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Abstract
Aging leads to numerous changes that affect many components of the immune system, called "immunosenescence". Indeed, elderly individuals exhibit dysregulated immune responses against pathogens, poor responses to vaccination, and increased susceptibility to many diseases including cancer, autoimmune disorders, and other chronic inflammatory diseases. Despite progressed understanding of immunosenescence, its detailed mechanisms are still not fully understood. With advances in medicine, the population of older cancer patients is expected to rapidly increase in the coming years. Cancer immunotherapies, including immune checkpoint inhibitors (ICIs), have been shown to be effective for multiple cancer types, whereas to date, few specific data for elderly individuals have been published. Some systemic reviews have demonstrated that ICIs exhibit similar efficacy in older cancer patients, but they seem to be less effective in very old patients. In addition, toxicities might be more frequently observed in such patients. Here, we provide a summary to better understand immunosenescence and an overview of its relationship with cancer and antitumor immunity, including the efficacy and toxicity of ICIs.
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2
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Sadighi Akha AA. Aging and the immune system: An overview. J Immunol Methods 2018; 463:21-26. [PMID: 30114401 DOI: 10.1016/j.jim.2018.08.005] [Citation(s) in RCA: 213] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 07/17/2018] [Accepted: 08/08/2018] [Indexed: 12/13/2022]
Abstract
The world is witnessing a rapid demographic shift towards an older population, a trend with major medical, social, economic and political implications. Aging is a multifaceted process, involving numerous molecular and cellular mechanisms in the context of different organ systems. A crucial component of aging is a set of functional and structural alterations in the immune system that can manifest as a decreased ability to fight infection, diminished response to vaccination, increased incidence of cancer, higher prevalence of autoimmunity and constitutive low-grade inflammation, among others. In addition to cell-intrinsic changes in both innate and adaptive immune cells, alterations in the stromal microenvironment in primary and secondary lymphoid organs play an important role in age-associated immune dysfunction. This article will provide a broad overview of these phenomena and point out some of their clinical and therapeutic implications.
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Affiliation(s)
- Amir A Sadighi Akha
- Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, United States.
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3
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Nikolich-Žugich J. The twilight of immunity: emerging concepts in aging of the immune system. Nat Immunol 2017; 19:10-19. [PMID: 29242543 DOI: 10.1038/s41590-017-0006-x] [Citation(s) in RCA: 608] [Impact Index Per Article: 86.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 10/26/2017] [Indexed: 02/06/2023]
Abstract
Immunosenescence is a series of age-related changes that affect the immune system and, with time, lead to increased vulnerability to infectious diseases. This Review addresses recent developments in the understanding of age-related changes that affect key components of immunity, including the effect of aging on cells of the (mostly adaptive) immune system, on soluble molecules that guide the maintenance and function of the immune system and on lymphoid organs that coordinate both the maintenance of lymphocytes and the initiation of immune responses. I further address the effect of the metagenome and exposome as key modifiers of immune-system aging and discuss a conceptual framework in which age-related changes in immunity might also affect the basic rules by which the immune system operates.
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Affiliation(s)
- Janko Nikolich-Žugich
- Department of Immunobiology and the Arizona Center on Aging, University of Arizona College of Medicine-Tucson, Tucson, AZ, USA.
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4
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Vaquero J, Nguyen Ho-Bouldoires TH, Clapéron A, Fouassier L. Role of the PDZ-scaffold protein NHERF1/EBP50 in cancer biology: from signaling regulation to clinical relevance. Oncogene 2017; 36:3067-3079. [PMID: 28068322 DOI: 10.1038/onc.2016.462] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/26/2016] [Accepted: 10/31/2016] [Indexed: 12/14/2022]
Abstract
The transmission of cellular information requires fine and subtle regulation of proteins that need to interact in a coordinated and specific way to form efficient signaling networks. The spatial and temporal coordination relies on scaffold proteins. Thanks to protein interaction domains such as PDZ domains, scaffold proteins organize multiprotein complexes enabling the proper transmission of cellular information through intracellular networks. NHERF1/EBP50 is a PDZ-scaffold protein that was initially identified as an organizer and regulator of transporters and channels at the apical side of epithelia through actin-binding ezrin-moesin-radixin proteins. Since, NHERF1/EBP50 has emerged as a major regulator of cancer signaling network by assembling cancer-related proteins. The PDZ-scaffold EBP50 carries either anti-tumor or pro-tumor functions, two antinomic functions dictated by EBP50 expression or subcellular localization. The dual function of NHERF1/EBP50 encompasses the regulation of several major signaling pathways engaged in cancer, including the receptor tyrosine kinases PDGFR and EGFR, PI3K/PTEN/AKT and Wnt-β-catenin pathways.
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Affiliation(s)
- J Vaquero
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), Paris, France.,FONDATION ARC, Villejuif, France
| | - T H Nguyen Ho-Bouldoires
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), Paris, France.,FONDATION ARC, Villejuif, France
| | - A Clapéron
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), Paris, France
| | - L Fouassier
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), Paris, France
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5
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Parameswaran N, Gupta N. Re-defining ERM function in lymphocyte activation and migration. Immunol Rev 2013; 256:63-79. [DOI: 10.1111/imr.12104] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Neetha Parameswaran
- Department of Immunology; Lerner Research Institute; Cleveland Clinic; Cleveland OH USA
| | - Neetu Gupta
- Department of Immunology; Lerner Research Institute; Cleveland Clinic; Cleveland OH USA
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Perkey E, Fingar D, Miller RA, Garcia GG. Increased mammalian target of rapamycin complex 2 signaling promotes age-related decline in CD4 T cell signaling and function. THE JOURNAL OF IMMUNOLOGY 2013; 191:4648-55. [PMID: 24078700 DOI: 10.4049/jimmunol.1300750] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
CD4 T cell function declines significantly during aging. Although the mammalian target of rapamycin (TOR) has been implicated in aging, the roles of the TOR complexes (TORC1, TORC2) in the functional declines of CD4 T cells remain unknown. In this study, we demonstrate that aging increases TORC2 signaling in murine CD4 T cells, a change blocked by long-term exposure to rapamycin, suggesting that functional defects may be the result of enhanced TORC2 function. Using overexpression of Rheb to activate TORC1 and Rictor plus Sin1 to augment TORC2 in naive CD4 T cells from young mice, we demonstrated that increased TORC2, but not TORC1, signaling results in aging-associated biochemical changes. Furthermore, elevated TORC2 signaling in naive CD4 T cells from young mice leads to in vivo functional declines. The data presented in this article suggest a novel model in which aging increases TORC2 signaling and leads to CD4 T cell defects in old mice.
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Affiliation(s)
- Eric Perkey
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan College of Literature, Science and the Arts, Ann Arbor, MI 48109
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Perkey E, Miller RA, Garcia GG. Ex vivo enzymatic treatment of aged CD4 T cells restores cognate T cell helper function and enhances antibody production in mice. THE JOURNAL OF IMMUNOLOGY 2012; 189:5582-9. [PMID: 23136198 DOI: 10.4049/jimmunol.1200487] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Previous in vitro studies showed that CD4 T cells from old mice have defects in TCR signaling, immune synapse formation, activation, and proliferation. We reported that removing a specific set of surface glycoproteins by ex vivo treatment with O-sialoglycoprotein endopeptidase (OSGE) can reverse many aspects of the age-related decline in CD4 T cell function. However, the specific mechanism by which this process occurs remains unclear, and it is unknown whether this enzymatic treatment can also restore important aspects of adaptive immunity in vivo. By using an in vivo model of the immune response based on adoptive transfer of CD4 T cells from pigeon cytochrome C-specific transgenic H-2(k/k) TCR-Vα(11)Vβ(3) CD4(+) mice to syngeneic hosts, we demonstrate that aging diminishes CD28 costimulatory signals in CD4 T cells. These age-associated defects include changes in phosphorylation of AKT and expression of glucose transporter type I, inducible T cell costimulatory molecule, and CD40L, suggesting that the lack of CD28 costimulation contributes to age-dependent loss of CD4 function. All of these deficits can be reversed by ex vivo OSGE treatment. Blocking B7-CD28 interactions on T cells prevents OSGE-mediated restoration of T cell function, suggesting that changes in surface glycosylation, including CD28, may be responsible for the age-related costimulation decline. Finally, we show that the age-related decline in CD4 cognate helper function for IgG production and long-term humoral immunity can also be restored by OSGE treatment of CD4 T cells prior to adoptive transfer.
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Affiliation(s)
- Eric Perkey
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan College of Literature, Science and the Arts, Ann Arbor, MI 48109, USA
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Gu X, Neric NJ, Crabb JS, Crabb JW, Bhattacharya SK, Rayborn ME, Hollyfield JG, Bonilha VL. Age-related changes in the retinal pigment epithelium (RPE). PLoS One 2012; 7:e38673. [PMID: 22701690 PMCID: PMC3372495 DOI: 10.1371/journal.pone.0038673] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 05/14/2012] [Indexed: 11/23/2022] Open
Abstract
Background Age-related changes in the retina are often accompanied by visual impairment but their mechanistic details remain poorly understood. Methodology Proteomic studies were pursued toward a better molecular understanding of retinal pigment epithelium (RPE) aging mechanisms. RPE cells were isolated from young adults (3–4 month-old) and old (24–25 month-old) F344BN rats, and separated into subcellular fractions containing apical microvilli (MV) and RPE cell bodies (CB) lacking their apical microvilli. Proteins were extracted in detergent, separated by SDS-PAGE, digested in situ with trypsin and analyzed by LC MS/MS. Select proteins detected in young and old rat RPE were further studied using immunofluorescence and Western blot analysis. Principal Findings A total of 356 proteins were identified in RPE MV from young and 378 in RPE MV from old rats, 48% of which were common to each age group. A total of 897 proteins were identified in RPE CB from young rats and 675 in old CB, 56% of which were common to each age group. Several of the identified proteins, including proteins involved in response to oxidative stress, displayed both quantitative and qualitative changes in overall abundance during RPE aging. Numerous proteins were identified for the first time in the RPE. One such protein, collectrin, was localized to the apical membrane of apical brush border of proximal tubules where it likely regulates several amino acid transporters. Elsewhere, collectrin is involved in pancreatic β cell proliferation and insulin secretion. In the RPE, collectrin expression was significantly modulated during RPE aging. Another age-regulated, newly described protein was DJ-1, a protein extensively studied in brain where oxidative stress-related functions have been described. Conclusions/Significance The data presented here reveals specific changes in the RPE during aging, providing the first protein database of RPE aging, which will facilitate future studies of age-related retinal diseases.
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Affiliation(s)
- Xiaorong Gu
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Nikolas J. Neric
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - John S. Crabb
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - John W. Crabb
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Sanjoy K. Bhattacharya
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States of America
| | - Mary E. Rayborn
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Joe G. Hollyfield
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Vera L. Bonilha
- The Cole Eye Institute, Department of Ophthalmic Research, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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Griffin P, Michel JJ, Huysman K, Logar AJ, Vallejo AN. Integration of immunity with physical and cognitive function in definitions of successful aging. Aging Dis 2012; 3:34-50. [PMID: 22500270 PMCID: PMC3320803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 02/27/2012] [Accepted: 02/27/2012] [Indexed: 05/31/2023] Open
Abstract
Studies comparing chronologically "young" versus "old" humans document age-related decline of classical immunological functions. However, older adults aged ≥65 years have very heterogeneous health phenotypes. A significant number of them are functionally independent and are surviving well into their 8(th)-11(th) decade life, observations indicating that aging or old age is not synonymous with immune incompetence. While there are dramatic age-related changes in the immune system, not all of these changes may be considered detrimental. Here, we review evidences for novel immunologic processes that become elaborated with advancing age that complement preserved classical immune functions and promote immune homeostasis later in life. We propose that elaboration such of late life immunologic properties is indicative of beneficial immune remodeling that is an integral component of successful aging, an emerging physiologic construct associated with similar age-related physiologic adaptations underlying maintenance of physical and cognitive function. We suggest that a systems approach integrating immune, physical, and cognitive functions, rather than a strict immunodeficiency-minded approach, will be key towards innovations in clinical interventions to better promote protective immunity and functional independence among the elderly.
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Affiliation(s)
- Patricia Griffin
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Joshua J. Michel
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Kristy Huysman
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Alison J. Logar
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Abbe N. Vallejo
- Department of Pediatrics, University of Pittsburgh School of Medicine; and Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
- Department of Immunology, the Pittsburgh Cancer Institute, and the McGowan Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
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Impairment of non-muscle myosin IIA in human CD4+ T cells contributes to functional deficits in the elderly. Cell Mol Immunol 2011; 9:86-96. [PMID: 21983869 DOI: 10.1038/cmi.2011.41] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Physiological aging imposes significant alterations in the repertoire of T cells and all associated functions. Although several studies have reported defects upon antigen-induced activation of T cells during aging, the molecular mechanisms that control T-cell receptor (TCR) downmodulation remain to be fully defined. While previous studies have assessed the role of F-actin in regulating activation-induced TCR internalization, few have delineated the roles of motor proteins, such as non-muscle myosin IIA (NMMIIA). In this study, we describe a series of experiments supporting the hypothesis that effective TCR downmodulation requires not only efficient reorganization of the actin cytoskeleton, but also functional NMMIIA. For the first time, we show that CD4(+) T cells from elderly human donors have dysfunctional NMMIIA that contributes to delaying activation-induced TCR internalization and impairing calcium mobilization. Additionally, our results demonstrate that chemical inhibition of NMMIIA in CD4(+) T cells from young donors also results in complete abrogation of TCR internalization, strongly supporting the fundamental role of NMMIIA in modulating this event. Recent observations that the generation of an efficient T-cell response requires migration prompted us to investigate whether NMMIIA also plays a regulatory role in CD4(+) T-cell migration. We show that chemical inhibition of NMMIIA downmodulates chemotactic migration in CD4(+) T cells from both young and elderly donors. Together, these data demonstrate a significant contribution of dysfunctional NMMIIA to TCR-mediated functional defects during aging.
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11
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Larbi A, Pawelec G, Wong SC, Goldeck D, Tai JJY, Fulop T. Impact of age on T cell signaling: a general defect or specific alterations? Ageing Res Rev 2011; 10:370-8. [PMID: 20933612 DOI: 10.1016/j.arr.2010.09.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 09/22/2010] [Accepted: 09/24/2010] [Indexed: 01/09/2023]
Abstract
Decreased immune responsiveness associated with aging is generally termed "immunosenescence". Several theories have been proposed to explain age-related declines in immune responses. Here, we will focus on and describe potential defects in T cell signal transduction from the membrane to the nucleus, leading to changes in the type, intensity and duration of the response as a major factor contributing to immunosenescence. We will first detail T cell signaling through the T cell receptor (TCR), CD28 and IL-2 receptor (IL-2R) and then discuss the observed age-related alterations to these signaling pathways. The role of membrane rafts in T cell signaling and T cell aging will be described. These factors will be considered in the context of the notion that age-related changes to T cell signaling may be attributed to changes in the functionality of the T cells due to shifts in T cell subpopulations with age. For this reason, we conclude by highlighting the application of multiparametric signaling analysis in leukocyte subsets using flow cytometry as a means to obtain a clearer picture with respect to age-related changes to immune signaling.
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12
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Garcia GG, Miller RA. Age-related defects in the cytoskeleton signaling pathways of CD4 T cells. Ageing Res Rev 2011; 10:26-34. [PMID: 19941976 DOI: 10.1016/j.arr.2009.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 11/18/2009] [Accepted: 11/18/2009] [Indexed: 11/25/2022]
Abstract
It has been postulated that the cytoskeleton controls many aspects of T cell function, including activation, proliferation and apoptosis. Recent advances in our understanding of F-actin polymerization and the Ezrin-Radixin-Moesin (ERM) family of cytoskeleton signal proteins have provided new insights into immunological synapse formation during T cell activation. During aging there is a significant decline of T cell function largely attributable to declines in activation of CD4 T cells and defects in the formation of the immunological synapse. Here we discuss recent progress in the understanding of how aging alters F-actin and ERM proteins in mouse CD4 T cells, and the implications of these changes for the T cell activation process.
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Baeyens N, Horman S, Vertommen D, Rider M, Morel N. Identification and functional implication of a Rho kinase-dependent moesin-EBP50 interaction in noradrenaline-stimulated artery. Am J Physiol Cell Physiol 2010; 299:C1530-40. [PMID: 20926777 DOI: 10.1152/ajpcell.00175.2010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ezrin, radixin, and moesin (ERM) proteins are known to be substrates of Rho kinase (ROCK), a key player in vascular smooth muscle regulation. Their function in arteries remains to be elucidated. The objective of the present study was to investigate ERM phosphorylation and function in rat aorta and mesenteric artery and the influence of ERM-binding phosphoprotein 50 (EBP50), a scaffold partner of ERM proteins in several cell types. In isolated arteries, ERM proteins are phosphorylated by PKC and ROCK with different kinetics after either agonist stimulation or KCl-induced depolarization. Immunoprecipitation of EBP50 in noradrenaline-stimulated arteries allowed identification of its interaction with moesin and several other proteins involved in cytoskeleton regulation. This interaction was inhibited by Y27632, a ROCK inhibitor. Moesin or EBP50 depletion after small interfering RNA transfection by reverse permeabilization in intact mesenteric arteries both potentiated the contractility in response to agonist stimulation without any effect on contractile response induced by high KCl. This effect was preserved in ionomycin-permeabilized arteries. These results indicate that, in agonist-stimulated arteries, the activation of ROCK leads to the binding of moesin to EBP50, which interacts with several components of the cytoskeleton, resulting in a decrease in the contractile response.
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Affiliation(s)
- Nicolas Baeyens
- Laboratory of Cell Physiology, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
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Biswas PS, Gupta S, Chang E, Song L, Stirzaker RA, Liao JK, Bhagat G, Pernis AB. Phosphorylation of IRF4 by ROCK2 regulates IL-17 and IL-21 production and the development of autoimmunity in mice. J Clin Invest 2010; 120:3280-95. [PMID: 20697158 PMCID: PMC2929726 DOI: 10.1172/jci42856] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 06/30/2010] [Indexed: 12/25/2022] Open
Abstract
Deregulated production of IL-17 and IL-21 plays a key pathogenic role in many autoimmune disorders. A delineation of the mechanisms that underlie the inappropriate synthesis of IL-17 and IL-21 in autoimmune diseases can thus provide important insights into potential therapies for these disorders. Here we have shown that the serine-threonine kinase Rho-associated, coiled-coil-containing protein kinase 2 (ROCK2) becomes activated in mouse T cells under Th17 skewing conditions and phosphorylates interferon regulatory factor 4 (IRF4), a transcription factor that is absolutely required for the production of IL-17 and IL-21. We furthermore demonstrated that ROCK2-mediated phosphorylation of IRF4 regulated the synthesis of IL-17 and IL-21 and the differentiation of Th17 cells. Whereas CD4+ T cells from WT mice activated ROCK2 physiologically under Th17 conditions, CD4+ T cells from 2 different mouse models of spontaneous autoimmunity aberrantly activated ROCK2 under neutral conditions. Moreover, administration of ROCK inhibitors ameliorated the deregulated production of IL-17 and IL-21 and the inflammatory and autoantibody responses observed in these autoimmune mice. Our findings thus uncover a crucial link among ROCK2, IRF4, and the production of IL-17 and IL-21 and support the idea that selective inhibition of ROCK2 could represent an important therapeutic regimen for the treatment of autoimmune disorders.
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Affiliation(s)
- Partha S Biswas
- Department of Medicine, Columbia University, New York, New York, USA
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15
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Shaffer MH, Huang Y, Corbo E, Wu GF, Velez M, Choi JK, Saotome I, Cannon JL, McClatchey AI, Sperling AI, Maltzman JS, Oliver PM, Bhandoola A, Laufer TM, Burkhardt JK. Ezrin is highly expressed in early thymocytes, but dispensable for T cell development in mice. PLoS One 2010; 5:e12404. [PMID: 20806059 PMCID: PMC2929185 DOI: 10.1371/journal.pone.0012404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 08/04/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Ezrin/radixin/moesin (ERM) proteins are highly homologous proteins that function to link cargo molecules to the actin cytoskeleton. Ezrin and moesin are both expressed in mature lymphocytes, where they play overlapping roles in cell signaling and polarity, but their role in lymphoid development has not been explored. METHODOLOGY/PRINCIPAL FINDINGS We characterized ERM protein expression in lymphoid tissues and analyzed the requirement for ezrin expression in lymphoid development. In wildtype mice, we found that most cells in the spleen and thymus express both ezrin and moesin, but little radixin. ERM protein expression in the thymus was differentially regulated, such that ezrin expression was highest in immature thymocytes and diminished during T cell development. In contrast, moesin expression was low in early thymocytes and upregulated during T cell development. Mice bearing a germline deletion of ezrin exhibited profound defects in the size and cellularity of the spleen and thymus, abnormal thymic architecture, diminished hematopoiesis, and increased proportions of granulocytic precursors. Further analysis using fetal liver chimeras and thymic transplants showed that ezrin expression is dispensable in hematopoietic and stromal lineages, and that most of the defects in lymphoid development in ezrin(-/-) mice likely arise as a consequence of nutritional stress. CONCLUSIONS/SIGNIFICANCE We conclude that despite high expression in lymphoid precursor cells, ezrin is dispensable for lymphoid development, most likely due to redundancy with moesin.
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Affiliation(s)
- Meredith H. Shaffer
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Yanping Huang
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Evann Corbo
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Gregory F. Wu
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Marielena Velez
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - John K. Choi
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Ichiko Saotome
- Department of Pathology, Massachusetts General Hospital (MGH) Cancer Center and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Judy L. Cannon
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Andrea I. McClatchey
- Department of Pathology, Massachusetts General Hospital (MGH) Cancer Center and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Anne I. Sperling
- Department of Medicine, University of Chicago, Chicago, Illinois, United States of America
| | - Jonathan S. Maltzman
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Paula M. Oliver
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Avinash Bhandoola
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Terri M. Laufer
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Janis K. Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Kohlmeier JE, Connor LM, Roberts AD, Cookenham T, Martin K, Woodland DL. Nonmalignant clonal expansions of memory CD8+ T cells that arise with age vary in their capacity to mount recall responses to infection. THE JOURNAL OF IMMUNOLOGY 2010; 185:3456-62. [PMID: 20720204 DOI: 10.4049/jimmunol.1001745] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Immune responsiveness declines with age in part due to the development of CD8(+) T cell clonal expansions (TCEs) that can dominate the peripheral T cell pool. Although some TCEs arise due to persistent Ag stimulation from chronic infections, others arise in the apparent absence of chronic infection. We have recently shown that this latter class of TCEs can arise over time from the memory CD8(+) T cell pool established by an acute viral infection. Unlike TCEs driven by chronic infections, these age-related TCEs do not display the phenotypic and in vitro functional characteristics of exhausted cells. However, the rate at which these age-related TCEs develop from the memory CD8(+) T cell pool, as well as their ability to mount a recall response to secondary pathogen challenge in vivo, is not known. In this study, we analyzed large cohorts of mice over time for the development of TCE following Sendai virus infection and found a progressive increase in the appearance of TCEs, such that most mice showed evidence of TCE within the memory T cell pool by 2 y postinfection. Using a dual adoptive transfer approach to address the recall potential of virus-specific TCEs, we also demonstrate that most TCEs examined are poorly responsive to a secondary infection. Therefore, we provide evidence that the development of TCE is a common occurrence due to the progressive dysregulation of the virus-specific memory T cell pool with age, but many TCEs are profoundly defective in their ability to mediate recall responses.
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Cicin-Sain L, Smyk-Pearson S, Smyk-Paerson S, Currier N, Byrd L, Koudelka C, Robinson T, Swarbrick G, Tackitt S, Legasse A, Fischer M, Nikolich-Zugich D, Park B, Hobbs T, Doane CJ, Mori M, Axthelm MK, Axthelm MT, Lewinsohn DA, Nikolich-Zugich J. Loss of naive T cells and repertoire constriction predict poor response to vaccination in old primates. THE JOURNAL OF IMMUNOLOGY 2010; 184:6739-45. [PMID: 20483749 DOI: 10.4049/jimmunol.0904193] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aging is usually accompanied by diminished immune protection upon infection or vaccination. Although aging results in well-characterized changes in the T cell compartment of long-lived, outbred, and pathogen-exposed organisms, their relevance for primary Ag responses remain unclear. Therefore, it remains unclear whether and to what extent the loss of naive T cells, their partial replacement by oligoclonal memory populations, and the consequent constriction of TCR repertoire limit the Ag responses in aging primates. We show in this study that aging rhesus monkeys (Macaca mulatta) exhibit poor CD8 T cell and B cell responses in the blood and poor CD8 responses in the lungs upon vaccination with the modified vaccinia strain Ankara. The function of APCs appeared to be maintained in aging monkeys, suggesting that the poor response was likely intrinsic to lymphocytes. We found that the loss of naive CD4 and CD8 T cells, and the appearance of persisting T cell clonal expansions predicted poor CD8 responses in individual monkeys. There was strong correlation between early CD8 responses in the transitory CD28+ CD62L- CD8+ T cell compartment and the peak Ab titers upon boost in individual animals, as well as a correlation of both parameters of immune response to the frequency of naive CD8+ T cells in old but not in adult monkeys. Therefore, our results argue that T cell repertoire constriction and naive cell loss have prognostic value for global immune function in aging primates.
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Affiliation(s)
- Luka Cicin-Sain
- Vaccine and Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA
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Quinn PJ. A lipid matrix model of membrane raft structure. Prog Lipid Res 2010; 49:390-406. [PMID: 20478335 DOI: 10.1016/j.plipres.2010.05.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 05/06/2010] [Indexed: 12/12/2022]
Abstract
Domains in cell membranes are created by lipid-lipid interactions and are referred to as membrane rafts. Reliable isolation methods have been developed which have shown that rafts from the same membranes have different proteins and can be sub-fractionated by immunoaffinity methods. Analysis of these raft subfractions shows that they are also comprised of different molecular species of lipids. The major lipid classes present are phospholipids, glycosphingolipids and cholesterol. Model studies show that mixtures of phospholipids, particularly sphingomyelin, and cholesterol form liquid-ordered phase with properties intermediate between a gel and fluid phase. This type of liquid-ordered phase dominates theories of domain formation and raft structure in biological membranes. Recently it has been shown that sphingolipids with long (22-26C) N-acyl fatty acids form quasi-crystalline bilayer structures with diacylphospholipids that have well-defined stoichiometries. A two tier heuristic model of membrane raft structure is proposed in which liquid-ordered phase created by a molecular complex between sphingolipids with hydrocarbon chains of approximately equal length and cholesterol acts as a primary staging area for selecting raft proteins. Tailoring of the lipid anchors of raft proteins takes place at this site. Assembly of lipid-anchored proteins on a scaffold of sphingolipids with asymmetric hydrocarbon chains and phospholipids arranged in a quasi-crystalline bilayer structure serves to concentrate and orient the proteins in a manner that couples them functionally within the membrane. Specificity is inherent in the quasi-crystalline lipid structure of liquid-ordered matrices formed by both types of complex into which protein lipid anchors are interpolated. An interaction between the sugar residues of the glycolipids and the raft proteins provides an additional level of specificity that distinguishes one raft from another.
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Affiliation(s)
- Peter J Quinn
- Biochemistry Department, King's College London, 150 Stamford Street, London, UK.
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Noh JY, Oh SH, Lee JH, Kwon YS, Ryu DJ, Lee KH. Can blood components with age-related changes influence the ageing of endothelial cells? Exp Dermatol 2010; 19:339-46. [DOI: 10.1111/j.1600-0625.2009.01010.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Age-related changes in lck-Vav signaling pathways in mouse CD4 T cells. Cell Immunol 2009; 259:100-4. [PMID: 19577230 DOI: 10.1016/j.cellimm.2009.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/28/2009] [Accepted: 06/01/2009] [Indexed: 11/24/2022]
Abstract
Activation of lck-fyn kinases during T cell receptor signaling leads to Vav phosphorylation, activation of downstream targets including Rac1, and a transient decline in ezrin and moesin phosphorylation. We have shown that age increases Rac1 activity and lowers ezrin and moesin phosphorylation in resting mouse CD4 cells, changes that could be the results of alterations in lck-Vav signaling. Analysis of Vav in CD4 cells from old mice shows increases in the phosphorylation of two key regulatory residues, Tyr160 and Tyr174, suggesting enhancement of Vav GTPase activity. In addition, analysis of lck status also shows age-related increases in phosphorylation of two key residues, Tyr394 and Tyr505, which have opposite effects on lck function. These changes in lck-Vav signals in resting CD4 cells may contribute in turn to age-related increases in Rac1 activity and declines in phosphorylation of cytoskeletal proteins including Ezrin and Moesin.
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Lee WW, Cui D, Czesnikiewicz-Guzik M, Vencio RZN, Shmulevich I, Aderem A, Weyand CM, Goronzy JJ. Age-dependent signature of metallothionein expression in primary CD4 T cell responses is due to sustained zinc signaling. Rejuvenation Res 2009; 11:1001-11. [PMID: 19072254 DOI: 10.1089/rej.2008.0747] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The ability to mount adaptive immune responses to vaccinations and viral infections declines with increasing age. To identify mechanisms leading to immunosenescence, primary CD4 T cell responses were examined in 60- to 75-year-old individuals lacking overt functional defects. Transcriptome analysis indicated a selective defect in zinc homeostasis. CD4 T cell activation was associated with zinc influx via the zinc transporter Zip6, leading to increased free cytoplasmic zinc and activation of negative feedback loops, including the induction of zinc-binding metallothioneins. In young adults, activation-induced cytoplasmic zinc concentrations declined after 2 days to below prestimulation levels. In contrast, activated naïve CD4 T cells from older individuals failed to downregulate cytoplasmic zinc, resulting in excessive induction of metallothioneins. Activation-induced metallothioneins regulated the redox state in activated T cells and accounted for an increased proliferation of old CD4 T cells, suggesting that regulation of T cell zinc homeostasis functions as a compensatory mechanism to preserve the replicative potential of naïve CD4 T cells with age.
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Affiliation(s)
- Won-Woo Lee
- Kathleen B and Mason I Lowance Center for Human Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
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