4+CD25+ T cells did not protect severe combined immunodeficient mice from arthritis when they were cotransferred with splenocytes from arthritic animals. Similarly, depletion of the CD4+CD25+ T cells did not enhance the onset of the disease or disease severity in severe combined immunodeficient mice. Moreover, CD28-deficient mice, which have very few CD4+CD25+ T cells, were highly resistant to PGIA. These findings indicate that the CD4+CD25+ regulatory T cells may not play a critical role in controlling PGIA.
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Affiliation(s)
- Tamas Bardos
- Section of Biochemistry and Molecular Biology, Department of Orthopedic Surgery, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
| | - Matyas Czipri
- Section of Biochemistry and Molecular Biology, Department of Orthopedic Surgery, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
| | - Csaba Vermes
- Section of Biochemistry and Molecular Biology, Department of Orthopedic Surgery, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
| | - Alison Finnegan
- Department Internal Medicine, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
- Department Immunology/Microbiology, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
| | - Katalin Mikecz
- Section of Biochemistry and Molecular Biology, Department of Orthopedic Surgery, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
- Department Immunology/Microbiology, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
- Department of Biochemistry, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
| | - Jian Zhang
- Section of Biochemistry and Molecular Biology, Department of Orthopedic Surgery, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
- Department Immunology/Microbiology, Rush University at Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, USA
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154
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Diehn M, Alizadeh AA, Rando OJ, Liu CL, Stankunas K, Botstein D, Crabtree GR, Brown PO. Genomic expression programs and the integration of the CD28 costimulatory signal in T cell activation. Proc Natl Acad Sci U S A 2002; 99:11796-801. [PMID: 12195013 PMCID: PMC129348 DOI: 10.1073/pnas.092284399] [Citation(s) in RCA: 253] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Optimal activation of T cells requires effective occupancy of both the antigen-specific T cell receptor and a second coreceptor such as CD28. We used cDNA microarrays to characterize the genomic expression program in human peripheral T cells responding to stimulation of these receptors. We found that CD28 agonists alone elicited few, but reproducible, changes in gene expression, whereas CD3 agonists elicited a multifaceted temporally choreographed gene expression program. The principal effect of simultaneous engagement of CD28 was to increase the amplitude of the CD3 transcriptional response. The induced genes whose expression was most enhanced by costimulation were significantly enriched for known targets of nuclear factor of activated T cells (NFAT) transcription factors. This enhancement was nearly abolished by blocking the nuclear translocation of NFATc by using the calcineurin inhibitor FK506. CD28 signaling promoted phosphorylation, and thus inactivation, of the NFAT nuclear export kinase glycogen synthase kinase-3 (GSK3), coincident with enhanced dephosphorylation of NFATc proteins. These results provide a detailed picture of the transcriptional program of T cell activation and suggest that enhancement of transcriptional activation by NFAT, through inhibition of its nuclear export, plays a key role in mediating the CD28 costimulatory signal.
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Affiliation(s)
- Maximilian Diehn
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
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