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Zhao X, Zhao X, Di W, Wang C. Inhibitors of Cyclophilin A: Current and Anticipated Pharmaceutical Agents for Inflammatory Diseases and Cancers. Molecules 2024; 29:1235. [PMID: 38542872 PMCID: PMC10974348 DOI: 10.3390/molecules29061235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/02/2024] [Accepted: 03/05/2024] [Indexed: 04/07/2024] Open
Abstract
Cyclophilin A, a widely prevalent cellular protein, exhibits peptidyl-prolyl cis-trans isomerase activity. This protein is predominantly located in the cytosol; additionally, it can be secreted by the cells in response to inflammatory stimuli. Cyclophilin A has been identified to be a key player in many of the biological events and is therefore involved in several diseases, including vascular and inflammatory diseases, immune disorders, aging, and cancers. It represents an attractive target for therapeutic intervention with small molecule inhibitors such as cyclosporin A. Recently, a number of novel inhibitors of cyclophilin A have emerged. However, it remains elusive whether and how many cyclophilin A inhibitors function in the inflammatory diseases and cancers. In this review, we discuss current available data about cyclophilin A inhibitors, including cyclosporin A and its derivatives, quinoxaline derivatives, and peptide analogues, and outline the most recent advances in clinical trials of these agents. Inhibitors of cyclophilin A are poised to enhance our comprehension of the molecular mechanisms that underpin inflammatory diseases and cancers associated with cyclophilin A. This advancement will aid in the development of innovative pharmaceutical treatments in the future.
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Affiliation(s)
- Xuemei Zhao
- School of Pharmaceutical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan 250000, China; (X.Z.); (W.D.)
| | - Xin Zhao
- School of Pharmaceutical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan 250000, China; (X.Z.); (W.D.)
| | - Weihua Di
- School of Pharmaceutical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan 250000, China; (X.Z.); (W.D.)
| | - Chang Wang
- School of Pharmaceutical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan 250000, China; (X.Z.); (W.D.)
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan 250000, China
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2
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Franz T, Negele J, Bruno P, Böttcher M, Mitchell-Flack M, Reemts L, Krone A, Mougiakakos D, Müller AJ, Zautner AE, Kahlfuss S. Pleiotropic effects of antibiotics on T cell metabolism and T cell-mediated immunity. Front Microbiol 2022; 13:975436. [DOI: 10.3389/fmicb.2022.975436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/23/2022] [Indexed: 11/13/2022] Open
Abstract
T cells orchestrate adaptive and innate immune responses against pathogens and transformed cells. However, T cells are also the main adaptive effector cells that mediate allergic and autoimmune reactions. Within the last few years, it has become abundantly clear that activation, differentiation, effector function, and environmental adaptation of T cells is closely linked to their energy metabolism. Beyond the provision of energy equivalents, metabolic pathways in T cells generate building blocks required for clonal expansion. Furthermore, metabolic intermediates directly serve as a source for epigenetic gene regulation by histone and DNA modification mechanisms. To date, several antibiotics were demonstrated to modulate the metabolism of T cells especially by altering mitochondrial function. Here, we set out to systematically review current evidence about how beta-lactam antibiotics, macrolides, fluoroquinolones, tetracyclines, oxazolidinones, nitroimidazoles, and amphenicols alter the metabolism and effector functions of CD4+ T helper cell populations and CD8+ T cells in vitro and in vivo. Based on this evidence, we have developed an overview on how the use of these antibiotics may be beneficial or detrimental in T cell-mediated physiological and pathogenic immune responses, such as allergic and autoimmune diseases, by altering the metabolism of different T cell populations.
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3
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Pua KH, Stiles DT, Sowa ME, Verdine GL. IMPDH2 Is an Intracellular Target of the Cyclophilin A and Sanglifehrin A Complex. Cell Rep 2017; 18:432-442. [PMID: 28076787 DOI: 10.1016/j.celrep.2016.12.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/21/2016] [Accepted: 12/10/2016] [Indexed: 11/16/2022] Open
Abstract
Natural products have demonstrated utility in the clinic and can also act as probes to understand complex cellular pathways. Sanglifehrin A (SFA) is a mixed polyketide and non-ribosomal peptide synthase natural product with sub-nano-molar affinity for its receptor cyclophilin A (PPIA). It has been shown to behave in vitro as an immune suppressant. Here, we identify inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) as an intracellular target of the PPIA-SFA binary complex. The formation of this ternary complex does not inhibit the enzymatic activity of IMPDH2. Rather, ternary complex formation modulates cell growth through interaction with the cystathionine-β-synthase (CBS) domain of IMPDH2. We further demonstrate that the SFA complex is highly isoform selective for IMPDH2 (versus IMPDH1). This work reveals a role for the CBS domains of IMPDH2 in cellular proliferation, suggesting a more complex role than previously suspected for IMPDH2 in T cell activation and proliferation.
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Affiliation(s)
- Khian Hong Pua
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Warp Drive Bio, Cambridge, MA 02139, USA
| | - Dylan T Stiles
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Warp Drive Bio, Cambridge, MA 02139, USA
| | - Mathew E Sowa
- Warp Drive Bio, Cambridge, MA 02139, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Gregory L Verdine
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Warp Drive Bio, Cambridge, MA 02139, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
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4
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Baroja-Mazo A, Revilla-Nuin B, Parrilla P, Martínez-Alarcón L, Ramírez P, Pons JA. Tolerance in liver transplantation: Biomarkers and clinical relevance. World J Gastroenterol 2016; 22:7676-91. [PMID: 27678350 PMCID: PMC5016367 DOI: 10.3748/wjg.v22.i34.7676] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/04/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023] Open
Abstract
Transplantation is the optimal treatment for end-stage organ failure, and modern immunosuppression has allowed important progress in short-term outcomes. However, immunosuppression poorly influences chronic rejection and elicits chronic toxicity in current clinical practice. Thus, a major goal in transplantation is to understand and induce tolerance. It is well established that human regulatory T cells expressing the transcription factor FoxP3 play important roles in the maintenance of immunological self-tolerance and immune homeostasis. The major regulatory T cell subsets and mechanisms of expansion that are critical for induction and long-term maintenance of graft tolerance and survival are being actively investigated. Likewise, other immune cells, such as dendritic cells, monocyte/macrophages or natural killer cells, have been described as part of the process known as "operational tolerance". However, translation of these results towards clinical practice needs solid tools to identify accurately and reliably patients who are going to be tolerant. In this way, a plethora of genetic and cellular biomarkers is raising and being validated worldwide in large multi-center clinical trials. Few of the studies performed so far have provided a detailed analysis of the impact of immunosuppression withdrawal on pre-existing complications derived from the long-term administration of immunosuppressive drugs and the side effects associated with them. The future of liver transplantation is aimed to develop new therapies which increase the actual low tolerant vs non-tolerant recipients ratio.
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5
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Lapp T, Maier P, Birnbaum F, Schlunck G, Reinhard T. [Immunosuppressives to prevent rejection reactions after allogeneic corneal transplantation]. Ophthalmologe 2015; 111:270-82. [PMID: 24633461 DOI: 10.1007/s00347-013-3016-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In order to prevent rejection of an allogeneic corneal transplant after perforating (high risk) keratoplasty, active agents from different classes of pharmacological substances are used, as with solid organ transplantation. In addition to glucocorticoids, antiproliferative agents, small molecule inhibitors and antibodies, those belonging to the group of macrolides with their many derivatives represent an interesting class of substances in this context. As a supplement to cyclosporin A (CSA) the most successful macrolide in transplantation medicine, animal experiments are currently being carried out to test newer macrolide derivatives, such as sanglifehrin A (SFA). This overview describes the classes of drugs and modes of action of currently administered standard medications in the clinical routine and new developments are presented.
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Affiliation(s)
- T Lapp
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Killianstr. 5, 79106, Freiburg im Breisgau, Deutschland,
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6
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Pollizzi KN, Powell JD. Regulation of T cells by mTOR: the known knowns and the known unknowns. Trends Immunol 2014; 36:13-20. [PMID: 25522665 DOI: 10.1016/j.it.2014.11.005] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 02/08/2023]
Abstract
Mammalian/mechanistic target of rapamycin (mTOR) is emerging as an important integrator of environmental cues critical for the regulation of T cell activation, differentiation, and function. Recent studies leveraging pharmacologic inhibition or T cell specific genetic deletion of signaling components in the mTOR pathway have provided important insights into the mechanisms involved, and have been informative in defining targets downstream of mTOR that promote immune regulation. However, these studies have also presented confusing and, at times, contradictory findings, highlighting the complexities involved in examining the mTOR pathway in distinct contexts. Here, we review current understanding of the roles of mTOR in T cell biology, highlighting emerging concepts and areas of investigation where the precise role of mTOR has yet to be fully discerned.
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Affiliation(s)
- Kristen N Pollizzi
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| | - Jonathan D Powell
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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7
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Abstract
One of the mechanisms that are in place to control the activation of mature T cells that bear self-reactive antigen receptors is anergy, a long-term state of hyporesponsiveness that is established in T cells in response to suboptimal stimulation. T cells receive signals that result not only from antigen recognition and costimulation but also from other sources, including cytokine receptors, inhibitory receptors or metabolic sensors. Integration of those signals will determine T cell fate. Under conditions that induce anergy, T cells activate a program of gene expression that leads to the production of proteins that block T cell receptor signaling and inhibit cytokine gene expression. In this review we will examine those signals that determine functional outcome following antigen encounter, review current knowledge of the factors that ensure signaling inhibition and epigenetic gene silencing in anergic cells and explore the mechanisms that lead to the reversal of anergy and the reacquisition of effector functions.
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Affiliation(s)
- Rut Valdor
- Department of Pathology. Albert Einstein College of Medicine. Bronx, NY. USA
| | - Fernando Macian
- Department of Pathology. Albert Einstein College of Medicine. Bronx, NY. USA
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8
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Powell JD, Heikamp EB, Pollizzi KN, Waickman AT. A modified model of T-cell differentiation based on mTOR activity and metabolism. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2013; 78:125-30. [PMID: 24100582 DOI: 10.1101/sqb.2013.78.020214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Current models of T-helper-cell differentiation depict the generation of effector cells from a naïve T cell based on the cytokine environment upon T-cell-receptor engagement. We propose a new model of CD4(+) T-cell activation, differentiation, and function whereby the outcome of antigen recognition is dictated by mTOR activity and the subsequent up-regulation of selective metabolic function. Such a model more readily explains the generation of effector and memory cells including the concept of effector and memory Foxp3(+) regulatory cells.
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Affiliation(s)
- Jonathan D Powell
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231
| | - Emily B Heikamp
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231
| | - Kristen N Pollizzi
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231
| | - Adam T Waickman
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231
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9
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Chappert P, Bouladoux N, Naik S, Schwartz RH. Specific gut commensal flora locally alters T cell tuning to endogenous ligands. Immunity 2013; 38:1198-210. [PMID: 23809163 DOI: 10.1016/j.immuni.2013.06.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 03/25/2013] [Indexed: 02/07/2023]
Abstract
Differences in gut commensal flora can dramatically influence autoimmune responses, but the mechanisms behind this are still unclear. We report, in a Th1-cell-driven murine model of autoimmune arthritis, that specific gut commensals, such as segmented filamentous bacteria, have the ability to modulate the activation threshold of self-reactive T cells. In the local microenvironment of gut-associated lymphoid tissues, inflammatory cytokines elicited by the commensal flora dynamically enhanced the antigen responsiveness of T cells that were otherwise tuned down to a systemic self-antigen. Together with subtle differences in early lineage differentiation, this ultimately led to an enhanced recruitment of pathogenic Th1 cells and the development of a more severe form of autoimmune arthritis. These findings define a key role for the gut commensal flora in sustaining ongoing autoimmune responses through the local fine tuning of T-cell-receptor-proximal activation events in autoreactive T cells.
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Affiliation(s)
- Pascal Chappert
- Laboratory of Cellular and Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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10
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Soliman GA. The role of mechanistic target of rapamycin (mTOR) complexes signaling in the immune responses. Nutrients 2013; 5:2231-57. [PMID: 23783557 PMCID: PMC3725503 DOI: 10.3390/nu5062231] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/05/2013] [Accepted: 06/05/2013] [Indexed: 12/17/2022] Open
Abstract
The mechanistic Target of Rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase which is a member of the PI3K related kinase (PIKK) family. mTOR emerged as a central node in cellular metabolism, cell growth, and differentiation, as well as cancer metabolism. mTOR senses the nutrients, energy, insulin, growth factors, and environmental cues and transmits signals to downstream targets to effectuate the cellular and metabolic response. Recently, mTOR was also implicated in the regulation of both the innate and adaptive immune responses. This paper will summarize the current knowledge of mTOR, as related to the immune microenvironment and immune responses.
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Affiliation(s)
- Ghada A Soliman
- Department of Health Promotion, Social and Behavioral Health Sciences, College of Public Health, University of Nebraska Medical Center, 984365 Nebraska Medical Center, Omaha, NE 68198, USA.
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11
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Waickman AT, Powell JD. Mammalian target of rapamycin integrates diverse inputs to guide the outcome of antigen recognition in T cells. THE JOURNAL OF IMMUNOLOGY 2012; 188:4721-9. [PMID: 22556133 DOI: 10.4049/jimmunol.1103143] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
T cells must integrate a diverse array of intrinsic and extrinsic signals upon Ag recognition. Although these signals have canonically been categorized into three distinct events--Signal 1 (TCR engagement), Signal 2 (costimulation or inhibition), and Signal 3 (cytokine exposure)--it is now appreciated that many other environmental cues also dictate the outcome of T cell activation. These include nutrient availability, the presence of growth factors and stress signals, as well as chemokine exposure. Although all of these distinct inputs initiate unique signaling cascades, they also modulate the activity of the evolutionarily conserved serine/threonine kinase mammalian target of rapamycin (mTOR). Indeed, mTOR serves to integrate these diverse environmental inputs, ultimately transmitting a signaling program that determines the fate of newly activated T cells. In this review, we highlight how diverse signals from the immune microenvironment can guide the outcome of TCR activation through the activation of the mTOR pathway.
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Affiliation(s)
- Adam T Waickman
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
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12
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O'Brien TF, Zhong XP. The role and regulation of mTOR in T-lymphocyte function. Arch Immunol Ther Exp (Warsz) 2012; 60:173-81. [PMID: 22484804 DOI: 10.1007/s00005-012-0171-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Accepted: 01/30/2012] [Indexed: 10/28/2022]
Abstract
The conversion of naïve T cells into effector T cells is initiated by stimulation through the T-cell receptor (TCR). Upon activation, T cells undergo significant morphological and functional changes, putting new metabolic demands on the cell. Past research has identified the mammalian target of rapamycin (mTOR) as a critical regulator of cell metabolism, and the development of new genetic models has begun to reveal an important role for this pathway in the homeostasis and function of T lymphocytes. In this review, we focus on the most recent findings that demonstrate the ability of mTOR to regulate T-cell activation, CD8(+) memory cell formation and function, and helper T lineage differentiation. Furthermore, we highlight the importance of tight control of mTOR signaling by tuberous sclerosis complex 1 for T-cell homeostasis, and the regulation of mTOR signaling by diacylglycerol kinases and the RasGRP1-Ras-Erk1/2 pathway in the context of TCR signaling.
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Affiliation(s)
- Thomas F O'Brien
- Department of Pediatrics-Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA
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13
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Ferreira PA, Orry A. From Drosophila to humans: reflections on the roles of the prolyl isomerases and chaperones, cyclophilins, in cell function and disease. J Neurogenet 2012; 26:132-43. [PMID: 22332926 DOI: 10.3109/01677063.2011.647143] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Despite remarkable advances in human genetics and other genetic model systems, the fruit fly, Drosophila melanogaster, remains a powerful experimental tool to probe with ease the inner workings of a myriad of biological and pathological processes, even when evolutionary forces impart apparent divergences to some of such processes. The understanding of such evolutionary differences provides mechanistic insights into genotype-phenotype correlations underpinning biological processes across metazoans. The pioneering work developed by the William Pak laboratory for the past four decades, and the work of others, epitomize the notion of how the Drosophila system breaks new fertile ground or complements research fields of high scientific and medical relevance. Among the three major genetic complementation groups produced by the Pak's laboratory and impairing distinct facets of photoreceptor neuronal function, the nina group (ninaA, …., ninaJ) selectively affects the biogenesis of G protein-coupled receptors (GPCRs), mediating the photoconversion and transduction of light stimuli. Among the nina genes identified, ninaA arguably assumes heightened significance for several reasons. First, it presents unique physiological selectivity toward the biogenesis of a subset of GPCRs, a standalone biological manifestation yet to be discerned for most mammalian homologues of NinaA. Second, NinaA belongs to a family of proteins, immunophilins, which are the primary targets for immunosuppressive drugs at the therapeutic forefront of a multitude of medical conditions. Third, NinaA closest homologue, cyclophilin B (CyPB/PPIB), is an immunophilin whose loss-of-function was found recently to cause osteogenesis imperfecta in the human. This report highlights advances made by studies on some members of immunophilins, the cyclophilins. Finally, it reexamines critically data and dogmas derived from past and recent genetic, structural, biological, and pathological studies on NinaA and few other cyclophilins that support some of such paradigms to be less than definite and advance our understanding of the roles of cyclophilins in cell function, disease, and therapeutic interventions.
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Affiliation(s)
- Paulo A Ferreira
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA.
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14
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Abstract
mTOR is an evolutionarily conserved serine/threonine kinase that plays a central role in integrating environmental cues in the form of growth factors, amino acids, and energy. In the study of the immune system, mTOR is emerging as a critical regulator of immune function because of its role in sensing and integrating cues from the immune microenvironment. With the greater appreciation of cellular metabolism as an important regulator of immune cell function, mTOR is proving to be a vital link between immune function and metabolism. In this review, we discuss the ability of mTOR to direct the adaptive immune response. Specifically, we focus on the role of mTOR in promoting differentiation, activation, and function in T cells, B cells, and antigen-presenting cells.
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Affiliation(s)
- Jonathan D Powell
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
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15
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Dazert E, Hall MN. mTOR signaling in disease. Curr Opin Cell Biol 2011; 23:744-55. [PMID: 21963299 DOI: 10.1016/j.ceb.2011.09.003] [Citation(s) in RCA: 357] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/07/2011] [Accepted: 09/08/2011] [Indexed: 01/11/2023]
Abstract
The target of rapamycin (TOR) is a highly conserved serine/threonine kinase and a central controller of cell growth, metabolism and aging. Mammalian TOR (mTOR) is activated in response to nutrients, growth factors and cellular energy. Dysregulated mTOR signaling has been implicated in major disease. Here we review recent findings on the role of mTOR in cancer, metabolic disorders, neurological diseases, and inflammation.
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Affiliation(s)
- Eva Dazert
- Biozentrum, University of Basel, CH4056 Basel, Switzerland
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16
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The cyclophilin-binding agent Sanglifehrin A is a dendritic cell chemokine and migration inhibitor. PLoS One 2011; 6:e18406. [PMID: 21483789 PMCID: PMC3069092 DOI: 10.1371/journal.pone.0018406] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Accepted: 03/07/2011] [Indexed: 01/10/2023] Open
Abstract
Sanglifehrin A (SFA) is a cyclophilin-binding immunosuppressant but the immunobiology of action is poorly understood. We and others have reported that SFA inhibits IL-12 production and antigen uptake in dendritic cells (DC) and exhibits lower activity against lymphocytes. Here we show that SFA suppresses DC chemokine production and migration. Gene expression analysis and subsequent protein level confirmation revealed that SFA suppressed CCL5, CCL17, CCL19, CXCL9 and CXCL10 expression in human monocyte-derived DC (moDC). A systems biology analysis, Onto Express, confirmed that SFA interferes with chemokine-chemokine receptor gene expression with the highest impact. Direct comparison with the related agent cyclosporine A (CsA) and dexamethasone indicated that SFA uniquely suppresses moDC chemokine expression. Competitive experiments with a 100-fold molar excess of CsA and with N-Methyl-Val-4-cyclosporin, representing a nonimmunosuppressive derivative of CsA indicated chemokine suppression through a cyclophilin-A independent pathway. Functional assays confirmed reduced migration of CD4+ Tcells and moDCs to supernatant of SFA-exposed moDCs. Vice versa, SFA-exposed moDC exhibited reduced migration against CCL19. Moreover, SFA suppressed expression of the ectoenzyme CD38 that was reported to regulate DC migration and cytokine production. These results identify SFA as a DC chemokine and migration inhibitor and provide novel insight into the immunobiology of SFA.
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17
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Gamper CJ, Powell JD. Genetic and biochemical regulation of CD4 T cell effector differentiation: insights from examination of T cell clonal anergy. Immunol Res 2010; 47:162-71. [PMID: 20077160 DOI: 10.1007/s12026-009-8147-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The two-signal model of T cell activation states that antigen recognition by TCR provides a tolerogenic signal (termed Signal 1) unless the T cell receives simultaneous costimulation (Signal 2) that permits antigen recognition to prime activation. Our efforts to characterize genetic and biochemical factors resulting from Signal 1 alone have identified signaling molecules, transcription factors, and an epigenetic regulator that each contribute to the anergic phenotype observed. However, our most striking finding is that the same factors identified using anergy to model T cell activation versus tolerance also participate in determining the outcome of the effector phenotype of fully activated T cells. We summarize our own findings and other recent advances in the genetic and biochemical understanding of T cell activation, tolerance, and plasticity in this review.
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Affiliation(s)
- Christopher J Gamper
- Department of Oncology, Sidney Kimmel Cancer Center, School of Medicine, Johns Hopkins University, CRB 1, Room 443, Baltimore, MD 21231, USA
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18
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Powell JD, Delgoffe GM. The mammalian target of rapamycin: linking T cell differentiation, function, and metabolism. Immunity 2010; 33:301-11. [PMID: 20870173 DOI: 10.1016/j.immuni.2010.09.002] [Citation(s) in RCA: 372] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Indexed: 12/19/2022]
Abstract
In the two-signal model of T cell activation, the outcome of antigen recognition is determined by the integration of multiple cues in the immune microenvironment. mTOR is an evolutionarily conserved PI3-kinase family member that plays a central role in integrating environmental cues in the form of amino acids, energy, and growth factors. Recently, an increasingly important role for mTOR in directing T cell activation and differentiation has become apparent. Here we review recent findings demonstrating the ability of mTOR to interpret signals in the immune microenvironment and program the generation of CD4(+) effector versus regulatory T cells, the generation of CD8(+) effector versus memory cells, T cell trafficking, and T cell activation versus anergy. The key theme to emerge from these studies is that the central role of mTOR provides a direct link between T cell metabolism and function.
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Affiliation(s)
- Jonathan D Powell
- Sidney-Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
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19
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Galat A, Bua J. Molecular aspects of cyclophilins mediating therapeutic actions of their ligands. Cell Mol Life Sci 2010; 67:3467-88. [PMID: 20602248 PMCID: PMC11115621 DOI: 10.1007/s00018-010-0437-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/04/2010] [Accepted: 06/10/2010] [Indexed: 12/14/2022]
Abstract
Cyclosporine A (CsA) is an immunosuppressive cyclic peptide that binds with a high affinity to 18 kDa human cyclophilin-A (hCyPA). CsA and its several natural derivatives have some pharmacological potential in treatment of diverse immune disorders. More than 20 paralogues of CyPA are expressed in the human body while expression levels and functions of numerous ORFs encoding cyclophilin-like sequences remain unknown. Certain derivatives of CsA devoid of immunosuppressive activity may have some potential in treatments of Alzheimer diseases, Hepatitis C and HIV infections, amyotrophic lateral sclerosis, congenital muscular dystrophy, asthma and various parasitic infections. Here, we discuss structural and functional aspects of the human cyclophilins and their interaction with various intra-cellular targets that can be under the control of CsA or its complexes with diverse cyclophilins that are selectively expressed in different cellular compartments. Some molecular aspects of the cyclophilins expressed in parasites invading humans and causing diseases were also analyzed.
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Affiliation(s)
- Andrzej Galat
- SIMOPRO, Institute de Biologie et de Technologies de Saclay, DSV/CEA, Bat. 152, CE-Saclay, Gif-sur-Yvette Cedex, France.
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Chappert P, Schwartz RH. Induction of T cell anergy: integration of environmental cues and infectious tolerance. Curr Opin Immunol 2010; 22:552-9. [PMID: 20869863 DOI: 10.1016/j.coi.2010.08.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 08/12/2010] [Indexed: 10/19/2022]
Abstract
Anergy is a state of long-term hyporesponsiveness in T cells that is characterized by an active repression of TCR signaling and IL-2 expression [1]. Several forms of anergy have been described and the past few years have brought to light an increasing number of 'anergic factors' involved in the induction and the active maintenance of the state in lymphocytes. The role of mTOR and other related metabolic sensors and regulators has recently emerged as of particular importance in broadening our view of anergy-inducing signals. We will discuss the role of these molecules in regulating the choice between anergy and activation, a decision faced by all T cells undergoing TCR stimulation. We will then explore the relationship between the induction of anergy and the induction of regulatory T cells as well as the potential crosstalk responsible for the phenomenon of infectious tolerance.
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Affiliation(s)
- Pascal Chappert
- Laboratory of Cellular and Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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21
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Baine I, Abe BT, Macian F. Regulation of T-cell tolerance by calcium/NFAT signaling. Immunol Rev 2009; 231:225-40. [PMID: 19754900 DOI: 10.1111/j.1600-065x.2009.00817.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cells that escape negative selection in the thymus must be inactivated or eliminated in the periphery through a series of mechanisms that include the induction of anergy, dominant suppression by regulatory T cells, and peripheral deletion of self-reactive T cells. Calcium signaling plays a central role in the induction of anergy in T cells, which become functionally inactivated and incapable of proliferating and expressing cytokines following antigen re-encounter. Suboptimal stimulation of T cells results in the activation of a calcium/calcineurin/nuclear factor of activated T cells-dependent cell-intrinsic program of self-inactivation. The proteins encoded by those genes are required to impose a state of functional unresponsiveness through different mechanisms that include downregulation of T-cell receptor signaling and inhibition of cytokine transcription.
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Affiliation(s)
- Ian Baine
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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22
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Zheng Y, Delgoffe GM, Meyer CF, Chan W, Powell JD. Anergic T cells are metabolically anergic. THE JOURNAL OF IMMUNOLOGY 2009; 183:6095-101. [PMID: 19841171 DOI: 10.4049/jimmunol.0803510] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Full T cell activation requires TCR engagement (signal 1) in the context of costimulation (signal 2). Costimulation is required for maximal expression of effector cytokines and prevention of T cell anergy. It has become increasingly clear that another major function of costimulation is to up-regulate the metabolic machinery necessary for T cell function. In this report we demonstrate that anergic T cells are metabolically anergic, in that upon full stimulation (signals 1 plus 2) they fail to up-regulate the machinery necessary to support increased metabolism. These findings suggest that one mechanism responsible for the maintenance of T cell anergy is failure to up-regulate the metabolic machinery. Furthermore, we demonstrate that by blocking leucine, glucose, and energy metabolism, T cell activation is mitigated. Additionally, inhibition of these metabolic pathways during T cell activation leads to anergy in Th1-differentiated cells. Overall, our findings extend the role of T cell metabolism in regulating T cell function.
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Affiliation(s)
- Yan Zheng
- The Sidney-Kimmel Cancer Research Center, The Johns Hopkins School of Medicine, Baltimore, MD 21231, USA
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23
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Abstract
The ultimate outcome of T cell receptor recognition is determined by the context in which the antigen is encountered. In this fashion both antigen-presenting cells and T cells must integrate multiple environmental cues in the form of pathogen-associated molecular patterns, cytokines and accessory molecule signals. The mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that plays a central role in integrating environmental signals critical to regulating metabolism and cell survival. In this paper we review the data demonstrating that mTOR integrates signals from the immune microenvironment and therefore facilitates the generation of the adaptive immune response. Specifically, we review the role of mTOR in promoting dendritic cell activation and maturation, in regulating full T cell activation versus anergy, and influencing the induction of regulatory T cells.
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Affiliation(s)
- Greg M Delgoffe
- Sidney-Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
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24
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Du JF, Li SY, Yu B. Rapamycin—rather than FK506—might promote allograft tolerance induced by CD4+CD25+ regulatory T cells. Surgery 2009; 146:526-7; author reply 527-8. [DOI: 10.1016/j.surg.2009.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 02/20/2009] [Indexed: 11/29/2022]
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25
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Abstract
T cells must integrate multiple environmental cues when deciding whether to mount an immunogenic or tolerogenic response. Since not all self-reactive T cells are eliminated during thymic development, mechanisms of peripheral tolerance such as T cell anergy contribute to preventing autoimmunity. Recent studies have implicated extracellular adenosine and the adenosine A(2A) receptor as playing an important role in inhibiting T cell effector function. Herein, we review the current literature regarding T cell anergy and the emerging literature implicating the A(2A) receptor as critical regulator of immune activation. Finally, we present evidence to suggest a possible role for adenosine A(2A) receptor signaling in T cell anergy.
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Affiliation(s)
- Paul E Zarek
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21231, USA
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26
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Abstract
The potent immunosuppressive action of rapamycin is commonly ascribed to inhibition of growth factor-induced T cell proliferation. However, it is now evident that the serine/threonine protein kinase mammalian target of rapamycin (mTOR) has an important role in the modulation of both innate and adaptive immune responses. mTOR regulates diverse functions of professional antigen-presenting cells, such as dendritic cells (DCs), and has important roles in the activation of effector T cells and the function and proliferation of regulatory T cells. In this Review, we discuss our current understanding of the mTOR pathway and the consequences of mTOR inhibition, both in DCs and T cells, including new data on the regulation of forkhead box P3 expression.
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Duré M, Macian F. IL-2 signaling prevents T cell anergy by inhibiting the expression of anergy-inducing genes. Mol Immunol 2008; 46:999-1006. [PMID: 18990450 DOI: 10.1016/j.molimm.2008.09.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 08/19/2008] [Accepted: 09/23/2008] [Indexed: 12/14/2022]
Abstract
T cell responses are determined by the environment in which antigen is encountered. In the absence of proper costimulation, anergizing stimuli induce the activation of a specific program of gene expression. Proteins encoded by these genes impose a state of functional unresponsiveness in anergic T cells through the activation of different mechanisms that include dampening of the T cell receptor signaling and direct inhibition of cytokine expression. Anergy can be reversed by stimulating T cells in the presence of interleukin (IL-)2. Signaling through the IL-2 receptor has been shown to activate mTOR, which plays an important role in the integration of signals that determine the fate of T cells. The mechanisms underlying the IL-2-dependent regulation of T cell tolerance are still not fully elucidated. In this study we show that IL-2 receptor signaling mediated through JAK3 and mTOR inhibits the expression of anergy-inducing genes independently of any effect on cell cycle progression. Interestingly, we also show that this effect is likely due to changes on the levels of AP-1 activation induced by IL-2 receptor signaling in T cells. Our data identifies a mechanism that can explain how IL-2 may prevent or reverse the establishment of anergy in T cells and, therefore, helps to understand how the cytokine environment can be determinant to shape the outcome of T cell responses - tolerance or activation - when antigen is encountered.
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Affiliation(s)
- Myrianne Duré
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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28
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The sound of silence: modulating anergy in T lymphocytes. Curr Opin Immunol 2007; 19:658-64. [PMID: 17949964 DOI: 10.1016/j.coi.2007.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Accepted: 08/31/2007] [Indexed: 01/22/2023]
Abstract
Understanding the intercellular and intracellular mechanisms that maintain anergy and prevent the induction of full effector function is one avenue that may allow us to manipulate immune responses. Recent studies of T cell receptor (TCR)-proximal signaling events in different models of T cell unresponsiveness have suggested that biochemically distinct forms of anergy may exist in vivo. T cell responsiveness can be altered through the control of the intracellular pool of key second messengers, such as diacylglycerol (DAG) or the lipid modification of signaling molecules, such as the Linker for activated T cells (LAT). Studies on the molecule programmed death-1 (PD-1) and its ligands have revealed that tissue-resident signals are essential in the maintenance of T cell unresponsiveness. Thus, the emerging view is that T cell anergy is a dynamic state whose establishment and maintenance can be influenced by numerous different signaling pathways.
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29
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Choi S, Schwartz RH. Molecular mechanisms for adaptive tolerance and other T cell anergy models. Semin Immunol 2007; 19:140-52. [PMID: 17400472 PMCID: PMC2045643 DOI: 10.1016/j.smim.2007.02.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 02/16/2007] [Indexed: 01/09/2023]
Abstract
Since the original description of T cell anergy in CD4 clones from mice and humans, a number of different unresponsive states have been described, both in vivo and in vitro, that have been called anergic. While initial attempts were made to understand the similarities between the different models, it has now become clear from biochemical experiments that many of them have different molecular mechanisms underlying their unresponsiveness. In this review we will detail our own work on the in vivo model referred to as adaptive tolerance and then attempt to compare this biochemical state to the multitude of other states that have been described in the literature.
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Affiliation(s)
- Seeyoung Choi
- National Institutes of Health, LCMI, NIAID, Bethesda, MD 20892-0420, USA
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30
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Mondino A, Mueller DL. mTOR at the crossroads of T cell proliferation and tolerance. Semin Immunol 2007; 19:162-72. [PMID: 17383196 PMCID: PMC1995654 DOI: 10.1016/j.smim.2007.02.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 02/19/2007] [Indexed: 12/20/2022]
Abstract
Several events control the activation, proliferation, and the continued Ag responsiveness of naïve and memory T lymphocytes. Here we review the individual contributions of TCR, CD28, and IL-2-driven signaling to T cell proliferation and anergy avoidance. The role of mTOR as a rheostat capable of integrating extracellular, plasma membrane-associated, and intracellular signals with relevance to T cell priming and tolerance is discussed.
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31
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Zheng Y, Collins SL, Lutz MA, Allen AN, Kole TP, Zarek PE, Powell JD. A role for mammalian target of rapamycin in regulating T cell activation versus anergy. THE JOURNAL OF IMMUNOLOGY 2007; 178:2163-70. [PMID: 17277121 DOI: 10.4049/jimmunol.178.4.2163] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Whether TCR engagement leads to activation or tolerance is determined by the concomitant delivery of multiple accessory signals, cytokines, and environmental cues. In this study, we demonstrate that the mammalian target of rapamycin (mTOR) integrates these signals and determines the outcome of TCR engagement with regard to activation or anergy. In vitro, Ag recognition in the setting of mTOR activation leads to full immune responses, whereas recognition in the setting of mTOR inhibition results in anergy. Full T cell activation is associated with an increase in the phosphorylation of the downstream mTOR target S6 kinase 1 at Thr(421)/Ser(424) and an increase in the mTOR-dependent cell surface expression of transferrin receptor (CD71). Alternatively, the induction of anergy results in markedly less S6 kinase 1 Thr(421)/Ser(424) phosphorylation and CD71 surface expression. Likewise, the reversal of anergy is associated not with proliferation, but rather the specific activation of mTOR. Importantly, T cells engineered to express a rapamycin-resistant mTOR construct are resistant to anergy induction caused by rapamycin. In vivo, mTOR inhibition promotes T cell anergy under conditions that would normally induce priming. Furthermore, by examining CD71 surface expression, we are able to distinguish and differentially isolate anergic and activated T cells in vivo. Overall, our data suggest that by integrating environmental cues, mTOR plays a central role in determining the outcome of Ag recognition.
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Affiliation(s)
- Yan Zheng
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University Medical Institutions, Baltimore, MD 21231, USA
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32
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Sànchez-Tilló E, Wojciechowska M, Comalada M, Farrera C, Lloberas J, Celada A. Cyclophilin A is required for M-CSF-dependent macrophage proliferation. Eur J Immunol 2006; 36:2515-24. [PMID: 16909430 DOI: 10.1002/eji.200535270] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The immunosuppressor sanglifehrin A (SfA) is a member of a family of immunophilin cyclophilin A-binding molecules and does not inhibit calcineurin activity. Sanglifehrin A inhibits M-CSF-dependent macrophage proliferation by arresting the G1 phase of the cell cycle but does not affect cell viability. This immunosuppressor exerts its action on proliferation by inactivating cyclin-dependent kinase 2 (Cdk2) activity. Moreover, c-myc expression is also repressed. In the early steps of M-CSF signaling, SfA inhibits the phosphorylation of Raf-1 and the external regulated kinases (ERK)1/2 and mitogen-activated protein kinase phosphatase-1, which are required for proliferation. The effects of SfA are not related to a block of the proteosome activity. These data show that immunophilin contributes to M-CSF-dependent proliferation through activation of the Raf-1/MEK/ERK pathway and the regulation of Cdk activities, which is required for cell cycle progression.
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Affiliation(s)
- Ester Sànchez-Tilló
- Macrophage Biology Group, Institute for Research in Biomedicine, Barcelona Science Park, University of Barcelona, Barcelona, Spain
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33
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Powell JD. The induction and maintenance of T cell anergy. Clin Immunol 2006; 120:239-46. [PMID: 16581297 DOI: 10.1016/j.clim.2006.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 02/11/2006] [Indexed: 10/24/2022]
Abstract
While the "true" role of T cell anergy in promoting peripheral tolerance continues to be debated, it is clear that studying the various models of anergy have led to important insight in terms of understanding the pathways and molecules responsible for T cell activation and inhibition. This review will examine our current understanding of CD4+ T cell anergy. In particular, it will focus on the signaling pathways responsible for both the induction and maintenance of anergy. Furthermore, it will examine how specifically targeting these pathways can be exploited clinically in terms of promoting tolerance in transplantation and autoimmunity and inhibiting tumor-induced tolerance in the case of tumor-immunotherapy.
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Affiliation(s)
- Jonathan D Powell
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD 21231, USA.
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Nikolaeva N, Bemelman FJ, Yong SL, van Lier RAW, ten Berge IJM. Rapamycin Does Not Induce Anergy but Inhibits Expansion and Differentiation of Alloreactive Human T Cells. Transplantation 2006; 81:445-54. [PMID: 16477233 DOI: 10.1097/01.tp.0000194860.21533.b9] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Studies in mice have shown that rapamycin inhibits cell cycle progression and promotes the development of clonal anergy. We here addressed the question if rapamycin can induce anergy of human T cells and studied the effects of rapamycin on activation, proliferation and expression of cytotoxic effector molecules of alloresponsive T cells in mixed lymphocyte cultures. METHODS Peripheral blood mononuclear cells from healthy individuals were labeled with CFSE to monitor subsequent cell divisions. Cells were cocultured with allogeneic irradiated cells in the presence or absence of rapamycin. Flowcytometric analysis was performed after staining for surface CD4, CD8, and CD25 and for intracellular perforin, granzyme B, active caspase-3, and TGF-beta. Bio-Plex cytokine assay was done to measure the secretion of IL-2, IL-4, IL-10, and IFN-gamma. RESULTS Addition of rapamycin at a final concentration of 10 ng/ml strongly decreased precursor frequencies of alloreactive CD4+ and CD8+ T cells. However, when these cells were washed and subsequently specifically restimulated in the absence of rapamycin, the proliferative capacity appeared normal. Next to lowering precursor frequencies, rapamycin also inhibited T cell expansion by inducing apoptosis in divided alloreactive CD4+ and CD8+ T cells. Rapamycin did not interfere with the formation of CD25brightCD4+ T cells during allogeneic stimulation and did not inhibit their suppressive function. Furthermore, the drug decreased production of effector molecules perforin and granzyme B by alloreactive T cells and diminished alloreactive cytotoxicity. CONCLUSION Our data show that rapamycin strongly inhibits proliferation and effector functions of alloreactive T cells in vitro, but does not induce alloantigen specific nonresponsiveness.
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Affiliation(s)
- Natalia Nikolaeva
- Department of Experimental Immunology, Academic Medical Centre, Amsterdam, the Netherlands
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35
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Härtel C, Iblher P, Puzik A, Wortmeier K, Ebel B, Schultz C, Müller-Steinhardt M. Immunosuppressive Activity of the Immunophilin-binding Drug Sanglifehrin A in Human Whole Blood: Potent Inhibition of Interleukin-6 Produced by Lymphocytes and Monocytes. Scand J Immunol 2006; 63:26-34. [PMID: 16398698 DOI: 10.1111/j.1365-3083.2006.01702.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The novel immunosuppressant Sanglifehrin A (SFA) is an immunophilin-binding metabolite with a yet unidentified mechanism of action. Several reports demonstrated the effects of SFA on proliferation and cytokine production of purified T cells with in part different results. However, less is known about the impact of SFA on the regulation of innate immune responses. We used a whole blood assay to investigate the impact of SFA on monocyte responses and T-lymphocyte activity/proliferation upon lipopolysaccharide (LPS) stimulation and anti-CD3/anti-CD28 costimulation, respectively. SFA was found to inhibit interleukin (IL)-2 protein expression of T lymphocytes. Whereas IL-2 mRNA expression was significantly reduced after 4 h of costimulation, the mRNA expression of IL-4 and IL-6 but not tumour necrosis factor (TNF)-alpha was inhibited by SFA both after 4 and 24 h of costimulation. The production of IL-2 and IL-6 protein in T lymphocytes was even strongly affected by SFA than the mRNA expression of the respective cytokine. Unlike other immunophilin-binding immunosuppressants, SFA also inhibited LPS-induced IL-6 and TNF-alpha mRNA and protein expression. At the single cell level, SFA was demonstrated to block the intracellular production of IL-6 in CD14+ monocytes but not the expression of other proinflammatory cytokines such as IL-8 and TNF-alpha. On the basis of these data, we propose that SFA may have a significant effect on the initiation and direction of immune responses. Considering the pleiotropic role of bioactive IL-6 production at the interface of innate and acquired immunity in a variety of disease conditions, it was found that these novel aspects of the unique immunosuppressive action could strongly impact on future clinical application of SFA.
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Affiliation(s)
- C Härtel
- Department of Pediatrics, University of Lübeck Medical School, Ratzeburger Allee, Lübeck, Germany.
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36
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Abbady AQ, Bronner C, Bathami K, Muller CD, Jeanblanc M, Mathieu E, Klein JP, Candolfi E, Mousli M. TCR pathway involves ICBP90 gene down-regulation via E2F binding sites. Biochem Pharmacol 2005; 70:570-9. [PMID: 15964557 DOI: 10.1016/j.bcp.2005.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 05/10/2005] [Accepted: 05/10/2005] [Indexed: 11/18/2022]
Abstract
Antigen-induced cell death is essential for function, growth and differentiation of T-lymphocytes through legation of the T cell receptor. Since TCR-induced cell death occurs at late G1 checkpoint of the cell cycle and considering that ICBP90 is critical for G1/S transition, we studied the ICBP90 regulation through the TCR pathway in Jurkat cells. ICBP90 expression was strongly decreased after TCR triggering concomitantly to cyclin D3 and topoisomerase IIalpha expression decreases. Cell stimulation with PMA and/or calcium ionophore A23187 down-regulated ICBP90 expression. The decrease of ICBP90 protein and mRNA expressions was accompanied with cell growth arrest. A luciferase reporter assay demonstrated that activation of TCR pathways inhibit ICBP90 gene promoter activity. Three consensus E2F binding sites (called from E2F-a to E2F-c) were identified in the ICBP90 gene promoter and were subjected to mutations. The E2F-a, located in a highly active promoter fragment, shows a strong positive functional activity in proliferating cells. E2F-a and E2F-c binding sites are involved in the TCR-induced down-regulation of ICBP90 gene transcription. Altogether, our data demonstrate that TCR signaling pathways regulate ICBP90 gene expression through pRb/E2F complex. We propose that ICBP90 down-regulation is a key event in G1 arrest preceding T cell death.
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Affiliation(s)
- Abdul-Qader Abbady
- INSERM UMR-S 392, and Laboratoire de Physiopathologie Cellulaire & Moléculaire et Infection, Institut de Parasitolgie et de Pathologie Tropicale, Faculté de Médecine, 3 rue Koeberlé, 67000 Strasbourg, France
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37
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Smith DW, Nagler-Anderson C. Preventing intolerance: the induction of nonresponsiveness to dietary and microbial antigens in the intestinal mucosa. THE JOURNAL OF IMMUNOLOGY 2005; 174:3851-7. [PMID: 15778338 DOI: 10.4049/jimmunol.174.7.3851] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The gut-associated lymphoid tissue (GALT) is constantly exposed to a variety of Ags and must therefore decipher a large number of distinct signals at all times. Responding correctly to each set of signals is crucial. When the GALT receives signals from the intestinal flora or food Ags, it must induce a state of nonresponsiveness (mucosal tolerance). In contrast, when pathogenic bacteria invade the intestinal mucosa, it is necessary to elicit strong T and B cell responses. The GALT is therefore in the position of constantly fighting intolerance to food and the commensal flora while effectively battling infectious microbes. Determining precisely which type of response to generate in each case is key to the prevention of immune dysregulation and tissue damage.
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Affiliation(s)
- Donald W Smith
- Mucosal Immunology Laboratory, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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38
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Kallen J, Sedrani R, Zenke G, Wagner J. Structure of human cyclophilin A in complex with the novel immunosuppressant sanglifehrin A at 1.6 A resolution. J Biol Chem 2005; 280:21965-71. [PMID: 15772070 DOI: 10.1074/jbc.m501623200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sanglifehrin A (SFA) is a novel immunosuppressant isolated from Streptomyces sp. that binds strongly to the human immunophilin cyclophilin A (CypA). SFA exerts its immunosuppressive activity through a mode of action different from that of all other known immunophilin-binding substances, namely cyclosporine A (CsA), FK506, and rapamycin. We have determined the crystal structure of human CypA in complex with SFA at 1.6 A resolution. The high resolution of the structure revealed the absolute configuration at all 17 chiral centers of SFA as well as the details of the CypA/SFA interactions. In particular, it was shown that the 22-membered macrocycle of SFA is deeply embedded in the same binding site as CsA and forms six direct hydrogen bonds with CypA. The effector domain of SFA, on the other hand, has a chemical and three-dimensional structure very different from CsA, already strongly suggesting different immunosuppressive mechanisms. Furthermore, two CypA.SFA complexes form a dimer in the crystal as well as in solution as shown by light scattering and size exclusion chromatography experiments. This observation raises the possibility that the dimer of CypA.SFA complexes is the molecular species mediating the immunosuppressive effect.
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Affiliation(s)
- Joerg Kallen
- Protein Structure Unit, Novartis Institutes for BioMedical Research, CH-4002 Basel, Switzerland.
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