1
|
Démoulins T, Baron ML, Gauchat D, Kettaf N, Reed SJ, Charpentier T, Kalinke U, Lamarre A, Ahmed R, Sékaly RP, Sarkar S, Kalia V. Induction of thymic atrophy and loss of thymic output by type-I interferons during chronic viral infection. Virology 2022; 567:77-86. [PMID: 35032866 DOI: 10.1016/j.virol.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 11/30/2021] [Accepted: 12/20/2021] [Indexed: 01/30/2023]
Abstract
Type-I interferon (IFN-I) signals exert a critical role in disease progression during viral infections. However, the immunomodulatory mechanisms by which IFN-I dictates disease outcomes remain to be fully defined. Here we report that IFN-I signals mediate thymic atrophy in viral infections, with more severe and prolonged loss of thymic output and unique kinetics and subtypes of IFN-α/β expression in chronic infection compared to acute infection. Loss of thymic output was linked to inhibition of early stages of thymopoiesis (DN1-DN2 transition, and DN3 proliferation) and pronounced apoptosis during the late DP stage. Notably, infection-associated thymic defects were largely abrogated upon ablation of IFNαβR and partially mitigated in the absence of CD8 T cells, thus implicating direct as well as indirect effects of IFN-I on thymocytes. These findings provide mechanistic underpinnings for immunotherapeutic strategies targeting IFN-1 signals to manipulate disease outcomes during chronic infections and cancers.
Collapse
Affiliation(s)
- Thomas Démoulins
- Institute of Virology and Immunology, Bern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | | | - Dominique Gauchat
- Centre Hospitalier de l'Université de Montréal (CHUM), 1000, rue Saint-Denis, Montréal, Québec, H2X 0C1, Canada
| | - Nadia Kettaf
- Laboratoire d'immunologie, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Saint-Luc, Montréal, QC, H2X 1P1, Canada
| | - Steven James Reed
- Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
| | - Tania Charpentier
- Centre INRS-Institut Armand-Frappier, 531, Boulevard des Prairies, Laval, Québec, H7V 1B7, Canada
| | - Ulrich Kalinke
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Alain Lamarre
- Centre INRS-Institut Armand-Frappier, 531, Boulevard des Prairies, Laval, Québec, H7V 1B7, Canada
| | - Rafi Ahmed
- Department of Microbiology & Immunology, School of Medicine, Emory University, 1510 Clifton Road, Atlanta, GA, USA
| | - Rafick-Pierre Sékaly
- Department of Pathology, Emory University Winship Cancer Center, Atlanta, GA, USA
| | - Surojit Sarkar
- Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA; Department of Pathology, University of Washington School of Medicine, Seattle, WA, 98195, USA; Department of Pediatrics, Division of Hematology and Oncology, University of Washington, Seattle, WA, 98195, USA.
| | - Vandana Kalia
- Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA; Department of Pediatrics, Division of Hematology and Oncology, University of Washington, Seattle, WA, 98195, USA.
| |
Collapse
|
2
|
Granadier D, Iovino L, Kinsella S, Dudakov JA. Dynamics of thymus function and T cell receptor repertoire breadth in health and disease. Semin Immunopathol 2021; 43:119-134. [PMID: 33608819 PMCID: PMC7894242 DOI: 10.1007/s00281-021-00840-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/12/2021] [Indexed: 12/26/2022]
Abstract
T cell recognition of unknown antigens relies on the tremendous diversity of the T cell receptor (TCR) repertoire; generation of which can only occur in the thymus. TCR repertoire breadth is thus critical for not only coordinating the adaptive response against pathogens but also for mounting a response against malignancies. However, thymic function is exquisitely sensitive to negative stimuli, which can come in the form of acute insult, such as that caused by stress, infection, or common cancer therapies; or chronic damage such as the progressive decline in thymic function with age. Whether it be prolonged T cell deficiency after hematopoietic cell transplantation (HCT) or constriction in the breadth of the peripheral TCR repertoire with age; these insults result in poor adaptive immune responses. In this review, we will discuss the importance of thymic function for generation of the TCR repertoire and how acute and chronic thymic damage influences immune health. We will also discuss methods that are used to measure thymic function in patients and strategies that have been developed to boost thymic function.
Collapse
Affiliation(s)
- David Granadier
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Immunotherapy Integrated Research Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA, USA
- Department of Molecular and Cellular Biology, University of Washington, Seattle, WA, USA
| | - Lorenzo Iovino
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Immunotherapy Integrated Research Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Sinéad Kinsella
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Immunotherapy Integrated Research Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Jarrod A Dudakov
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
- Immunotherapy Integrated Research Center, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
- Department of Immunology, University of Washington, Seattle, WA, USA.
| |
Collapse
|
3
|
Kinsella S, Dudakov JA. When the Damage Is Done: Injury and Repair in Thymus Function. Front Immunol 2020; 11:1745. [PMID: 32903477 PMCID: PMC7435010 DOI: 10.3389/fimmu.2020.01745] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/30/2020] [Indexed: 01/02/2023] Open
Abstract
Even though the thymus is exquisitely sensitive to acute insults like infection, shock, or common cancer therapies such as cytoreductive chemo- or radiation-therapy, it also has a remarkable capacity for repair. This phenomenon of endogenous thymic regeneration has been known for longer even than its primary function to generate T cells, however, the underlying mechanisms controlling the process have been largely unstudied. Although there is likely continual thymic involution and regeneration in response to stress and infection in otherwise healthy people, acute and profound thymic damage such as that caused by common cancer cytoreductive therapies or the conditioning regimes as part of hematopoietic cell transplantation (HCT), leads to prolonged T cell deficiency; precipitating high morbidity and mortality from opportunistic infections and may even facilitate cancer relapse. Furthermore, this capacity for regeneration declines with age as a function of thymic involution; which even at steady state leads to reduced capacity to respond to new pathogens, vaccines, and immunotherapy. Consequently, there is a real clinical need for strategies that can boost thymic function and enhance T cell immunity. One approach to the development of such therapies is to exploit the processes of endogenous thymic regeneration into novel pharmacologic strategies to boost T cell reconstitution in clinical settings of immune depletion such as HCT. In this review, we will highlight recent work that has revealed the mechanisms by which the thymus is capable of repairing itself and how this knowledge is being used to develop novel therapies to boost immune function.
Collapse
Affiliation(s)
- Sinéad Kinsella
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Jarrod A. Dudakov
- Program in Immunology, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
- Immunotherapy Integrated Research Center, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
- Department of Immunology, University of Washington, Seattle, WA, United States
| |
Collapse
|
4
|
Goggins JA, Kurtz JR, McLachlan JB. Control of Persistent Salmonella Infection Relies on Constant Thymic Output Despite Increased Peripheral Antigen-Specific T Cell Immunity. Pathogens 2020; 9:pathogens9080605. [PMID: 32722409 PMCID: PMC7459538 DOI: 10.3390/pathogens9080605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 12/24/2022] Open
Abstract
Recent thymic emigrants are the youngest subset of peripheral T cells and their involvement in combating persistent bacterial infections has not been explored. Here, we hypothesized that CD4+ recent thymic emigrants are essential immune mediators during persistent Salmonella infection. To test this, we thymectomized adult mice either prior to, or during, persistent Salmonella infection. We found that thymic output is crucial in the formation of protective immune responses during the early formation of a Salmonella infection but is dispensable once persistent Salmonella infection is established. Further, we show that thymectomized mice demonstrate increased infection-associated mortality and bacterial burdens. Unexpectedly, numbers of Salmonella-specific CD4+ T cells were significantly increased in thymectomized mice compared to sham control mice. Lastly, we found that T cells from thymectomized mice may be impaired in producing the effector cytokine IL-17 at early time points of infection, compared to thymically intact mice. Together, these results imply a unique role for thymic output in the formation of immune responses against a persistent, enteric pathogen.
Collapse
|
5
|
Elsaesser HJ, Mohtashami M, Osokine I, Snell LM, Cunningham CR, Boukhaled GM, McGavern DB, Zúñiga-Pflücker JC, Brooks DG. Chronic virus infection drives CD8 T cell-mediated thymic destruction and impaired negative selection. Proc Natl Acad Sci U S A 2020; 117:5420-5429. [PMID: 32094187 PMCID: PMC7071912 DOI: 10.1073/pnas.1913776117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chronic infection provokes alterations in inflammatory and suppressive pathways that potentially affect the function and integrity of multiple tissues, impacting both ongoing immune control and restorative immune therapies. Here we demonstrate that chronic lymphocytic choriomeningitis virus infection rapidly triggers severe thymic depletion, mediated by CD8 T cell-intrinsic type I interferon (IFN) and signal transducer and activator of transcription 2 (Stat2) signaling. Occurring temporal to T cell exhaustion, thymic cellularity reconstituted despite ongoing viral replication, with a rapid secondary thymic depletion following immune restoration by anti-programmed death-ligand 1 (PDL1) blockade. Therapeutic hematopoietic stem cell transplant (HSCT) during chronic infection generated new antiviral CD8 T cells, despite sustained virus replication in the thymus, indicating an impairment in negative selection. Consequently, low amounts of high-affinity self-reactive T cells also escaped the thymus following HSCT during chronic infection. Thus, by altering the stringency and partially impairing negative selection, the host generates new virus-specific T cells to replenish the fight against the chronic infection, but also has the potentially dangerous effect of enabling the escape of self-reactive T cells.
Collapse
Affiliation(s)
- Heidi J Elsaesser
- Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2M9, Canada
| | - Mahmood Mohtashami
- Department of Immunology, University of Toronto, Toronto, ON M5S 1A8 Canada
- Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Ivan Osokine
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Laura M Snell
- Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2M9, Canada
| | - Cameron R Cunningham
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Giselle M Boukhaled
- Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2M9, Canada
| | - Dorian B McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20824
| | - Juan Carlos Zúñiga-Pflücker
- Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2M9, Canada
- Department of Immunology, University of Toronto, Toronto, ON M5S 1A8 Canada
- Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - David G Brooks
- Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2M9, Canada;
- Department of Immunology, University of Toronto, Toronto, ON M5S 1A8 Canada
| |
Collapse
|
6
|
Kallies A, Zehn D, Utzschneider DT. Precursor exhausted T cells: key to successful immunotherapy? Nat Rev Immunol 2019; 20:128-136. [PMID: 31591533 DOI: 10.1038/s41577-019-0223-7] [Citation(s) in RCA: 235] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2019] [Indexed: 12/14/2022]
Abstract
Cytotoxic T cell immunity in response to chronic infections and tumours is maintained by a specialized population of CD8+ T cells that exhibit hallmarks of both exhausted and memory cells and give rise to terminally differentiated exhausted effector cells that contribute to viral or tumour control. Importantly, recent work suggests these cells, which we refer to as 'precursor exhausted' T (TPEX) cells, are responsible for the proliferative burst that generates effector T cells in response to immune checkpoint blockade targeting programmed cell death 1 (PD1), and increased TPEX cell frequencies have recently been linked to increased patient survival. We believe the recent discovery of TPEX cells not only represents a paradigm shift in our understanding of the mechanisms that maintain CD8+ T cell responses in chronic infections and tumours but also opens up unexpected avenues for the development of new and innovative therapeutic approaches. In this Opinion article, we discuss the differentiation and function of TPEX cells and suggest that targeting these cells may be key for successful immunotherapy.
Collapse
Affiliation(s)
- Axel Kallies
- Department of Microbiology & Immunology Melbourne, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia.
| | - Dietmar Zehn
- Division of Animal Physiology and Immunology, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Daniel T Utzschneider
- Department of Microbiology & Immunology Melbourne, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia.
| |
Collapse
|
7
|
Zlamy M, Almanzar G, Parson W, Schmidt C, Leierer J, Weinberger B, Jeller V, Unsinn K, Eyrich M, Würzner R, Prelog M. Efforts of the human immune system to maintain the peripheral CD8+ T cell compartment after childhood thymectomy. IMMUNITY & AGEING 2016; 13:3. [PMID: 26839574 PMCID: PMC4736487 DOI: 10.1186/s12979-016-0058-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/15/2016] [Indexed: 12/19/2022]
Abstract
Background Homeostatic mechanisms to maintain the T cell compartment diversity indicate an ongoing process of thymic activity and peripheral T cell renewal during human life. These processes are expected to be accelerated after childhood thymectomy and by the influence of cytomegalovirus (CMV) inducing a prematurely aged immune system. The study aimed to investigate proportional changes and replicative history of CD8+ T cells, of recent thymic emigrants (RTEs) and CD103+ T cells (mostly gut-experienced) and the role of Interleukin-(IL)-7 and IL-7 receptor (CD127)-expressing T cells in thymectomized patients compared to young and old healthy controls. Results Decreased proportions of naive and CD31 + CD8+ T cells were demonstrated after thymectomy, with higher proliferative activity of CD127-expressing T cells and significantly shorter relative telomere lengths (RTLs) and lower T cell receptor excision circles (TRECs). Increased circulating CD103+ T cells and a skewed T cell receptor (TCR) repertoire were found after thymectomy similar to elderly persons. Naive T cells were influenced by age at thymectomy and further decreased by CMV. Conclusions After childhood thymectomy, the immune system demonstrated constant efforts of the peripheral CD8+ T cell compartment to maintain homeostasis. Supposedly it tries to fill the void of RTEs by peripheral T cell proliferation, by at least partly IL-7-mediated mechanisms and by proportional increase of circulating CD103+ T cells, reminiscent of immune aging in elderly. Although other findings were less significant compared to healthy elderly, early thymectomy demonstrated immunological alterations of CD8+ T cells which mimic features of premature immunosenescence in humans.
Collapse
Affiliation(s)
- Manuela Zlamy
- Department of Pediatrics, Medical University Innsbruck, Innsbruck, Austria
| | - Giovanni Almanzar
- Department of Pediatrics, University Hospital Wuerzburg, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| | - Walther Parson
- Institute of Legal Medicine, Medical University Innsbruck, Innsbruck, Austria ; Penn State Eberly College of Science, University Park, PA USA
| | - Christian Schmidt
- Department of Haematology and Oncology, University of Greifswald, Greifswald, Germany
| | - Johannes Leierer
- Department of Internal Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Birgit Weinberger
- Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
| | - Verena Jeller
- Department of Pediatrics, Medical University Innsbruck, Innsbruck, Austria
| | - Karin Unsinn
- Department of Radiology, Medical University Innsbruck, Innsbruck, Austria
| | - Matthias Eyrich
- Department of Pediatrics, University Hospital Wuerzburg, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| | - Reinhard Würzner
- Department of Hygiene and Medical Microbiology, Medical University Innsbruck, Innsbruck, Austria
| | - Martina Prelog
- Department of Pediatrics, University Hospital Wuerzburg, University of Wuerzburg, Josef-Schneider-Str. 2, 97080 Wuerzburg, Germany
| |
Collapse
|
8
|
Abstract
In chronic infections and cancer, T cells are exposed to persistent antigen and/or inflammatory signals. This scenario is often associated with the deterioration of T cell function: a state called 'exhaustion'. Exhausted T cells lose robust effector functions, express multiple inhibitory receptors and are defined by an altered transcriptional programme. T cell exhaustion is often associated with inefficient control of persisting infections and tumours, but revitalization of exhausted T cells can reinvigorate immunity. Here, we review recent advances that provide a clearer molecular understanding of T cell exhaustion and reveal new therapeutic targets for persisting infections and cancer.
Collapse
Affiliation(s)
- E John Wherry
- Department of Microbiology and Institute for Immunology, University of Pennsylvania Perelman School Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Makoto Kurachi
- Department of Microbiology and Institute for Immunology, University of Pennsylvania Perelman School Medicine, Philadelphia, Pennsylvania 19104, USA
| |
Collapse
|
9
|
Molecular and cellular insights into T cell exhaustion. NATURE REVIEWS. IMMUNOLOGY 2015. [PMID: 26205583 DOI: 10.1038/nri3862.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In chronic infections and cancer, T cells are exposed to persistent antigen and/or inflammatory signals. This scenario is often associated with the deterioration of T cell function: a state called 'exhaustion'. Exhausted T cells lose robust effector functions, express multiple inhibitory receptors and are defined by an altered transcriptional programme. T cell exhaustion is often associated with inefficient control of persisting infections and tumours, but revitalization of exhausted T cells can reinvigorate immunity. Here, we review recent advances that provide a clearer molecular understanding of T cell exhaustion and reveal new therapeutic targets for persisting infections and cancer.
Collapse
|
10
|
Zehn D, Wherry EJ. Immune Memory and Exhaustion: Clinically Relevant Lessons from the LCMV Model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 850:137-52. [PMID: 26324351 DOI: 10.1007/978-3-319-15774-0_10] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The development of dysfunctional or exhausted T cells is characteristic of immune responses to chronic viral infections and cancer. Exhausted T cells are defined by reduced effector function, sustained upregulation of multiple inhibitory receptors, an altered transcriptional program and perturbations of normal memory development and homeostasis. This review focuses on (a) illustrating milestone discoveries that led to our present understanding of T cell exhaustion, (b) summarizing recent developments in the field, and (c) identifying new challenges for translational research. Exhausted T cells are now recognized as key therapeutic targets in human infections and cancer. Much of our knowledge of the clinically relevant process of exhaustion derives from studies in the mouse model of Lymphocytic choriomeningitis virus (LCMV) infection. Studies using this model have formed the foundation for our understanding of human T cell memory and exhaustion. We will use this example to discuss recent advances in our understanding of T cell exhaustion and illustrate the value of integrated mouse and human studies and will emphasize the benefits of bi-directional mouse-to-human and human-to-mouse research approaches.
Collapse
Affiliation(s)
- D Zehn
- Division of Immunology and Allergy, Lausanne University Hospital, Lausanne, Switzerland,
| | | |
Collapse
|
11
|
Takamura S, Kajiwara E, Tsuji-Kawahara S, Masumoto T, Fujisawa M, Kato M, Chikaishi T, Kawasaki Y, Kinoshita S, Itoi M, Sakaguchi N, Miyazawa M. Infection of adult thymus with murine retrovirus induces virus-specific central tolerance that prevents functional memory CD8+ T cell differentiation. PLoS Pathog 2014; 10:e1003937. [PMID: 24651250 PMCID: PMC3961338 DOI: 10.1371/journal.ppat.1003937] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 01/07/2014] [Indexed: 12/12/2022] Open
Abstract
In chronic viral infections, persistent antigen presentation causes progressive exhaustion of virus-specific CD8+ T cells. It has become clear, however, that virus-specific naïve CD8+ T cells newly generated from the thymus can be primed with persisting antigens. In the setting of low antigen density and resolved inflammation, newly primed CD8+ T cells are preferentially recruited into the functional memory pool. Thus, continual recruitment of naïve CD8+ T cells from the thymus is important for preserving the population of functional memory CD8+ T cells in chronically infected animals. Friend virus (FV) is the pathogenic murine retrovirus that establishes chronic infection in adult mice, which is bolstered by the profound exhaustion of virus-specific CD8+ T cells induced during the early phase of infection. Here we show an additional evasion strategy in which FV disseminates efficiently into the thymus, ultimately leading to clonal deletion of thymocytes that are reactive to FV antigens. Owing to the resultant lack of virus-specific recent thymic emigrants, along with the above exhaustion of antigen-experienced peripheral CD8+ T cells, mice chronically infected with FV fail to establish a functional virus-specific CD8+ T cell pool, and are highly susceptible to challenge with tumor cells expressing FV-encoded antigen. However, FV-specific naïve CD8+ T cells generated in uninfected mice can be primed and differentiate into functional memory CD8+ T cells upon their transfer into chronically infected animals. These findings indicate that virus-induced central tolerance that develops during the chronic phase of infection accelerates the accumulation of dysfunctional memory CD8+ T cells.
Collapse
Affiliation(s)
- Shiki Takamura
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
- * E-mail: (ST); (MM)
| | - Eiji Kajiwara
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | | | - Tomoko Masumoto
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | - Makoto Fujisawa
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | - Maiko Kato
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | - Tomomi Chikaishi
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | - Yuri Kawasaki
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | - Saori Kinoshita
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
| | - Manami Itoi
- Department of Immunology and Microbiology, Meiji University of Integrative Medicine, Kyoto, Japan
| | - Nobuo Sakaguchi
- Department of Immunology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Masaaki Miyazawa
- Department of Immunology, Kinki University Faculty of Medicine, Osaka, Japan
- * E-mail: (ST); (MM)
| |
Collapse
|
12
|
Tolerance has its limits: how the thymus copes with infection. Trends Immunol 2013; 34:502-10. [PMID: 23871487 DOI: 10.1016/j.it.2013.06.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/25/2013] [Accepted: 06/17/2013] [Indexed: 01/11/2023]
Abstract
The thymus is required for T cell differentiation; a process that depends on which antigens are encountered by thymocytes, the environment surrounding the differentiating cells, and the thymic architecture. These features are altered by local infection of the thymus and by the inflammatory mediators that accompany systemic infection. Although once believed to be an immune privileged site, it is now known that antimicrobial responses are recruited to the thymus. Resolving infection in the thymus is important because chronic persistence of microbes impairs the differentiation of pathogen-specific T cells and diminishes resistance to infection. Understanding how these mechanisms contribute to disease susceptibility, particularly in infants with developing T cell repertoires, requires further investigation.
Collapse
|
13
|
De Boer RJ, Perelson AS. Quantifying T lymphocyte turnover. J Theor Biol 2013; 327:45-87. [PMID: 23313150 PMCID: PMC3640348 DOI: 10.1016/j.jtbi.2012.12.025] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 12/13/2012] [Accepted: 12/30/2012] [Indexed: 01/13/2023]
Abstract
Peripheral T cell populations are maintained by production of naive T cells in the thymus, clonal expansion of activated cells, cellular self-renewal (or homeostatic proliferation), and density dependent cell life spans. A variety of experimental techniques have been employed to quantify the relative contributions of these processes. In modern studies lymphocytes are typically labeled with 5-bromo-2'-deoxyuridine (BrdU), deuterium, or the fluorescent dye carboxy-fluorescein diacetate succinimidyl ester (CFSE), their division history has been studied by monitoring telomere shortening and the dilution of T cell receptor excision circles (TRECs) or the dye CFSE, and clonal expansion has been documented by recording changes in the population densities of antigen specific cells. Proper interpretation of such data in terms of the underlying rates of T cell production, division, and death has proven to be notoriously difficult and involves mathematical modeling. We review the various models that have been developed for each of these techniques, discuss which models seem most appropriate for what type of data, reveal open problems that require better models, and pinpoint how the assumptions underlying a mathematical model may influence the interpretation of data. Elaborating various successful cases where modeling has delivered new insights in T cell population dynamics, this review provides quantitative estimates of several processes involved in the maintenance of naive and memory, CD4(+) and CD8(+) T cell pools in mice and men.
Collapse
Affiliation(s)
- Rob J De Boer
- Theoretical Biology & Bioinformatics, Utrecht University, The Netherlands; Santa Fe Institute, Santa Fe, NM 87501, USA.
| | | |
Collapse
|
14
|
T cells maintain an exhausted phenotype after antigen withdrawal and population reexpansion. Nat Immunol 2013; 14:603-10. [PMID: 23644506 DOI: 10.1038/ni.2606] [Citation(s) in RCA: 216] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 04/04/2013] [Indexed: 01/10/2023]
Abstract
During chronic infection, pathogen-specific CD8(+) T cells upregulate expression of molecules such as the inhibitory surface receptor PD-1, have diminished cytokine production and are thought to undergo terminal differentiation into exhausted cells. Here we found that T cells with memory-like properties were generated during chronic infection. After transfer into naive mice, these cells robustly proliferated and controlled a viral infection. The reexpanded T cell populations continued to have the exhausted phenotype they acquired during the chronic infection. Thus, the cells underwent a form of differentiation that was stably transmitted to daughter cells. We therefore propose that during persistent infection, effector T cells stably differentiate into a state that is optimized to limit viral replication without causing overwhelming immunological pathology.
Collapse
|
15
|
Affiliation(s)
- Pamela J. Fink
- Department of Immunology, University of Washington, Seattle, Washington 98195;
| |
Collapse
|
16
|
Freeman ML, Burkum CE, Jensen MK, Woodland DL, Blackman MA. γ-Herpesvirus reactivation differentially stimulates epitope-specific CD8 T cell responses. THE JOURNAL OF IMMUNOLOGY 2012; 188:3812-9. [PMID: 22407914 DOI: 10.4049/jimmunol.1102787] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The γ-herpesviruses are characterized by their ability to establish lifelong latency. Subsequent immune suppression leads to viral reactivation from latency and the onset of a variety of pathologies, including lymphoproliferative disease and cancers. CD8 T cells play a key role in preventing reactivation of latent virus. Therefore, to develop effective therapeutic immune strategies, it is essential to understand the maintenance of CD8 T cell responses during latency. Because the γ-herpesviruses are highly species-specific and mice cannot be infected with the human pathogens, EBV or Kaposi's sarcoma-associated herpesvirus, we have used a natural rodent γ-herpesvirus experimental infection model, γ-herpesvirus-68. In this report, we show that during long-term latent infection, naive CD8 T cells are recruited into the ongoing immune response in an epitope-specific manner. When virus reactivation is induced in vivo, the recruitment of CD8 T cells for some, but not all, epitopes is enhanced. The variation in recruitment is not due to differences in epitope presentation. We also show that CD8 T cells that are newly stimulated during reactivation are functionally impaired compared with acutely stimulated cells in terms of cytokine production. Thus, our results demonstrate unexpected complexity in the response of CD8 T cells specific for different viral epitopes that were stimulated during acute infection, quiescent latency, and reactivation.
Collapse
|
17
|
Fink PJ, Hendricks DW. Post-thymic maturation: young T cells assert their individuality. Nat Rev Immunol 2011; 11:544-9. [PMID: 21779032 DOI: 10.1038/nri3028] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
T cell maturation was once thought to occur entirely within the thymus. Now, evidence is mounting that the youngest peripheral T cells in both mice and humans comprise a distinct population from their more mature, yet still naive, counterparts. These cells, termed recent thymic emigrants (RTEs), undergo a process of post-thymic maturation that can be monitored at the levels of cell phenotype and immune function. Understanding this final maturation step in the process of generating useful and safe T cells is of clinical relevance, given that RTEs are over-represented in neonates and in adults recovering from lymphopenia. Post-thymic maturation may function to ensure T cell fitness and self tolerance.
Collapse
Affiliation(s)
- Pamela J Fink
- Department of Immunology, University of Washington, Seattle, Washington, USA.
| | | |
Collapse
|
18
|
Walton SM, Torti N, Mandaric S, Oxenius A. T-cell help permits memory CD8(+) T-cell inflation during cytomegalovirus latency. Eur J Immunol 2011; 41:2248-59. [PMID: 21590767 DOI: 10.1002/eji.201141575] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 04/12/2011] [Accepted: 05/09/2011] [Indexed: 01/10/2023]
Abstract
CD4(+) T cells are implied to sustain CD8(+) T-cell responses during persistent infections. As CD4(+) T cells are often themselves antiviral effectors, they might shape CD8(+) T-cell responses via help or via controlling antigen load. We used persistent murine CMV (MCMV) infection to dissect the impact of CD4(+) T cells on virus-specific CD8(+) T cells, distinguishing between increased viral load in the absence of CD4(+) T cells and CD4(+) T-cell-mediated helper mechanisms. Absence of T-helper cells was associated with sustained lytic MCMV replication and led to a slow and gradual reduction of the size and function of the MCMV-specific CD8(+) T-cell pool. However, when virus replication was controlled in the absence of CD4(+) T cells, CD8(+) T-cell function was comparably impaired, but in addition CD8(+) T-cell inflation, a hallmark of CMV infection, was completely abolished. Thus, CD8(+) T-cell inflation during latent CMV infection is strongly dependent on CD4(+) T-cell helper functions, which can partially be compensated by ongoing lytic viral replication in the absence of CD4(+) T cells.
Collapse
Affiliation(s)
- Senta M Walton
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | | | | | | |
Collapse
|
19
|
Loewendorf AI, Arens R, Purton JF, Surh CD, Benedict CA. Dissecting the requirements for maintenance of the CMV-specific memory T-cell pool. Viral Immunol 2011; 24:351-5. [PMID: 21721929 DOI: 10.1089/vim.2010.0140] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cytomegalovirus (CMV) infection promotes a broad T-cell response, with the resulting memory cells displaying diverse phenotypes. CMV establishes lifelong persistence/latency, and it is thought that viral antigens expressed during this period may regulate the expansion and/or maintenance of "inflationary" CD8 T-memory populations that display an effector memory phenotype. We show here that mouse CMV (MCMV)-specific inflationary memory T cells do not decrease in number after thymectomy, indicating that recent thymic emigrants are not strictly required for their maintenance. Furthermore, persistent MCMV replication in the salivary gland does not significantly impact the T-cell memory compartment, as surgical removal did not alter its composition. These results shed light upon the mechanisms required for maintenance of the large, MCMV-specific T-cell memory pool.
Collapse
Affiliation(s)
- Andrea I Loewendorf
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA
| | | | | | | | | |
Collapse
|
20
|
Abstract
T cell exhaustion is a state of T cell dysfunction that arises during many chronic infections and cancer. It is defined by poor effector function, sustained expression of inhibitory receptors and a transcriptional state distinct from that of functional effector or memory T cells. Exhaustion prevents optimal control of infection and tumors. Recently, a clearer picture of the functional and phenotypic profile of exhausted T cells has emerged and T cell exhaustion has been defined in many experimental and clinical settings. Although the pathways involved remain to be fully defined, advances in the molecular delineation of T cell exhaustion are clarifying the underlying causes of this state of differentiation and also suggest promising therapeutic opportunities.
Collapse
Affiliation(s)
- E John Wherry
- Department of Microbiology, Institute for Immunology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
21
|
Bannard O, Kraman M, Fearon DT. Cutting edge: Virus-specific CD8+ T cell clones and the maintenance of replicative function during a persistent viral infection. THE JOURNAL OF IMMUNOLOGY 2010; 185:7141-5. [PMID: 21068412 DOI: 10.4049/jimmunol.1002537] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Persistent viral infections induce the differentiation and accumulation of large numbers of senescent CD8(+) T cells, raising the possibility that repetitive stimulation drives clones of T cells to senesce. It is therefore unclear whether T cell responses are maintained by the self-renewal of Ag-experienced peripheral T cell subsets or by the continuous recruitment of newly generated naive T cells during chronic infections. Using a transgenic mouse model that permits the indelible marking of granzyme B-expressing cells, we found that T cells primed during the initial stages of a persistent murine γ-herpes infection persisted and continued to divide during a latent phase of up to 7 mo. Such cells maintained an ability to extensively replicate in response to challenge with influenza virus expressing the same Ag. Therefore, Ag-experienced, virus-specific CD8(+) T cell populations contain a subset that maintains replicative potential, despite long-term, persistent antigenic stimulation.
Collapse
Affiliation(s)
- Oliver Bannard
- Wellcome Trust Immunology Unit, University of Cambridge, Cambridge, United Kingdom
| | | | | |
Collapse
|
22
|
Ganusov VV, Lukacher AE, Byers AM. Persistence of viral infection despite similar killing efficacy of antiviral CD8(+) T cells during acute and chronic phases of infection. Virology 2010; 405:193-200. [PMID: 20580390 DOI: 10.1016/j.virol.2010.05.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 05/24/2010] [Accepted: 05/24/2010] [Indexed: 01/21/2023]
Abstract
Why some viruses establish chronic infections while others do not is poorly understood. One possibility is that the host's immune response is impaired during chronic infections and is unable to clear the virus from the host. In this report, we use a recently proposed framework to estimate the per capita killing efficacy of CD8(+) T cells, specific for the polyoma virus (PyV), which establishes a chronic infection in mice. Surprisingly, the estimated per cell killing efficacy of PyV-specific effector CD8(+) T cells during the acute phase of the infection was very similar to the efficacy of effector CD8(+) T cells specific to lymphocytic choriomeningitis virus (LCMV-Armstrong), which is cleared from the host. Our results suggest that persistence of PyV does not result from the generation of an inefficient PyV-specific CD8(+) T cell response, and that other host or viral factors are responsible for the ability of PyV to establish chronic infection.
Collapse
Affiliation(s)
- Vitaly V Ganusov
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
| | | | | |
Collapse
|
23
|
Nakayama Y, Plisch EH, Sullivan J, Thomas C, Czuprynski CJ, Williams BRG, Suresh M. Role of PKR and Type I IFNs in viral control during primary and secondary infection. PLoS Pathog 2010; 6:e1000966. [PMID: 20585572 PMCID: PMC2891951 DOI: 10.1371/journal.ppat.1000966] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 05/25/2010] [Indexed: 12/12/2022] Open
Abstract
Type I interferons (IFNs) are known to mediate viral control, and also promote survival and expansion of virus-specific CD8+ T cells. However, it is unclear whether signaling cascades involved in eliciting these diverse cellular effects are also distinct. One of the best-characterized anti-viral signaling mechanisms of Type I IFNs is mediated by the IFN-inducible dsRNA activated protein kinase, PKR. Here, we have investigated the role of PKR and Type I IFNs in regulating viral clearance and CD8+ T cell response during primary and secondary viral infections. Our studies demonstrate differential requirement for PKR, in viral control versus elicitation of CD8+ T cell responses during primary infection of mice with lymphocytic choriomeningitis virus (LCMV). PKR-deficient mice mounted potent CD8+ T cell responses, but failed to effectively control LCMV. The compromised LCMV control in the absence of PKR was multifactorial, and linked to less effective CD8+ T cell-mediated viral suppression, enhanced viral replication in cells, and lower steady state expression levels of IFN-responsive genes. Moreover, we show that despite normal expansion of memory CD8+ T cells and differentiation into effectors during a secondary response, effective clearance of LCMV but not vaccinia virus required PKR activity in infected cells. In the absence of Type I IFN signaling, secondary effector CD8+ T cells were ineffective in controlling both LCMV and vaccinia virus replication in vivo. These findings provide insight into cellular pathways of Type I IFN actions, and highlight the under-appreciated importance of innate immune mechanisms of viral control during secondary infections, despite the accelerated responses of memory CD8+ T cells. Additionally, the results presented here have furthered our understanding of the immune correlates of anti-viral protective immunity, which have implications in the rational design of vaccines.
Collapse
Affiliation(s)
- Yumi Nakayama
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Erin H. Plisch
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jeremy Sullivan
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chester Thomas
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Charles J. Czuprynski
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Bryan R. G. Williams
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - M. Suresh
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| |
Collapse
|
24
|
Liou LY, Walsh KB, Vartanian AR, Beltran-Valero de Bernabe D, Welch M, Campbell KP, Oldstone MBA, Kunz S. Functional glycosylation of dystroglycan is crucial for thymocyte development in the mouse. PLoS One 2010; 5:e9915. [PMID: 20369005 PMCID: PMC2848029 DOI: 10.1371/journal.pone.0009915] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 03/02/2010] [Indexed: 12/03/2022] Open
Abstract
Background Alpha-dystroglycan (α-DG) is a cell surface receptor providing a molecular link between the extracellular matrix (ECM) and the actin-based cytoskeleton. During its biosynthesis, α-DG undergoes specific and unusual O-glycosylation crucial for its function as a high-affinity cellular receptor for ECM proteins. Methodology/Principal Findings We report that expression of functionally glycosylated α-DG during thymic development is tightly regulated in developing T cells and largely confined to CD4−CD8− double negative (DN) thymocytes. Ablation of DG in T cells had no effect on proliferation, migration or effector function but did reduce the size of the thymus due to a significant loss in absolute numbers of thymocytes. While numbers of DN thymocytes appeared normal, a marked reduction in CD4+CD8+ double positive (DP) thymocytes occurred. In the periphery mature naïve T cells deficient in DG showed both normal proliferation in response to allogeneic cells and normal migration, effector and memory T cell function when tested in acute infection of mice with either lymphocytic choriomeningitis virus (LCMV) or influenza virus. Conclusions/Significance Our study demonstrates that DG function is modulated by glycosylation during T cell development in vivo and that DG is essential for normal development and differentiation of T cells.
Collapse
Affiliation(s)
- Li-Ying Liou
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Kevin B. Walsh
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Arineh R. Vartanian
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Daniel Beltran-Valero de Bernabe
- Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Departments of Neurology and Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Megan Welch
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Kevin P. Campbell
- Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Departments of Neurology and Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa, United States of America
| | - Michael B. A. Oldstone
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- Department of Infectology, Scripps Florida, Jupiter, Florida, United States of America
- * E-mail: (MBAO); (SK)
| | - Stefan Kunz
- Viral-Immunobiology Laboratory, Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
- * E-mail: (MBAO); (SK)
| |
Collapse
|
25
|
Sauce D, Larsen M, Fastenackels S, Duperrier A, Keller M, Grubeck-Loebenstein B, Ferrand C, Debré P, Sidi D, Appay V. Evidence of premature immune aging in patients thymectomized during early childhood. J Clin Invest 2009; 119:3070-8. [PMID: 19770514 DOI: 10.1172/jci39269] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Accepted: 07/16/2009] [Indexed: 12/31/2022] Open
Abstract
While the thymus is known to be essential for the initial production of T cells during early life, its contribution to immune development remains a matter of debate. In fact, during cardiac surgery in newborns, the thymus is completely resected to enable better access to the heart to correct congenital heart defects, suggesting that it may be dispensable during childhood and adulthood. Here, we show that young adults thymectomized during early childhood exhibit an altered T cell compartment. Specifically, absolute CD4+ and CD8+ T cell counts were decreased, and these T cell populations showed substantial loss of naive cells and accumulation of oligoclonal memory cells. A subgroup of these young patients (22 years old) exhibited a particularly altered T cell profile that is usually seen in elderly individuals (more than 75 years old). This condition was directly related to CMV infection and the induction of strong CMV-specific T cell responses, which may exhaust the naive T cell pool in the absence of adequate T cell renewal from the thymus. Together, these marked immunological alterations are reminiscent of the immune risk phenotype, which is defined by a cluster of immune markers predictive of increased mortality in the elderly. Overall, our data highlight the importance of the thymus in maintaining the integrity of T cell immunity during adult life.
Collapse
Affiliation(s)
- Delphine Sauce
- Infections and Immunity, INSERM UMRS 945, Avenir Group, Hôpital Pitié-Salpêtrière, UPMC University of Paris 06, Paris, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
High antigen levels are the cause of T cell exhaustion during chronic viral infection. Proc Natl Acad Sci U S A 2009; 106:8623-8. [PMID: 19433785 DOI: 10.1073/pnas.0809818106] [Citation(s) in RCA: 296] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Many persistent viral infections induce dysfunctional T cell responses. Although a negative correlation exists between viral load and T cell responses during chronic infection, it is not known whether high antigen levels are the cause or just the consequence of T cell exhaustion. Furthermore, it is unclear what role antigen presentation by bone-marrow (BM) derived versus infected parenchymal cells has on T cell exhaustion. To address these issues, we examined the influence of antigen presentation by different cell types on CD8(+) T cell responses during persistent infection of mice with lymphocytic choriomeningitis virus (LCMV) clone 13. We generated BM chimeric mice, in which non-BM derived cells were MHC class I deficient. Virus-specific CD8(+) T cells in lymphoid and nonlymphoid tissues were increased in both number and ability to produce cytokines in these mice soon after infection. However, viral clearance from infected MHC I(-/-) parenchyma was significantly impaired, despite increased populations of cytokine producing CTL. The CD8(+) T cell response was overwhelmed by sustained antigen persistence, becoming increasingly exhausted within 4-6 weeks. Thus, we find that (i) sustained antigen presentation directly drives T cell exhaustion during a chronic viral infection, (ii) CTL require direct antigen-MHC interactions to clear virus-infected cells, and (iii) persistent interactions with antigen presented on both hematopoietic and nonhematopoietic cells negatively impacts virus-specific T cell responses during chronic infection.
Collapse
|
27
|
WIESEL MELANIE, WALTON SENTA, RICHTER KIRSTEN, OXENIUS ANNETTE. Virus-specific CD8 T cells: activation, differentiation and memory formation. APMIS 2009; 117:356-81. [DOI: 10.1111/j.1600-0463.2009.02459.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
28
|
Tang C, Yamada H, Shibata K, Yoshida SI, Wajjwalku W, Yoshikai Y. IL-15 protects antigen-specific CD8+ T cell contraction after Mycobacterium bovis bacillus Calmette-Guérin infection. J Leukoc Biol 2009; 86:187-94. [PMID: 19389797 DOI: 10.1189/jlb.0608363] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We reported previously that IL-15 plays a critical role in protecting effector CD8(+) T cells from apoptosis during the contraction phase following acute infection with Listeria monocytogenes by inducing antiapoptotic molecules. In the present study, we examined the effects of in vivo administration of rIL-15 on contraction of CD8(+) T cells after chronic infection with Mycobacterium bovis BCG and on the efficacy of BCG vaccination against Mycobacterium tuberculosis infection. Antigen-specific CD8(+) T cells reached an expansion peak at approximately Day 21, followed by a contraction after inoculation with rBCG expressing OVA. In vivo administration of rIL-15 from Days 22 to 42 after BCG inoculation inhibited apoptosis of effector CD8(+) T cells by up-regulating their Bcl-2 expression, resulting in a significant increase of antigen-specific memory CD8(+) T cells producing IFN-gamma. However, the IL-15 treatment did not elicit improved efficacy of BCG vaccination against M. tuberculosis. These results suggest that IL-15 plays a critical role in protecting activated CD8(+) T cells from apoptosis during the contraction phase following BCG inoculation, although IL-15 administration alone at the contraction phase might not be sufficient to protect the efficient memory T cell responses against subsequent infection with M. tuberculosis.
Collapse
Affiliation(s)
- Ce Tang
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Higashi-ku, Fukuoka, Japan
| | | | | | | | | | | |
Collapse
|
29
|
Althaus CL, Ganusov VV, De Boer RJ. Dynamics of CD8+ T cell responses during acute and chronic lymphocytic choriomeningitis virus infection. THE JOURNAL OF IMMUNOLOGY 2007; 179:2944-51. [PMID: 17709509 DOI: 10.4049/jimmunol.179.5.2944] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Infection of mice with lymphocytic choriomeningitis virus (LCMV) is frequently used to study the underlying principles of viral infections and immune responses. We fit a mathematical model to recently published data characterizing Ag-specific CD8+ T cell responses during acute (Armstrong) and chronic (clone 13) LCMV infection. This allows us to analyze the differences in the dynamics of CD8+ T cell responses against different types of LCMV infections. For the four CD8+ T cell responses studied, we find that, compared with the responses against acute infection, responses against chronic infection are generally characterized by an earlier peak and a faster contraction phase thereafter. Furthermore, the model allows us to give a new interpretation of the effect of thymectomy on the dynamics of CD8+ T cell responses during chronic LCMV infection: a smaller number of naive precursor cells is sufficient to account for the observed differences in the responses in thymectomized mice. Finally, we compare data characterizing LCMV-specific CD8+ T cell responses from different laboratories. Although the data were derived from the same experimental model, we find quantitative differences that can be solved by introducing a scaling factor. Also, we find kinetic differences that are at least partly due to the infrequent measurements of CD8+ T cells in the different laboratories.
Collapse
|
30
|
Shin H, Wherry EJ. CD8 T cell dysfunction during chronic viral infection. Curr Opin Immunol 2007; 19:408-15. [PMID: 17656078 DOI: 10.1016/j.coi.2007.06.004] [Citation(s) in RCA: 268] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 06/08/2007] [Indexed: 12/11/2022]
Abstract
Clearance of primary infection often leads to the development of highly functional memory T cells capable of rapid and long-lasting protective immunity. By contrast, chronic infections can result in T cell dysfunction and poor pathogen control. In this review, we will discuss recent work that highlights two main types of T cell dysfunction during chronic infection: exhaustion of effector functions and altered memory T cell development.
Collapse
Affiliation(s)
- Haina Shin
- Immunology Program, The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | | |
Collapse
|
31
|
Whitmire JK, Eam B, Benning N, Whitton JL. Direct interferon-gamma signaling dramatically enhances CD4+ and CD8+ T cell memory. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2007; 179:1190-7. [PMID: 17617612 DOI: 10.4049/jimmunol.179.2.1190] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Studies in IFN-gamma-deficient mice suggest that the delivery of IFN-gamma to CD8(+) T cells early in virus infection programs their eventual contraction, thereby reducing the abundance of CD8(+) memory T cells. In this study, we show that such mice fail to completely eliminate virus infection and that, when evaluated without the confounding factor of persisting Ag, both CD4(+) and CD8(+) T cells undergo profound contraction when they are unable to receive IFN-gamma signals. Furthermore, the abundance of CD4(+) and CD8(+) memory cells that express the IFN-gamma receptor is approximately 100-fold higher than cells lacking this molecule. Thus, direct IFN-gamma signaling is not required for T cell contraction during virus infection, and it enhances, rather than suppresses, the development of virus-specific CD4(+) and CD8(+) T cell memory.
Collapse
|
32
|
Shin H, Blackburn SD, Blattman JN, Wherry EJ. Viral antigen and extensive division maintain virus-specific CD8 T cells during chronic infection. ACTA ACUST UNITED AC 2007; 204:941-9. [PMID: 17420267 PMCID: PMC2118542 DOI: 10.1084/jem.20061937] [Citation(s) in RCA: 213] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Efficient maintenance of memory CD8 T cells is central to long-term protective immunity. IL-7– and IL-15–driven homeostatic proliferation is essential for long-term memory CD8 T cell persistence after acute infections. During chronic infections, however, virus-specific CD8 T cells respond poorly to these cytokines. Yet, virus-specific CD8 T cells often persist for long periods of time during chronic infections. We have addressed this apparent paradox by examining the mechanism for maintaining virus-specific CD8 T cells during chronic infection. We find that homeostatic cytokines (e.g., IL-7/15), inflammatory signals, and priming of recent thymic emigrants are not sufficient to maintain virus-specific CD8 T cells over time during chronic infection. Rather, our results demonstrate that viral peptide is required for virus-specific CD8 T cell persistence during chronic infection. Moreover, this viral antigen-dependent maintenance results in a dramatically different type of T cell division than is normally observed during memory T cell homeostasis. Rather than undergoing slow, steady homeostatic turnover during chronic viral infection, CD8 T cells undergo extensive peptide-dependent division, yet cell numbers remain relatively stable. These results indicate that antigen-specific CD8 T cell responses during persisting infection are maintained by a mechanism distinct from that after acute infection.
Collapse
Affiliation(s)
- Haina Shin
- Immunology Program, The Wistar Institute, Philadelphia, PA 19104, USA
| | | | | | | |
Collapse
|
33
|
Vezys V, Masopust D, Kemball CC, Barber DL, O'Mara LA, Larsen CP, Pearson TC, Ahmed R, Lukacher AE. Continuous recruitment of naive T cells contributes to heterogeneity of antiviral CD8 T cells during persistent infection. ACTA ACUST UNITED AC 2006; 203:2263-9. [PMID: 16966427 PMCID: PMC2118117 DOI: 10.1084/jem.20060995] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Numerous microbes establish persistent infections, accompanied by antigen-specific CD8 T cell activation. Pathogen-specific T cells in chronically infected hosts are often phenotypically and functionally variable, as well as distinct from T cells responding to nonpersistent infections; this phenotypic heterogeneity has been attributed to an ongoing reencounter with antigen. Paradoxically, maintenance of memory CD8 T cells to acutely resolved infections is antigen independent, whereas there is a dependence on antigen for T cell survival in chronically infected hosts. Using two chronic viral infections, we demonstrate that new naive antigen-specific CD8 T cells are primed after the acute phase of infection. These newly recruited T cells are phenotypically distinct from those primed earlier. Long-lived antiviral CD8 T cells are defective in self-renewal, and lack of thymic output results in the decline of virus-specific CD8 T cells, indicating that newly generated T cells preserve antiviral CD8 T cell populations during chronic infection. These findings reveal a novel role for antigen in maintaining virus-specific CD8 T cells during persistent infection and provide insight toward understanding T cell differentiation in chronic infection.
Collapse
Affiliation(s)
- Vaiva Vezys
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | | | | | | | | | | | |
Collapse
|