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Zhang H, Jadhav RR, Cao W, Goronzy IN, Zhao TV, Jin J, Ohtsuki S, Hu Z, Morales J, Greenleaf WJ, Weyand CM, Goronzy JJ. Aging-associated HELIOS deficiency in naive CD4 + T cells alters chromatin remodeling and promotes effector cell responses. Nat Immunol 2023; 24:96-109. [PMID: 36510022 PMCID: PMC10118794 DOI: 10.1038/s41590-022-01369-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 10/24/2022] [Indexed: 12/14/2022]
Abstract
Immune aging combines cellular defects in adaptive immunity with the activation of pathways causing a low-inflammatory state. Here we examined the influence of age on the kinetic changes in the epigenomic and transcriptional landscape induced by T cell receptor (TCR) stimulation in naive CD4+ T cells. Despite attenuated TCR signaling in older adults, TCR activation accelerated remodeling of the epigenome and induced transcription factor networks favoring effector cell differentiation. We identified increased phosphorylation of STAT5, at least in part due to aberrant IL-2 receptor and lower HELIOS expression, as upstream regulators. Human HELIOS-deficient, naive CD4+ T cells, when transferred into human-synovium-mouse chimeras, infiltrated tissues more efficiently. Inhibition of IL-2 or STAT5 activity in T cell responses of older adults restored the epigenetic response pattern to the one seen in young adults. In summary, reduced HELIOS expression in non-regulatory naive CD4+ T cells in older adults directs T cell fate decisions toward inflammatory effector cells that infiltrate tissue.
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Affiliation(s)
- Huimin Zhang
- Department of Immunology, Mayo Clinic, Rochester, MN, USA
- Department of Medicine, Stanford University, Stanford, CA, USA
| | - Rohit R Jadhav
- Department of Immunology, Mayo Clinic, Rochester, MN, USA
- Department of Medicine, Stanford University, Stanford, CA, USA
| | - Wenqiang Cao
- Department of Immunology, Mayo Clinic, Rochester, MN, USA
- Department of Medicine, Stanford University, Stanford, CA, USA
- Health Sciences Institute, China Medical University, Shenyang, China
| | - Isabel N Goronzy
- Biochemistry and Molecular Biophysics, California Institute of Technology, Pasadena, CA, USA
| | - Tuantuan V Zhao
- Department of Medicine, Stanford University, Stanford, CA, USA
- Department of Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA
| | - Jun Jin
- Department of Immunology, Mayo Clinic, Rochester, MN, USA
- Department of Medicine, Stanford University, Stanford, CA, USA
| | - Shozo Ohtsuki
- Department of Medicine, Stanford University, Stanford, CA, USA
- Department of Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA
| | - Zhaolan Hu
- Department of Medicine, Stanford University, Stanford, CA, USA
- Department of Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA
| | - Jose Morales
- Department of Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA
| | | | - Cornelia M Weyand
- Department of Immunology, Mayo Clinic, Rochester, MN, USA
- Department of Medicine, Stanford University, Stanford, CA, USA
- Department of Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA
| | - Jörg J Goronzy
- Department of Immunology, Mayo Clinic, Rochester, MN, USA.
- Department of Medicine, Stanford University, Stanford, CA, USA.
- Department of Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA.
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Large-scale prediction of key dynamic interacting proteins in multiple cancers. Int J Biol Macromol 2022; 220:1124-1132. [PMID: 36027989 DOI: 10.1016/j.ijbiomac.2022.08.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/15/2022] [Accepted: 08/17/2022] [Indexed: 11/21/2022]
Abstract
Tracking cancer dynamic protein-protein interactions (PPIs) and deciphering their pathogenesis remain a challenge. We presented a dynamic PPIs' hypothesis: permanent and transient interactions might achieve dynamic switchings from normal cells to malignancy, which could cause maintenance functions to be interrupted and transient functions to be sustained. Based on the hypothesis, we first predicted >1400 key cancer genes (KCG) by applying PPI-express we proposed to 18 cancer gene expression datasets. We then further screened out key dynamic interactions (KDI) of cancer based on KCG and transient and permanent interactions under both conditions. Two prominent functional characteristics, "Cell cycle-related" and "Immune-related", were presented for KCG, suggesting that these might be their general characteristics. We found that, compared to permanent to transient KDI pairs (P2T) in the network, transient to permanent (T2P) have significantly higher edge betweenness (EB), and P2T pairs tending to locate intra-functional modules may play roles in maintaining normal biological functions, while T2P KDI pairs tending to locate inter-modules may play roles in biological signal transduction. It was consistent with our hypothesis. Also, we analyzed network characteristics of KDI pairs and their functions. Our findings of KDI may serve to understand and explain a few hallmarks of cancer.
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Witkowski JM, Fulop T, Bryl E. Immunosenescence and COVID-19. Mech Ageing Dev 2022; 204:111672. [PMID: 35378106 PMCID: PMC8975602 DOI: 10.1016/j.mad.2022.111672] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 12/13/2022]
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Torrelles JB, Restrepo BI, Bai Y, Ross C, Schlesinger LS, Turner J. The Impact of Aging on the Lung Alveolar Environment, Predetermining Susceptibility to Respiratory Infections. FRONTIERS IN AGING 2022; 3:818700. [PMID: 35821836 PMCID: PMC9261427 DOI: 10.3389/fragi.2022.818700] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/03/2022] [Indexed: 12/15/2022]
Abstract
Respiratory infections are one of the top causes of death in the elderly population, displaying susceptibility factors with increasing age that are potentially amenable to interventions. We posit that with increasing age there are predictable tissue-specific changes that prevent the immune system from working effectively in the lung. This mini-review highlights recent evidence for altered local tissue environment factors as we age focusing on increased tissue oxidative stress with associated immune cell changes, likely driven by the byproducts of age-associated inflammatory disease. Potential intervention points are presented.
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Affiliation(s)
- Jordi B. Torrelles
- Population Health and Host-Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Blanca I. Restrepo
- School of Public Health in Brownsville, University of Texas Health Houston, Brownsville, TX, United States
- South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Yidong Bai
- Department of Cell Systems and Anatomy, UT-Health San Antonio, San Antonio, TX, United States
| | - Corinna Ross
- Population Health and Host-Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
- Soutwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Larry S. Schlesinger
- Population Health and Host-Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Joanne Turner
- Population Health and Host-Pathogen Interactions Programs, Texas Biomedical Research Institute, San Antonio, TX, United States
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5
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Witkowski JM. Immune system aging and the aging-related diseases in the COVIID-19 era. Immunol Lett 2022; 243:19-27. [PMID: 35108570 PMCID: PMC8801734 DOI: 10.1016/j.imlet.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/26/2022] [Accepted: 01/29/2022] [Indexed: 12/13/2022]
Abstract
The interest in the process of aging, and specifically in how aging affects the working of our immune system, has recently enormously grown among both specialists (immunologists and gerontologists) and representatives of other disciplines of health sciences. An obvious reason for this interest is the current pandemics of COVID-19, known to affect the elderly more than younger people. In this paper current knowledge about mechanisms and complex facets of human immune system aging is presented, stemming from the knowledge about the working of various parts of the immune system, and leading to understanding of immunological mechanisms of chronic, inflammatory, aging-related diseases and of COVID-19.
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Affiliation(s)
- Jacek M Witkowski
- Department of Pathophysiology, Medical University of Gdańsk, Dębinki 7, 80-211, Gdańsk, Poland.
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Zöphel D, Hof C, Lis A. Altered Ca 2+ Homeostasis in Immune Cells during Aging: Role of Ion Channels. Int J Mol Sci 2020; 22:ijms22010110. [PMID: 33374304 PMCID: PMC7794837 DOI: 10.3390/ijms22010110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/29/2022] Open
Abstract
Aging is an unstoppable process and begins shortly after birth. Each cell of the organism is affected by the irreversible process, not only with equal density but also at varying ages and with different speed. Therefore, aging can also be understood as an adaptation to a continually changing cellular environment. One of these very prominent changes in age affects Ca2+ signaling. Especially immune cells highly rely on Ca2+-dependent processes and a strictly regulated Ca2+ homeostasis. The intricate patterns of impaired immune cell function may represent a deficit or compensatory mechanisms. Besides, altered immune function through Ca2+ signaling can profoundly affect the development of age-related disease. This review attempts to summarize changes in Ca2+ signaling due to channels and receptors in T cells and beyond in the context of aging.
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Affiliation(s)
| | | | - Annette Lis
- Correspondence: ; Tel.: +49-(0)-06841-1616318; Fax: +49-(0)-6841-1616302
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Warny M, Helby J, Nordestgaard BG, Birgens H, Bojesen SE. Lymphopenia and risk of infection and infection-related death in 98,344 individuals from a prospective Danish population-based study. PLoS Med 2018; 15:e1002685. [PMID: 30383787 PMCID: PMC6211632 DOI: 10.1371/journal.pmed.1002685] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 10/02/2018] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Neutropenia increases the risk of infection, but it is unknown if this also applies to lymphopenia. We therefore tested the hypotheses that lymphopenia is associated with increased risk of infection and infection-related death in the general population. METHODS AND FINDINGS Of the invited 220,424 individuals, 99,191 attended examination. We analyzed 98,344 individuals from the Copenhagen General Population Study (Denmark), examined from November 25, 2003, to July 9, 2013, and with available blood lymphocyte count at date of examination. During a median of 6 years of follow-up, they developed 8,401 infections and experienced 1,045 infection-related deaths. Due to the completeness of the Danish civil and health registries, none of the 98,344 individuals were lost to follow-up, and those emigrating (n = 385) or dying (n = 5,636) had their follow-up truncated at the day of emigration or death. At date of examination, mean age was 58 years, and 44,181 (44.9%) were men. Individuals with lymphopenia (lymphocyte count < 1.1 × 109/l, n = 2,352) compared to those with lymphocytes in the reference range (1.1-3.7 × 109/l, n = 93,538) had multivariable-adjusted hazard ratios of 1.41 (95% CI 1.28-1.56) for any infection, 1.31 (1.14-1.52) for pneumonia, 1.44 (1.15-1.79) for skin infection, 1.26 (1.02-1.56) for urinary tract infection, 1.51 (1.21-1.89) for sepsis, 1.38 (1.01-1.88) for diarrheal disease, 2.15 (1.16-3.98) for endocarditis, and 2.26 (1.21-4.24) for other infections. The corresponding hazard ratio for infection-related death was 1.70 (95% CI 1.37-2.10). Analyses were adjusted for age, sex, smoking status, cumulative smoking, alcohol intake, body mass index, plasma C-reactive protein, blood neutrophil count, recent infection, Charlson comorbidity index, autoimmune diseases, medication use, and immunodeficiency/hematologic disease. The findings were robust in all stratified analyses and also when including only events later than 2 years after first examination. However, due to the observational design, the study cannot address questions of causality, and our analyses might theoretically have been affected by residual confounding and reverse causation. In principle, fluctuating lymphocyte counts over time might also have influenced analyses, but lymphocyte counts in 5,181 individuals measured 10 years after first examination showed a regression dilution ratio of 0.68. CONCLUSIONS Lymphopenia was associated with increased risk of hospitalization with infection and increased risk of infection-related death in the general population. Notably, causality cannot be deduced from our data.
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Affiliation(s)
- Marie Warny
- Department of Hematology, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
- Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Jens Helby
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
- Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
| | - Børge Grønne Nordestgaard
- Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
- Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
| | - Henrik Birgens
- Department of Hematology, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
- Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Stig Egil Bojesen
- Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
- Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
- * E-mail:
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Busse S, Steiner J, Micheel J, Dobrowolny H, Mawrin C, Krause TJ, Adamaszek M, Bogerts B, Bommhardt U, Hartig R, Busse M. Age-related increase of VGF-expression in T lymphocytes. Aging (Albany NY) 2015; 6:440-53. [PMID: 25013207 PMCID: PMC4100807 DOI: 10.18632/aging.100656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
VGF is a protein expressed by neurons and processed into several peptides. It plays a role in energy homeostasis and promotes growth and survival. Recently, VGF mRNA was detected in peripheral leukocytes. Since it is known that aging is associated with a decrease in the development and function of neuronal as well as immune cells, we addressed the question whether a peripheral expression of VGF by CD3+ T cells and CD56+ NK cells is correlated with age. Therefore, the frequency of VGF+CD3+ and VGF+CD56+ cells was determined in mentally healthy volunteers aged between 22 and 88. We found an age-dependent increase in the number of VGF+CD3+ T cells that correlated with HbA1c and the body mass index (BMI). VGF-expression by NK cells was age-independent. Blockade of VGF reduced proliferation and secretion of cytokines such as IL-2, IL-17A, IL-1β, IL-10 and TNF by CD3+ T cells and PBMCs. Rapamycin-mediated T cell blockade significantly reduced the frequency of VGF-expressing T cells. We conclude that VGF contributes to survival and function of peripheral T cells. The age-dependent increase in VGF-expression could serve as mechanism that counterregulates the decrease in functionality of T lymphocytes.
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Affiliation(s)
- Stefan Busse
- Department of Psychiatry, University of Magdeburg, Magdeburg, Germany
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9
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Larbi A, Fortin C, Dupuis G, Berrougui H, Khalil A, Fulop T. Immunomodulatory role of high-density lipoproteins: impact on immunosenescence. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9712. [PMID: 25216565 PMCID: PMC4162887 DOI: 10.1007/s11357-014-9712-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 09/02/2014] [Indexed: 06/03/2023]
Abstract
Natural aging is accompanied by a dysregulation of the host immune response that has well-known clinical consequences but poorly defined underlying causes. It has previously been reported that advancing age is associated with an increase in membrane cholesterol level in T cells. The aim of this study was to investigate whether high-density lipoprotein (HDL) can modulate the age-related accumulation of membrane cholesterol in T cells and impact on their subsequent responsiveness. Our data reveal that cholesterol metabolism, influx, and efflux are altered in T cells with aging, which may in part explain the increase in membrane cholesterol level observed in T cells in elderly individuals. HDL was unable to promote reverse cholesterol transport in T cells from elderly subjects with the same efficiency as was observed in T cells from young subjects besides unchanged ABCA-1 and SR-BI expressions. HDL exhibited a short-acting co-stimulatory effect by enhancing T cell production of interleukin-2 (IL-2). Moreover, HDL from healthy normolipemic individuals exerted differential effects on T cell proliferation that depended on the age of the HDL donor. Finally, HDL modulated TCR/CD28 activation by inducing sustained signaling through pLck, pERK, and pAkt. These data suggest that HDL has immunomodulatory effects on T cells that are influenced by age.
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Affiliation(s)
- Anis Larbi
- />Singapore Immunology Network (SIgN), Biopolis, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Carl Fortin
- />Research Center on Aging, University of Sherbrooke, Sherbrooke, Canada
| | - Gilles Dupuis
- />Clinical Research Center, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Canada
| | - Hicham Berrougui
- />Research Center on Aging, University of Sherbrooke, Sherbrooke, Canada
| | - Abdelouahed Khalil
- />Research Center on Aging, University of Sherbrooke, Sherbrooke, Canada
| | - Tamas Fulop
- />Research Center on Aging, University of Sherbrooke, Sherbrooke, Canada
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10
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Inal A, Koç B, Bircan HY, Ogan E, Yavuz A, Kemik O. The effects of aging on lymphocyte subgroups in males and females. Med Sci Monit Basic Res 2014; 20:93-6. [PMID: 25033372 PMCID: PMC4106926 DOI: 10.12659/msmbr.891239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background Age-associated immune senescence is a catch-all phrase that has been used to describe a plethora of changes to the immune system across the lifespan. Aging is associated with a decline in immune function. Our aim in this study was to investigate how lymphocyte subgroups in peripheral blood are affected by aging among males and females. Material/Methods Study participants were 70 healthy individuals from 3 different age groups, observed from January 2010 to January 2012. The average levels of CD3+, CD4+, CD8+, CD19+, CD16+/CD56+, CD3+/CD69+, and CD19+/CD69+ were determined for each group and compared in terms of age and sex. Results We found significant reduction in the level of CD3+T cells related with age, but no significant changes in CD19+ B cell levels (p<0.005). Aging significantly reduces activated B cell (CD19+/CD69+) levels in males (p<0.005). Conclusions Our results show that there may be differences between males and females in terms of immune senescence.
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Affiliation(s)
- Ali Inal
- Department of Immunology, Baskent University, Faculty of Medicine, Istanbul, Turkey
| | - Bora Koç
- Department of General and Transplantation Surgery, Baskent University, Faculty of Medicine, Istanbul, Turkey
| | - Huseyin Yuce Bircan
- Department of General and Transplantation Surgery, Baskent University, Faculty of Medicine, Istanbul, Turkey
| | - Ebru Ogan
- Department of Immunology, Baskent University, Faculty of Medicine, Istanbul, Turkey
| | - Alpaslan Yavuz
- Department of Radiology, Yuzuncu Yil University, Medical Faculty, Van, Turkey
| | - Ozgur Kemik
- Department of General Surgery, Yuzuncu Yil University, Medical Faculty, Van, Turkey
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11
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Le Page A, Fortin C, Garneau H, Allard N, Tsvetkova K, Tan CTY, Larbi A, Dupuis G, Fülöp T. Downregulation of inhibitory SRC homology 2 domain-containing phosphatase-1 (SHP-1) leads to recovery of T cell responses in elderly. Cell Commun Signal 2014; 12:2. [PMID: 24405902 PMCID: PMC3896791 DOI: 10.1186/1478-811x-12-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 01/04/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Immune responses are generally impaired in aged mammals. T cells have been extensively studied in this context due to the initial discovery of their reduced proliferative capacity with aging. The decreased responses involve altered signaling events associated with the early steps of T cell activation. The underlying causes of these changes are not fully understood but point to alterations in assembly of the machinery for T cell activation. Here, we have tested the hypothesis that the T cell pool in elderly subjects displayed reduced functional capacities due to altered negative feedback mechanisms that participate in the regulation of the early steps of T cell activation. Such conditions tip the immune balance in favor of altered T cell activation and a related decreased response in aging. RESULTS We present evidence that the tyrosine phosphatase SHP-1, a key regulator of T cell signal transduction machinery is, at least in part, responsible for the impaired T cell activation in aging. We used tyrosine-specific mAbs and Western blot analysis to show that a deregulation of the Csk/PAG loop in activated T cells from elderly individuals favored the inactive form of tyrosine-phosphorylated Lck (Y505). Confocal microscopy analysis revealed that the dynamic movements of these regulatory proteins in lipid raft microdomains was altered in T cells of aged individuals. Enzymic assays showed that SHP-1 activity was upregulated in T cells of aged donors, in contrast to young subjects. Pharmacological inhibition of SHP-1 resulted in recovery of TCR/CD28-dependent lymphocyte proliferation and IL-2 production of aged individuals to levels approaching those of young donors. Significant differences in the active (Y394) and inactive (Y505) phosphorylation sites of Lck in response to T cell activation were observed in elderly donors as compared to young subjects, independently of CD45 isoform expression. CONCLUSIONS Our data suggest that the role of SHP-1 in T cell activation extends to its increased effect in negative feedback in aging. Modulation of SHP-1 activity could be a target to restore altered T cell functions in aging. These observations could have far reaching consequences for improvement of immunosenescence and its clinical consequences such as infections, altered response to vaccination.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Tamas Fülöp
- Research Center on Aging, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 1036 rue Belvedere sud, Sherbrooke, J1H 4C4, Quebec, Canada.
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12
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Abstract
The decline of the immune system appears to be an intractable consequence of aging, leading to increased susceptibility to infections, reduced effectiveness of vaccination and higher incidences of many diseases including osteoporosis and cancer in the elderly. These outcomes can be attributed, at least in part, to a phenomenon known as T cell replicative senescence, a terminal state characterized by dysregulated immune function, loss of the CD28 costimulatory molecule, shortened telomeres and elevated production of proinflammatory cytokines. Senescent CD8 T cells, which accumulate in the elderly, have been shown to frequently bear antigen specificity against cytomegalovirus (CMV), suggesting that this common and persistent infection may drive immune senescence and result in functional and phenotypic changes to the T cell repertoire. Senescent T cells have also been identified in patients with certain cancers, autoimmune diseases and chronic infections, such as HIV. This review discusses the in vivo and in vitro evidence for the contribution of CD8 T cell replicative senescence to a plethora of age-related pathologies and a few possible therapeutic avenues to delay or prevent this differentiative end-state in T cells. The age-associated remodeling of the immune system, through accumulation of senescent T cells has farreaching consequences on the individual and society alike, for the current healthcare system needs to meet the urgent demands of the increasing proportions of the elderly in the US and abroad.
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Affiliation(s)
- Jennifer P Chou
- Dept of Pathology &Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1732, USA
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13
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Moro-García MA, Alonso-Arias R, López-Larrea C. Molecular mechanisms involved in the aging of the T-cell immune response. Curr Genomics 2013; 13:589-602. [PMID: 23730199 PMCID: PMC3492799 DOI: 10.2174/138920212803759749] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/28/2012] [Accepted: 08/31/2012] [Indexed: 12/24/2022] Open
Abstract
T-lymphocytes play a central role in the effector and regulatory mechanisms of the adaptive immune response. Upon exiting the thymus they begin to undergo a series of phenotypic and functional changes that continue throughout the lifetime and being most pronounced in the elderly. The reason postulated for this is that the dynamic processes of repeated interaction with cognate antigens lead to multiple division cycles involving a high degree of cell differentiation, senescence, restriction of the T-cell receptor (TCR) repertoire, and cell cycle arrest. This cell cycle arrest is associated with the loss of telomere sequences from the ends of chromosomes. Telomere length is reduced at each cell cycle, and critically short telomeres recruit components of the DNA repair machinery and trigger replicative senescence or apoptosis. Repetitively stimulated T-cells become refractory to telomerase induction, suffer telomere erosion and enter replicative senescence. The latter is characterized by the accumulation of highly differentiated T-cells with new acquired functional capabilities, which can be caused by aberrant expression of genes normally suppressed by epigenetic mechanisms in CD4+ or CD8+ T-cells. Age-dependent demethylation and overexpression of genes normally suppressed by DNA methylation have been demonstrated in senescent subsets of T-lymphocytes. Thus, T-cells, principally CD4+CD28null T-cells, aberrantly express genes, including those of the KIR gene family and cytotoxic proteins such as perforin, and overexpress CD70, IFN-γ, LFA-1 and others. In summary, owing to a lifetime of exposure to and proliferation against a variety of pathogens, highly differentiated T-cells suffer molecular modifications that alter their cellular homeostasis mechanisms.
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14
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Chen G, Lustig A, Weng NP. T cell aging: a review of the transcriptional changes determined from genome-wide analysis. Front Immunol 2013; 4:121. [PMID: 23730304 PMCID: PMC3657702 DOI: 10.3389/fimmu.2013.00121] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 05/06/2013] [Indexed: 12/14/2022] Open
Abstract
Age carries a detrimental impact on T cell function. In the past decade, analyses of the genome-scale transcriptional changes of T cells during aging have yielded a large amount of data and provided a global view of gene expression changes in T cells from aged hosts as well as subsets of T cells accumulated with age. Here, we aim to review the changes of gene expression in thymocytes and peripheral mature T cells, as well as the subsets of T cells accumulated with age, and discuss the gene networks and signaling pathways that are altered with aging in T cells. We also discuss future direction for furthering the understanding of the molecular basis of gene expression alterations in aged T cells, which could potentially provide opportunities for gene-based clinical interventions.
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Affiliation(s)
- Guobing Chen
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health Baltimore, MD, USA
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15
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Chou JP, Effros RB. T cell replicative senescence in human aging. Curr Pharm Des 2013; 19:1680-98. [PMID: 23061726 PMCID: PMC3749774 DOI: 10.2174/138161213805219711] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 10/01/2012] [Indexed: 12/17/2022]
Abstract
The decline of the immune system appears to be an intractable consequence of aging, leading to increased susceptibility to infections, reduced effectiveness of vaccination and higher incidences of many diseases including osteoporosis and cancer in the elderly. These outcomes can be attributed, at least in part, to a phenomenon known as T cell replicative senescence, a terminal state characterized by dysregulated immune function, loss of the CD28 costimulatory molecule, shortened telomeres and elevated production of proinflammatory cytokines. Senescent CD8 T cells, which accumulate in the elderly, have been shown to frequently bear antigen specificity against cytomegalovirus (CMV), suggesting that this common and persistent infection may drive immune senescence and result in functional and phenotypic changes to the T cell repertoire. Senescent T cells have also been identified in patients with certain cancers, autoimmune diseases and chronic infections, such as HIV. This review discusses the in vivo and in vitro evidence for the contribution of CD8 T cell replicative senescence to a plethora of age-related pathologies and a few possible therapeutic avenues to delay or prevent this differentiative end-state in T cells. The age-associated remodeling of the immune system, through accumulation of senescent T cells has farreaching consequences on the individual and society alike, for the current healthcare system needs to meet the urgent demands of the increasing proportions of the elderly in the US and abroad.
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Affiliation(s)
- Jennifer P Chou
- Dept of Pathology &Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1732, USA
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NK cells in healthy aging and age-associated diseases. J Biomed Biotechnol 2012; 2012:195956. [PMID: 23251076 PMCID: PMC3517269 DOI: 10.1155/2012/195956] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 09/10/2012] [Indexed: 01/10/2023] Open
Abstract
NK cells exhibit the highest cytotoxic capacity within the immune system. Alteration of their number or functionality may have a deep impact on overall immunity. This is of particular relevance in aging where the elderly population becomes more susceptible to infection, cancer, autoimmune diseases, and neurodegenerative diseases amongst others. As the fraction of elderly increases worldwide, it becomes urgent to better understand the aging of the immune system to prevent and cure the elderly population. For this, a better understanding of the function and phenotype of the different immune cells and their subsets is necessary. We review here NK cell functions and phenotype in healthy aging as well as in various age-associated diseases.
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Abstract
With the improvement of medical care and hygienic conditions, there has been a tremendous increment in human lifespan. However, many of the elderly (>65 years) display chronic illnesses, and a majority requires frequent and longer hospitalization. The robustness of the immune system to eliminate or control infections is often eroded with advancing age. Nevertheless, some elderly individuals do cope better than others. The origin of these inter-individual differences may come from genetic, lifestyle conditions (nutrition, socio-economic parameters), as well as the type, number and recurrence of pathogens encountered during life. The theory we are supporting is that chronic infections, through life, will induce profound changes in the immune system probably due to unbalanced inflammatory profiles. Persistent viruses such a cytomegalovirus are not eliminated and are a driven force to immune exhaustion. Because of their age, elderly individuals may have seen more of these chronic stimulators and have experienced more reactivation episodes ultimately leading to shrinkage of their repertoire and overall immune robustness. This review integrates updates on immunity with advancing age and its impact on associated clinical conditions.
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Sakaguchi S, Benham H, Cope AP, Thomas R. T‐cell receptor signaling and the pathogenesis of autoimmune arthritis: insights from mouse and man. Immunol Cell Biol 2012; 90:277-87. [DOI: 10.1038/icb.2012.4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Shimon Sakaguchi
- Laboratory of Experimental Immunology, WPI Immunology Frontier Research Center, Osaka University Suita Japan
- Department of Experimental Pathology, Institute for Frontier Medical Sciences, Kyoto University Kyoto Japan
| | - Helen Benham
- The University of Queensland, Diamantina Institute, Princess Alexandra Hospital Brisbane Queensland Australia
| | - Andrew P Cope
- Academic Department of Rheumatology, Centre for Molecular and Cellular Biology of Inflammation, Division of Immunology, Infection and Inflammatory Diseases, School of Medicine, King's College London London UK
| | - Ranjeny Thomas
- The University of Queensland, Diamantina Institute, Princess Alexandra Hospital Brisbane Queensland Australia
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Molano A, Meydani SN. Vitamin E, signalosomes and gene expression in T cells. Mol Aspects Med 2011; 33:55-62. [PMID: 22138304 DOI: 10.1016/j.mam.2011.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/14/2011] [Accepted: 11/15/2011] [Indexed: 12/11/2022]
Abstract
CD4+T cells from aged humans or mice show significant reductions in IL-2 production upon activation. The resulting decreased proliferation is linked to higher risks of infection in the elderly. Several lines of evidence indicate that intrinsic defects preferentially affecting the naïve subset of CD4+T cells contribute to this reduced IL-2 production. Comparison of the biochemical pathways that transduce activation signals from the T cell receptor to the IL-2 promoter in young and old CD4+T cells has demonstrated age-related impairments at initial molecular events, in particular the phosphorylation of kinases and adapter proteins involved in the formation of signalosomes - complex multiprotein assemblies that provide the framework for effective signal transduction. Confocal microscopy has demonstrated a series of age-related impairments in effective immune synapse formation. Vitamin E can reverse many of these CD4+T cell age-associated defects, including reduced levels of phosphorylation of critical signaling/adapter proteins as well as defective immune synapse formation. Vitamin E also enhances IL-2 production, expression of several cell cycle control proteins, and proliferation. Although the precise mechanisms underlying this effect are not understood, it is possible that this antioxidant lipophilic vitamin can prevent the propagation of polyunsaturated fatty acid peroxidation in the cell membrane, influence the biochemical characteristics of specific lipid bilayer microdomains involved in signal transduction, modulate the activity of kinases/phosphatases, or interact with intracellular receptors.
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Affiliation(s)
- Alberto Molano
- Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
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Larbi A, Pawelec G, Wong SC, Goldeck D, Tai JJY, Fulop T. Impact of age on T cell signaling: a general defect or specific alterations? Ageing Res Rev 2011; 10:370-8. [PMID: 20933612 DOI: 10.1016/j.arr.2010.09.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 09/22/2010] [Accepted: 09/24/2010] [Indexed: 01/09/2023]
Abstract
Decreased immune responsiveness associated with aging is generally termed "immunosenescence". Several theories have been proposed to explain age-related declines in immune responses. Here, we will focus on and describe potential defects in T cell signal transduction from the membrane to the nucleus, leading to changes in the type, intensity and duration of the response as a major factor contributing to immunosenescence. We will first detail T cell signaling through the T cell receptor (TCR), CD28 and IL-2 receptor (IL-2R) and then discuss the observed age-related alterations to these signaling pathways. The role of membrane rafts in T cell signaling and T cell aging will be described. These factors will be considered in the context of the notion that age-related changes to T cell signaling may be attributed to changes in the functionality of the T cells due to shifts in T cell subpopulations with age. For this reason, we conclude by highlighting the application of multiparametric signaling analysis in leukocyte subsets using flow cytometry as a means to obtain a clearer picture with respect to age-related changes to immune signaling.
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PTPN22 1858C>T (R620W) functional polymorphism and human longevity. Mol Biol Rep 2010; 38:4231-5. [PMID: 21113673 DOI: 10.1007/s11033-010-0546-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 11/17/2010] [Indexed: 01/03/2023]
Abstract
The PTPN22 gene, located on chromosome 1p13, encoding lymphoid protein tyrosine phosphatase (LYP), plays a crucial role in the negative control of T lymphocyte activation. Since the age-related change in T-cell signal transduction may be one of the most important causes of cell-mediated immune response decline with ageing, we performed a population-based association study to test whether the PTPN22 1858C>T (R620W) functional polymorphism affects the ability to survive to old age and to reach even exceptional life expectancy. 892 unrelated healthy individuals (age range 8-106 years, 403 males and 489 females) from central Italy were studied. For both gender, the frequency of PTPN22*T1858 carriers does not differ significantly in nona/centenarians and in octogenarians respect to young group. Allele and genotype frequencies of age groups were compared to those reported in previously published studied carried out on control individuals with Italic ancestry (N = 1393), further confirming results obtained from our sample population. Overall, our study suggests that PTPN22*T1858 allele is not negatively selected at oldest ages and we speculate that its increased ability to protect individuals against development of infectious diseases may counteract its deleterious effect on immune system leading to autoimmunity.
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Ohno-Iwashita Y, Shimada Y, Hayashi M, Inomata M. Plasma membrane microdomains in aging and disease. Geriatr Gerontol Int 2010; 10 Suppl 1:S41-52. [DOI: 10.1111/j.1447-0594.2010.00600.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Age-related changes in lck-Vav signaling pathways in mouse CD4 T cells. Cell Immunol 2009; 259:100-4. [PMID: 19577230 DOI: 10.1016/j.cellimm.2009.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/28/2009] [Accepted: 06/01/2009] [Indexed: 11/24/2022]
Abstract
Activation of lck-fyn kinases during T cell receptor signaling leads to Vav phosphorylation, activation of downstream targets including Rac1, and a transient decline in ezrin and moesin phosphorylation. We have shown that age increases Rac1 activity and lowers ezrin and moesin phosphorylation in resting mouse CD4 cells, changes that could be the results of alterations in lck-Vav signaling. Analysis of Vav in CD4 cells from old mice shows increases in the phosphorylation of two key regulatory residues, Tyr160 and Tyr174, suggesting enhancement of Vav GTPase activity. In addition, analysis of lck status also shows age-related increases in phosphorylation of two key residues, Tyr394 and Tyr505, which have opposite effects on lck function. These changes in lck-Vav signals in resting CD4 cells may contribute in turn to age-related increases in Rac1 activity and declines in phosphorylation of cytoskeletal proteins including Ezrin and Moesin.
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Twohig JP, Pappworth IY, Sivasankar B, Kulik L, Bull M, Holers VM, Wang EC, Marchbank KJ. Defective B cell ontogeny and humoral immune response in mice prematurely expressing human complement receptor 2 (CR2, CD21) is similar to that seen in aging wild type mice. Mol Immunol 2009; 46:2002-13. [PMID: 19359041 PMCID: PMC2706330 DOI: 10.1016/j.molimm.2009.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 03/12/2009] [Accepted: 03/14/2009] [Indexed: 02/03/2023]
Abstract
Mice prematurely expressing human CR2 (hCR2) in the B cell lineage have a defective B cell ontogeny and humoral immune response. We have previously determined altered tyrosine phosphorylation patterns within hCR2 transgenic mice, suggesting that irreversible changes in B cell signaling pathways had occurred, which could explain the B cell unresponsiveness associated with hCR2 transgene expression. In support of that assertion, we found that increasing antigen dose or addition of adjuvant had a minimal impact on the ability of B cells to respond to antigen. However, analysis of aged hCR2high mice (1 year plus) revealed that both B cell numbers, B cell sub-population distribution including expansion of a newly described B regulatory cell subset, and immune responses were comparable with age-matched hCR2 negative mice. Finally, we established that B cell unresponsiveness to antigen in aging wild type mice (1 year plus) was equivalent to that noted in 3-month-old hCR2high mice. This data provides evidence that 3-month-old hCR2high mice have a humoral immune system resembling aged mice and suggests that further examination of the precise molecular and cellular parallells between aged wild type mice and 3-month-old hCR2high mice could provide an important insight into the mechanisms which lead to B cell unresponsiveness in the aging immune system.
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Affiliation(s)
- Jason P. Twohig
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
| | - Isabel Y. Pappworth
- Institute of Human Genetics, Newcastle University, Center for Life, Central Parkway, Newcastle NE1 3BZ, UK
| | | | - Liudmila Kulik
- Departments of Medicine and Immunology, University of Colorado, SOM, Denver, CO, USA
| | - Melanie Bull
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
| | - V. Michael Holers
- Departments of Medicine and Immunology, University of Colorado, SOM, Denver, CO, USA
| | - Eddie C.Y. Wang
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
| | - Kevin J. Marchbank
- Institute of Human Genetics, Newcastle University, Center for Life, Central Parkway, Newcastle NE1 3BZ, UK
- Corresponding author. Tel.: +44 191 222 5998; fax: +44 191 222 8988.
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Immune receptor signaling, aging and autoimmunity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 640:312-24. [PMID: 19065799 DOI: 10.1007/978-0-387-09789-3_21] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Aging is associated with a myriad of changes including alterations in glucose metabolism, brain function, hormonal regulation, muscle homeostasis and the immune system. Aged dividuals, generally still defined as over 65 years old, differ from middle-aged or young donors in many features of the immune system. The major observation is that the elderly population is not able to cope with infections as well as younger adults and recovery generally takes longer. Moreover, some diseases first appear with advancing age and are likely associated with dysfunction of the immune system. Thus, Alzheimer's disease, atherosclerosis, type II diabetes and some autoimmune disorders are linked to changes in immune function. One major immune cell population implicated as being responsible for the initiation and chronicity of immune dysfunction leading to diseases or immunosuppression is the T-cell. Although many changes in B-cell and innate immune function in aging are associated with the appearance of disease, they are not as well studied and clearly demarcated as changes in the T-cell compartment. The adaptive immune system is coordinated by T-cells, the activation of which is required for the initiation, maintenance and termination of responses against pathogens. Changes in the expression and functions of the T-cell receptor (TCR) for antigen and its co-receptors are closely associated with immunosenescence. Certain similar changes have also been found in some other disease states, e.g., rheumatoid arthritis, systemic lupus erythematosus and cancer. In this chapter, we will summarize our knowledge about multichain immune recognition receptor signaling, mainly the TCR, in aging and autoimmune diseases.
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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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Marko MG, Ahmed T, Bunnell SC, Wu D, Chung H, Huber BT, Meydani SN. Age-associated decline in effective immune synapse formation of CD4(+) T cells is reversed by vitamin E supplementation. THE JOURNAL OF IMMUNOLOGY 2007; 178:1443-9. [PMID: 17237392 DOI: 10.4049/jimmunol.178.3.1443] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aging is associated with reduced IL-2 production and T cell proliferation. Vitamin E supplementation, in aged animals and humans, increases cell division and IL-2 production by naive T cells. The immune synapse forms at the site of contact between a T cell and an APC and participates in T cell activation. We evaluated whether vitamin E affects the redistribution of signaling proteins to the immune synapse. Purified CD4(+) T cells, from the spleens of young and old mice, were treated with vitamin E before stimulation with a surrogate APC expressing anti-CD3. Using confocal fluorescent microscopy, we observed that CD4(+) T cells from old mice were significantly less likely to recruit signaling proteins to the immune synapse than cells from young mice. Vitamin E increased the percentage of old CD4(+) T cells capable of forming an effective immune synapse. Similar results were found following in vivo supplementation with vitamin E. When compared with memory cells, naive T cells from aged mice were more defective in immune synapse formation and were more responsive to vitamin E supplementation. These data show, for the first time, that vitamin E significantly improves age-related early T cell signaling events in naive CD4(+) T cells.
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Affiliation(s)
- Melissa G Marko
- Nutritional Immunology Laboratory, Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
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Han SN, Adolfsson O, Lee CK, Prolla TA, Ordovas J, Meydani SN. Age and Vitamin E-Induced Changes in Gene Expression Profiles of T Cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:6052-61. [PMID: 17056531 DOI: 10.4049/jimmunol.177.9.6052] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cells are vulnerable to age-associated changes. Vitamin E has been shown to improve T cell functions in the old. We studied gene expression profiles of T cells to better understand the underlying mechanisms of age and vitamin E-induced changes in T cell function. Young and old C57BL mice were fed diets containing 30 (control) or 500 (supplemented) ppm of vitamin E for 4 wks. Gene expression profiles of T cells were assessed using microarray analysis with/without anti-CD3/anti-CD28 stimulation. Genes associated with cytokines/chemokines, transcriptional regulation, signal transduction, cell cycle, and apoptosis were significantly up-regulated upon stimulation. Higher SOCS3 and lower growth factor independent 1 (Gfi-1) expression in old T cells may contribute to age-associated decline in proliferation. Higher Gadd45 and lower Bcl2 expression may contribute to increased apoptosis in old T cells. Vitamin E supplementation resulted in higher expression of genes involved in cell cycle regulation (Ccnb2, Cdc2, Cdc6) in old T cells. Vitamin E supplementation resulted in higher up-regulation of IL-2 expression in young and old T cells and lower up-regulation of IL-4 expression in old T cells following stimulation. These findings suggest that aging has significant effects on the expression of genes associated with signal transduction, transcriptional regulation, and apoptosis pathways in T cells, and vitamin E has a significant impact on the expression of genes associated with cell cycle and Th1/Th2 balance in old T cells. Further studies are needed to determine whether these changes are due to the effects of aging at a single-cell level or to the shift in the ratio of naïve:memory T cells with age.
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Affiliation(s)
- Sung Nim Han
- Nutritional Immunology Laboratory, Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA.
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Hasler P, Zouali M. Immune receptor signaling, aging, and autoimmunity. Cell Immunol 2005; 233:102-8. [PMID: 15936745 DOI: 10.1016/j.cellimm.2005.04.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Accepted: 04/21/2005] [Indexed: 01/19/2023]
Abstract
With advancing age, the immune system undergoes changes that predispose to autoimmune reactivity. Aging reduces the efficiency of physical barriers, decreasing protection against invasive pathogens, and exposing previously hidden antigens in the body's own tissues. Self-antigens acquire alterations that increase their immunogenicity. In addition, the ability of innate immunity to eliminate infectious agents deteriorates, resulting in inappropriate persistence of immune stimulation and antigen levels exceeding the threshold for the activation of B or T cells. B cell turnover is reduced and numbers of naïve T cells decline to the advantage of increasing numbers of memory T cells. In parallel, the loss of co-stimulatory T cell molecules may increase reactivity of T cells, and render them less susceptible to downregulation. Since optimal immune reactivity requires a tight balance of transduction pathways in both T and B lymphocytes, and because these pathways are altered in systemic autoimmune diseases, we would like to propose that, with age, alterations of the immune receptor signaling machinery underlie the higher incidence of autoimmune phenomena in the elderly. Consistently, aging is associated with alterations in several components of the signaling complex in B cells, memory and naïve T cells, and a reduced activation of several lipid rafts-associated proteins. Because the coincidence of autoimmune disease with other ailments increases the burden of disease and limits therapeutic options in the aged, further investigation of these pathways in the elderly represents a challenge that will need to be addressed in order to devise effective preventive and therapeutic interventions.
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Affiliation(s)
- Paul Hasler
- Institut National de Santé et de Recherche Médicale, INSERM U430, Immunopathologie Humaine, 15 rue de l'Ecole de Médecine, 75006 Paris, France
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Larbi A, Dupuis G, Douziech N, Khalil A, Fülöp T. Low-grade inflammation with aging has consequences for T-lymphocyte signaling. Ann N Y Acad Sci 2005; 1030:125-33. [PMID: 15659789 DOI: 10.1196/annals.1329.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
T lymphocytes are key players of immune responses that are associated with immune senescence because their functions are the most affected with aging. Defects in signal delivery to the nucleus have been demonstrated, by our group and others, in human aging and may explain the dysfunctions that occur in T cells with aging. Although aging has been related to a decline in several biological functions, it is also associated with a basal low-grade proinflammatory state and an increase in oxidative stress that lead to changes and damage. However, there are no clear data concerning the basal state of activation of T lymphocytes and its putative link with the low-grade inflammation observed with aging. Since membrane microdomains (lipid rafts) are specialized plasma membrane structures involved in T-lymphocyte activation, we studied the effect of aging on the phosphorylation state of signaling molecules associated with lipid rafts. We found that the signaling molecules in T lymphocytes from elderly donors were hyperphosphorylated and that the high basal state of phosphorylation did not allow activation exposure to a T-cell stimulus. We found that the cholesterol composition is changed in lipid rafts of resting T cells. We analyzed lipid raft distribution in situ using confocal microscopy and found a disorganization of these microdomains in T cells from aged donors. In conclusion, we show a link between aging, T-lymphocyte lipid rafts, immune senescence, and low-grade inflammation.
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Affiliation(s)
- Anis Larbi
- Research Center on Aging, University of Sherbrooke Geriatric Institute, Sherbrooke, Quebec, Canada
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Larbi A, Khalil A, Douziech N, Guérard KP, Fülöp T. Oxidized low-density lipoproteins induced inflammatory process during atherogenesis with aging. Radiat Phys Chem Oxf Engl 1993 2005. [DOI: 10.1016/j.radphyschem.2004.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Yokoyama T, Du J, Kawamoto Y, Suzuki H, Nakashima I. Inhibition of Fas-mediated apoptotic cell death of murine T lymphocytes in a mouse model of immunosenescence in linkage to deterioration in cell membrane raft function. Immunology 2004; 112:64-71. [PMID: 15096185 PMCID: PMC1782464 DOI: 10.1111/j.1365-2567.2004.01850.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We previously developed a transgenic mouse line into which a rabbit protein kinase Calpha (PKCalpha) gene fused to a human CD2 promoter/enhancer was introduced, and we found that immunosenescence was facilitated in these transgenic mice. In this study, we found that along with age-dependent increase in the level of protein expression of PKCalpha and its translocation to the membrane, activated T cells became less sensitive to apoptosis-inducing anti-Fas antibody. The capacity of T cells to express Fas antigen on their surfaces in response to anti-CD3 and interleukin-2 was impaired in PKCalpha-transgenic mice of relatively advanced age, although background Fas expression levels on T cells from those mice were high. We then found that out of proportion to a high level of cell surface Fas expression the density of cholera toxin B (CTx)-binding raft elements decreased in PKCalpha-transgenic mice of relatively advanced age and to a lesser extent in normal mice of advanced age. Correspondingly, the expression level of raft-associating Lck was decreased in these mice. These findings suggest for the first time that immunosenescence of T cells involves a decrease in density of cell surface CTx-binding raft elements, which might underlie a deterioration in T-cell signal pathway for either cell death or cell activation.
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Affiliation(s)
- Toshihiro Yokoyama
- Department of Immunology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Larbi A, Douziech N, Khalil A, Dupuis G, Gheraïri S, Guérard KP, Fülöp T. Effects of methyl-β-cyclodextrin on T lymphocytes lipid rafts with aging. Exp Gerontol 2004; 39:551-8. [PMID: 15050290 DOI: 10.1016/j.exger.2003.10.031] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2003] [Revised: 09/07/2003] [Accepted: 10/09/2003] [Indexed: 02/06/2023]
Abstract
Aging is associated with a decline in immune functions. Among them, T-cell activation is altered at several points of the signaling cascade following TCR engagement. Recent findings suggest that lipid rafts act as a platform in the initiation of T-cell activation. We have previously demonstrated that cholesterol content in T-cells increased with aging, especially in lipid rafts. Cholesterol, which is a major component of lipid rafts, serves to stabilize their structure. We hypothesized that restoring T-cell cholesterol content and membrane fluidity would restore, at least in part, T-cell function via lipid rafts. We measured the lipid rafts coalescence, the p56(Lck) and linker of activated T-cell (LAT) signaling molecules recruitment and activation, the cholesterol content and fluidity in T-cell membrane after different methyl-beta-cyclodextrin (MBCD) treatments. Our results show that high concentration of MBCD (10 mM) completely disorganized the lipid rafts in T-cell membranes of young and elderly donors, however, T-cells from elderly donors were less sensitive than T-cells of young donors to low concentration of MBCD (0.5 mM). p56(Lck) and LAT recruitment and activation were affected in T-cells of both aged groups. MBCD treatment did not affect the cholesterol content and fluidity of T-cell membranes of young donors, while the cholesterol content was decreased and fluidity increased in lipid rafts of elderly donors. These results suggested that cholesterol extraction by MBCD increased the fluidity and disrupted lipid rafts organization. The increase in cholesterol content in lipid rafts with aging and its decrease by biochemical extraction were able to affect early signaling molecules activation. Restoring cholesterol content and fluidity may have beneficial effects, however, MBCD disorganized the membrane and this might not completely restore the T-cell activation via lipid rafts with aging. Altogether these results suggest that defects in cholesterol cellular homeostasis may be part of T-cell immunosenescence via lipid rafts dysfunction.
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Affiliation(s)
- Anis Larbi
- Research Center on Aging, Sherbrooke Geriatric University Institute, University of Sherbrooke, Sherbrooke, Que., Canada J1H 5N4
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Larbi A, Douziech N, Dupuis G, Khalil A, Pelletier H, Guerard KP, Fülöp T. Age-associated alterations in the recruitment of signal-transduction proteins to lipid rafts in human T lymphocytes. J Leukoc Biol 2003; 75:373-81. [PMID: 14657209 DOI: 10.1189/jlb.0703319] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aging is associated with a decline in T cell activation and proliferation, but the underlying mechanisms are not fully understood. Recent findings suggest that lipid rafts act as a platform in the initiation of T cell activation by selectively recruiting signaling proteins associated with formation of the initial complex of signal transduction. We tested the hypothesis that lipid raft properties are altered in T lymphocytes from elderly, healthy individuals in comparison with young subjects. Results showed that the cholesterol content of lipid rafts derived from these cells was consistently higher in the case of elderly donors and that membrane fluidity was decreased. In addition, lipid rafts coalescence to the site of T cell receptor engagement was impaired in T cells from elderly donors. The recruitment of p56(lck), linker of activated T cells, and their tyrosine-phosphorylated forms to lipid rafts was decreased in activated T cells from aged individuals. CD45 was not recruited to the lipid raft fractions in either group of subjects. Our data suggest that some properties of lipid rafts are altered in aging, and this finding may be part of the causes for the decline in T cell functions that are observed in elderly individuals.
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Affiliation(s)
- Anis Larbi
- Research Center on Aging, Geriatric Institute, Clinical Research Center, University of Sherbrooke, 1036 Belvedere St. South, Sherbrooke, QC, Canada J1H 4C4
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Fülöp T, Larbi A, Dupuis G, Pawelec G. Ageing, autoimmunity and arthritis: Perturbations of TCR signal transduction pathways with ageing - a biochemical paradigm for the ageing immune system. Arthritis Res Ther 2003; 5:290-302. [PMID: 14680505 PMCID: PMC333419 DOI: 10.1186/ar1019] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2003] [Revised: 10/01/2003] [Accepted: 10/13/2003] [Indexed: 02/07/2023] Open
Abstract
It is widely accepted that cell-mediated immune functions decline with age, rendering an individual more susceptible to infection and possibly cancer, as well as to age-associated autoimmune diseases. The exact causes of T-cell functional decline are not known. One possible cause could be the development of defects in the transduction of mitogenic signals following TCR stimulation. This T-cell hyporesponsiveness due to defects of signalling through the TCR either from healthy elderly subjects or from individuals with autoimmune diseases such as rheumatoid arthritis or systemic lupus erythematosus results in an impaired ability to mount efficient immune responses and to maintain responsiveness to foreign antigens. This implies that a high proportion of autoreactive T cells might accumulate either intrathymically or in the periphery. T-cell anergy and differential TCR signalling could thus also be key players in the disruption of tolerance and the onset of autoimmune diseases. The increasing number of the elderly may lead to an increase of clinically important autoimmune diseases. We will review the signal transduction changes through the TCR-CD3 complex in T lymphocytes from healthy elderly subjects, which result in a modification of the activation of transcription factors involved in IL-2 gene expression leading to decreased IL-2 production. The putative contribution of altered T-cell signalling with ageing in the development of autoimmune diseases will be also discussed.
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Affiliation(s)
- Tamàs Fülöp
- Research Center on Ageing, Sherbrooke Geriatric University Institute, University of Sherbrooke, Quebec, Canada.
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Fulop T, Douziech N, Larbi A, Dupuis G. The role of lipid rafts in T lymphocyte signal transduction with aging. Ann N Y Acad Sci 2002; 973:302-4. [PMID: 12485883 DOI: 10.1111/j.1749-6632.2002.tb04655.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tamas Fulop
- Institut Universitaire de Gériatrie de Sherbrooke, Center on Aging Research, Faculty of Medicine, Université de Shebrooke, Sherbrooke, Qc, J1H, 4C4 Canada
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Turner J, Orme IM. Identification of altered integrin alpha/beta chain expression on T cells from old mice infected with Mycobacterium tuberculosis. Exp Gerontol 2002; 37:907-16. [PMID: 12086699 DOI: 10.1016/s0531-5565(02)00026-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During the natural aging process there is a gradual acquisition of T cell surface markers normally associated with cellular activation and memory. Because of this it is difficult to identify cells which are capable of responding to new antigenic challenge in older individuals, which therefore hinders the study of the immune response to infectious diseases. In this study we demonstrate that during natural aging there was an expansion in T cells that expressed the beta1 and beta2 integrins. Fewer CD8 T cells from old mice expressed beta7 integrins, however, they remained unchanged on CD4 T cells. In this study we also measured the expression of alphabeta integrin chains on the surface of T cells from mice of increasing age in response to an infection with Mycobacterium tuberculosis. We found that VLA-2 expression was increased on CD8 T cells from old mice however, the majority of integrins were unchanged in response to infection, in consequence of the increased expression of these molecules normally found in un-infected old mice. These findings are consistent with the hypothesis that age-associated changes occur in the number of cells that express molecules that allow T cells to traffic to inflammatory sites.
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Affiliation(s)
- Joanne Turner
- Mycobacterial Research Laboratories, Department of Microbiology, Colorado State University, Fort Collins 80523, USA.
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Chakravarti B, Abraham GN. Effect of age and oxidative stress on tyrosine phosphorylation of ZAP-70. Mech Ageing Dev 2002; 123:297-311. [PMID: 11744042 DOI: 10.1016/s0047-6374(01)00350-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Oxidative stress is believed to be one of the leading contributors to the aging process and loss of cellular function with aging. Although, several age-associated phenomena have been correlated with reactive oxygen species, the role of oxidative stress in the age-related decline of T-cell activity is not yet clear. The present study was carried out to determine the effect of reactive oxygen species on tyrosine phosphorylation of ZAP-70, a key enzyme in the T-cell signal transduction pathway. Our previous as well as present studies have demonstrated an age-related down-regulation of tyrosine phosphorylation of ZAP-70 following activation of freshly isolated T cells with various stimulating agents. Currently, we observe that under mild and chronic oxidative stress, tyrosine phosphorylation of ZAP-70 is impaired following stimulation of the T cells with anti-CD3 antibody. Interestingly, in contrast to our observation using freshly isolated T cells, there is no age-associated impairment of tyrosine phosphorylation of ZAP-70 when T cells, cultured for 2 days in a serum-free medium in the presence or in the absence of oxidative stress, are stimulated with anti-CD3 antibody. The current observation suggests that the age-associated down-regulation of tyrosine phosphorylation of ZAP-70 is not an intrinsic defect inherent of the T cells due to aging and is reversible. We also observed that under oxidative stress in vitro, there was no significant difference in inhibition of tyrosine phosphorylation of ZAP-70 in T cells isolated from elderly and young donors. Finally, it was also noted that the down-regulation of tyrosine phosphorylation of ZAP-70 under oxidative stress in young and elderly donors was not due to impairment in the net expression of ZAP-70 under oxidative stress thereby suggesting that dysregulation in the balance of kinase-phosphatase activities under oxidative stress might have been implicated in the observed phenomenon.
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Affiliation(s)
- Bulbul Chakravarti
- Department of Medicine and Center on Aging, University of Rochester Cancer Center, University of Rochester Medical Center, Rochester, New York, NY 14642, USA.
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39
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Alterations in signal transduction inT lymphocytes and neutrophils with ageing. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1566-3124(02)13006-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Douziech N, Seres I, Larbi A, Szikszay E, Roy PM, Arcand M, Dupuis G, Fulop T. Modulation of human lymphocyte proliferative response with aging. Exp Gerontol 2002; 37:369-87. [PMID: 11772524 DOI: 10.1016/s0531-5565(01)00204-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Previously, we have demonstrated age-associated alterations in transmembrane signaling. One of the most reproducible alterations found in the immune response with aging is the decrease of lymphocyte proliferation on stimulation with various different mitogens. Here, we confirm that proliferative responses to stimulation with phytohaemagglutin (PHA), recombinant human IL-2, or anti-CD3 monoclonal antibody are all greater in the young (20-25 years) than old (60-87 years) population. We attempted to modulate the proliferative response using various agents acting at different levels of transmembrane signaling (pertussis toxin, cholera toxin, isoproterenol, PMA, Ca ionophore A23187), as well as at the level of the lymphocyte plasma membrane (methyl-beta-cyclodextrin, MBCD), or by using antioxidant vitamins (Vitamin E or C). None of these agents was able to restore effectively the proliferative response of lymphocytes from the aged to the level of young subjects. Even the combination of A23187 and PMA acting directly on calcium metabolism and protein kinase C activity was insufficient to restore the decreased mitogenic capacity of T cells from elderly subjects. Cyclodextrin, which decreases the cholesterol content of the membrane, increased the proliferative response of lymphocytes of elderly subjects, but not to the level of the young. Vitamin E had a very strong inhibitory effect on lymphocyte stimulation in both the age groups, except in combination with MBCD in T cells of the elderly, while Vitamin C had no significant modulatory effect. MAPK ERK and p38 activation was found to be decreased with aging in T cells after anti-CD3 mAb stimulation. Vitamin E but not Vitamin C strongly inhibited MAPK ERK or p38 activation. The direct activation of certain molecules or the modulation of the cholesterol content of the membrane seems to be effective immunomodulatory interventions with aging.
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Affiliation(s)
- Nadine Douziech
- Centre de Recherche en Gérontologie et Gériatrie, Institut Universitaire de Gériatrie de Sherbrooke, 1036 rue Belvedère sud, Sherbrooke, Quebec, Canada J1H 4C4
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Chapter 7 Altered T-lymphocyte calcium signaling and age-related disease. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1566-3124(02)10019-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Dailey RW, Eun SY, Russell CE, Vogel LA. B cells of aged mice show decreased expansion in response to antigen, but are normal in effector function. Cell Immunol 2001; 214:99-109. [PMID: 12088409 DOI: 10.1006/cimm.2001.1894] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Increased dysfunction of the immune system with age can be attributed to developmental changes in cell types critical for proper immune responses. Previous studies have shown defects in humoral responses of aged individuals, but have not distinguished between aged T-cell/microenvironment and intrinsic B-cell defects. Here adoptive transfer of antigen-specific transgenic B cells compared early immunopoeisis from young and aged donors in a young recipient environment. B cells from aged donors demonstrated decreased antigen-induced expansion, particularly in the lymph nodes; however, they acquired a germinal center phenotype at frequencies similar to B cells from young donors. Additionally, aged B cells produced equivalent levels of antigen-specific antibody that underwent affinity maturation and isotype switching and demonstrated similar numbers of antibody-secreting cells of switched isotype. Thus, the ability of aged B cells to respond appropriately to T-dependent antigens and differentiate into high-affinity, isotype-switched, antibody-secreting cells appears to be intact.
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Affiliation(s)
- R W Dailey
- Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
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Affiliation(s)
- B Chakravarti
- Department of Chemistry, College of Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, USA.
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Abstract
T cell responses are altered in the aged in a manner usually interpreted as detrimental to host defences against infectious agents and possibly also against cancer. T cell dysregulation may be caused by any or a combination of stem cell deficits, compromised T cell differentiation, inefficient antigen processing and presentation by antigen presenting cells, suboptimal processing of the antigenic signal by T cells or inability of the T cell to respond appropriately thereafter. This review will focus on altered T cell signalling in ageing, encompassing not only alterations in signal transduction by the antigen-specific T cell receptor, but changes in the balance of positive and negative T cell costimulation and the resultant modified cytokine environment, the response to which is itself altered in ageing.
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Affiliation(s)
- G Pawelec
- Tübingen Ageing and Tumour Immunology Group, Second Department of Internal Medicine, University of Tübingen Medical School, Zentrum für Medizinsche Forschung, Waldhörnlestr. 22, D-72072, Tubingen, Germany.
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Mariani E, Pulsatelli L, Meneghetti A, Dolzani P, Mazzetti I, Neri S, Ravaglia G, Forti P, Facchini A. Different IL-8 production by T and NK lymphocytes in elderly subjects. Mech Ageing Dev 2001; 122:1383-95. [PMID: 11470128 DOI: 10.1016/s0047-6374(01)00270-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A gradual decline in the functional activity of the immune system is described with advancing age. The adaptive immune system seems the most severely affected, but some age-associated modifications also occurs in NK cells. Several studies investigated the age related changes of cytokine production, while little is known about chemokines, whose importance in regulating immune-response becomes even more evident. In this study we investigated whether the ability of T lymphocytes and NK cells to produce IL-8, either spontaneously or after activation, respectively with anti-CD3 monoclonal antibody or interleukin 2 (IL-2) was affected by age. We demonstrated that: (a) T lymphocytes and NK cells spontaneously produced detectable amounts of IL-8; (b) anti-CD3 stimulation of T lymphocytes significantly increased IL-8 production and the increment was more evident in the nonagenarian subjects; (c) similarly, IL-2 stimulation of NK cells rose the production of IL-8 but the amount produced by the old was lower than the one produced by the young group. Because of the co-stimulatory role of chemokines on NK responses and given the demonstrated importance of NK cells in defence against viral infections, the decreased production of IL-8 can be involved in the defective functional activity of NK cells from old subjects.
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Affiliation(s)
- E Mariani
- Dipartimento di Medicina Interna e Gastroenterologia, University of Bologna, Bologna, Italy.
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Fülöp T, Douziech N, Goulet AC, Desgeorges S, Linteau A, Lacombe G, Dupuis G. Cyclodextrin modulation of T lymphocyte signal transduction with aging. Mech Ageing Dev 2001; 122:1413-30. [PMID: 11470130 DOI: 10.1016/s0047-6374(01)00274-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
There is an alteration of the immune response in aging that leads to the increased incidence of infections, cancers and autoimmune disorders. The aim of the present study was to investigate whether there exists changes in signal transduction under the IL-2 receptor stimulation and the role of plasma membrane cholesterol in the activation of T cells with aging. We report age-related changes in the JAK-STAT signalling pathway that results in decreased tyrosine phosphorylation of STAT5. We present evidence for the importance of cholesterol content in regulating signalling pathways in T cells and in modulating their proliferation by using the plasma membrane cholesterol-depleting agent methyl-beta-cyclodexrin (MBCD). MBCD treatment (0.5 mM) induced a significant decrease in the cholesterol content of T cells of elderly subjects whereas it was increased in T cells of young subjects. MBCD induced changes in the phosphorylation of p56(lck), especially in T cells of elderly subjects. The proliferation of MBCD-treated T cells decreased in lymphocytes of young subjects but did not change in T cells of elderly subjects. These results suggest a role for plasma membrane cholesterol in the regulation of the TcR signalling pathways with differential effects related to aging. However, the data suggest that modulation of the plasma membrane cholesterol content alone may not be enough to restore signal transduction changes with aging.
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Affiliation(s)
- T Fülöp
- Centre de Recherche en Gérontologie et Gériatrie, Institut Universitaire de Geriatrie de Sherbrooke, 1036 rue Belvedère sud, Sherbrooke, Québec, Canada, J1H 4C4.
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Fulöp T, Douziech N, Jacob MP, Hauck M, Wallach J, Robert L. Age-related alterations in the signal transduction pathways of the elastin-laminin receptor. PATHOLOGIE-BIOLOGIE 2001; 49:339-48. [PMID: 11428170 DOI: 10.1016/s0369-8114(01)00143-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
With aging we assist to alterations in the vascular structure and function. One important factor in these vascular wall changes is the degradation of the elastin fibre major protein: elastin. Elastin peptides derived from the degradation are present in human sera. Elastin peptides induce on fibroblasts, phagocytic cells, lymphocytes, smooth muscle cells and endothelial cells, a variety of biological effects mediated by the elastin-laminin receptor which has been demonstrated to be present on the membrane of these cells. The transduction pathway of the ELR receptor involves the activation of phospholipase C (PLC) by a pertussis toxin sensitive G-protein. PLC induces the production of inositol trisphosphate (IP3) leading to the increase of the intracellular free calcium on one hand, and of diacylglycerol (DAG) which stimulates the translocation to the membrane of PKC leading to the phosphorylation of members of the MAPK family, such as p42/p44 MAPK. A progressive age dependent uncoupling of the elastin-laminin receptor occurs impairing its transduction pathway and which results in alteration of the calcium signaling and loss in calcium homeostasis of the cells. These alterations in the signal transduction of the elastin-laminin receptor result in modified activities of parenchymal and phagocytic cells with aging, such as free radical production and elastase release. Thus, these age-related alterations in the elastin-laminin receptor signal transduction may be involved in the atherogenesis.
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Affiliation(s)
- T Fulöp
- Laboratoire de biogérontologie, institut universitaire de gériatrie et département de médecine interne, faculté de médecine, université de Sherbrooke, Québec, Canada.
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Tamura T, Kunimatsu T, Yee ST, Igarashi O, Utsuyama M, Tanaka S, Miyazaki SI, Hirokawa K, Nariuchi H. Molecular mechanism of the impairment in activation signal transduction in CD4(+) T cells from old mice. Int Immunol 2000; 12:1205-15. [PMID: 10917895 DOI: 10.1093/intimm/12.8.1205] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
It is well known that IL-2 production of CD4(+) T cells from old mice (old T cells) is impaired. In this study, we have examined TCR complex zeta chain expression of old T cells and their TCR downstream signal transduction pathways stimulated with anti-CD3. Activation of protein tyrosine kinases, Fyn and ZAP-70, and turnover of inositol phosphates stimulated with anti-CD3 were severely impaired in old T cells, although levels of these proteins were comparable to those in young T cells. Increase in intracellular Ca2+ concentration in old T cells was also impaired. Old T cells starting the Ca(2+) oscillation by the anti-CD3 stimulation were severely decreased in number and the oscillation waves were broader in shape. T cells with zeta-FcvarepsilonRgamma heterodimer in the TCR-CD3 complex were increased in proportion in old T cells with a concomitant decrease in the T cells with zeta-zeta homodimer. The density of the TCR-CD3 complex on old T cells was confirmed to be comparable to that on young T cells. The impairment in TCR downstream signal transduction pathways and the increase in zeta-FcvarepsilonRgamma heterodimer in the TCR-CD3 complex were confirmed to be the situation in Th1 clones established from old mice. These results indicate that old T cells are impaired in response to TCR stimulation, because T cells with the TCR-CD3 complex containing the zeta-FcvarepsilonRgamma heterodimer are increased in proportion in old T cells.
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MESH Headings
- Aging/immunology
- Animals
- CD4-Positive T-Lymphocytes/immunology
- Calcium Signaling
- Cells, Cultured
- Dimerization
- Gene Expression Regulation
- Inositol Phosphates/metabolism
- Interleukin-2/biosynthesis
- Interleukin-2/genetics
- Membrane Proteins/chemistry
- Membrane Proteins/immunology
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-fyn
- Receptor-CD3 Complex, Antigen, T-Cell/chemistry
- Receptor-CD3 Complex, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/immunology
- Receptors, IgE/chemistry
- Receptors, IgE/immunology
- Signal Transduction/physiology
- ZAP-70 Protein-Tyrosine Kinase
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Affiliation(s)
- T Tamura
- Department of Allergology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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Abstract
There is an ever increasing interest in the study of the aging process. This review is aimed to make an overview of the biological aging research in Canada. I will summarize, to the best of my knowledge, the biological aging research undertaken actually in Canadian institutions dealing with various aspects of this research using many different experimental approaches, models from animals to humans and a huge array of techniques. The biological aging research is developing continuously in Canada, however, it is very important that we assist in a near future to its huge explosion if we would respond to the needs of an ever increasing aging population. Initiatives recently proposed by the Canadian government concerning the creation of Canadian Institutes on Health Research will provide good opportunities to establish a performant, cost-effective, and innovative biological aging research.
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Affiliation(s)
- T Fulop
- Centre de Recherche, Institut Universitaire de Gériatrie and Département de Médecine Interne, Faculté de Médecine, Université de Sherbrooke, 1036 rue Belvedere sud, Sherbrooke, Québec, Canada.
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