251
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Tabas I. Macrophage death and defective inflammation resolution in atherosclerosis. Nat Rev Immunol 2009; 10:36-46. [PMID: 19960040 DOI: 10.1038/nri2675] [Citation(s) in RCA: 818] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A key event in atherosclerosis is a maladaptive inflammatory response to subendothelial lipoproteins. A crucial aspect of this response is a failure to resolve inflammation, which normally involves the suppression of inflammatory cell influx, effective clearance of apoptotic cells and promotion of inflammatory cell egress. Defects in these processes promote the progression of atherosclerotic lesions into dangerous plaques, which can trigger atherothrombotic vascular disease, the leading cause of death in industrialized societies. In this Review I provide an overview of these concepts, with a focus on macrophage death and defective apoptotic cell clearance, and discuss new therapeutic strategies designed to boost inflammation resolution in atherosclerosis.
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Affiliation(s)
- Ira Tabas
- Department of Medicine, Physiology and Cellular Biophysics, Columbia University, New York, New York 10032, USA.
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252
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Agrawal S, Gollapudi P, Elahimehr R, Pahl MV, Vaziri ND. Effects of end-stage renal disease and haemodialysis on dendritic cell subsets and basal and LPS-stimulated cytokine production. Nephrol Dial Transplant 2009; 25:737-46. [PMID: 19903659 DOI: 10.1093/ndt/gfp580] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Although bacterial infections have dramatically declined as a cause of death in the general population, they remain a major cause of mortality in patients with end-stage renal disease (ESRD). Moreover, the response to vaccination is profoundly impaired in this population. Dendritic cells (DC) are the major antigen-presenting cells that bridge the innate and adaptive immune responses. Activation of DC by pathogens results in secretion of inflammatory cytokines and up-regulation of co-stimulatory molecules. The activated DC prime naïve T and B cells to the captured antigens. METHODS Using flow cytometry, the number and phenotype of circulating DC [myeloid DC (mDC) and plasmacytoid DC (pDC)] were quantified in pre- and post-dialysis blood samples from 20 ESRD patients maintained on haemodialysis. Ten normal individuals served as controls. In addition, the level of DC activation and their response to lipopolysaccharide (LPS) stimulation were determined by assessing expression of co-stimulatory molecule, CD86, and antigen-presenting molecule, HLA-DR, as well as production of TNFalpha, IFNalpha and IL-6. RESULTS Compared to the control group, the circulating dendritic cell count was significantly reduced in the ESRD patients before dialysis and declined further after dialysis. The reduction in pDC numbers was more striking than mDC. The magnitude of the LPS-induced up-regulation of CD86 was comparable among the study groups as well as pre- and post-dialysis samples. However, LPS-induced TNFalpha production was significantly reduced in the post-dialysis samples with no significant difference in IL-6 and IFNalpha productions among the study groups and in pre- and post-dialysis samples. CONCLUSIONS ESRD results in significant DC depletion which is largely due to diminished plasmacytoid DC subset. Haemodialysis procedure intensifies DC depletion and impairs LPS-induced TNFalpha production.
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Affiliation(s)
- Sudhanshu Agrawal
- Department of Medicine, University of California, Irvine, Irvine, CA, USA
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253
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Schiffrin EJ, Morley JE, Donnet-Hughes A, Guigoz Y. The inflammatory status of the elderly: the intestinal contribution. Mutat Res 2009; 690:50-6. [PMID: 19666034 DOI: 10.1016/j.mrfmmm.2009.07.011] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 07/22/2009] [Accepted: 07/31/2009] [Indexed: 12/23/2022]
Abstract
A common finding in the elderly population is a chronic subclinical inflammatory status that coexists with immune dysfunction. These interconnected processes are of sufficient magnitude to impact health and survival time. In this review we discuss the different signals that may stimulate the inflammatory process in the aging population as well as the molecular and cellular components that can participate in the initiation, the modulation or termination of the said process. A special interest has been devoted to the intestine as a source of signals that can amplify local and systemic inflammation. Sentinel cells in the splanchnic area are normally exposed to more than one stimulus at a given time. In the intestine of the elderly, endogenous molecules produced by the cellular aging process and stress as well as exogenous evolutionarily conserved molecules from bacteria, are integrated into a network of receptors and molecular signalling pathways that result in chronic inflammatory activation. It is thus possible that nutritional interventions which modify the intestinal ecology can diminish the pro-inflammatory effects of the microbiota and thereby reinforce the mucosal barrier or modulate the cellular activation pathways.
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Affiliation(s)
- Eduardo J Schiffrin
- Nestlé Nutrition, HealthCare Nutrition, Route des Avouillons 30, CH-1196 Gland, Nestec Ltd., Vevey, Switzerland
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254
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Reactive oxygen intermediate-induced pathomechanisms contribute to immunosenescence, chronic inflammation and autoimmunity. Mech Ageing Dev 2009; 130:564-87. [PMID: 19632262 DOI: 10.1016/j.mad.2009.07.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 06/07/2009] [Accepted: 07/15/2009] [Indexed: 02/07/2023]
Abstract
Deregulation of reactive oxygen intermediates (ROI) resulting in either too high or too low concentrations are commonly recognized to be at least in part responsible for many changes associated with aging. This article reviews ROI-dependent mechanisms critically contributing to the decline of immune function during physiologic - or premature - aging. While ROI serve important effector functions in cellular metabolism, signalling and host defence, their fine-tuned generation declines over time, and ROI-mediated damage to several cellular components and/or signalling deviations become increasingly prevalent. Although distinct ROI-associated pathomechanisms contribute to immunosenescence of the innate and adaptive immune system, mutual amplification of dysfunctions may often result in hyporesponsiveness and immunodeficiency, or in chronic inflammation with hyperresponsiveness/deregulation, or both. In this context, we point out how imbalanced ROI contribute ambiguously to driving immunosenescence, chronic inflammation and autoimmunity. Although ROI may offer a distinct potential for therapeutic targeting along with the charming opportunity to rescue from deleterious processes of aging and chronic inflammatory diseases, such modifications, owing to the complexity of metabolic interactions, may carry a marked risk of unforeseen side effects.
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255
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Jing Y, Shaheen E, Drake RR, Chen N, Gravenstein S, Deng Y. Aging is associated with a numerical and functional decline in plasmacytoid dendritic cells, whereas myeloid dendritic cells are relatively unaltered in human peripheral blood. Hum Immunol 2009; 70:777-84. [PMID: 19596035 DOI: 10.1016/j.humimm.2009.07.005] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 06/29/2009] [Accepted: 07/02/2009] [Indexed: 12/13/2022]
Abstract
Dendritic cells (DC) are potent antigen-presenting cells that initiate and regulate T-cell responses. In this study, the numbers and functional cytokine secretions of plasmacytoid and myeloid DC (pDC and mDC, respectively) in peripheral blood from young and elderly subjects were compared. Overall, pDC numbers in peripheral blood were lower in healthy elderly compared with healthy young subjects (p = 0.016). In response to influenza virus stimulation, isolated pDC from healthy elderly subjects secreted less interferon (IFN)-alpha compared with those from healthy young subjects. The decline in IFN-alpha secretion was associated with a reduced proportion of pDC that expressed Toll-like receptor-7 or Toll-like receptor-9. In contrast, there was little difference in the numbers and cytokine secretion function between healthy young and healthy elderly subjects (p = 0.82). However, in peripheral blood from frail elderly subjects, the numbers of mDC were severely depleted as compared with either healthy young or elderly subjects (p = 0.014 and 0.007, respectively). Thus, aging was associated with the numerical and functional decline in pDC, but not mDC, in healthy young versus elderly subject group comparisons, while declining health in the elderly can profoundly impact mDC negatively. Because of the importance of pDC for antiviral responses, the age-related changes in pDC likely contribute to the impaired immune response to viral infections in elderly persons, especially when combined with the mDC dysfunction occurring in those with compromised health.
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Affiliation(s)
- Yu Jing
- Department of Microbiology and Molecular Cell Biology, and the Glennan Center for Geriatrics and Gerontology, Department of Internal Medicine, Eastern Virginia Medical School, Norfolk, Virginia, USA
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256
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Panda A, Arjona A, Sapey E, Bai F, Fikrig E, Montgomery RR, Lord JM, Shaw AC. Human innate immunosenescence: causes and consequences for immunity in old age. Trends Immunol 2009; 30:325-33. [PMID: 19541535 DOI: 10.1016/j.it.2009.05.004] [Citation(s) in RCA: 367] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 05/07/2009] [Accepted: 05/07/2009] [Indexed: 10/20/2022]
Abstract
The past decade has seen an explosion in research focusing on innate immunity. Through a wide range of mechanisms including phagocytosis, intracellular killing and activation of proinflammatory or antiviral cytokine production, the cells of the innate immune system initiate and support adaptive immunity. The effects of aging on innate immune responses remain incompletely understood, particularly in humans. Here we review advances in the study of human immunosenescence in the diverse cells of the innate immune system, including neutrophils, monocytes, macrophages, natural killer and natural killer T (NKT) cells and dendritic cells-with a focus on consequences for the response to infection or vaccination in old age.
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Affiliation(s)
- Alexander Panda
- Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
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257
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Bisoendial RJ, Birjmohun RS, Akdim F, van 't Veer C, Spek CA, Hartman D, de Groot ER, Bankaitis-Davis DM, Kastelein JJP, Stroes ESG. C-reactive protein elicits white blood cell activation in humans. Am J Med 2009; 122:582.e1-9. [PMID: 19486722 DOI: 10.1016/j.amjmed.2008.11.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2008] [Revised: 11/02/2008] [Accepted: 11/26/2008] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Consistent epidemiologic evidence suggests that acute infections increase the risk for acute cardiovascular events. We tested in humans whether activation of peripheral leukocytes in reaction to the administration of recombinant human C-reactive protein (rhCRP) may provide a mechanism for infectious diseases to promote atherosclerotic disease. METHODS AND RESULTS By using quantitative real-time polymerase chain reaction analysis, whole-blood expression profiles were analyzed for 95 inflammatory markers before and after infusion of 1.25 mg/kg rhCRP in 5 male volunteers. Relevant transcript levels were measured at baseline and 4 and 8 hours after rhCRP-infusion. CRP caused significant up-regulation of matrix metalloproteinase (MMP)-9, monocyte chemoattractant protein (MCP)-1, plasminogen activator urokinase, macrophage inflammatory protein 1 alpha, and nuclear factor of kappa B inhibitor mRNAs in peripheral leukocytes. mRNA up-regulation of MMP-9 and MCP-1 was 17- and 11-fold, respectively. The corresponding increase in plasma protein levels of MMP-9 (78+/-32 ng/mL to 109+/-41 ng/mL; P=.014) and MCP-1 (312+/-92 pg/mL to 2590+/-898 pg/mL; P=.007) closely mirrored mRNA findings. Also, in whole-blood culture stimulation assays, CRP induced proinflammatory changes. Notably, heat inactivation abolished the capacity of CRP to evoke these proinflammatory changes, excluding a role for contaminants within the purified CRP preparation. CONCLUSION CRP elicits activation of peripheral leukocytes with ensuing secretion of plaque-destabilizing mediators. These findings are consistent with the hypothesis that infectious diseases trigger manifestations of atherosclerosis, in which CRP elevation might contribute to the onset of cardiovascular events.
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Affiliation(s)
- Radjesh J Bisoendial
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands.
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258
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Qu P, Du H, Li Y, Yan C. Myeloid-specific expression of Api6/AIM/Sp alpha induces systemic inflammation and adenocarcinoma in the lung. THE JOURNAL OF IMMUNOLOGY 2009; 182:1648-59. [PMID: 19155514 DOI: 10.4049/jimmunol.182.3.1648] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
To study the functional role of apoptosis inhibition of myeloid lineage cells in tumor formation, apoptosis inhibitor 6 (Api6/AIM/Sp alpha) was overexpressed in a myeloid-specific c-fms-rtTA/(TetO)(7)-CMV-Api6 bitransgenic mouse model under the control of the c-fms promoter/intron 2. In this bitransgenic system, the Api6-Flag fusion protein was expressed in myeloid lineage cells after doxycycline treatment. Induction of Api6 abnormally elevated levels of macrophages, neutrophils, and dendritic cells in the bone marrow, blood, and lung in vivo. BrdU incorporation and annexin V binding studies showed systemically increased cell proliferation and inhibition of apoptosis in myeloid lineage cells. Api6 overexpression activated oncogenic signaling pathways, including Stat3, Erk1/2, and p38 in myeloid lineage cells in multiple organs of the bitransgenic mice. In the lung, severe inflammation and massive tissue remodeling were observed in association with increased expression of procancer cytokines/chemokines, decreased expression of proapoptosis molecule genes, and increased expression of matrix metalloproteinase genes as a result of Api6 overexpression. Oncogenic CD11b(+)/Gr-1(+) myeloid-derived suppressor cells were systemically increased. After Api6 overexpression, lung adenocarcinoma was observed in bitransgenic mice with a 35% incidence rate. These studies suggest that dysregulation of myeloid cell populations by extracellular Api6 signaling leads to abnormal myelopoiesis and lung cancer.
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Affiliation(s)
- Peng Qu
- Center for Immunobiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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259
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Bauer ME, Jeckel CMM, Luz C. The role of stress factors during aging of the immune system. Ann N Y Acad Sci 2009; 1153:139-52. [PMID: 19236337 DOI: 10.1111/j.1749-6632.2008.03966.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This manuscript reviews current evidence suggesting that aging of the immune system (immunosenescence) may be closely related to chronic stress and stress factors. Healthy aging has been associated with emotional distress in parallel to increased cortisol to dehydroepiandrosterone (DHEA) ratio. The impaired DHEA secretion together with the increase of cortisol results in an enhanced exposure of lymphoid cells to deleterious glucocorticoid actions. The lack of appropriated growth hormone signaling during immunosenescence is also discussed. It follows that altered neuroendocrine functions could be underlying several immunosenescence features. Indeed, changes in both innate and adaptive immune responses during aging are also similarly reported during chronic glucocorticoid exposure. In addition, chronically stressed elderly subjects may be particularly at risk of stress-related pathology because of further alterations in both neuroendocrine and immune systems. The accelerated senescent features induced by chronic stress include higher oxidative stress, reduced telomere length, chronic glucocorticoid exposure, thymic involution, changes in cellular trafficking, reduced cell-mediated immunity, steroid resistance, and chronic low-grade inflammation. These senescent features are related to increased morbidity and mortality among chronically stressed elderly people. Overall, these data suggest that chronic stress leads to premature aging of key allostatic systems involved in the adaptation of the organisms to environmental changes. Stress management and psychosocial support may thus promote a better quality of life for elderly people and at the same time reduce hospitalization costs.
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Affiliation(s)
- Moisés E Bauer
- Faculdade de Biociências and Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
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260
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The importance of the age factor in cancer vaccination at older age. Cancer Immunol Immunother 2009; 58:1969-77. [PMID: 19259666 DOI: 10.1007/s00262-009-0683-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Accepted: 02/05/2009] [Indexed: 12/17/2022]
Abstract
Cancer is an age-related disease, and with the graying of the society there is an increasing need to optimize cancer management and therapy to elderly patients. Vaccine therapy for cancer is less toxic than chemotherapy or radiation and could be, therefore, especially effective in older, more frail cancer patients. However, it has been shown that older individuals do not respond to vaccine therapy as well as younger adults. This has been attributed to T cell unresponsiveness, a phenomenon also observed in cancer patients per se. Therefore, research is needed to establish whether age-specific tumor-immunological variables permit optimal use of cancer vaccines and therapy in the elderly. This review summarizes the current knowledge of T cell unresponsiveness in cancer patients and elderly, and the results of cancer vaccination in preclinical models at young and old age. Finally, new directions that may lead to effective cancer vaccination at older age will be proposed.
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261
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Agrawal A, Tay J, Ton S, Agrawal S, Gupta S. Increased reactivity of dendritic cells from aged subjects to self-antigen, the human DNA. THE JOURNAL OF IMMUNOLOGY 2009; 182:1138-45. [PMID: 19124757 DOI: 10.4049/jimmunol.182.2.1138] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Diminished immune functions and chronic inflammation are hallmarks of aging. The underlying causes are not well understood. In this investigation, we show an increased reactivity of dendritic cells (DCs) from aged subjects to self-Ags as one of the potential mechanisms contributing to age-associated inflammation. Consistent with this, DCs from aged subjects display increased reactivity to intracellular human DNA, a self-Ag, by secreting enhanced quantities of type I IFN and IL-6 compared with the DCs from young subjects. Furthermore, this is accompanied by an increased up-regulation of costimulatory molecules CD80 and CD86. These DNA-primed DCs from aged subjects enhanced T cell proliferation compared with the young subjects, further substantiating our findings. Investigations of signaling mechanisms revealed that DNA-stimulated DCs from aged subjects displayed a significantly higher level of IFN regulatory factor-3 and NF-kappaB activity compared with their young counterparts. More importantly, DCs from aged subjects displayed a higher level of NF-kappaB activation at the basal level, suggesting an increased state of activation. This activated state of DCs may be responsible for their increased reactivity to self-Ags such as DNA, which in turn contributes to the age-associated chronic inflammation.
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Affiliation(s)
- Anshu Agrawal
- Division of Basic and Clinical Immunology, Department of Medicine, University of California, Irvine, CA 92697, USA.
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262
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Fortin CF, McDonald PP, Lesur O, Fülöp T. Aging and neutrophils: there is still much to do. Rejuvenation Res 2009; 11:873-82. [PMID: 18847379 DOI: 10.1089/rej.2008.0750] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human neutrophils are activated by a wide array of compounds through their receptors. This elicits their classical functions, such as chemotaxis, phagocytosis, and the production of reactive oxygen species (ROS). Upon stimulation, neutrophils also produce lipid and immune mediators and can present antigen through the major histocompatibility complex I (MHC-I). The age-related impairment of the classical functions of neutrophils is well described, but experimental evidence showing alterations in the production of mediators and antigen presentation with aging are lacking. This review highlights the role of neutrophils in age-related pathologies such as Alzheimer's disease, atherosclerosis, cancer, and autoimmune diseases. Furthermore, we discuss how aging potentially affects the production and release of mediators by human neutrophils in ways that may contribute to the development of these pathologies.
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Affiliation(s)
- Carl F Fortin
- Pulmonary Division, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada.
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263
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Moretto MM, Lawlor EM, Khan IA. Aging mice exhibit a functional defect in mucosal dendritic cell response against an intracellular pathogen. THE JOURNAL OF IMMUNOLOGY 2008; 181:7977-84. [PMID: 19017989 DOI: 10.4049/jimmunol.181.11.7977] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Down-regulation of the immune response in aging individuals puts this population at a potential risk against infectious agents. In-depth studies conducted in humans and mouse models have demonstrated that with increasing age, the T cell immune response against pathogens is compromised and response to vaccinations is subdued. In the present study, using a mouse model, we demonstrate that older animals exhibit greater susceptibility to Encephalitozoon cuniculi infection, and their ability to evoke an Ag-specific T cell response at the gut mucosal site is reduced. The dampening of T cell immunity was due to the defective priming by the dendritic cells (DC) isolated from the mucosal tissues of aging animals. When primed with DC from younger mice, T cells from older animals were able to exhibit an optimal Ag-specific response. The functional defect in DC from older mice can be attributed to a large extent to reduced IL-15 message in these cells, which can be reversed by addition of exogenous IL-15 to the cultures. IL-15 treatment led to optimal expression of costimulatory molecules (CD80 and CD86) on the surface of older DC and restored their ability to prime a T cell response against the pathogen. To our knowledge, this is the first report which demonstrates the inability of the DC population from aging animals to prime a robust T cell response against an infectious agent. Moreover, the observation that IL-15 treatment can reverse this defect has far-reaching implications in developing strategies to increase vaccination protocols for aging populations.
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Affiliation(s)
- Magali M Moretto
- Department of Microbiology, Immunology and Tropical Medecine, George Washington University, Washington, DC 20037, USA
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264
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Grolleau-Julius A, Abernathy L, Harning E, Yung RL. Mechanisms of murine dendritic cell antitumor dysfunction in aging. Cancer Immunol Immunother 2008; 58:1935-9. [PMID: 19082999 DOI: 10.1007/s00262-008-0636-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 11/23/2008] [Indexed: 11/28/2022]
Abstract
Effective cancer immunotherapy depends on the body's ability to generate tumor antigen-presenting cells and tumor-reactive effector lymphocytes. As the most potent antigen presenting cells (APCs), dendritic cells (DCs) are capable of sensitizing T cells to new and recall antigens. Clinical trials of antigen-pulsed autologous DCs have been conducted in patients with a number of hematological and solid cancers, including malignant melanoma, lymphoma, myeloma, and non-small cell lung cancer. These studies suggest that antigen-loaded DC vaccination is a potentially safe and effective cancer therapy. However, the clinical results have been variable. Since the elderly are preferentially affected by diseases targeted by DC-directed immunotherapy, it is quite striking that few studies to date have focused on the effect of aging on DC function, a key aspect of optimal immunotherapy design in an aging population. In the present paper, we will discuss the consequences of aging on murine bone marrow-derived DC function and their use in cancer immunotherapy.
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Affiliation(s)
- Annabelle Grolleau-Julius
- Divisions of Geriatric Medicine and Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109-0940, USA.
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265
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Stout-Delgado HW, Yang X, Walker WE, Tesar BM, Goldstein DR. Aging impairs IFN regulatory factor 7 up-regulation in plasmacytoid dendritic cells during TLR9 activation. THE JOURNAL OF IMMUNOLOGY 2008; 181:6747-56. [PMID: 18981092 DOI: 10.4049/jimmunol.181.10.6747] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plasmacytoid dendritic cells (pDCs) are innate sensors that produce IFN-alpha in response to viral infections. Determining how aging alters the cellular and molecular function of these cells may provide an explanation of increased susceptibility of older people to viral infections. Hence, we examined whether aging critically impairs pDC function during infection with HSV-2, a viral pathogen that activates TLR9. We found that impaired IFN-alpha production by aged murine pDCs led to impaired viral clearance with aging. Upon TLR9 activation, aged pDCs displayed defective up-regulation of IFN-regulatory factor 7, a key adaptor in the type I IFN pathway, as compared with younger counterparts. Aged pDCs had more oxidative stress, and reducing oxidative stress in aged pDCs partly recovered the age-induced IFN-alpha defect during TLR9 activation. In sum, aging impairs the type I IFN pathway in pDCs, and this alteration may contribute to the increased susceptibility of older people to certain viral infections.
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Affiliation(s)
- Heather W Stout-Delgado
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
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266
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Espía M, Sebastián C, Mulero M, Giralt M, Mallol J, Celada A, Lloberas J. Granulocyte macrophage--colony-stimulating factor-dependent proliferation is impaired in macrophages from senescence-accelerated mice. J Gerontol A Biol Sci Med Sci 2008; 63:1161-7. [PMID: 19038830 DOI: 10.1093/gerona/63.11.1161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A senescence-accelerated (SAMP8) mouse model was used to determine the effect of aging on the immune system. We produced in vitro bone marrow-derived macrophages from SAMP8 mice and compared them against senescence-resistant, long-lived mice (SAMR1). Although macrophages from both strains of mice proliferated in a similar manner in response to monocyte-colony-stimulating factor (M-CSF), SAMP8 macrophages showed an impaired response to granulocyte macrophage-colony-stimulating factor (GM-CSF). Similar levels of external regulated kinases (ERK)1/2 and signaling transducer and activator of transcription 5 (STAT5) phosphorylation were observed in macrophages from both strains of mice. The lack of proliferation was not caused by the induction of apoptosis. Differentiation of bone marrow cells into dendritic cells was similar in both strains of mice, as was the induction of major histocompatibility complex (MHC) class II molecules by interferon-gamma (IFN-gamma). Finally, we determined the density of Langerhans cells in vivo in the skin of the two mouse strains, but no differences were found.
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Affiliation(s)
- Marta Espía
- Macroophage Biology Group, Institute for Research in Biomedicine, Barcelona, Barcelona Science Park, C/ Josep Samitier 1-5, E-08028 Barcelona, Spain
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267
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Agrawal S, Gupta S, Agrawal A. Vaccinia virus proteins activate human dendritic cells to induce T cell responses in vitro. Vaccine 2008; 27:88-92. [PMID: 18977270 DOI: 10.1016/j.vaccine.2008.10.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 09/25/2008] [Accepted: 10/07/2008] [Indexed: 12/14/2022]
Abstract
The mechanisms of protection elicited by smallpox vaccine in humans have not been delineated. Dendritic cells (DCs) are the most potent of professional antigen presenting cells which on activation modulate both innate and adaptive immune responses. Immunogenic proteins of vaccinia virus have been identified with protein microarray technology. We have investigated the effect of three most immunogenic proteins, D8L, D13L, and H3L on human monocyte-derived DCs with a view to understand the mechanisms underlying the immunogenicity of these proteins. Our data show that all three proteins activate and mature DCs, induce secretion of cytokines IL-12p70, IL-10, TNF-alpha, IL-6 from DCs, and rVV protein-loaded DCs induce secretion of IFN-gamma and proliferation of T cells with selective expansion of effector memory T cells. Overall D13L and H3L proteins are more immunogenic than D8L. Taken together data suggest that these peptides are highly immunogenic and can modulate an effective innate and adaptive response in humans in vitro.
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Affiliation(s)
- Sudhanshu Agrawal
- Division of Basic and Clinical Immunology, University of California, Irvine, CA 92697, USA
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268
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Derhovanessian E, Solana R, Larbi A, Pawelec G. Immunity, ageing and cancer. IMMUNITY & AGEING 2008; 5:11. [PMID: 18816370 PMCID: PMC2564902 DOI: 10.1186/1742-4933-5-11] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Accepted: 09/24/2008] [Indexed: 11/22/2022]
Abstract
Compromised immunity contributes to the decreased ability of the elderly to control infectious disease and to their generally poor response to vaccination. It is controversial as to how far this phenomenon contributes to the well-known age-associated increase in the occurrence of many cancers in the elderly. However, should the immune system be important in controlling cancer, for which there is a great deal of evidence, it is logical to propose that dysfunctional immunity in the elderly would contribute to compromised immunosurveillance and increased cancer occurrence. The chronological age at which immunosenescence becomes clinically important is known to be influenced by many factors, including the pathogen load to which individuals are exposed throughout life. It is proposed here that the cancer antigen load may have a similar effect on "immune exhaustion" and that pathogen load and tumor load may act additively to accelerate immunosenescence. Understanding how and why immune responsiveness changes in humans as they age is essential for developing strategies to prevent or restore dysregulated immunity and assure healthy longevity, clearly possible only if cancer is avoided. Here, we provide an overview of the impact of age on human immune competence, emphasizing T-cell-dependent adaptive immunity, which is the most sensitive to ageing. This knowledge will pave the way for rational interventions to maintain or restore appropriate immune function not only in the elderly but also in the cancer patient.
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269
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Grolleau-Julius A, Harning EK, Abernathy LM, Yung RL. Impaired dendritic cell function in aging leads to defective antitumor immunity. Cancer Res 2008; 68:6341-9. [PMID: 18676859 DOI: 10.1158/0008-5472.can-07-5769] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We recently reported that bone marrow-derived dendritic cells (DC) from aged miced are less effective than their young counterparts in inducing the regression of B16-ovalbumin (OVA) melanomas. To examine the underlying mechanisms, we investigated the effect of aging on DC tumor antigen presentation and migration. Although aging does not affect the ability of DCs to present OVA peptide((257-264)), DCs from aged mice are less efficient than those from young mice in stimulating OVA-specific T cells in vitro. Phenotypic analysis revealed a selective decrease in DC-specific/intracellular adhesion molecule type-3-grabbing nonintegrin (DC-SIGN) level in aged DCs. Adoptive transfer experiments showed defective in vivo DC trafficking in aging. This correlates with impaired in vitro migration and defective CCR7 signaling in response to CCL21 in aged DCs. Interestingly, vaccination of young mice using old OVA peptide((257-264))-pulsed DCs (OVA PP-DC) resulted in impaired activation of OVA-specific CD8(+) T cells in vivo. Effector functions of these T cells, as determined by IFN-gamma production and cytotoxic activity, were similar to those obtained from mice vaccinated with young OVA PP-DCs. A decreased influx of intratumor CD8(+) T cells was also observed. Importantly, although defective in vivo migration could be restored by increasing the number of old DCs injected, the aging defect in DC tumor surveillance and OVA-specific CD8(+) T-cell induction remained. Taken together, our findings suggest that defective T-cell stimulation contributes to the observed impaired DC tumor immunotherapeutic response in aging.
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Affiliation(s)
- Annabelle Grolleau-Julius
- Department of Internal Medicine, Division of Geriatric Medicine, University of Michigan and Geriatric Research Education and Clinical Centers, Ann Arbor Veterans Affairs Health System, Ann Arbor, Michigan 48109, USA
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270
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Wang L, Chen Y, Sternberg P, Cai J. Essential roles of the PI3 kinase/Akt pathway in regulating Nrf2-dependent antioxidant functions in the RPE. Invest Ophthalmol Vis Sci 2008; 49:1671-8. [PMID: 18385090 DOI: 10.1167/iovs.07-1099] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
PURPOSE To investigate functional interactions between the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and the nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent antioxidant system in cultured human retinal pigment epithelium (RPE) cells. METHODS Cultured ARPE-19 cells were treated with different concentrations of PI3K inhibitors, followed by exposure to sulforaphane, an Nrf2 inducer. Akt phosphorylation was detected by Western blot analysis. Intracellular glutathione (GSH) content was measured by HPLC. Expression of genes downstream of Nrf2, including glutamate-cysteine ligase (GCL) and glutathione S-transferase, was measured by quantitative RT-PCR. Nrf2 activity was measured by a dual luciferase assay after transfection of a reporter plasmid containing the antioxidant response element (ARE). The small interference RNA approach was used to knock down Nrf2 in the RPE. Nrf2 localization was determined by subcellular fractionation and Western blot analyses. RESULTS PI3K inhibitors wortmannin and LY294002 caused dose-dependent cellular and mitochondrial GSH depletion and downregulation of the modulatory subunit of GCL in cultured RPE cells. Both the basal and the induced Nrf2 activities were inhibited by wortmannin and LY294002. Overexpression of a constitutively active form of Akt potentiated Nrf2 activation, and the effect of Akt was blocked by siRNA that knocked down Nrf2. LY294002 also inhibited sulforaphane-induced Nrf2 nuclear translocation. CONCLUSIONS The PI3K/Akt pathway plays key roles in regulating Nrf2-ARE-dependent protection against oxidative stress in the RPE.
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Affiliation(s)
- Ling Wang
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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271
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Alterations in dendritic cell function in aged mice: potential implications for immunotherapy design. Biogerontology 2008; 10:13-25. [DOI: 10.1007/s10522-008-9150-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Accepted: 05/13/2008] [Indexed: 10/22/2022]
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272
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Larbi A, Franceschi C, Mazzatti D, Solana R, Wikby A, Pawelec G. Aging of the immune system as a prognostic factor for human longevity. Physiology (Bethesda) 2008; 23:64-74. [PMID: 18400689 DOI: 10.1152/physiol.00040.2007] [Citation(s) in RCA: 200] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Accumulating data are documenting an inverse relationship between immune status, response to vaccination, health, and longevity, suggesting that the immune system becomes less effective with advancing age and that this is clinically relevant. The mechanisms and consequences of age-associated immune alterations, designated immunosenescence, are briefly reviewed here.
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Affiliation(s)
- Anis Larbi
- University of Tübingen, Center for Medical Research,Tübingen, Germany.
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273
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Gravekamp C, Kim SH, Castro F. Cancer vaccination: manipulation of immune responses at old age. Mech Ageing Dev 2008; 130:67-75. [PMID: 18561984 DOI: 10.1016/j.mad.2008.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 04/18/2008] [Accepted: 05/02/2008] [Indexed: 01/07/2023]
Abstract
The incidence of cancer has increased over the last decade, mainly due to an increase in the elderly population. Vaccine therapy for cancer is less toxic than chemotherapy or radiation and could be, therefore, especially effective in older, more frail cancer patients. However, it has been shown that older individuals do not respond to vaccine therapy as well as younger adults. This has been attributed to T-cell unresponsiveness, a phenomenon also observed in cancer patients per se. This review summarizes the current knowledge of impaired T-cell responses in cancer patients and the elderly, and the results of cancer vaccination in preclinical models at young and old age. Finally, various approaches how to manipulate immune responses against cancer by vaccination at older age will be proposed.
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Affiliation(s)
- Claudia Gravekamp
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA.
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274
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Bates JT, Honko AN, Graff AH, Kock ND, Mizel SB. Mucosal adjuvant activity of flagellin in aged mice. Mech Ageing Dev 2008; 129:271-81. [PMID: 18367233 DOI: 10.1016/j.mad.2008.01.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 12/11/2007] [Accepted: 01/25/2008] [Indexed: 01/22/2023]
Abstract
We evaluated the ability of flagellin, a highly effective mucosal adjuvant in mice and non-human primates, to promote mucosal innate and adaptive immunity in aged mice. We found that intratracheal instillation of flagellin induced a stronger respiratory innate response in aged mice than in young mice, and that intranasal instillation of flagellin was equally effective at triggering recruitment of T and B lymphocytes to the draining lymph nodes of young and aged mice. Intranasal immunization of aged mice with flagellin and the Yersinia pestis protein F1 promoted specific IgG and IgA production, but at lower levels and lower avidities than in young mice. Although intranasal instillation of flagellin and F1 antigen increased germinal center formation and size in young mice, it did not do so in aged mice. Our findings are consistent with the conclusion that flagellin can promote adaptive immune responses in aged mice, but at a less robust level than in young mice.
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Affiliation(s)
- John T Bates
- Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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275
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Huang MC, Liao JJ, Bonasera S, Longo DL, Goetzl EJ. Nuclear factor-kappaB-dependent reversal of aging-induced alterations in T cell cytokines. FASEB J 2008; 22:2142-50. [PMID: 18267981 DOI: 10.1096/fj.07-103721] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Immunosenescence is characterized by decreases in protective immune responses and increases in inflammation and autoimmunity. The T helper (Th)17 subset of cluster-of-differentiation (CD)4 T cells, which is identified by its generation of interleukin (IL) -17, is implicated in autoimmune pathogenesis. To elucidate immunosenescent changes in Th17 cell cytokines, splenic CD4 T cells from 22- to 24-month-old (old) mice and 6- to 10-wk-old (young) mice were incubated on anti-CD3 plus anti-CD28 (anti-T cell antigen receptor) antibodies. After 96 h, T cells of old C57BL/6 and CBA mice generated up to 20-fold more IL-17 and up to 3-fold more IL-6 than those of young mice; T cells of young mice generated up to 5-fold more IL-21 than those of old mice; and no difference was found for IFN-gamma. At 24 h, cytokine mRNA levels paralleled 96 h cytokine concentrations. Naive CD4 T cells from old mice incubated on anti-T cell antigen receptor antibodies with transforming growth factor-beta, IL-1, IL-6, and IL-23 to induce de novo differentiation of Th17 cells had more IL-17 mRNA and produced more IL-17 than those of young mice. BAY11-7082 and the phytochemicals triptolide and butein suppressed nuclear concentrations of nuclear factor-kappaB and secreted levels of IL-17, IL-21, and IFN-gamma in parallel, with greater potency in Th17 cells from young than old mice. Pharmacological correction of altered generation of Th17 cell cytokines in immunosenescence represents a novel therapeutic approach to aging-induced inflammatory diseases.
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Affiliation(s)
- Mei-Chuan Huang
- Department of Medicine, University of California, San Francisco, California, USA
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276
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Kang K, Kim H, Kim KI, Yang Y, Yoon DY, Kim JH, Ryu JH, Noh EJ, Jeon SD, Lim JS. SK-126, a synthetic compound, regulates the production of inflammatory cytokines induced by LPS in antigen-presenting cells. Biochem Pharmacol 2007; 75:1054-64. [PMID: 18054895 DOI: 10.1016/j.bcp.2007.10.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 10/24/2007] [Accepted: 10/29/2007] [Indexed: 12/30/2022]
Abstract
A variety of mediators released by immune cells triggers or enhances specific aspects of the inflammatory response. Dendritic cells (DCs) play an essential role in the innate immune system by shaping the adaptive immune responses and by controlling the production of cytokines in response to inflammatory stimuli. In the present study, we investigated whether SK-126, a pyridine derivative based on gentianine originated from a natural product, can affect the LPS-induced inflammatory cytokine production in DC. Interestingly, treatment of mouse bone marrow-derived dendritic cells (BMDCs) and the murine dendritic cell line, DC 2.4, with SK-126 completely suppressed LPS-induced TNF-alpha expression at both transcriptional and protein levels. In contrast to TNF-alpha, SK-126 enhanced IL-10 expression at both transcriptional and protein levels. To determine signaling pathways involved in the regulation of inflammatory cytokines, we examined the involvement of MAPK and the transcription factor, NF-kappaB. SK-126 enhanced ERK1/2 and p38 activation following LPS stimulation, but it did not induce phosphorylation of SAPK/JNK and NF-kappaB. Also, STAT3 phosphorylation after LPS stimulation was increased by SK-126 to a large extent. Using specific inhibitors, we confirmed that SK-126 has dual effects in which it suppresses TNF-alpha production and enhances IL-10 production via the up-regulation of ERK1/2 and p38. Finally, LPS-induced inflammatory responses such as TNF-alpha production in vivo were significantly reduced by treatment with SK-126. Therefore, our findings suggest that SK-126 may be a useful drug candidate to treat inflammatory diseases in which pro- or anti-inflammatory cytokines play a significant role in their pathogenesis.
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Affiliation(s)
- Kyeongah Kang
- Department of Biological Science and the Research Center for Women's Diseases, Sookmyung Women's University, Seoul 140-742, Republic of Korea
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Agrawal A, Agrawal S, Tay J, Gupta S. Biology of dendritic cells in aging. J Clin Immunol 2007; 28:14-20. [PMID: 17828583 DOI: 10.1007/s10875-007-9127-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 08/07/2007] [Indexed: 01/09/2023]
Abstract
Dendritic cells are central to the generation of both immunity and tolerance. This review focuses on the alterations in the functions of dendritic cells in aged and its consequences on both tolerance and immunity. We have discussed certain mechanisms responsible for the defective dendritic cell function associated with aging.
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Affiliation(s)
- Anshu Agrawal
- Division of Basic and Clinical Immunology, University of California, Irvine, CA 92697, USA.
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