201
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Behrens F, Himsel A, Rehart S, Stanczyk J, Beutel B, Zimmermann SY, Koehl U, Möller B, Gay S, Kaltwasser JP, Pfeilschifter JM, Radeke HH. Imbalance in distribution of functional autologous regulatory T cells in rheumatoid arthritis. Ann Rheum Dis 2007; 66:1151-6. [PMID: 17392348 PMCID: PMC1955165 DOI: 10.1136/ard.2006.068320] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2007] [Indexed: 01/09/2023]
Abstract
OBJECTIVES Regulatory T cells (Tregs) exert their anti-inflammatory activity predominantly by cell contact-dependent mechanisms. A study was undertaken to investigate the regulatory capacity of autologous peripheral blood Tregs in contact with synovial tissue cell cultures, and to evaluate their presence in peripheral blood, synovial tissue and synovial fluid of patients with rheumatoid arthritis (RA). METHODS 44 patients with RA and 5 with osteoarthritis were included in the study. The frequency of interferon (IFN)gamma-secreting cells was quantified in synovial tissue cell cultures, CD3-depleted synovial tissue cell cultures, synovial tissue cultures co-cultured with autologous CD4+ and with CD4+CD25+ peripheral blood T cells by ELISPOT. Total CD3+, Th1 polarised and Tregs were quantified by real-time PCR for CD3epsilon, T-bet and FoxP3 mRNA, and by immunohistochemistry for FoxP3 protein. RESULTS RA synovial tissue cell cultures exhibited spontaneous expression of IFNgamma which was abrogated by depletion of CD3+ T cells and specifically reduced by co-culture with autologous peripheral blood Treg. The presence of Treg in RA synovitis was indicated by FoxP3 mRNA expression and confirmed by immunohistochemistry. The amount of FoxP3 transcripts, however, was lower in the synovial membrane than in peripheral blood or synovial fluid. The T-bet/FoxP3 ratio correlated with both a higher grade of synovial tissue lymphocyte infiltration and higher disease activity. CONCLUSION This study has shown, for the first time in human RA, the efficacy of autologous Tregs in reducing the inflammatory activity of synovial tissue cell cultures ex vivo, while in the synovium FoxP3+ Tregs of patients with RA are reduced compared with peripheral blood and synovial fluid. This local imbalance of Th1 and Treg may be responsible for repeated rheumatic flares and thus will be of interest as a target for future treatments.
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Affiliation(s)
- Frank Behrens
- pharmazentrum frankfurt, ZAFES Clinic of Goethe University, Frankfurt, Germany
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202
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Beyer M, Schultze JL. CD4+CD25highFOXP3+ regulatory T cells in peripheral blood are primarily of effector memory phenotype. J Clin Oncol 2007; 25:2628-30; author reply 2630-2. [PMID: 17577047 DOI: 10.1200/jco.2006.08.0192] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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203
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Rosenkranz D, Weyer S, Tolosa E, Gaenslen A, Berg D, Leyhe T, Gasser T, Stoltze L. Higher frequency of regulatory T cells in the elderly and increased suppressive activity in neurodegeneration. J Neuroimmunol 2007; 188:117-27. [PMID: 17582512 DOI: 10.1016/j.jneuroim.2007.05.011] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 05/10/2007] [Accepted: 05/11/2007] [Indexed: 12/14/2022]
Abstract
The involvement of regulatory T cells (Treg) in autoimmune-disease development has been demonstrated. However, their alteration during ageing and age-related diseases has not been thoroughly investigated yet. Alzheimer (AD) and Parkinson disease (PD), are related to protein-misfolding and are accompanied by neuroinflammation. Since, it has been hypothesized that the neuroinflammation attempts to prevent disease development, we speculated that changes in Treg might affect any relevant immune mechanism. The analysis of Treg from AD and PD patients as well as non-affected individuals, revealed that the frequency of Treg (CD4(+)Foxp3(+)) increases with age and is accompanied by intensified suppressive activity for Treg in patients.
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204
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Menning A, Höpken UE, Siegmund K, Lipp M, Hamann A, Huehn J. Distinctive role of CCR7 in migration and functional activity of naive- and effector/memory-like Treg subsets. Eur J Immunol 2007; 37:1575-83. [PMID: 17474155 DOI: 10.1002/eji.200737201] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Foxp3+CD25+CD4+ Treg play a fundamental role in the maintenance of self tolerance and the control of inflammatory reactions. Previous data demonstrated a division of labor between naive- and effector/memory-like Treg subsets, which is largely based on their lymph node-recirculating and inflammation-seeking migration behavior, respectively. The chemokine receptor CCR7 is expressed on both types of Treg subsets, albeit at different levels. Whether it fulfills similar or distinct roles in these subsets has not been studied so far. We here show that the recirculation of naive-like Treg through LN and, to some extent, the gut is dependent on CCR7. Lack of CCR7 not only prevents recirculation, but also almost completely abolishes the ability of naive-like Treg to control the priming phase of an immune response. In contrast, CCR7 deficiency in effector/memory-like Treg promotes their accumulation in inflamed sites, compatible with a role of CCR7 for exit from the tissue. Local Treg accumulation was accompanied by an enhanced suppression of inflammation. Together, our findings provide conclusive evidence that CCR7 expression on Treg differentially controls in vivo function of the naive- and effector/memory-like subsets.
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MESH Headings
- Adoptive Transfer/methods
- Animals
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/transplantation
- Cell Movement/genetics
- Cell Movement/physiology
- Cell Proliferation
- Forkhead Transcription Factors/genetics
- Forkhead Transcription Factors/metabolism
- Hypersensitivity, Delayed/immunology
- Immune Tolerance/immunology
- Lymphocyte Activation
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Mice, Transgenic
- Ovalbumin/immunology
- Peptide Fragments/immunology
- Receptors, CCR7
- Receptors, Chemokine/genetics
- Receptors, Chemokine/physiology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/transplantation
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/transplantation
- Th1 Cells/immunology
- Th1 Cells/transplantation
- Vaccination
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Affiliation(s)
- Astrid Menning
- Experimentelle Rheumatologie, Charité Universitätsmedizin Berlin, Berlin, Germany
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205
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Baatar D, Olkhanud P, Sumitomo K, Taub D, Gress R, Biragyn A. Human peripheral blood T regulatory cells (Tregs), functionally primed CCR4+ Tregs and unprimed CCR4- Tregs, regulate effector T cells using FasL. THE JOURNAL OF IMMUNOLOGY 2007; 178:4891-900. [PMID: 17404270 PMCID: PMC2262930 DOI: 10.4049/jimmunol.178.8.4891] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Regulatory CD25(+)CD4(+) T cells (Tregs) play an important role in the control of peripheral tolerance. In this study we demonstrate that human peripheral blood Tregs can be divided into two distinct populations based on the expression of CCR4. The majority ( approximately 75%) of freshly isolated Tregs express CCR4 and presumably represent memory-type Tregs. Interestingly, CCR4(-) Tregs require anti-CD3 Ab-mediated activation to acquire a regulatory activity, while CCR4(+) Tregs appear to be already primed to suppress the proliferation of CD8(+) T cells. CCR4 is also expressed on CD25(low)CD4(+) T cells (CCR4(+) non-Tregs) that mostly suppress Th1-type polarization without affecting T cell proliferation, presumably via the production of immunomodulatory cytokines like IL-10. In contrast, CCR4(+) Tregs express FasL to primarily regulate T cell proliferation via a contact-mediated process involving FasL/Fas signaling, a major regulatory pathway of T cell homeostasis. Finally, we also demonstrate that the depletion of CCR4(+) T cells leads to Th1-type polarization of CD4(+) T cells and augmentation of CD8(+) T cell responses to tumor Ags.
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Affiliation(s)
- Dolgor Baatar
- Laboratory of Immunology, Gerontology Research Center, National Institute on Aging, Baltimore, MD 21224
| | - Purevdorj Olkhanud
- Laboratory of Immunology, Gerontology Research Center, National Institute on Aging, Baltimore, MD 21224
| | - Kenya Sumitomo
- Laboratory of Immunology, Gerontology Research Center, National Institute on Aging, Baltimore, MD 21224
| | - Dennis Taub
- Laboratory of Immunology, Gerontology Research Center, National Institute on Aging, Baltimore, MD 21224
| | - Ronald Gress
- Experimental Transplantation and Immunology Branch, National Caner Institute, Bethesda, MD 20892
| | - Arya Biragyn
- Laboratory of Immunology, Gerontology Research Center, National Institute on Aging, Baltimore, MD 21224
- Address correspondence and reprint requests to Dr. Arya Biragyn, Gerontology Research Center, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Box 21, Baltimore, Maryland 21224. E-mail address:
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206
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Dell’Agnola C, Biragyn A. Clinical utilization of chemokines to combat cancer: the double-edged sword. Expert Rev Vaccines 2007; 6:267-83. [PMID: 17408375 PMCID: PMC2262932 DOI: 10.1586/14760584.6.2.267] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Chemokines are a small group of related chemo-attractant peptides that play an essential role in the homeostatic maintenance of the immune system. They control the recruitment of cells needed for the induction and activation of innate and adaptive immune responses. However, tumors also utilize chemokines to actively progress and evade immunosurveillance. In fact, chemokines are involved directly or indirectly in almost every aspect of tumorigenesis. They mediate survival and metastatic spread of tumors, promote new blood vessel formation (neovascularization) and induce an immunosuppressive microenvironment via recruitment of immunosuppressive cells. As a result, a number of therapeutic strategies have been proposed to target almost every step of the chemokine/chemokine receptor involvement in tumors. Yet, despite occasional success stories, most of them appear to be ineffective or impractical, presumably due to 'nonspecific' harm of cells needed for the elimination of tumor escapees and maintenance of immunological memory. The strategy would only be effective if it also promoted antitumor adaptive immune responses capable of combating a residual disease and tumor relapse.
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Affiliation(s)
- Chiara Dell’Agnola
- Chiara Dell’Agnola, MD, Research Assistant, Department of Clinical and Experimental Medicine, Division of Oncology, University of Verona, Ospedale Policlinico GB Rossi, Piazzale Ludovico Scuro 10, 37134 Verona, Italy, Tel.: +39 045 812 8121 (office), +39 045 812 8502 (secretary), Fax: +39 045 802 7410,
| | - Arya Biragyn
- Author for correspondence National Institute on Aging, 5600 Nathan Shock Drive, Laboratory of Immunology, Gerontology Research Center National Institute on Aging, Baltimore, MD 21224, USA Tel.: +1 410 558 8680, Fax: +1 410 558 8284,
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207
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Schneider MA, Meingassner JG, Lipp M, Moore HD, Rot A. CCR7 is required for the in vivo function of CD4+ CD25+ regulatory T cells. ACTA ACUST UNITED AC 2007; 204:735-45. [PMID: 17371928 PMCID: PMC2118557 DOI: 10.1084/jem.20061405] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
CCR7-mediated migration of naive T cells into the secondary lymphoid organs is a prerequisite for their encounter with mature dendritic cells, the productive presentation of cognate antigen, and consequent T cell proliferation and effector differentiation. Therefore, CCR7 was suggested to play an important role in the initiation of adaptive immune responses. In this study, we show that primary immunity can also develop in the absence of CCR7. Moreover, CCR7-deficient knockout (KO) mice display augmented immune responses. Our data cumulatively suggest that enhanced immunity in CCR7 KO mice is caused by the defective lymph node (LN) positioning of FoxP3+ CD4+ CD25+ regulatory T cells (T reg cells) and the consequent impediment of their function. The FoxP3+ T reg cells express CCR7 and, after their adoptive transfer, migrate into the LNs of wild-type mice. Here, they proliferate in situ upon antigen stimulation and inhibit the generation of antigen-specific T cells. Conversely, transferred CCR7-deficient T reg cells fail to migrate into the LNs and suppress antigen-induced T cell responses. The transfer of combinations of naive and T reg cells from wild-type and CCR7 KO mice into syngeneic severe combined immunodeficient mice directly demonstrates that CCR7-deficient T reg cells are less effective than their wild-type counterparts in preventing the development of inflammatory bowel disease.
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MESH Headings
- Animals
- Antigens, CD/metabolism
- Cell Proliferation
- Dermatitis, Contact/genetics
- Dermatitis, Contact/metabolism
- Dermatitis, Contact/pathology
- Forkhead Transcription Factors/metabolism
- Gene Expression Regulation
- Hyaluronan Receptors/metabolism
- Integrin alpha Chains/metabolism
- Interleukin-2 Receptor alpha Subunit/metabolism
- Lymph Nodes/metabolism
- Mice
- Mice, Knockout
- Receptors, Antigen, T-Cell/metabolism
- Receptors, CCR2
- Receptors, CCR7
- Receptors, Chemokine/deficiency
- Receptors, Chemokine/genetics
- Receptors, Chemokine/metabolism
- Spleen/metabolism
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
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208
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Akbar AN, Vukmanovic-Stejic M, Taams LS, Macallan DC. The dynamic co-evolution of memory and regulatory CD4+ T cells in the periphery. Nat Rev Immunol 2007; 7:231-7. [PMID: 17318234 DOI: 10.1038/nri2037] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Whereas memory T cells are required to maintain immunity, regulatory T cells have to keep the immune system in check to prevent excessive inflammation and/or autoimmunity. Both cell types must be present during the lifetime of the organism. However, it is not clear whether both subsets are regulated in tandem or independently of each other, especially because thymic involution severely restricts the production of T-cell populations during ageing. In this Opinion article, we discuss recent evidence in both mice and humans that supports the hypothesis that some CD4(+)CD25(+)FOXP3(+)regulatory T cells can differentiate from rapidly proliferating memory T cells in the periphery.
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Affiliation(s)
- Arne N Akbar
- Department of Immunology and Molecular Pathology, Division of Infection and Immunity, Windeyer Institute of Medical Sciences, University College London, London W1T 4JF, UK.
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209
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van Roon JAG, Bijlsma JWJ, Lafeber FPJG. Diversity of regulatory T cells to control arthritis. Best Pract Res Clin Rheumatol 2007; 20:897-913. [PMID: 16980213 DOI: 10.1016/j.berh.2006.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
During follow-up of the suppressive functions of CD4+ T helper (Th) 2 cells in recent years, the suppressive capacities of newly recognised CD4+ Th cells with more widespread suppressive potential have been extensively investigated. These Th cells, collectively termed regulatory T cells, are characterised by the secretion of specific cytokines, such as interleukin (IL)-10 (Tr1 Th cells), transforming growth factor (TGF)beta (Th3 cells) or the constitutive expression of CD25 (naturally occurring T regulatory cells, nTregs). The balance of these regulatory T cells with pro-inflammatory effector T cells, such as Th1 (interferon (IFN)gamma secreting), Th17 (IL-17 secreting) and CD25- Th cells, has been shown to be of pivotal importance for the development and persistence of autoimmune diseases. The high potential of regulatory T cells (in particular nTregs), to efficiently suppress several arthritic responses both in humans and in animal models of arthritis, make them therapeutic targets of interest in arthritic conditions such as rheumatoid arthritis.
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Affiliation(s)
- Joel A G van Roon
- Department of Rheumatology and Clinical Immunology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
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210
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Sharma S, Dominguez AL, Lustgarten J. High accumulation of T regulatory cells prevents the activation of immune responses in aged animals. THE JOURNAL OF IMMUNOLOGY 2007; 177:8348-55. [PMID: 17142731 DOI: 10.4049/jimmunol.177.12.8348] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In our previous in vivo study we demonstrated that young BALB/c mice effectively rejected the BM-185 tumor cells expressing enhanced GFP (EGFP) as a surrogate tumor Ag. In contrast, old BALB/c mice succumbed to the BM-185-EGFP tumors, indicating that there is a deficiency in old animals preventing the rejection of immunogenic tumors. There is cumulative evidence indicating that regulatory T (T(reg)) cells control the activation of primary and memory T cell responses. However, very little is known about whether there is a relation between T(regs) and the lack of immune responses in the aged. We evaluated young and aged animals, and our results demonstrated that there are significantly more CD4+CD25+FoxP3+ and CD8+CD25+FoxP3+ T(regs) in the spleen and lymph nodes of old animals when compared with the young. Depletion of CD25+ cells with anti-CD25 mAb induces the rejection of BM-185-EGFP cells, restores antitumor T cell cytotoxic activity, and results in the generation of a protective memory response against the BM-185 wild-type tumors in old mice. Furthermore, vaccination with CpG-oligodeoxynucleotide decreases the number of T(reg) cells in old animals to the same levels as young mice, restoring the primary and memory antitumor immune responses against BM-185-EGFP tumors. Taken together, these results indicate that there is a direct correlation between the expansion of T(reg) cells and immune deficiency in the old, and that depletion of these cells might be critical for restoring immune responses in aged animals.
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Affiliation(s)
- Sanjay Sharma
- Sidney Kimmel Cancer Center, San Diego, CA 92121, USA
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211
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Franz B, Fritzsching B, Riehl A, Oberle N, Klemke CD, Sykora J, Quick S, Stumpf C, Hartmann M, Enk A, Ruzicka T, Krammer PH, Suri-Payer E, Kuhn A. Low number of regulatory T cells in skin lesions of patients with cutaneous lupus erythematosus. ACTA ACUST UNITED AC 2007; 56:1910-20. [PMID: 17530636 DOI: 10.1002/art.22699] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To define the phenotype and function of CD4+,CD25+ regulatory T cells (Treg) in patients with cutaneous lupus erythematosus (CLE), a heterogeneous autoimmune disease characterized primarily by inflammatory skin lesions. METHODS The number of Treg in skin specimens obtained from patients with various subtypes of CLE was investigated by immunohistochemical analysis, using anti-Foxp3 and anti-CD4 monoclonal antibodies. Furthermore, characterization of peripheral blood CD4+,CD25+ Treg from normal healthy donors and patients with CLE was carried out by flow cytometry, analyzing the expression of Foxp3 and Treg subpopulations. We also purified CD4+,CD25(high) Treg obtained from patients with CLE and tested the sensitivity of these cells to CD95L-mediated apoptosis. RESULTS Quantitative analysis of CD4+ T cells in skin lesions from patients with CLE revealed that the number was similar to that in lesions from patients with other chronic inflammatory diseases, but the number of Foxp3+ Treg in CLE was significantly reduced. There was no correlation between disease subtype and the frequency of Foxp3+ Treg in the skin of patients with CLE. In peripheral blood, no significant differences were observed in the number and phenotype of CD4+,CD25+ Treg or in the sensitivity to apoptosis of CD4+,CD25(high) Treg derived from patients with CLE and those derived from normal healthy donors. CONCLUSION These data suggest that an organ-specific abnormality of Treg in the skin underscores the importance of analyzing Treg in the affected tissue. Such a local process might give insight into the pathogenic mechanisms of CLE and differs from a global peripheral dysfunction as reported for patients with a systemic manifestation of the disease.
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Affiliation(s)
- B Franz
- German Cancer Research Center, Heidelberg, Germany
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212
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Goldstein I, Ben-Horin S, Koltakov A, Chermoshnuk H, Polevoy V, Berkun Y, Amariglio N, Bank I. α1β1 Integrin+ and Regulatory Foxp3+ T Cells Constitute Two Functionally Distinct Human CD4+ T Cell Subsets Oppositely Modulated by TNFα Blockade. THE JOURNAL OF IMMUNOLOGY 2006; 178:201-10. [PMID: 17182556 DOI: 10.4049/jimmunol.178.1.201] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The expression of the collagen receptor alpha(1)beta(1) integrin (VLA-1) on CD4(+) T cells is largely restricted to CCR7(-)CD45RO(+) cells that localize to inflamed tissues. Moreover, neutralizing alpha(1) integrin, in vivo, has been shown to compromise cell-mediated immunity. Our current study shows that the expression of VLA-1 on human CD4(+) T cells is restricted to conventional effectors. In contrast, Foxp3(+) T regulatory cells (Tregs) do not express this receptor. Moreover, Foxp3 or VLA-1 expression remained a mutually exclusive event in CD4(+) T cells even upon polyclonal anti-CD3-induced activation. Because TNFalpha blockade ameliorates certain T cell-dependent autoimmune disorders in humans, we investigated, in vitro, whether neutralizing TNFalpha affected the balance between the proinflammatory VLA-1(+) effectors and the counteracting Tregs. We found that anti-CD3 stimulation of freshly isolated PBL from healthy individuals, coupled with continuous TNFalpha blockade, inhibited the typical activation-dependent generation of CD4(+)VLA-1(+) Th1 cells. In contrast, it augmented the outgrowth of VLA-1(neg/dim)CD25(high) and Foxp3(+)CD4(+) T cells. Indeed, repeated anti-CD3 stimulation coupled with TNFalpha blockade generated CD4(+) T cell lines enriched for VLA-1(-)Foxp3(+) Tregs. Importantly, these CD4(+) T cells displayed potent suppressive functions toward autologous CD4(+) PBL, including the suppression of the activation-dependent induction of VLA-1(+) effectors. Thus, we propose a novel mechanism by which anti-TNFalpha therapy may restore self-tolerance, by shifting the balance between VLA-1(+) effectors and Foxp3(+) Tregs, during immune activation, in favor of the latter suppressor cell population.
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Affiliation(s)
- Itamar Goldstein
- Laboratory for Immunoregulation, Chaim Sheba Medical Center, Tel Aviv University, Tel Hashomer, Israel.
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213
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Pillai V, Ortega SB, Wang CK, Karandikar NJ. Transient regulatory T-cells: a state attained by all activated human T-cells. Clin Immunol 2006; 123:18-29. [PMID: 17185041 PMCID: PMC1868523 DOI: 10.1016/j.clim.2006.10.014] [Citation(s) in RCA: 273] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 10/31/2006] [Accepted: 10/31/2006] [Indexed: 12/17/2022]
Abstract
CD4(+)CD25(+)FOXP3(+) regulatory T-cells (T(regs)) form an important arm of the immune system responsible for suppressing untoward immune responses. T(regs) can be thymically derived or peripherally induced, even from CD4(+)CD25(-)FOXP3(-) T-cells. FOXP3 expression and in vitro suppressive activity are considered unique hallmarks of this dedicated and stable lineage of regulatory cells. Here we show that virtually all human CD4(+)CD25(-)FOXP3(-) T-cells and CD8(+)CD25(-)FOXP3(-) T-cells attain a transient FOXP3(+)CD25(+) state during activation. In this state of activation, these cells possess the classic phenotype of T(regs), in that they express similar markers and inhibit in vitro proliferation of autologous CD4(+)CD25(-) T-cells. This state is characterized by suppressed IFN-gamma production and robust TNF-alpha and IL-10 production. Interestingly, the great majority of the activated cells eventually downregulate FOXP3 expression, with a concomitant drop in suppressive ability. Our results show that, in humans, FOXP3 expression and T(reg) functionality are not exclusive features of a stable or unique lineage of T-cells but may also be a transient state attained by almost all T-cells. These results warrant caution in interpreting human studies using FOXP3 and suppressive activity as readouts and suggest that attempts to induce "T(regs)" may paradoxically result in induction of effector T-cells, unless stability is confirmed.
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Affiliation(s)
- Vinodh Pillai
- Department of Pathology, The University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9072, USA
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214
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Illoh K, Campbell C, Illoh O, Diehl J, Cherry J, Elkhaloun A, Chen Y, Hallenbeck J. Mucosal tolerance to E-selectin and response to systemic inflammation. J Cereb Blood Flow Metab 2006; 26:1538-50. [PMID: 16596122 PMCID: PMC1853373 DOI: 10.1038/sj.jcbfm.9600308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mucosal tolerance to E-selectin has been shown to prevent stroke and reduce brain infarcts in experimental stroke models. However, the effective E-selectin dose range required to achieve mucosal tolerance and the precise mechanisms of neuroprotection remain unclear. We sought to examine the mechanisms of cytoprotection using gene expression profiling of tissues in the setting of mucosal tolerance and inflammatory challenge. Using spontaneously hypertensive rats (SHRs), we achieved immune tolerance with 0.1 to 5 microg E-selectin per nasal instillation and observed a dose-related anti-E-selectin immunoglobulin G antibody production. We also show the distinct patterns of gene expression changes in the brain and spleen with the different tolerizing doses and lipopolysaccharide (LPS) exposure. Prominent differences were seen with such genes as insulin-like growth factors in the brain and downregulation of those encoding the major histocompatibility complex class I molecules in the spleen. In all, mucosal tolerance to E-selectin and subsequent exposure to LPS resulted in significant tissue changes. These changes, while giving an insight to the underlying mechanisms, serve as possible targets for future studies to facilitate translation to human clinical trials.
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Affiliation(s)
- Kachi Illoh
- Department of Neurology, University of Texas Health Sciences Center, Houston, Texas 77030, USA.
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215
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Abstract
Increasing evidence supports the existence of elevated numbers of regulatory T cells (T(reg) cells) in solid tumors and hematologic malignancies. Whereas the biology of CD4(+)CD25(+)FOXP3(+) T(reg) cells in murine models seems to be rather straightforward, studies in human diseases are more difficult to interpret due to expression of CD25 on activated effector T cells as well as T(reg) cells. More importantly, early studies in human tumors were mainly focused on CD4(+)CD25(+) T(reg) cells lacking interrogation of more specific markers such as FOXP3 expression. Although the increase of T(reg) cells seems to be a characteristic feature in most tumors, little is known about the molecular and cellular mechanisms responsible for the increase and maintenance of elevated levels of T(reg) cells in cancer. We will discuss earlier data in the context of recent findings in T(reg)-cell biology with a particular emphasis on CD4(+)CD25(high)FOXP3(+) T(reg) cells in human malignancies.
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Affiliation(s)
- Marc Beyer
- Molecular Tumor Biology and Tumor Immunology Clinic I for Internal Medicine, University of Cologne, Joseph-Stelzmann Str 9/Haus 16, 50931 Cologne, Germany
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216
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Valmori D, Tosello V, Souleimanian NE, Godefroy E, Scotto L, Wang Y, Ayyoub M. Rapamycin-mediated enrichment of T cells with regulatory activity in stimulated CD4+ T cell cultures is not due to the selective expansion of naturally occurring regulatory T cells but to the induction of regulatory functions in conventional CD4+ T cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:944-9. [PMID: 16818749 DOI: 10.4049/jimmunol.177.2.944] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rapamycin is an immunosuppressive drug currently used in different clinical settings. Although the capacity of rapamycin to inhibit the mammalian target of rapamycin serine/threonine protein kinase and therefore T cell cycle progression is well known, its effects are complex and not completely understood. It has been reported recently that TCR-mediated stimulation of murine CD4+ T cells in the presence of rapamycin results in increased proportions of CD4+ T cells with suppressive functions, suggesting that the drug may also exert its immunosuppressive activity by promoting the selective expansion of naturally occurring CD4+ regulatory T cells (Treg). In this study, we show that stimulation of human circulating CD4+ T cells in the presence of rapamycin results indeed in highly increased suppressor activity. By assessing the effect of rapamycin on the growth of nonregulatory and Treg populations of defined differentiation stages purified ex vivo from circulating CD4+ T cells, we could demonstrate that this phenomenon is not due to a selective expansion of naturally occurring Tregs, but to the capacity of rapamycin to induce, upon TCR-mediated stimulation, suppressor functions in conventional CD4+ T cells. This condition, however, is temporary and reversible as it is dependent upon the continuous presence of rapamycin.
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Affiliation(s)
- Danila Valmori
- Ludwig Institute Clinical Trial Center, Department of Medicine, Columbia University College of Physicians and Surgeons, Black Building 20-09, 650 West 168th Street, New York, NY 10032, USA.
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217
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Hoffmann P, Eder R, Boeld TJ, Doser K, Piseshka B, Andreesen R, Edinger M. Only the CD45RA+ subpopulation of CD4+CD25high T cells gives rise to homogeneous regulatory T-cell lines upon in vitro expansion. Blood 2006; 108:4260-7. [PMID: 16917003 DOI: 10.1182/blood-2006-06-027409] [Citation(s) in RCA: 335] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Thymus-derived CD4+ CD25+ regulatory T cells suppress autoreactive CD4+ and CD8+ T cells and thereby protect from autoimmunity. In animal models, adoptive transfer of CD4+ CD25+ regulatory T cells has been shown to prevent and even cure autoimmune diseases as well as pathogenic alloresponses after solid organ and stem-cell transplantations. We recently described methods for the efficient in vitro expansion of human regulatory T cells for clinical applications. We now demonstrate that only CCR7- and L-selectin (CD62L)-coexpressing cells within expanded CD4+ CD25high T cells maintain phenotypic and functional characteristics of regulatory T cells. Further analysis revealed that these cells originate from CD45RA+ naive cells within the CD4+ CD25high T-cell compartment, as only this subpopulation homogeneously expressed CD62L, CCR7, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), and forkhead box P3 (FOXP3), produced no inflammatory cytokines and maintained robust suppressive activity after expansion. In contrast, cell lines derived from CD45RA- memory-type CD4+ CD25high T cells lost expression of lymph node homing receptors CCR7 and CD62L, contained interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) as well as IL-10-secreting cells, showed only moderate suppression and, most importantly, did not maintain FOXP3 expression. Based on these unexpected findings, we suggest that isolation and expansion of CD45RA+ naive CD4+ CD25high T cells is the best strategy for adoptive regulatory T (Treg)-cell therapies.
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MESH Headings
- Antigens, CD/biosynthesis
- Antigens, CD/immunology
- Antigens, Differentiation/biosynthesis
- Antigens, Differentiation/immunology
- CTLA-4 Antigen
- Cell Differentiation/immunology
- Cell Proliferation
- Cells, Cultured
- Cytokines/biosynthesis
- Cytokines/immunology
- Female
- Forkhead Transcription Factors/biosynthesis
- Forkhead Transcription Factors/immunology
- Gene Expression Regulation/immunology
- Humans
- Immunotherapy, Adoptive
- L-Selectin/biosynthesis
- L-Selectin/immunology
- Leukocyte Common Antigens/biosynthesis
- Leukocyte Common Antigens/immunology
- Male
- Receptors, CCR7
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/immunology
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
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Affiliation(s)
- Petra Hoffmann
- Institute of Immunology, Department of Hematology & Oncology, University Hospital Regensburg, Regensburg, Germany.
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218
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Fritzsching B, Oberle N, Pauly E, Geffers R, Buer J, Poschl J, Krammer P, Linderkamp O, Suri-Payer E. Naive regulatory T cells: a novel subpopulation defined by resistance toward CD95L-mediated cell death. Blood 2006; 108:3371-8. [PMID: 16868256 DOI: 10.1182/blood-2006-02-005660] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Most CD4(+)CD25(hi)FOXP3(+) regulatory T cells (T(regs)) from adult peripheral blood express high levels of CD45RO and CD95 and are prone to CD95L-mediated apoptosis in contrast to conventional T cells (T(convs)). However, a T(reg) subpopulation remained consistently apoptosis resistant. Gene microarray and 6-color flow cytometry analysis including FOXP3 revealed an increase in naive T-cell markers on the CD95L-resistant T(regs) compared with most T(regs). In contrast to T(regs) found in adult humans, most CD4(+)CD25(+)FOXP3(+) T cells found in cord blood are naive and exhibit low CD95 expression. Furthermore, most of these newborn T(regs) are not sensitive toward CD95L similar to naive T(regs) from adult individuals. After short stimulation with anti-CD3/CD28 monoclonal antibodies (mAbs), cord blood T(regs) strongly up-regulated CD95 and were sensitized toward CD95L. This functional change was paralleled by a rapid up-regulation of memory T-cell markers on cord blood T(regs) that are frequently found on adult memory T(regs). In summary, we show a clear functional difference between naive and memory T(regs) that could result in different survival rates of those 2 cell populations in vivo. This new observation could be crucial for the planning of therapeutic application of T(regs).
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Affiliation(s)
- Benedikt Fritzsching
- Department of Neonatology, Children's Hospital, University of Heidelberg, Im Neuenheimer Feld 153, 69120 Heidelberg, Germany.
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219
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Lim HW, Broxmeyer HE, Kim CH. Regulation of Trafficking Receptor Expression in Human Forkhead Box P3+Regulatory T Cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:840-51. [DOI: 10.4049/jimmunol.177.2.840] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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220
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Seddiki N, Santner-Nanan B, Martinson J, Zaunders J, Sasson S, Landay A, Solomon M, Selby W, Alexander SI, Nanan R, Kelleher A, Fazekas de St Groth B. Expression of interleukin (IL)-2 and IL-7 receptors discriminates between human regulatory and activated T cells. ACTA ACUST UNITED AC 2006; 203:1693-700. [PMID: 16818676 PMCID: PMC2118333 DOI: 10.1084/jem.20060468] [Citation(s) in RCA: 1185] [Impact Index Per Article: 65.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abnormalities in CD4(+)CD25(+)Foxp3(+) regulatory T (T reg) cells have been implicated in susceptibility to allergic, autoimmune, and immunoinflammatory conditions. However, phenotypic and functional assessment of human T reg cells has been hampered by difficulty in distinguishing between CD25-expressing activated and regulatory T cells. Here, we show that expression of CD127, the alpha chain of the interleukin-7 receptor, allows an unambiguous flow cytometry-based distinction to be made between CD127(lo) T reg cells and CD127(hi) conventional T cells within the CD25(+)CD45RO(+)RA(-) effector/memory and CD45RA(+)RO(-) naive compartments in peripheral blood and lymph node. In healthy volunteers, peripheral blood CD25(+)CD127(lo) cells comprised 6.35 +/- 0.26% of CD4(+) T cells, of which 2.05 +/- 0.14% expressed the naive subset marker CD45RA. Expression of FoxP3 protein and the CD127(lo) phenotype were highly correlated within the CD4(+)CD25(+) population. Moreover, both effector/memory and naive CD25(+)CD127(lo) cells manifested suppressive activity in vitro, whereas CD25(+)CD127(hi) cells did not. Cell surface expression of CD127 therefore allows accurate estimation of T reg cell numbers and isolation of pure populations for in vitro studies and should contribute to our understanding of regulatory abnormalities in immunopathic diseases.
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Affiliation(s)
- Nabila Seddiki
- Centenary Institute of Cancer Medicine and Cell Biology, Faculty of Medicine, University of Sydney, Newtown, NSW 2042, Australia
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221
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Affiliation(s)
- D Chen
- Department of Ophthalmology, Immunobiology and the Recanti/Miller Transplantation Institute, Mount Sinai School of Medicine, New York, NY, USA
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222
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Eksteen B, Miles A, Curbishley SM, Tselepis C, Grant AJ, Walker LSK, Adams DH. Epithelial Inflammation Is Associated with CCL28 Production and the Recruitment of Regulatory T Cells Expressing CCR10. THE JOURNAL OF IMMUNOLOGY 2006; 177:593-603. [PMID: 16785557 DOI: 10.4049/jimmunol.177.1.593] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mucosal tissues require constant immune surveillance to clear harmful pathogens while maintaining tolerance to self Ags. Regulatory T cells (Tregs) play a central role in this process and expression of alpha(E)beta(7) has been reported to define a subset of Tregs with tropism for inflamed tissues. However, the signals responsible for recruiting Tregs to epithelial surfaces are poorly understood. We have isolated a subset of CCR10-expressing CD25+CD4+Foxp3+ Tregs with potent anti-inflammatory properties from chronically inflamed human liver. The CCR10+ Tregs were detected around bile ducts that expressed increased levels of the CCR10 ligand CCL28. CCL28 was secreted by primary human cholangiocytes in vitro in response to LPS, IL-1beta, or bile acids. Exposure of CCR10+ Tregs to CCL28 in vitro stimulated migration and adhesion to mucosal addressin cell adhesion molecule-1 and VCAM-1. Liver-derived CCR10+ Tregs expressed low levels of CCR7 but high levels of CXCR3, a chemokine receptor associated with infiltration into inflamed tissue and contained a subset of alpha(E)beta7(+) cells. We propose that CXCR3 promotes the recruitment of Tregs to inflamed tissues and CCR10 allows them to respond to CCL28 secreted by epithelial cells resulting in the accumulation of CCR10+ Tregs at mucosal surfaces.
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MESH Headings
- Bile Ducts/immunology
- Bile Ducts/metabolism
- Bile Ducts/pathology
- Cells, Cultured
- Chemokines/biosynthesis
- Chemokines/metabolism
- Chemokines, CC
- Chemotaxis, Leukocyte/immunology
- Cholangitis, Sclerosing/immunology
- Cholangitis, Sclerosing/metabolism
- Cholangitis, Sclerosing/pathology
- Chronic Disease
- Epithelial Cells/immunology
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Forkhead Transcription Factors/biosynthesis
- Humans
- Immunity, Mucosal
- Inflammation Mediators/metabolism
- Inflammation Mediators/physiology
- Interleukin-1/pharmacology
- Interleukin-10/biosynthesis
- Interleukin-10/metabolism
- Lipopolysaccharides/pharmacology
- Liver Cirrhosis, Biliary/immunology
- Liver Cirrhosis, Biliary/metabolism
- Liver Cirrhosis, Biliary/pathology
- Liver Diseases, Alcoholic/immunology
- Liver Diseases, Alcoholic/metabolism
- Liver Diseases, Alcoholic/pathology
- Receptors, CCR10
- Receptors, CCR7
- Receptors, CXCR3
- Receptors, Chemokine/biosynthesis
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocyte Subsets/pathology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- T-Lymphocytes, Regulatory/pathology
- Up-Regulation/immunology
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Affiliation(s)
- Bertus Eksteen
- Liver Research Laboratories, Medical Research Council for Immune Regulation, Institute for Biomedical Research, University of Birmingham, Birmingham B15 2TH, UK
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223
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Beyer M, Kochanek M, Giese T, Endl E, Weihrauch MR, Knolle PA, Classen S, Schultze JL. In vivo peripheral expansion of naive CD4+CD25highFoxP3+ regulatory T cells in patients with multiple myeloma. Blood 2006; 107:3940-9. [PMID: 16410445 DOI: 10.1182/blood-2005-09-3671] [Citation(s) in RCA: 231] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In solid tumors, leukemias, and lymphomas, increased frequencies of functional CD4+CD25high regulatory T cells (Treg cells) have been previously demonstrated. In healthy individuals, Treg cells consist not only of memory but also of naive T cells, which can undergo peripheral expansion and are characterized by a relative enrichment for autoreactive T-cell receptors. Here, we demonstrate in patients with premalignant monoclonal gammopathy of undetermined significance and patients with multiple myeloma that functional FoxP3+ Treg cells of naive, central, and effector memory phenotype as determined by CCR7 and CD45RA expression are significantly expanded. Low frequencies of T-cell receptor excision circles in naive Treg cells in both healthy controls and multiple myeloma patients point to peripheral expansion as the prominent mechanism of increased frequencies of naive Treg cells in these cancer patients. These findings strongly suggest that the increase of functional Treg cells in cancer patients is a response to the process of malignant transformation.
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MESH Headings
- Antigens, CD/blood
- Antigens, CD/genetics
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- Flow Cytometry
- Forkhead Transcription Factors/blood
- Forkhead Transcription Factors/genetics
- Forkhead Transcription Factors/immunology
- Humans
- Leukocyte Common Antigens/blood
- Leukocyte Common Antigens/genetics
- Multiple Myeloma/blood
- Multiple Myeloma/immunology
- Receptors, Antigen, T-Cell/blood
- Receptors, Antigen, T-Cell/immunology
- Receptors, CCR7
- Receptors, Chemokine/blood
- Receptors, Chemokine/genetics
- Receptors, Interleukin-2/blood
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Affiliation(s)
- Marc Beyer
- Molecular Tumor Biology and Tumor Immunology, Clinic I for Internal Medicine, University of Cologne, Joseph-Stelzmann Strasse 9/Haus 16, 50931 Cologne, Germany
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224
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Vojdani A, Erde J. Regulatory T Cells, a Potent Immunoregulatory Target for CAM Researchers: Modulating Allergic and Infectious Disease Pathology (II). EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2006; 3:209-15. [PMID: 16786050 PMCID: PMC1475941 DOI: 10.1093/ecam/nel020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Accepted: 03/16/2006] [Indexed: 01/13/2023]
Abstract
Regulatory T (Treg) cells maintain dominant control of immune responses to foreign materials and microbes. Appropriate Treg cell suppression of immune responses is essential for the maintenance of efficacious defensive responses and the limitation of collateral tissue damage due to excess inflammation. Allergy and infection are well studied and frequent afflictions in which Treg cells play an essential role. As such, they provide excellent models to communicate the significance and relevance of Treg cells to complementary and alternative medicine (CAM).
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225
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Dejaco C, Duftner C, Schirmer M. Are regulatory T-cells linked with aging? Exp Gerontol 2006; 41:339-45. [PMID: 16516426 DOI: 10.1016/j.exger.2006.01.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 01/11/2006] [Accepted: 01/24/2006] [Indexed: 01/10/2023]
Abstract
There is increasing evidence for an active and 'dominant' tolerance mediated by regulatory T-cells. Out of these CD4+ 'naturally occurring' regulatory T-cells (TREGs) are currently the main research focus in this field. TREGs exert their suppressive function in vitro in a contact-dependent manner and preferentially express high levels of CD25 and the forkhead and winged-helix family transcription factor forkhead box P3 (FOXP3). Age-related increment of the prevalences of CD4+ CD25(hi) TREGs were described controversially, and whether such changes explain immune dysfunction in the elderly is still unclear. During aging thymic TREG output may decrease with significant loss of thymic capacity to generate new T-cells, and TREG homeostasis has been shown to be sustained by alternative pathways like peripheral generation of TREGs. An imbalance of TREG homeostasis would then predispose to immune dysfunction in aged individuals explaining their higher risk of immune-mediated diseases, cancer or infections.
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Affiliation(s)
- Christian Dejaco
- Division of General Internal Medicine, Clinical Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria
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226
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Dietert RR, Piepenbrink MS. Perinatal immunotoxicity: why adult exposure assessment fails to predict risk. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:477-83. [PMID: 16581533 PMCID: PMC1440768 DOI: 10.1289/ehp.8566] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Recent research has pointed to the developing immune system as a remarkably sensitive toxicologic target for environmental chemicals and drugs. In fact, the perinatal period before and just after birth is replete with dynamic immune changes, many of which do not occur in adults. These include not only the basic maturation and distribution of immune cell types and selection against autoreactive lymphocytes but also changes designed specifically to protect the pregnancy against immune-mediated miscarriage. The newborn is then faced with critical immune maturational adjustments to achieve an immune balance necessary to combat myriad childhood and later-life diseases. All these processes set the fetus and neonate completely apart from the adult regarding immunotoxicologic risk. Yet for decades, safety evaluation has relied almost exclusively upon exposure of the adult immune system to predict perinatal immune risk. Recent workshops and forums have suggested a benefit in employing alternative exposures that include exposure throughout early life stages. However, issues remain concerning when and where such applications might be required. In this review we discuss the reasons why immunotoxic assessment is important for current childhood diseases and why adult exposure assessment cannot predict the effect of xenobiotics on the developing immune system. It also provides examples of developmental immunotoxicants where age-based risk appears to differ. Finally, it stresses the need to replace adult exposure assessment for immune evaluation with protocols that can protect the developing immune system.
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Affiliation(s)
- Rodney R Dietert
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, North Tower Road, Ithaca, NY 14853, USA.
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227
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Dejaco C, Duftner C, Grubeck-Loebenstein B, Schirmer M. Imbalance of regulatory T cells in human autoimmune diseases. Immunology 2006; 117:289-300. [PMID: 16476048 PMCID: PMC1782226 DOI: 10.1111/j.1365-2567.2005.02317.x] [Citation(s) in RCA: 269] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The breakdown of mechanisms assuring the recognition of self and non-self is a hallmark feature of autoimmune diseases. In the past 10 years, there has been a steadily increasing interest in a subpopulation of regulatory T cells, which exert their suppressive function in vitro in a contact-dependent manner and preferentially express high levels of CD25 and forkhead and winged-helix family transcription factor forkhead box P3 (FOXP3) (TREGs). Recent findings of changed prevalences and functional efficiencies indicate that these TREGs play a unique role in autoimmune diseases. Clinical findings in patients with mutated FOXP3 genes and a specific polymorphism in the promotor region of FOXP3 also support the role of FOXP3 as a 'master control gene' in the development and functioning of TREGs. Both altered generation of TREGs and insufficient suppression of inflammation in autoimmune diseases are considered to be crucial for the initiation and perpetuation of disease. TREG-related somatic cell therapy is considered as an intriguing new intervention to approach autoimmune diseases.
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Affiliation(s)
- Christian Dejaco
- Clinical Department of Internal Medicine, Innsbruck Medical University, Innsbruck, Austria
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228
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Seddiki N, Santner-Nanan B, Tangye SG, Alexander SI, Solomon M, Lee S, Nanan R, Fazekas de Saint Groth B. Persistence of naive CD45RA+ regulatory T cells in adult life. Blood 2005; 107:2830-8. [PMID: 16332974 DOI: 10.1182/blood-2005-06-2403] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Regulatory T cells (TREGs) constitutively expressing CD4, CD25, and the transcription factor Foxp3 can prevent a wide range of experimental and spontaneous autoimmune diseases in mice. In humans, CD4+CD25bright T cells, predominantly within the CD45RO+ activated/memory subset in adults and the CD45RA+ naive T-cell subset in infants, are considered to be the equivalent subset. Using novel combinations of monoclonal antibodies (mAbs), we examined expression of CD25 in human infant thymus, cord blood, adult peripheral blood, lymph node, and spleen. In addition to the CD4+CD25bright T cells, subfractionation on the basis of CD45 splice variants indicated that all samples contained a second distinct population of cells expressing a slightly lower level of CD25. In adult peripheral blood, this population expressed a naive CD45RA+ phenotype. The corresponding population in lymph node, spleen, and cord blood showed some evidence of activation, and expressed markers characteristic of TREGs, such as cytotoxic T lymphocyte-associated antigen 4 (CTLA-4). Sorted CD4+CD25+CD45RA+ T cells from both cord and adult blood expressed very high levels of mRNA for Foxp3 and manifested equivalent suppressive activity in vitro, indicating that they are bone fide members of the regulatory T-cell lineage. Targeting naive TREGs in adults may offer new means of preventing and treating autoimmune disease.
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Affiliation(s)
- Nabila Seddiki
- Centenary Institute of Cancer Medicine and Cell Biology, Locked Bag No. 6, Newtown, NSW, Australia 2042
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