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McGovern KE, Sonar SA, Watanabe M, Coplen CP, Bradshaw CM, Nikolich JŽ. The aging of the immune system and its implications for transplantation. GeroScience 2023:10.1007/s11357-022-00720-2. [PMID: 36626019 PMCID: PMC9838392 DOI: 10.1007/s11357-022-00720-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 12/21/2022] [Indexed: 01/11/2023] Open
Abstract
By the last third of life, most mammals, including humans, exhibit a decline in immune cell numbers, immune organ structure, and immune defense of the organism, commonly known as immunosenescence. This decline leads to clinical manifestations of increased susceptibility to infections, particularly those caused by emerging and reemerging microorganisms, which can reach staggering levels-infection with SARS-CoV-2 has been 270-fold more lethal to older adults over 80 years of age, compared to their 18-39-year-old counterparts. However, while this would be expected to be beneficial to situations where hyporeactivity of the immune system may be desirable, this is not always the case. Here, we discuss the cellular and molecular underpinnings of immunosenescence as they pertain to outcomes of solid organ and hematopoietic transplantation.
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Affiliation(s)
- Kathryn E McGovern
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
- Arizona Center On Aging, The University of Arizona, University of Arizona College of Medicine-Tucson, Tucson, AZ, 85724, USA
- BIO5 Institute, University of Arizona, Tucson, AZ, USA
| | - Sandip A Sonar
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
- Arizona Center On Aging, The University of Arizona, University of Arizona College of Medicine-Tucson, Tucson, AZ, 85724, USA
| | - Makiko Watanabe
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
- Arizona Center On Aging, The University of Arizona, University of Arizona College of Medicine-Tucson, Tucson, AZ, 85724, USA
| | - Christopher P Coplen
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
- Arizona Center On Aging, The University of Arizona, University of Arizona College of Medicine-Tucson, Tucson, AZ, 85724, USA
| | - Christine M Bradshaw
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA
- Arizona Center On Aging, The University of Arizona, University of Arizona College of Medicine-Tucson, Tucson, AZ, 85724, USA
| | - Janko Ž Nikolich
- Department of Immunobiology, University of Arizona, Tucson, AZ, 85724, USA.
- Arizona Center On Aging, The University of Arizona, University of Arizona College of Medicine-Tucson, Tucson, AZ, 85724, USA.
- BIO5 Institute, University of Arizona, Tucson, AZ, USA.
- The Aegis Consortium for Pandemic-free Future, University of Arizona Health Sciences, University of Arizona, Tucson, 85719, USA.
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2
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Lancaster JN, Keatinge‐Clay DE, Srinivasan J, Li Y, Selden HJ, Nam S, Richie ER, Ehrlich LIR. Central tolerance is impaired in the middle-aged thymic environment. Aging Cell 2022; 21:e13624. [PMID: 35561351 PMCID: PMC9197411 DOI: 10.1111/acel.13624] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/03/2022] [Accepted: 04/20/2022] [Indexed: 12/03/2022] Open
Abstract
One of the earliest hallmarks of immune aging is thymus involution, which not only reduces the number of newly generated and exported T cells, but also alters the composition and organization of the thymus microenvironment. Thymic T‐cell export continues into adulthood, yet the impact of thymus involution on the quality of newly generated T‐cell clones is not well established. Notably, the number and proportion of medullary thymic epithelial cells (mTECs) and expression of tissue‐restricted antigens (TRAs) decline with age, suggesting the involuting thymus may not promote efficient central tolerance. Here, we demonstrate that the middle‐aged thymic environment does not support rapid motility of medullary thymocytes, potentially diminishing their ability to scan antigen presenting cells (APCs) that display the diverse self‐antigens that induce central tolerance. Consistent with this possibility, thymic slice assays reveal that the middle‐aged thymic environment does not support efficient negative selection or regulatory T‐cell (Treg) induction of thymocytes responsive to either TRAs or ubiquitous self‐antigens. This decline in central tolerance is not universal, but instead impacts lower‐avidity self‐antigens that are either less abundant or bind to TCRs with moderate affinities. Additionally, the decline in thymic tolerance by middle age is accompanied by both a reduction in mTECs and hematopoietic APC subsets that cooperate to drive central tolerance. Thus, age‐associated changes in the thymic environment result in impaired central tolerance against moderate‐avidity self‐antigens, potentially resulting in export of increasingly autoreactive naive T cells, with a deficit of Treg counterparts by middle age.
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Affiliation(s)
- Jessica N. Lancaster
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | | | - Jayashree Srinivasan
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Yu Li
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Hilary J. Selden
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Seohee Nam
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
| | - Ellen R. Richie
- Department of Epigenetics and Molecular Carcinogenesis The University of Texas MD Anderson Cancer Center Houston Texas USA
| | - Lauren I. R. Ehrlich
- Department of Molecular Biosciences The University of Texas at Austin Austin Texas USA
- Department of Oncology Dell Medical School at The University of Texas at Austin Austin Texas USA
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3
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Padilha de Lima A, Macedo Rogero M, Araujo Viel T, Garay-Malpartida HM, Aprahamian I, Lima Ribeiro SM. Interplay between Inflammaging, Frailty and Nutrition in Covid-19: Preventive and Adjuvant Treatment Perspectives. J Nutr Health Aging 2022; 26:67-76. [PMID: 35067706 PMCID: PMC8713542 DOI: 10.1007/s12603-021-1720-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 10/06/2021] [Indexed: 02/06/2023]
Abstract
As humans age, their immune system undergoes modifications, including a low-grade inflammatory status called inflammaging. These changes are associated with a loss of physical and immune resilience, amplifying the risk of being malnourished and frail. Under the COVID-19 scenario, inflammaging increases the susceptibility to poor prognostics. We aimed to bring the current concepts of inflammaging and its relationship with frailty and COVID-19 prognostic; highlight the importance of evaluating the nutritional risk together with frailty aiming to monitor older adults in COVID-19 scenario; explore some compounds with potential to modulate inflammaging in perspective to manage the COVID-19 infection. Substances such as probiotics and senolytics can help reduce the high inflammatory status. Also, the periodic evaluation of nutrition risk and frailty will allow interventions, assuring the appropriate care.
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Affiliation(s)
- A Padilha de Lima
- Sandra Maria Lima Ribeiro, University of São Paulo- Public Health School, Av Dr. Arnaldo 715, Sao Paulo- SP- Brazil, e-mail:
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4
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Sharma R, Diwan B, Sharma A, Witkowski JM. Emerging cellular senescence-centric understanding of immunological aging and its potential modulation through dietary bioactive components. Biogerontology 2022; 23:699-729. [PMID: 36261747 PMCID: PMC9581456 DOI: 10.1007/s10522-022-09995-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 10/12/2022] [Indexed: 12/13/2022]
Abstract
Immunological aging is strongly associated with the observable deleterious effects of human aging. Our understanding of the causes, effects, and therapeutics of aging immune cells has long been considered within the sole purview of immunosenescence. However, it is being progressively realized that immunosenescence may not be the only determinant of immunological aging. The cellular senescence-centric theory of aging proposes a more fundamental and specific role of immune cells in regulating senescent cell (SC) burden in aging tissues that has augmented the notion of senescence immunotherapy. Now, in addition, several emerging studies are suggesting that cellular senescence itself may be prevalent in aging immune cells, and that senescent immune cells exhibiting characteristic markers of cellular senescence, similar to non-leucocyte cells, could be among the key drivers of various facets of physiological aging. The present review integrates the current knowledge related to immunosenescence and cellular senescence in immune cells per se, and aims at providing a cohesive overview of these two phenomena and their significance in immunity and aging. We present evidence and rationalize that understanding the extent and impact of cellular senescence in immune cells vis-à-vis immunosenescence is necessary for truly comprehending the notion of an 'aged immune cell'. In addition, we also discuss the emerging significance of dietary factors such as phytochemicals, probiotic bacteria, fatty acids, and micronutrients as possible modulators of immunosenescence and cellular senescence. Evidence and opportunities related to nutritional bioactive components and immunological aging have been deliberated to augment potential nutrition-oriented immunotherapy during aging.
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Affiliation(s)
- Rohit Sharma
- grid.430140.20000 0004 1799 5083Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Solan, 173229 India
| | - Bhawna Diwan
- grid.430140.20000 0004 1799 5083Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Solan, 173229 India
| | - Anamika Sharma
- grid.464631.20000 0004 1775 3615Department of Biological Sciences, National Institute of Pharmaceutical Education and Research, Hyderabad, 500037 India
| | - Jacek M. Witkowski
- grid.11451.300000 0001 0531 3426Department of Pathophysiology, Medical University of Gdańsk, Dębinki 7, 80-211 Gdańsk, Poland
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5
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Srinivasan J, Lancaster JN, Singarapu N, Hale LP, Ehrlich LIR, Richie ER. Age-Related Changes in Thymic Central Tolerance. Front Immunol 2021; 12:676236. [PMID: 33968086 PMCID: PMC8100025 DOI: 10.3389/fimmu.2021.676236] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/06/2021] [Indexed: 01/03/2023] Open
Abstract
Thymic epithelial cells (TECs) and hematopoietic antigen presenting cells (HAPCs) in the thymus microenvironment provide essential signals to self-reactive thymocytes that induce either negative selection or generation of regulatory T cells (Treg), both of which are required to establish and maintain central tolerance throughout life. HAPCs and TECs are comprised of multiple subsets that play distinct and overlapping roles in central tolerance. Changes that occur in the composition and function of TEC and HAPC subsets across the lifespan have potential consequences for central tolerance. In keeping with this possibility, there are age-associated changes in the cellular composition and function of T cells and Treg. This review summarizes changes in T cell and Treg function during the perinatal to adult transition and in the course of normal aging, and relates these changes to age-associated alterations in thymic HAPC and TEC subsets.
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Affiliation(s)
- Jayashree Srinivasan
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | | | - Nandini Singarapu
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, TX, United States
| | - Laura P Hale
- Department of Pathology, Duke University School of Medicine, Durham, NC, United States
| | - Lauren I R Ehrlich
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
| | - Ellen R Richie
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, TX, United States
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6
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Thomas R, Oh J, Wang W, Su DM. Thymic atrophy creates holes in Treg-mediated immuno-regulation via impairment of an antigen-specific clone. Immunology 2021; 163:478-492. [PMID: 33786850 DOI: 10.1111/imm.13333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/14/2022] Open
Abstract
Age-related thymic atrophy results in reduced output of naïve conventional T (Tcon) cells. However, its impact on regulatory T (Treg) cells is insufficiently understood. Given evidence that thymic Treg (tTreg) cell generation is enhanced in the aged, atrophy thymus and that the aged periphery accumulates peripheral Treg (pTreg) cells, we asked why these Treg cells are unable to effectively attenuate increased autoreactivity-induced chronic inflammation in the elderly. We designed a mock-self-antigen chimera mouse model, in which membrane-bound ovalbumin (mOVA) transgenic mice, bearing a FoxN1-floxed gene for induction of conditional thymic atrophy, received OVA-specific (OT-II) T-cell receptor (TCR) transgenic progenitor cells. The chimeric mice with thymic atrophy exhibited a significant decrease in OVA-specific tTreg and pTreg cells but not polyclonal (pan)-Treg cells. These OVA-specific pTreg cells were significantly less able to suppress OVA-specific stimulation-induced proliferation in vitro and exhibited lower FoxP3 expression. Additionally, we conducted preliminary TCR repertoire diversity sequencing for Treg cells among recent thymic emigrants (RTEs) from RagGFP -FoxP3RFP dual-reporter mice and observed a trend for decreased diversity in mice with thymic atrophy compared to littermates with normal thymus. These data indicate that although the effects of age-related thymic atrophy do not affect pan-Treg generation, certain tissue-specific Treg clones may experience abnormal agonist selection. This, combined with enhanced pan-pTreg cells, may greatly contribute to age-related chronic inflammation, even in the absence of acute autoimmune disease in the elderly.
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Affiliation(s)
- Rachel Thomas
- Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Jiyoung Oh
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weikan Wang
- Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Dong-Ming Su
- Department of Microbiology, Immunology and Genetics, University of North Texas Health Science Center, Fort Worth, TX, USA
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7
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Marx A, Yamada Y, Simon-Keller K, Schalke B, Willcox N, Ströbel P, Weis CA. Thymus and autoimmunity. Semin Immunopathol 2021; 43:45-64. [PMID: 33537838 PMCID: PMC7925479 DOI: 10.1007/s00281-021-00842-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
The thymus prevents autoimmune diseases through mechanisms that operate in the cortex and medulla, comprising positive and negative selection and the generation of regulatory T-cells (Tregs). Egress from the thymus through the perivascular space (PVS) to the blood is another possible checkpoint, as shown by some autoimmune/immunodeficiency syndromes. In polygenic autoimmune diseases, subtle thymic dysfunctions may compound genetic, hormonal and environmental cues. Here, we cover (a) tolerance-inducing cell types, whether thymic epithelial or tuft cells, or dendritic, B- or thymic myoid cells; (b) tolerance-inducing mechanisms and their failure in relation to thymic anatomic compartments, and with special emphasis on human monogenic and polygenic autoimmune diseases and the related thymic pathologies, if known; (c) polymorphisms and mutations of tolerance-related genes with an impact on positive selection (e.g. the gene encoding the thymoproteasome-specific subunit, PSMB11), promiscuous gene expression (e.g. AIRE, PRKDC, FEZF2, CHD4), Treg development (e.g. SATB1, FOXP3), T-cell migration (e.g. TAGAP) and egress from the thymus (e.g. MTS1, CORO1A); (d) myasthenia gravis as the prototypic outcome of an inflamed or disordered neoplastic ‘sick thymus’.
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Affiliation(s)
- Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Yosuke Yamada
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
- Department of Diagnostic Pathology, Kyoto University Hospital, Kyoto, 606-8507, Japan
| | - Katja Simon-Keller
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Berthold Schalke
- Department of Neurology, Bezirkskrankenhaus, University of Regensburg, 93042, Regensburg, Germany
| | - Nick Willcox
- Neurosciences Group, Nuffield Department of Clinical Neurology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Philipp Ströbel
- Institute of Pathology, University Medical Center Göttingen, University of Göttigen, 37075, Göttingen, Germany
| | - Cleo-Aron Weis
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
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8
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Bulut O, Kilic G, Domínguez-Andrés J, Netea MG. Overcoming immune dysfunction in the elderly: trained immunity as a novel approach. Int Immunol 2020; 32:741-753. [PMID: 32766848 PMCID: PMC7680842 DOI: 10.1093/intimm/dxaa052] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022] Open
Abstract
People with advanced age have a higher susceptibility to infections and exhibit increased mortality and morbidity as the ability of the immune system to combat infections decreases with age. While innate immune cells display functional defects such as decreased phagocytosis, chemotaxis and cytokine production, adaptive immune cells exhibit reduced receptor diversity, defective antibody production and a sharp decline in naive cell populations. Successful responses to vaccination in the elderly are critical to prevent common infections such as influenza and pneumonia, but vaccine efficacy decreases in older individuals compared with young adults. Trained immunity is a newly emerging concept that showed that innate immune cells possess non-specific immunological memory established through epigenetic and metabolic reprogramming upon encountering certain pathogenic stimuli. Clinical studies suggest that trained immunity can be utilized to enhance immune responses against infections and improve the efficiency of vaccinations in adults; however, how trained immunity responses are shaped with advanced age is still an open question. In this review, we provide an overview of the age-related changes in the immune system with a focus on innate immunity, discuss current vaccination strategies for the elderly, present the concept of trained immunity and propose it as a novel approach to enhance responses against infections and vaccinations in the elderly population.
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Affiliation(s)
- Ozlem Bulut
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
| | - Gizem Kilic
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
| | - Jorge Domínguez-Andrés
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Department of Genomics and Immunoregulation, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
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Gardner JK, Mamotte CD, Jackaman C, Nelson DJ. Modulation of dendritic cell and T cell cross-talk during aging: The potential role of checkpoint inhibitory molecules. Ageing Res Rev 2017; 38:40-51. [PMID: 28736117 DOI: 10.1016/j.arr.2017.07.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/17/2017] [Accepted: 07/17/2017] [Indexed: 12/24/2022]
Abstract
Dendritic cells (DCs) undergo continuous changes throughout life, and there is evidence that elderly DCs have a reduced capacity to stimulate T cells, which may contribute to impaired anti-tumour immune responses in elderly people with cancer. Changes in checkpoint inhibitory molecules/pathways during aging may be one mechanism that impairs the ability of elderly DCs to activate T cells. However, little is currently known regarding the combined effects of aging and cancer on DC and T cell inhibitory molecules/pathways. In this review, we discuss our current understanding of the influence of aging and cancer on key DC and T cell inhibitory molecules/pathways, the potential underlying cellular and molecular mechanisms contributing to their modulation, and the possibility of therapeutically targeting inhibitory molecules in elderly cancer patients.
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Mikušová R, Mešťanová V, Polák Š, Varga I. What do we know about the structure of human thymic Hassall’s corpuscles? A histochemical, immunohistochemical, and electron microscopic study. Ann Anat 2017; 211:140-148. [DOI: 10.1016/j.aanat.2017.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/08/2017] [Accepted: 02/23/2017] [Indexed: 10/20/2022]
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11
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Mešťanová V, Varga I. Morphological view on the evolution of the immunity and lymphoid organs of vertebrates, focused on thymus. Biologia (Bratisl) 2016. [DOI: 10.1515/biolog-2016-0137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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12
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Savino W, Mendes-da-Cruz DA, Lepletier A, Dardenne M. Hormonal control of T-cell development in health and disease. Nat Rev Endocrinol 2016; 12:77-89. [PMID: 26437623 DOI: 10.1038/nrendo.2015.168] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The physiology of the thymus, the primary lymphoid organ in which T cells are generated, is controlled by hormones. Data from animal models indicate that several peptide and nonpeptide hormones act pleiotropically within the thymus to modulate the proliferation, differentiation, migration and death by apoptosis of developing thymocytes. For example, growth hormone and prolactin can enhance thymocyte proliferation and migration, whereas glucocorticoids lead to the apoptosis of these developing cells. The thymus undergoes progressive age-dependent atrophy with a loss of cells being generated and exported, therefore, hormone-based therapies are being developed as an alternative strategy to rejuvenate the organ, as well as to augment thymocyte proliferation and the export of mature T cells to peripheral lymphoid organs. Some hormones (such as growth hormone and progonadoliberin-1) are also being used as therapeutic agents to treat immunodeficiency disorders associated with thymic atrophy, such as HIV infection. In this Review, we discuss the accumulating data that shows the thymus gland is under complex and multifaceted hormonal control that affects the process of T-cell development in health and disease.
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Affiliation(s)
- Wilson Savino
- Laboratory of Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Avenue Brasil 4365, 21045-900, Manguinhos, Rio de Janeiro, Brazil
| | - Daniella Arêas Mendes-da-Cruz
- Laboratory of Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Avenue Brasil 4365, 21045-900, Manguinhos, Rio de Janeiro, Brazil
| | - Ailin Lepletier
- Laboratory of Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Avenue Brasil 4365, 21045-900, Manguinhos, Rio de Janeiro, Brazil
| | - Mireille Dardenne
- Hôpital Necker, CNRS UMR 8147, Université Paris Descartes, 75015 Paris, France
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Abstract
Increasing evidence has revealed the incidence of cancer augments with aging, which could be attributed to a multitude of age-associated changes including the dysregulation of the immune system. Although many reports demonstrate the efficacy of cancer immunotherapies in numerous preclinical studies, most experiments have been performed in young animals. Studies from our group and others show that cancer immunotherapy could be ineffective in old mice, even though the same therapeutic treatment works efficiently in young mice. Given that cancer occurs mostly in the elderly, we should take age-associated immune dysregulation into consideration to achieve the effectiveness of immunotherapeutic interventions in the old. Understanding both age-related and tumor-related immune alterations might be equally important in improving the effectiveness of immunotherapy. This article reviews a number of age-associated immune alterations with specific attention given to the impact on antitumor responses, and also discusses possible strategies for optimization of immunotherapeutic interventions in the elderly.
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Affiliation(s)
- Kei Tomihara
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama City, Toyama 930-0194, Japan
| | - Tyler J Curiel
- Department of Medicine, Cancer Therapy & Research Center, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Bin Zhang
- Robert H. Lurie Comprehensive Cancer Center, Department of Medicine-Division of Hematology/Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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14
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Rezzani R, Nardo L, Favero G, Peroni M, Rodella LF. Thymus and aging: morphological, radiological, and functional overview. AGE (DORDRECHT, NETHERLANDS) 2014; 36:313-51. [PMID: 23877171 PMCID: PMC3889907 DOI: 10.1007/s11357-013-9564-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 07/01/2013] [Indexed: 05/20/2023]
Abstract
Aging is a continuous process that induces many alterations in the cytoarchitecture of different organs and systems both in humans and animals. Moreover, it is associated with increased susceptibility to infectious, autoimmune, and neoplastic processes. The thymus is a primary lymphoid organ responsible for the production of immunocompetent T cells and, with aging, it atrophies and declines in functions. Universality of thymic involution in all species possessing thymus, including human, indicates it as a long-standing evolutionary event. Although it is accepted that many factors contribute to age-associated thymic involution, little is known about the mechanisms involved in the process. The exact time point of the initiation is not well defined. To address the issue, we report the exact age of thymus throughout the review so that readers can have a nicely pictured synoptic view of the process. Focusing our attention on the different stages of the development of the thymus gland (natal, postnatal, adult, and old), we describe chronologically the morphological changes of the gland. We report that the thymic morphology and cell types are evolutionarily preserved in several vertebrate species. This finding is important in understanding the similar problems caused by senescence and other diseases. Another point that we considered very important is to indicate the assessment of the thymus through radiological images to highlight its variability in shape, size, and anatomical conformation.
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Affiliation(s)
- Rita Rezzani
- Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, Viale Europa 11, 25123, Brescia, Italy,
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15
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Nutrition, diet and immunosenescence. Mech Ageing Dev 2013; 136-137:116-28. [PMID: 24373813 DOI: 10.1016/j.mad.2013.12.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 12/05/2013] [Accepted: 12/16/2013] [Indexed: 01/10/2023]
Abstract
Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly.
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Liu B, Xu N, Man Y, Shen H, Avital I, Stojadinovic A, Liao DJ. Apoptosis in Living Animals Is Assisted by Scavenger Cells and Thus May Not Mainly Go through the Cytochrome C-Caspase Pathway. J Cancer 2013; 4:716-23. [PMID: 24312141 PMCID: PMC3842440 DOI: 10.7150/jca.7577] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/19/2013] [Indexed: 11/21/2022] Open
Abstract
Because billions of cells die every day in their bodies, animals have evolutionarily developed apoptosis to preserve the tissue environment from adverse effects of dead cells, a process achieved via phagocytosis of the cell corpses by professional or amateur phagocytes that are collectively referred to as scavengers. Hence, apoptosis is a merger of two procedures separately occurring inside the dying and the scavenger cells, respectively. The task of apoptosis research is to study how these death procedures occur without hurting the host tissues, and recruitment of in vitro system into the study must be justified for this purpose. Cells in culture have no motivation to preserve the environment, and their death does not involve corpse clearance by scavengers. Therefore, programmed cell death in culture should be redefined, for example as stress-induced cell death, to avoid many sources of confusions, since the word “apoptosis” had already been defined, prior to the era of cell culture, as a silent and beneficial cell suicide with corpse clearance as a distinctive hallmark. We should start over again on apoptosis research by determining whether different physiological apoptotic procedures in animals involve the cytochrome c-caspase pathway, since it has been established from cultured cells as a central mechanism of “apoptosis” but whether it overarches any physiological apoptotic procedure in animals is still unclear. Probably, cells in living animals are programmed to use scavengers to assist their apoptosis but cells in culture have no scavengers to help and thus need to go mainly through the cytochrome c-caspase pathway.
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Affiliation(s)
- Bingya Liu
- 1. Shanghai Key Laboratory of Gastric Neoplasms, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China
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Martins PNA, Tullius SG, Markmann JF. Immunosenescence and immune response in organ transplantation. Int Rev Immunol 2013; 33:162-73. [PMID: 24127845 DOI: 10.3109/08830185.2013.829469] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The immune system undergoes a complex and continuous remodeling with aging. Immunosenescence results into both quantitative and qualitative changes of specific cellular subpopulations that have major impact on allorecognition and alloresponse, and consequently on graft rejection and tolerance. Here, we are going to review the immunological changes associated with the aging process relevant for transplantation. Interventions to selectively target changes associated with the senescence process seem promising therapeutic strategies to improve transplantation outcome.
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Affiliation(s)
- Paulo Ney Aguiar Martins
- Division of Transplantation, Department of Surgery, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
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Heinbokel T, Elkhal A, Liu G, Edtinger K, Tullius SG. Immunosenescence and organ transplantation. Transplant Rev (Orlando) 2013; 27:65-75. [PMID: 23639337 PMCID: PMC3718545 DOI: 10.1016/j.trre.2013.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 12/17/2012] [Accepted: 03/19/2013] [Indexed: 12/22/2022]
Abstract
Increasing numbers of elderly transplant recipients and a growing demand for organs from older donors impose pressing challenges on transplantation medicine. Continuous and complex modifications of the immune system in parallel to aging have a major impact on transplant outcome and organ quality. Both, altered alloimmune responses and increased immunogenicity of organs present risk factors for inferior patient and graft survival. Moreover, a growing body of knowledge on age-dependent modifications of allorecognition and alloimmune responses may require age-adapted immunosuppression and organ allocation. Here, we summarize relevant aspects of immunosenescence and their possible clinical impact on organ transplantation.
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Affiliation(s)
- Timm Heinbokel
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
- Institute of Medical Immunology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Abdallah Elkhal
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Guangxiang Liu
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Karoline Edtinger
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Stefan G. Tullius
- Division of Transplant Surgery and Transplant Surgery Research Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
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19
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Heinbokel T, Hock K, Liu G, Edtinger K, Elkhal A, Tullius SG. Impact of immunosenescence on transplant outcome. Transpl Int 2012. [DOI: 10.1111/tri.12013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | | | - Guangxiang Liu
- Transplant Surgery Research Laboratory and Division of Transplant Surgery; Brigham and Women's Hospital; Harvard Medical School; Boston; MA; USA
| | - Karoline Edtinger
- Transplant Surgery Research Laboratory and Division of Transplant Surgery; Brigham and Women's Hospital; Harvard Medical School; Boston; MA; USA
| | - Abdallah Elkhal
- Transplant Surgery Research Laboratory and Division of Transplant Surgery; Brigham and Women's Hospital; Harvard Medical School; Boston; MA; USA
| | - Stefan G. Tullius
- Transplant Surgery Research Laboratory and Division of Transplant Surgery; Brigham and Women's Hospital; Harvard Medical School; Boston; MA; USA
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20
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HL C, R B, L J, TR H, PA H, CJ B, DH C. Characterization of MHC-II antigen presentation by B cells and monocytes from older individuals. Clin Immunol 2012; 144:172-7. [PMID: 22797466 PMCID: PMC3466105 DOI: 10.1016/j.clim.2012.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 05/22/2012] [Accepted: 06/11/2012] [Indexed: 01/27/2023]
Abstract
In this study we examine the effects of aging on antigen presentation of B cells and monocytes. We compared the antigen presentation function of peripheral blood B cells from young and old subjects using a system that specifically measures the B cell receptor (BCR)-mediated MHC-II antigen presentation. Monocytes were studied as well. Overall the mean magnitude of antigen presentation of soluble antigen and peptide was not different in older and younger subjects for both B cells and monocytes. Older subjects, however, showed increased heterogeneity of BCR-mediated antigen presentation by their B cells. The magnitude and variability of peptide presentation, which do not require uptake and processing, were the same between groups. Presentation by monocytes had similar variability between the older and younger subjects. These data suggest that poor B cell antigen processing, which results in diminished presentation in some older individuals may contribute to poor vaccine responses.
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Affiliation(s)
- Clark HL
- Division of Infectious Disease, Case Western Reserve University School of Medicine. 10900 Euclid Ave, BRB 1001, Cleveland, OH 44106-4984
| | - Banks R
- GRECC, Louis Stokes Cleveland VA Hospital, United States. 10701 East Boulevard Cleveland, OH 44106
| | - Jones L
- Division of Infectious Disease, Case Western Reserve University School of Medicine. 10900 Euclid Ave, BRB 1001, Cleveland, OH 44106-4984
- GRECC, Louis Stokes Cleveland VA Hospital, United States. 10701 East Boulevard Cleveland, OH 44106
| | - Hornick TR
- GRECC, Louis Stokes Cleveland VA Hospital, United States. 10701 East Boulevard Cleveland, OH 44106
| | - Higgins PA
- GRECC, Louis Stokes Cleveland VA Hospital, United States. 10701 East Boulevard Cleveland, OH 44106
- School of Nursing, Case Western Reserve University. 2120 Cornell Road Cleveland, Ohio 44106-4904
| | - Burant CJ
- GRECC, Louis Stokes Cleveland VA Hospital, United States. 10701 East Boulevard Cleveland, OH 44106
- School of Nursing, Case Western Reserve University. 2120 Cornell Road Cleveland, Ohio 44106-4904
| | - Canaday DH
- Division of Infectious Disease, Case Western Reserve University School of Medicine. 10900 Euclid Ave, BRB 1001, Cleveland, OH 44106-4984
- GRECC, Louis Stokes Cleveland VA Hospital, United States. 10701 East Boulevard Cleveland, OH 44106
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21
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Agrawal A, Gupta S. Impact of aging on dendritic cell functions in humans. Ageing Res Rev 2011; 10:336-45. [PMID: 20619360 DOI: 10.1016/j.arr.2010.06.004] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 06/18/2010] [Accepted: 06/21/2010] [Indexed: 12/12/2022]
Abstract
Aging is a paradox of reduced immunity and chronic inflammation. Dendritic cells are central orchestrators of the immune response with a key role in the generation of immunity and maintenance of tolerance. The functions of DCs are compromised with age. There is no major effect on the numbers and phenotype of DC subsets in aged subjects; nevertheless, their capacity to phagocytose antigens and migrate is impaired with age. There is aberrant cytokine secretion by various DC subsets with CDCs secreting increased basal level of pro-inflammatory cytokines but the response on stimulation to foreign antigens is decreased. In contrast, the response to self-antigens is increased suggesting erosion of peripheral self tolerance. PDC subset also secretes reduced IFN-α in response to viruses. The capacity of DCs to prime T cell responses is also affected. Aging thus has a profound affect on DC functions. Present review summarizes the effect of advancing age on DC functions in humans in the context of both immunity and tolerance.
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Affiliation(s)
- Anshu Agrawal
- Division of Basic and Clinical Immunology, Med. Sci. I C-240A, University of California, Irvine 92697, CA, USA.
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22
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Jiang J, Fisher E, Bennett AJ, Murasko DM. Enhancement of virus-specific expansion of transgenic CD8 T cells in aged mice by dendritic cells. Mech Ageing Dev 2010; 131:580-3. [PMID: 20728463 DOI: 10.1016/j.mad.2010.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 07/02/2010] [Accepted: 08/12/2010] [Indexed: 11/16/2022]
Abstract
Aging is associated with a decreased CD8 T cell response to multiple antigens and to virus infection. Although both intrinsic and extrinsic factors have been shown to contribute to the decrease, the mechanisms are still largely unknown. In this study, the role of dendritic cells (DCs) in the age-associated decrease was examined. Influenza-specific TCR transgenic CD8 T cells of young mice demonstrated limited expansion in response to influenza infection when adoptively transferred to aged compared to young mice. This decreased response in aged mice could be significantly enhanced when DCs of young mice were co-transferred. Co-transfer of DCs had no impact in young recipient mice. Adoptive transfer of the DCs also increased the endogenous CD8 T cell response of intact aged mice, although to a lesser degree. These results suggest that the diminished CD8 T cell response to virus infection in aged mice is partially attributable to age-associated changes in DCs.
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Affiliation(s)
- Jiu Jiang
- Department of Biology, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
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23
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van Dommelen SLH, Rizzitelli A, Chidgey A, Boyd R, Shortman K, Wu L. Regeneration of dendritic cells in aged mice. Cell Mol Immunol 2010; 7:108-15. [PMID: 20118970 DOI: 10.1038/cmi.2009.114] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Age-related thymic involution causes a decreased output of thymocytes from the thymus, thereby resulting in impairment of T cell-mediated immunity. While alterations in the T cell and non-haematopoietic stromal compartments have been described, the effects of thymic involution on thymic dendritic cells (DC) are not clearly known. Thymic DC play an essential role in shaping T cell-mediated immune responses by deleting self-reactive thymocytes to establish central tolerance and by inducing regulatory T-cell (Treg) development. It is therefore important to assess the prevalence of and alterations to thymic DC with age, as this may impact on their function. We assessed the numbers and proportions of the three distinct subsets of thymic DC in ageing mice, and showed that these subsets are differentially regulated. This is expected as thymic DC subsets have different origins of development. We further assessed the responses of thymic DC in a regenerative environment, such as that induced by sex-steroid ablation (SSA), and clearly showed that, consistent with global thymus regrowth, all three DC populations increased in numbers and regained their relative proportions to thymocytes after an initial lag period. These findings are important for the clinical translation of thymic regenerative approaches, and indicate that SSA facilitates the maintenance of critical processes such as negative selection and Treg induction through promoting thymic DC regeneration.
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Abstract
An age-related decline in immune responses in the elderly results in greater susceptibility to infection and reduced responses to vaccination. This decline in immune function affects both innate and adaptive immune systems. A meeting of experts in immunology and gerontology in Paris, France, in April 2008, considered current understanding of immunosenescence and its clinical consequences. Essential features of immunosenescence include: reduced natural killer cell cytotoxicity on a per cell basis; reduced number and function of dendritic cells in blood; decreased pools of naive T and B cells; and increases in the number of memory and effector T and B cells. In particular, an accumulation of late differentiated effector T cells, commonly associated with cytomegalovirus infection, contributes to a decline in the capacity of the adaptive immune system to respond to novel antigens. Consequently, vaccine responsiveness is compromised in the elderly, especially frail patients. Strategies to address the effects of immunosenescence include ensuring that seroprotective antibody levels against preventable infectious diseases are maintained throughout adulthood, and improving diet and exercise to address the effects of frailty. New vaccines are being developed, such as intradermal and high-dose vaccines for influenza, to improve the efficacy of immunization in the elderly. In the future, the development and use of markers of immunosenescence to identify patients who may have impaired responses to vaccination, as well as the use of end-points other than antibody titers to assess vaccine efficacy, may help to reduce morbidity and mortality due to infections in the elderly.
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25
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Kumar R, Burns EA. Age-related decline in immunity: implications for vaccine responsiveness. Expert Rev Vaccines 2008; 7:467-79. [PMID: 18444893 DOI: 10.1586/14760584.7.4.467] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Aging is associated with declines in immune system function, or 'immunosenescence', leading to progressive deterioration in both innate and adaptive immunity. These changes contribute to the decreased response to vaccines seen in many older adults, and morbidity and mortality from infection. Infections (e.g., influenza, pneumonia and septicemia) appear among the top ten most-common causes of death in adults in the USA aged 55 years and older. As immunosenescence has gathered more attention in the scientific and healthcare communities, investigators have demonstrated more links between immunosenescent changes and morbidity and mortality related to infections and declining vaccine responses. This review summarizes the recent literature on age-dependent defects in adaptive and innate immunity, data linking these defects to poor vaccine response and morbidity and mortality, current recommendations for vaccinations and potential strategies to improve vaccine efficacy in older adults.
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Affiliation(s)
- Rajesh Kumar
- Medical College of Wisconsin, 5000 W National Avenue, CC-G, Milwaukee, WI 53295, USA.
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26
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Sharma S, Dominguez AL, Hoelzinger DB, Lustgarten J. CpG-ODN but not other TLR-ligands restore the antitumor responses in old mice: the implications for vaccinations in the aged. Cancer Immunol Immunother 2008; 57:549-61. [PMID: 17828396 PMCID: PMC11031019 DOI: 10.1007/s00262-007-0393-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 08/15/2007] [Indexed: 12/11/2022]
Abstract
AIM There is accumulative evidence indicating that targeting antigen presenting cells (APCs) with different types of adjuvants could result in the induction of antitumor immune responses. It has been hypothesized that APCs function may be altered in the elderly contributing to a decline in the immune function. We evaluated whether targeting APCs following injection with Poly I:C, LPS, flagellin, imiquimod and CpG-ODN would induce an antitumor response in the old. MATERIALS AND METHODS The immune and antitumor responses induce Poly I:C, LPS, flagellin, imiquimod and CpG-ODN were compared in young (2 month old) and old (18 months) mice. RESULTS Our results indicated that only intratumoral (i.t.) injections of CpG-ODN completely rejected the tumor in both young and old mice. Injections of Poly I:C also induced the rejection of tumors in the young but not in the old. Furthermore, i.t. injections of CpG-ODN promoted the development of protective memory responses in the young and the old. Analysis of the immune responses in the old indicated that CpG-ODN but not Poly-I:C induces: a pro-inflammatory Th1 type response; accumulation and activation of CD4+, CD8+ T and, NK cell responses; activation of APCs; and reduction in the number of Tregs. The activation of these immune-parameters positively correlates with the induction of an antitumor response. CONCLUSIONS These studies indicate that there are differences in the level of stimulation with TLR-ligands between young and old APCs and that the aged immune responses can be rescued and exploited for the induction of tumor immunity by targeting APCs with specific TLR-ligands. These results have important clinical implications for developing immunization strategies containing TLR-ligands that will be effective in both the young and old.
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Affiliation(s)
- Sanjay Sharma
- Cancer Center Scottsdale, Mayo Clinic Arizona, 13400 East Shea Boulevard, Scottsdale, AZ 85259 USA
| | - Ana Lucia Dominguez
- Cancer Center Scottsdale, Mayo Clinic Arizona, 13400 East Shea Boulevard, Scottsdale, AZ 85259 USA
| | - Dominique B. Hoelzinger
- Cancer Center Scottsdale, Mayo Clinic Arizona, 13400 East Shea Boulevard, Scottsdale, AZ 85259 USA
| | - Joseph Lustgarten
- Cancer Center Scottsdale, Mayo Clinic Arizona, 13400 East Shea Boulevard, Scottsdale, AZ 85259 USA
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27
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Pinchuk LM, Filipov NM. Differential effects of age on circulating and splenic leukocyte populations in C57BL/6 and BALB/c male mice. IMMUNITY & AGEING 2008; 5:1. [PMID: 18267021 PMCID: PMC2268915 DOI: 10.1186/1742-4933-5-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Accepted: 02/11/2008] [Indexed: 02/05/2023]
Abstract
BACKGROUND Despite several reports on age-related phenotypic changes of the immune system's cells, studies that use a multipoint age comparison between the specific and innate immune cell populations of prototypical Th1- and Th2-type polarized mouse strains are still lacking. RESULTS Using a multipoint age comparison approach, cells from the two major immune system compartments, peripheral blood and spleen, and flow cytometry analysis, we found several principal differences in T cell and professional antigen presenting cell (APC) populations originating from a prototypical T helper (Th) 1 mouse strain, C57BL/6, and a prototypical Th2 strain, BALB/c. For example, regardless of age, there were strain differences in both peripheral blood mononuclear cells (PBMC) and spleens in the proportion of CD4+ (higher in the BALB/c strain), CD8+ T cells and CD11b+/CD11c+ APC (greater in C57BL/6 mice). Other differences were present only in PBMC (MHC class II + and CD19+ were greater in C57BL/6 mice) or differences were evident in the spleens but not in circulation (CD3+ T cells were greater in C57BL/6 mice). There were populations of cells that increased with age in PBMC and spleens of both strains (MHC class II+), decreased in the periphery and spleens of both strains (CD11b+) or did not change in the PBMC and spleens of both strains (CD8+). We also found strain and age differences in the distribution of naïve and memory/activated splenic T cells, e.g., BALB/c mice had more memory/activated and less naive CD8+ and CD4+ T cells and the C57BL/6 mice. CONCLUSION Our data provide important information on the principal differences, within the context of age, in T cell and professional APC populations between the prototypical Th1 mouse strain C57BL/6 and the prototypical Th2 strain BALB/c. Although the age-related changes that occur may be rather subtle, they may be very relevant in conditions of disease and stress. Importantly, our data indicate that age and strain should be considered in concert in the selection of appropriate mouse models for immunological research.
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Affiliation(s)
- Lesya M Pinchuk
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
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28
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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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29
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Shurin MR, Shurin GV, Chatta GS. Aging and the dendritic cell system: implications for cancer. Crit Rev Oncol Hematol 2007; 64:90-105. [PMID: 17446082 PMCID: PMC2084365 DOI: 10.1016/j.critrevonc.2007.03.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 03/14/2007] [Accepted: 03/15/2007] [Indexed: 10/23/2022] Open
Abstract
The immune system shows a decline in responsiveness to antigens both with aging, as well as in the presence of tumors. The malfunction of the immune system with age can be attributed to developmental and functional alterations in several cell populations. Previous studies have shown defects in humoral responses and abnormalities in T cell function in aged individuals, but have not distinguished between abnormalities in antigen presentation and intrinsic T cell or B cell defects in aged individuals. Dendritic cells (DC) play a pivotal role in regulating immune responses by presenting antigens to naïve T lymphocytes, modulating Th1/Th2/Th3/Treg balance, producing numerous regulatory cytokines and chemokines, and modifying survival of immune effectors. DC are receiving increased attention due to their involvement in the immunobiology of tolerance and autoimmunity, as well as their potential role as biological adjuvants in tumor vaccines. Recent advances in the molecular and cell biology of different DC populations allow for addressing the issue of DC and aging both in rodents and humans. Since DC play a crucial role in initiating and regulating immune responses, it is reasonable to hypothesize that they are directly involved in altered antitumor immunity in aging. However, the results of studies focusing on DC in the elderly are conflicting. The present review summarizes the available human and experimental animal data on quantitative and qualitative alterations of DC in aging and discusses the potential role of the DC system in the increased incidence of cancer in the elderly.
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Affiliation(s)
- Michael R Shurin
- University of Pittsburgh Cancer Institute, Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
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30
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Agrawal A, Agrawal S, Gupta S. Dendritic cells in human aging. Exp Gerontol 2006; 42:421-6. [PMID: 17182207 PMCID: PMC1909691 DOI: 10.1016/j.exger.2006.11.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 11/13/2006] [Accepted: 11/13/2006] [Indexed: 02/02/2023]
Abstract
Dendritic cells (DCs) play a critical role in linking innate and adaptive immunity. A role of DCs in immunosenescence and chronic inflammation associated with aging has not been investigated in detail. In this article, we will briefly review DCs biology and changes associated with human aging.
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Affiliation(s)
- Anshu Agrawal
- Division of Basic and Clinical Immunology, University of California, Irvine, CA 92697, United States
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31
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Savchenko AS, Hasegawa G, Naito M. Development and maturation of thymic dendritic cells during human ontogeny. Cell Tissue Res 2006; 325:455-60. [PMID: 16670919 DOI: 10.1007/s00441-006-0202-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2006] [Accepted: 03/16/2006] [Indexed: 10/24/2022]
Abstract
Thymic dendritic cells (TDC) are dendritic cells situated mainly in the cortico-medullary zone and in the medullary region of the thymus. However, the phenotype of TDC during ontogeny is poorly documented. The aim of this study has been to investigate the development and maturation of TDC during human ontogeny. Immunohistochemical analyses and immunoelectron-microscopic investigation of 21 human thymus specimens have been performed to detect the subtypes of TDC by using various DC-related and DC-development-related markers. TDC express a Langerhans-cell-like phenotype during human ontogeny. Cells expressing thymic stromal lymphopoietin receptor have been observed in Hassal's corpuscles of the thymus. Granulocyte/macrophage colony-stimulating factor (GM-CSF) is also expressed in thymic epithelial cells (TEC) localized in Hassal's corpuscles. During human ontogeny, GM-CSF is produced by TEC of Hassal's corpuscles and might play a key role in the differentiation of TDC having Langerhans-cell-like phenotypes.
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Affiliation(s)
- Alexander S Savchenko
- Department of Cellular Function, Division of Cellular and Molecular Pathology, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi-dori 1-757, Niigata, 951-8510, Japan.
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32
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Rosen D, Lee JH, Cuttitta F, Rafiqi F, Degan S, Sunday ME. Accelerated thymic maturation and autoreactive T cells in bronchopulmonary dysplasia. Am J Respir Crit Care Med 2006; 174:75-83. [PMID: 16574933 PMCID: PMC2662921 DOI: 10.1164/rccm.200511-1784oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Bronchopulmonary dysplasia (BPD), a chronic lung disease of newborns triggered by oxygen and barotrauma, is characterized by arrested alveolarization. Increased levels of bombesin-like peptides shortly after birth mediate lung injury: anti-bombesin antibody 2A11 protects against BPD in two baboon models. The role of adaptive immunity in BPD has not been explored previously. OBJECTIVES Our goal was to test the hypothesis that thymic architecture and/or T-cell function is altered with BPD, leading to autoimmunity and immunodeficiency. METHODS Thymic structure was analyzed by histopathology of thymic architecture and immunohistochemistry for thymic maturation markers (terminal deoxynucleotidyl transferase, proliferating cell nuclear antigen, CD4, and CD8). Thymic cortical epithelial cells (nurse cells) were studied using HLA-DR and protein gene product 9.5 as markers. Functional analysis was performed with "mixed lymphocyte reaction" of thymocyte or splenocyte responder cells with autologous lung cells as the stimulators. MEASUREMENTS AND MAIN RESULTS 2A11 treatment attenuates thymic cortical involution in BPD animals, sustaining terminal deoxynucleotidyl transferase-positive prothymocytes and thymocyte proliferation. BPD animals have increased CD4(+) cells in thymic cortex and lung interstitium, which are reduced by 2A11. Conversely, cortical protein gene product 9.5/HLA-DR-positive thymic nurse cells are depleted in BPD animals, but are preserved by 2A11-treatment. Whereas fetal thymocytes and splenocytes respond to phythemagglutinin/ionomycin and to a lesser extent, to autologous lung, BPD thymocytes and splenocytes are phythemagglutinin/ionomycin-unresponsive, and yet react strongly to autologous lung. The 2A11 normalizes these responses. CONCLUSIONS These observations suggest that bombesin-like peptides mediate premature thymic maturation and thymic nurse-cell depletion, leading to autoreactive T cells that could contribute to lung injury.
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Affiliation(s)
- Dennis Rosen
- Division of Pulmonary Medicine, Department of Medicine, Children's and Brigham and Women's Hospitals, and Harvard Medical School, Boston, Massachusetts, USA
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