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Abstract
Historically, the immune system was believed to develop along a linear axis of maturity from fetal life to adulthood. Now, it is clear that distinct layers of immune cells are generated from unique waves of hematopoietic progenitors during different windows of development. This model, known as the layered immune model, has provided a useful framework for understanding why distinct lineages of B cells and γδ T cells arise in succession and display unique functions in adulthood. However, the layered immune model has not been applied to CD8+ T cells, which are still often viewed as a uniform population of cells belonging to the same lineage, with functional differences between cells arising from environmental factors encountered during infection. Recent studies have challenged this idea, demonstrating that not all CD8+ T cells are created equally and that the functions of individual CD8+ T cells in adults are linked to when they were created in the host. In this review, we discuss the accumulating evidence suggesting there are distinct ontogenetic subpopulations of CD8+ T cells and propose that the layered immune model be extended to the CD8+ T cell compartment.
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Affiliation(s)
- Cybelle Tabilas
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
- Co-first author
| | - Norah L. Smith
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
- Co-first author
| | - Brian D. Rudd
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
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2
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Pieren DKJ, Boer MC, de Wit J. The adaptive immune system in early life: The shift makes it count. Front Immunol 2022; 13:1031924. [PMID: 36466865 PMCID: PMC9712958 DOI: 10.3389/fimmu.2022.1031924] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/31/2022] [Indexed: 10/13/2023] Open
Abstract
Respiratory infectious diseases encountered early in life may result in life-threatening disease in neonates, which is primarily explained by the relatively naive neonatal immune system. Whereas vaccines are not readily available for all infectious diseases, vaccinations have greatly reduced childhood mortality. However, repeated vaccinations are required to reach protective immunity in infants and not all vaccinations are effective at young age. Moreover, protective adaptive immunity elicited by vaccination wanes more rapidly at young age compared to adulthood. The infant adaptive immune system has previously been considered immature but this paradigm has changed during the past years. Recent evidence shows that the early life adaptive immune system is equipped with a strong innate-like effector function to eliminate acute pathogenic threats. These strong innate-like effector capacities are in turn kept in check by a tolerogenic counterpart of the adaptive system that may have evolved to maintain balance and to reduce collateral damage. In this review, we provide insight into these aspects of the early life's adaptive immune system by addressing recent literature. Moreover, we speculate that this shift from innate-like and tolerogenic adaptive immune features towards formation of immune memory may underlie different efficacy of infant vaccination in these different phases of immune development. Therefore, presence of innate-like and tolerogenic features of the adaptive immune system may be used as a biomarker to improve vaccination strategies against respiratory and other infections in early life.
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Affiliation(s)
| | | | - Jelle de Wit
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
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3
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Eder JM, Sacco RE. Ex vivo activated CD4+ T cells from young calves exhibit Th2-biased effector function with distinct metabolic reprogramming compared to adult cows. Vet Immunol Immunopathol 2022; 248:110418. [DOI: 10.1016/j.vetimm.2022.110418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/29/2022] [Accepted: 04/02/2022] [Indexed: 10/18/2022]
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4
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Ucciferri CC, Dunn SE. Effect of puberty on the immune system: Relevance to multiple sclerosis. Front Pediatr 2022; 10:1059083. [PMID: 36533239 PMCID: PMC9755749 DOI: 10.3389/fped.2022.1059083] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/03/2022] [Indexed: 12/03/2022] Open
Abstract
Puberty is a dynamic period marked by changing levels of sex hormones, the development of secondary sexual characteristics and reproductive maturity. This period has profound effects on various organ systems, including the immune system. The critical changes that occur in the immune system during pubertal onset have been shown to have implications for autoimmune conditions, including Multiple Sclerosis (MS). MS is rare prior to puberty but can manifest in children after puberty. This disease also has a clear female preponderance that only arises following pubertal onset, highlighting a potential role for sex hormones in autoimmunity. Early onset of puberty has also been shown to be a risk factor for MS. The purpose of this review is to overview the evidence that puberty regulates MS susceptibility and disease activity. Given that there is a paucity of studies that directly evaluate the effects of puberty on the immune system, we also discuss how the immune system is different in children and mice of pre- vs. post-pubertal ages and describe how gonadal hormones may regulate these immune mechanisms. We present evidence that puberty enhances the expression of co-stimulatory molecules and cytokine production by type 2 dendritic cells (DC2s) and plasmacytoid dendritic cells (pDCs), increases T helper 1 (Th1), Th17, and T follicular helper immunity, and promotes immunoglobulin (Ig)G antibody production. Overall, this review highlights how the immune system undergoes a functional maturation during puberty, which has the potential to explain the higher prevalence of MS and other autoimmune diseases seen in adolescence.
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Affiliation(s)
- Carmen C Ucciferri
- Department of Immunology, The University of Toronto, Toronto, ON, Canada
| | - Shannon E Dunn
- Department of Immunology, The University of Toronto, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, ON, Canada.,Women's College Research Institute, Women's College Hospital, Toronto, ON, Canada
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5
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Thapa P, Guyer RS, Yang AY, Parks CA, Brusko TM, Brusko M, Connors TJ, Farber DL. Infant T cells are developmentally adapted for robust lung immune responses through enhanced T cell receptor signaling. Sci Immunol 2021; 6:eabj0789. [PMID: 34890254 PMCID: PMC8765725 DOI: 10.1126/sciimmunol.abj0789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Infants require coordinated immune responses to prevent succumbing to multiple infectious challenges during early life, particularly in the respiratory tract. The mechanisms by which infant T cells are functionally adapted for these responses are not well understood. Here, we demonstrated using an in vivo mouse cotransfer model that infant T cells generated greater numbers of lung-homing effector cells in response to influenza infection compared with adult T cells in the same host, due to augmented T cell receptor (TCR)–mediated signaling. Mouse infant T cells showed increased sensitivity to low antigen doses, originating at the interface between T cells and antigen-bearing accessory cells—through actin-mediated mobilization of signaling molecules to the immune synapse. This enhanced signaling was also observed in human infant versus adult T cells. Our findings provide a mechanism for how infants control pathogen load and dissemination, which is important for designing developmentally targeted strategies for promoting immune responses at this vulnerable life stage.
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Affiliation(s)
- Puspa Thapa
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York NY 10032
| | - Rebecca S. Guyer
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York NY 10032
| | - Alexander Y. Yang
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York NY 10032
| | - Christopher A. Parks
- Columbia Center for Translational Immunology, Columbia University Irving Medical Center, New York, NY 10032
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032
| | - Todd M. Brusko
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32611
| | - Maigan Brusko
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32611
| | - Thomas J. Connors
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032
| | - Donna L. Farber
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York NY 10032
- Department of Surgery, Columbia University Irving Medical Center, New York, NY 10032
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6
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Holm SR, Jenkins BJ, Cronin JG, Jones N, Thornton CA. A role for metabolism in determining neonatal immune function. Pediatr Allergy Immunol 2021; 32:1616-1628. [PMID: 34170575 DOI: 10.1111/pai.13583] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 05/19/2021] [Accepted: 06/03/2021] [Indexed: 01/04/2023]
Abstract
Immune responses of neonates differ markedly to those of adults, with skewed cytokine phenotypes, reduced inflammatory properties and drastically diminished memory function. Recent research efforts have started to unravel the role of cellular metabolism in determining immune cell fate and function. For studies in humans, much of the work on metabolic mechanisms underpinning innate and adaptive immune responses by different haematopoietic cell types is in adults. Studies investigating the contribution of metabolic adaptation in the unique setting of early life are just emerging, and much more work is needed to elucidate the contribution of metabolism to neonatal immune responses. Here, we discuss our current understanding of neonatal immune responses, examine some of the latest developments in neonatal immunometabolism and consider the possible role of altered metabolism to the distinctive immune phenotype of the neonate. Understanding the role of metabolism in regulating immune function at this critical stage in life has direct benefit for the child by affording opportunities to maximize immediate and long-term health. Additionally, gaining insight into the diversity of human immune function and naturally evolved immunometabolic strategies that modulate immune function could be harnessed for a wide range of opportunities including new therapeutic approaches.
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Affiliation(s)
- Sean R Holm
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
| | - Ben J Jenkins
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
| | - James G Cronin
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
| | - Nicholas Jones
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
| | - Catherine A Thornton
- Institute of Life Science, Swansea University Medical School, Swansea University, Swansea, UK
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7
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Lee JG, Jaeger KE, Seki Y, Wei Lim Y, Cunha C, Vuchkovska A, Nelson AJ, Nikolai A, Kim D, Nishimura M, Knight KL, White P, Iwashima M. Human CD36 hi monocytes induce Foxp3 + CD25 + T cells with regulatory functions from CD4 and CD8 subsets. Immunology 2021; 163:293-309. [PMID: 33524161 DOI: 10.1111/imm.13316] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 12/31/2020] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
The fetal and neonatal immune systems are uniquely poised to generate tolerance to self, maternal and environmental antigens encountered in the womb and shortly after birth. However, the tolerogenic nature of fetal and neonatal immunity can be detrimental in the context of pathogens, leading to overwhelming bacterial infections or chronic viral infections. A variety of mechanisms contribute to fetal and neonatal tolerance, including a propensity to generate Foxp3+ regulatory T cells (Treg cells). However, the mechanism(s) of fetal Foxp3+ T-cell differentiation, the specific antigen-presenting cells required and factors that inhibit Treg generation after the neonatal period are poorly understood. Here, we demonstrate that a subset of CD14+ monocytes expressing the scavenger molecule, CD36, can generate CD4+ and CD8+ T cells that coexpress Foxp3 and T-bet from both umbilical cord blood. These Foxp3+ T-bet+ T cells potently suppress T-cell proliferation and ameliorate xenogeneic graft-versus-host disease. CD14+ CD36+ monocytes provide known Treg-inducing signals: membrane-bound transforming growth factor-beta and retinoic acid. Unexpectedly, adult peripheral blood monocytes are also capable of inducing Foxp3+ T cells from both cord blood and adult peripheral naïve T cells. The induction of Foxp3+ T cells in umbilical cord blood by monocytes was inhibited by the lymphoid fraction of adult peripheral blood cells. These studies highlight a novel immunoregulatory role of monocytes and suggest that antigen presentation by CD36hi monocytes may contribute to the peripheral development of Foxp3+ T-bet+ T cells with regulatory functions in both neonates and adults.
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Affiliation(s)
- Jessica G Lee
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Kathleen E Jaeger
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Yoichi Seki
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Yi Wei Lim
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Christina Cunha
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Aleksandra Vuchkovska
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Alexander J Nelson
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Anya Nikolai
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Dan Kim
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Michael Nishimura
- Department of Surgery, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Katherine L Knight
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Paula White
- Department of Obstetrics and Gynecology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Makio Iwashima
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.,Van Kampen Cardio-Pulmonary Research Laboratory, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
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8
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Eichinger KM, Kosanovich JL, Lipp M, Empey KM, Petrovsky N. Strategies for active and passive pediatric RSV immunization. Ther Adv Vaccines Immunother 2021; 9:2515135520981516. [PMID: 33623860 PMCID: PMC7879001 DOI: 10.1177/2515135520981516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 11/20/2020] [Indexed: 12/26/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in children worldwide, with the most severe disease occurring in very young infants. Despite half a century of research there still are no licensed RSV vaccines. Difficulties in RSV vaccine development stem from a number of factors, including: (a) a very short time frame between birth and first RSV exposure; (b) interfering effects of maternal antibodies; and (c) differentially regulated immune responses in infants causing a marked T helper 2 (Th2) immune bias. This review seeks to provide an age-specific understanding of RSV immunity critical to the development of a successful pediatric RSV vaccine. Historical and future approaches to the prevention of infant RSV are reviewed, including passive protection using monoclonal antibodies or maternal immunization strategies versus active infant immunization using pre-fusion forms of RSV F protein antigens formulated with novel adjuvants such as Advax that avoid excess Th2 immune polarization.
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Affiliation(s)
- Katherine M. Eichinger
- Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, and Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jessica L. Kosanovich
- Department of Pharmacy and Therapeutics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Madeline Lipp
- Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kerry M. Empey
- Department of Pharmacy and Therapeutics, Department of Pharmaceutical Sciences, School of Medicine and Clinical and Translational Science Institute, University of Pittsburgh School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nikolai Petrovsky
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia 5042, Australia and Vaxine Pty Ltd, Warradale, SA 5046, Australia
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9
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Davenport MP, Smith NL, Rudd BD. Building a T cell compartment: how immune cell development shapes function. Nat Rev Immunol 2020; 20:499-506. [PMID: 32493982 DOI: 10.1038/s41577-020-0332-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2020] [Indexed: 02/06/2023]
Abstract
We are just beginning to understand the diversity of the peripheral T cell compartment, which arises from the specialization of different T cell subsets and the plasticity of individual naive T cells to adopt different fates. Although the progeny of a single T cell can differentiate into many phenotypes following infection, individual T cells are biased towards particular phenotypes. These biases are typically ascribed to random factors that occur during and after antigenic stimulation. However, the T cell compartment does not remain static with age, and shifting immune challenges during ontogeny give rise to T cells with distinct functional properties. Here, we argue that the developmental history of naive T cells creates a 'hidden layer' of diversity that persists into adulthood. Insight into this diversity can provide a new perspective on immunity and immunotherapy across the lifespan.
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Affiliation(s)
- Miles P Davenport
- Kirby Institute for Infection and Immunity, University of New South Wales Australia, Sydney, New South Wales, Australia.
| | - Norah L Smith
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Brian D Rudd
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
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10
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Oherle K, Acker E, Bonfield M, Wang T, Gray J, Lang I, Bridges J, Lewkowich I, Xu Y, Ahlfeld S, Zacharias W, Alenghat T, Deshmukh H. Insulin-like Growth Factor 1 Supports a Pulmonary Niche that Promotes Type 3 Innate Lymphoid Cell Development in Newborn Lungs. Immunity 2020; 52:275-294.e9. [PMID: 32075728 PMCID: PMC7382307 DOI: 10.1016/j.immuni.2020.01.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 05/16/2019] [Accepted: 01/17/2020] [Indexed: 02/07/2023]
Abstract
Type 3 innate lymphoid cells (ILC3s) are critical for lung defense against bacterial pneumonia in the neonatal period, but the signals that guide pulmonary ILC3 development remain unclear. Here, we demonstrated that pulmonary ILC3s descended from ILC precursors that populated a niche defined by fibroblasts in the developing lung. Alveolar fibroblasts produced insulin-like growth factor 1 (IGF1), which instructed expansion and maturation of pulmonary ILC precursors. Conditional ablation of IGF1 in alveolar fibroblasts or deletion of the IGF-1 receptor from ILC precursors interrupted ILC3 biogenesis and rendered newborn mice susceptible to pneumonia. Premature infants with bronchopulmonary dysplasia, characterized by interrupted postnatal alveolar development and increased morbidity to respiratory infections, had reduced IGF1 concentrations and pulmonary ILC3 numbers. These findings indicate that the newborn period is a critical window in pulmonary immunity development, and disrupted lung development in prematurely born infants may have enduring effects on host resistance to respiratory infections.
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Affiliation(s)
- Katherine Oherle
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA
| | - Elizabeth Acker
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA
| | - Madeline Bonfield
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Immunology Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Timothy Wang
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Jerilyn Gray
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA
| | - Ian Lang
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA
| | - James Bridges
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Ian Lewkowich
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Yan Xu
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Shawn Ahlfeld
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - William Zacharias
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Theresa Alenghat
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Hitesh Deshmukh
- Division of Neonatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45219, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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11
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Fike AJ, Kumova OK, Carey AJ. Dissecting the defects in the neonatal CD8 + T-cell response. J Leukoc Biol 2019; 106:1051-1061. [PMID: 31260598 DOI: 10.1002/jlb.5ru0319-105r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/24/2019] [Accepted: 06/10/2019] [Indexed: 12/26/2022] Open
Abstract
The neonatal period presents a complex scenario where the threshold of reactivity toward colonizing microbiota, maternal antigens, autoantigens, and pathogens must be carefully moderated and balanced. CD8+ T cells are critical for the response against intracellular bacteria and viruses, but this immune compartment maintains altered function relative to adult counterparts because of the unique challenges which infants face. Here, we review our current understanding of the factors which may promote the attenuation and altered function of the neonatal CD8+ T-cell response and potential avenues for future study. Specifically, we have focused on the neonatal CD8+ T-cell ontogeny, memory formation, TCR structure and repertoire, TCR inhibitory receptors, and the clinical implications of altered neonatal CD8+ T-cell function. Special emphasis has been placed on examining the response of preterm neonates relative to term neonates and adults.
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Affiliation(s)
- Adam J Fike
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Ogan K Kumova
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Alison J Carey
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.,Department of Pediatrics, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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12
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Role of Regulatory T Cells in Tumor-Bearing Mice Treated with Allo-Hematopoietic Stem Cell Transplantation Plus Thymus Transplantation. J Immunol Res 2018; 2018:7271097. [PMID: 30057919 PMCID: PMC6051097 DOI: 10.1155/2018/7271097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/10/2018] [Accepted: 05/23/2018] [Indexed: 01/05/2023] Open
Abstract
We recently developed a new allogeneic hematopoietic stem cell transplantation method (allo-HSCT) combined with thymus transplantation (TT) from the same donor (allo-HSCT + TT). This method induces elevated T cell function with mild graft-versus-host disease (GVHD) in comparison to conventional HSCT alone and HSCT + donor lymphocyte infusion (DLI). This new method is effective against several intractable diseases, including malignant tumors, for which conventional treatments are ineffective. Regulatory T (Treg) cells play an important role in the enhanced graft-versus-tumor (GVT) effect and reduction of GVHD, thus leading to longer survival. Replacement and reduction of elevated Treg cells by donor-derived allo-Treg cells from the transplanted thymus may play one of crucial roles in the effect. This review discusses the role of Treg cells in a tumor-bearing mouse model treated with allo-HSCT + TT.
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13
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Crespo J, Wu K, Li W, Kryczek I, Maj T, Vatan L, Wei S, Opipari AW, Zou W. Human Naive T Cells Express Functional CXCL8 and Promote Tumorigenesis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:814-820. [PMID: 29802127 PMCID: PMC6039239 DOI: 10.4049/jimmunol.1700755] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 04/29/2018] [Indexed: 01/18/2023]
Abstract
Naive T cells are thought to be functionally quiescent. In this study, we studied and compared the phenotype, cytokine profile, and potential function of human naive CD4+ T cells in umbilical cord and peripheral blood. We found that naive CD4+ T cells, but not memory T cells, expressed high levels of chemokine CXCL8. CXCL8+ naive T cells were preferentially enriched CD31+ T cells and did not express T cell activation markers or typical Th effector cytokines, including IFN-γ, IL-4, IL-17, and IL-22. In addition, upon activation, naive T cells retained high levels of CXCL8 expression. Furthermore, we showed that naive T cell-derived CXCL8 mediated neutrophil migration in the in vitro migration assay, supported tumor sphere formation, and promoted tumor growth in an in vivo human xenograft model. Thus, human naive T cells are phenotypically and functionally heterogeneous and can carry out active functions in immune responses.
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Affiliation(s)
- Joel Crespo
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
- Graduate Program in Immunology, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Ke Wu
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
- Department of Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wei Li
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
- Department of Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ilona Kryczek
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Tomasz Maj
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Linda Vatan
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Shuang Wei
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Anthony W Opipari
- Department of Obstetrics and Gynecology, University of Michigan School of Medicine, Ann Arbor, MI 48109
| | - Weiping Zou
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109;
- Graduate Program in Immunology, University of Michigan School of Medicine, Ann Arbor, MI 48109
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109
- University of Michigan Rogel Cancer Center, University of Michigan School of Medicine, Ann Arbor, MI 48109; and
- Graduate Program in Tumor Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109
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14
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Min B. Spontaneous T Cell Proliferation: A Physiologic Process to Create and Maintain Homeostatic Balance and Diversity of the Immune System. Front Immunol 2018; 9:547. [PMID: 29616038 PMCID: PMC5868360 DOI: 10.3389/fimmu.2018.00547] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 03/05/2018] [Indexed: 11/14/2022] Open
Abstract
Naive T lymphocytes undergo heterogeneous proliferative responses when introduced into lymphopenic hosts, referred to as “homeostatic proliferation” and “spontaneous proliferation.” Spontaneous proliferation is a unique process through which the immune system generates memory phenotype cells with increasing T cell receptors repertoire complexity. Here, the mechanisms that initiate and control spontaneous proliferation are discussed.
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Affiliation(s)
- Booki Min
- Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, United States
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15
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Zhang S, Zhang X, Wang K, Xu X, Li M, Zhang J, Zhang Y, Hao J, Sun X, Chen Y, Liu X, Chang Y, Jin R, Wu H, Ge Q. Newly Generated CD4 + T Cells Acquire Metabolic Quiescence after Thymic Egress. THE JOURNAL OF IMMUNOLOGY 2017; 200:1064-1077. [PMID: 29288207 DOI: 10.4049/jimmunol.1700721] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 11/27/2017] [Indexed: 12/19/2022]
Abstract
Mature naive T cells circulate through the secondary lymphoid organs in an actively enforced quiescent state. Impaired cell survival and cell functions could be found when T cells have defects in quiescence. One of the key features of T cell quiescence is low basal metabolic activity. It remains unclear at which developmental stage T cells acquire this metabolic quiescence. We compared mitochondria among CD4 single-positive (SP) T cells in the thymus, CD4+ recent thymic emigrants (RTEs), and mature naive T cells in the periphery. The results demonstrate that RTEs and naive T cells had reduced mitochondrial content and mitochondrial reactive oxygen species when compared with SP thymocytes. This downregulation of mitochondria requires T cell egress from the thymus and occurs early after young T cells enter the circulation. Autophagic clearance of mitochondria, but not mitochondria biogenesis or fission/fusion, contributes to mitochondrial downregulation in RTEs. The enhanced apoptosis signal-regulating kinase 1/MAPKs and reduced mechanistic target of rapamycin activities in RTEs relative to SP thymocytes may be involved in this mitochondrial reduction. These results indicate that the gain of metabolic quiescence is one of the important maturation processes during SP-RTE transition. Together with functional maturation, it promotes the survival and full responsiveness to activating stimuli in young T cells.
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Affiliation(s)
- Shusong Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xinwei Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Ke Wang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xi Xu
- Center for Molecular Metabolism, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Mingyang Li
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Jun Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Yan Zhang
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Jie Hao
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xiuyuan Sun
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Yingyu Chen
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohui Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yingjun Chang
- Peking University Institute of Hematology, People's Hospital, Beijing 100044, China; and
| | - Rong Jin
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; .,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
| | - Hounan Wu
- Peking University Medical and Health Analytical Center, Peking University Health Science Center, Beijing 100191, China
| | - Qing Ge
- Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; .,Key Laboratory of Medical Immunology, Ministry of Health, Peking University Health Science Center, Beijing 100191, China
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16
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The significance of neonatal thymectomy for shaping the immune system in children with congenital heart defects. POLISH JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 2017; 14:258-262. [PMID: 29354179 PMCID: PMC5767777 DOI: 10.5114/kitp.2017.72231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 11/12/2017] [Indexed: 11/23/2022]
Abstract
The thymus plays an important role in the development of the immune cell pool; it serves as the primary location for T-lymphocyte maturation. Early cardiac surgical interventions for congenital heart defects are necessarily associated with thymectomy, i.e. the partial or complete removal of the thymus. A newborn infant already has a functioning thymus and developed cells of the immune system. However, thymectomy eliminates the primary location where T cells differentiate and mature. This study summarizes the current knowledge of the cellular disturbances and potential clinical consequences associated with performing thymectomy in children treated surgically for congenital heart defects.
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17
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Lang MJ, Mori M, Ruer-Laventie J, Pieters J. A Coronin 1–Dependent Decision Switch in Juvenile Mice Determines the Population of the Peripheral Naive T Cell Compartment. THE JOURNAL OF IMMUNOLOGY 2017; 199:2421-2431. [DOI: 10.4049/jimmunol.1700438] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/31/2017] [Indexed: 11/19/2022]
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18
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Dong M, Artusa P, Kelly SA, Fournier M, Baldwin TA, Mandl JN, Melichar HJ. Alterations in the Thymic Selection Threshold Skew the Self-Reactivity of the TCR Repertoire in Neonates. THE JOURNAL OF IMMUNOLOGY 2017; 199:965-973. [PMID: 28659353 DOI: 10.4049/jimmunol.1602137] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 06/02/2017] [Indexed: 12/19/2022]
Abstract
Neonatal and adult T cells differ in their effector functions. Although it is known that cell-intrinsic differences in mature T cells contribute to this phenomenon, the factors involved remain unclear. Given emerging evidence that the binding strength of a TCR for self-peptide presented by MHC (self-pMHC) impacts T cell function, we sought to determine whether altered thymic selection influences the self-reactivity of the TCR repertoire during ontogeny. We found that conventional and regulatory T cell subsets in the thymus of neonates and young mice expressed higher levels of cell surface CD5, a surrogate marker for TCR avidity for self-pMHC, as compared with their adult counterparts, and this difference in self-reactivity was independent of the germline bias of the neonatal TCR repertoire. The increased binding strength of the TCR repertoire for self-pMHC in neonates was not solely due to reported defects in clonal deletion. Rather, our data suggest that thymic selection is altered in young mice such that thymocytes bearing TCRs with low affinity for self-peptide are not efficiently selected into the neonatal repertoire, and stronger TCR signals accompany both conventional and regulatory T cell selection. Importantly, the distinct levels of T cell self-reactivity reflect physiologically relevant differences based on the preferential expansion of T cells from young mice to fill a lymphopenic environment. Therefore, differences in thymic selection in young versus adult mice skew the TCR repertoire, and the relatively higher self-reactivity of the T cell pool may contribute to the distinct immune responses observed in neonates.
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Affiliation(s)
- Mengqi Dong
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada.,Department of Microbiology, Infectious Diseases, and Immunology, University of Montreal, Montreal, Quebec H3T 1J4, Canada
| | - Patricio Artusa
- Department of Physiology and McGill Research Centre for Complex Traits, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Stephanie A Kelly
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada; and
| | - Marilaine Fournier
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada
| | - Troy A Baldwin
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada; and
| | - Judith N Mandl
- Department of Physiology and McGill Research Centre for Complex Traits, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Heather J Melichar
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec H1T 2M4, Canada; .,Department of Medicine, University of Montreal, Montreal, Quebec H3T 1J4, Canada
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19
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Cunningham CA, Bergsbaken T, Fink PJ. Cutting Edge: Defective Aerobic Glycolysis Defines the Distinct Effector Function in Antigen-Activated CD8 + Recent Thymic Emigrants. THE JOURNAL OF IMMUNOLOGY 2017; 198:4575-4580. [PMID: 28507025 DOI: 10.4049/jimmunol.1700465] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 04/25/2017] [Indexed: 01/03/2023]
Abstract
Recent thymic emigrants (RTEs) are the youngest peripheral T cells that have completed thymic selection and egress to the lymphoid periphery. RTEs are functionally distinct from their more mature but still naive T cell counterparts, because they exhibit dampened proliferation and reduced cytokine production upon activation. In this article, we show that, compared with more mature but still naive T cells, RTEs are impaired in their ability to perform aerobic glycolysis following activation. Impaired metabolism underlies the reduced IFN-γ production observed in activated RTEs. This failure to undergo Ag-induced aerobic glycolysis is caused by reduced mTORC1 activity and diminished Myc induction in RTEs. Critically, exogenous IL-2 restores Myc expression in RTEs, driving aerobic glycolysis and IFN-γ production to the level of mature T cells. These results reveal a previously unknown metabolic component to postthymic T cell maturation.
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Affiliation(s)
- Cody A Cunningham
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Tessa Bergsbaken
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109
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20
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Ellestad KK, Anderson CC. Two Strikes and You’re Out? The Pathogenic Interplay of Coinhibitor Deficiency and Lymphopenia-Induced Proliferation. THE JOURNAL OF IMMUNOLOGY 2017; 198:2534-2541. [DOI: 10.4049/jimmunol.1601884] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/10/2017] [Indexed: 12/15/2022]
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21
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dela Peña-Ponce MG, Rodriguez-Nieves J, Bernhardt J, Tuck R, Choudhary N, Mengual M, Mollan KR, Hudgens MG, Peter-Wohl S, De Paris K. Increasing JAK/STAT Signaling Function of Infant CD4 + T Cells during the First Year of Life. Front Pediatr 2017; 5:15. [PMID: 28271056 PMCID: PMC5318443 DOI: 10.3389/fped.2017.00015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/20/2017] [Indexed: 12/17/2022] Open
Abstract
Most infant deaths occur in the first year of life. Yet, our knowledge of immune development during this period is scarce and derived from cord blood (CB) only. To more effectively combat pediatric diseases, a deeper understanding of the kinetics and the factors that regulate the maturation of immune functions in early life is needed. Increased disease susceptibility of infants is generally attributed to T helper 2-biased immune responses. The differentiation of CD4+ T cells along a specific T helper cell lineage is dependent on the pathogen type, and on costimulatory and cytokine signals provided by antigen-presenting cells. Cytokines also regulate many other aspects of the host immune response. Therefore, toward the goal of increasing our knowledge of early immune development, we defined the temporal development of the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling function of CD4+ T cells using cross-sectional blood samples from healthy infants ages 0 (birth) to 14 months. We specifically focused on cytokines important in T cell differentiation (IFN-γ, IL-12, and IL-4) or in T cell survival and expansion (IL-2 and IL-7) in infant CD4+ T cells. Independent of the cytokine tested, JAK/STAT signaling in infant compared to adult CD4+ T cells was impaired at birth, but increased during the first year, with the most pronounced changes occurring in the first 6 months. The relative change in JAK/STAT signaling of infant CD4+ T cells with age was distinct for each cytokine tested. Thus, while about 60% of CB CD4+ T cells could efficiently activate STAT6 in response to IL-4, less than 5% of CB CD4+ T cells were able to activate the JAK/STAT pathway in response to IFN-γ, IL-12 or IL-2. By 4-6 months of age, the activation of the cytokine-specific STAT molecules was comparable to adults in response to IL-4 and IFN-γ, while IL-2- and IL-12-induced STAT activation remained below adult levels even at 1 year. These results suggest that common developmental and cytokine-specific factors regulate the maturation of the JAK/STAT signaling function in CD4+ T cells during the first year of life.
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Affiliation(s)
- Myra Grace dela Peña-Ponce
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Jennifer Rodriguez-Nieves
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Janice Bernhardt
- Division of Neonatal Perinatal Medicine, Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Ryan Tuck
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Neelima Choudhary
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Michael Mengual
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Katie R. Mollan
- Lineberger Cancer Center, Center for AIDS Research, University of North Carolina, Chapel Hill, NC, USA
| | - Michael G. Hudgens
- Gillings School of Global Public Health, Center for AIDS Research, University of North Carolina, Chapel Hill, NC, USA
| | - Sigal Peter-Wohl
- Division of Neonatal Perinatal Medicine, Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Kristina De Paris
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
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22
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Galindo-Albarrán A, López-Portales O, Gutiérrez-Reyna D, Rodríguez-Jorge O, Sánchez-Villanueva J, Ramírez-Pliego O, Bergon A, Loriod B, Holota H, Imbert J, Hernández-Mendoza A, Ferrier P, Carrillo-de Santa Pau E, Valencia A, Spicuglia S, Santana M. CD8 + T Cells from Human Neonates Are Biased toward an Innate Immune Response. Cell Rep 2016; 17:2151-2160. [DOI: 10.1016/j.celrep.2016.10.056] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 07/03/2016] [Accepted: 09/22/2016] [Indexed: 12/11/2022] Open
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23
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Friesen TJ, Ji Q, Fink PJ. Recent thymic emigrants are tolerized in the absence of inflammation. J Exp Med 2016; 213:913-20. [PMID: 27139493 PMCID: PMC4886366 DOI: 10.1084/jem.20151990] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/06/2016] [Indexed: 12/20/2022] Open
Abstract
T cell development requires a period of postthymic maturation. Why this is the case has remained a mystery, particularly given the rigors of intrathymic developmental checkpoints, successfully traversed by only ∼5% of thymocytes. We now show that the first few weeks of T cell residence in the lymphoid periphery define a period of heightened susceptibility to tolerance induction to tissue-restricted antigens (TRAs), the outcome of which depends on the context in which recent thymic emigrants (RTEs) encounter antigen. After encounter with TRAs in the absence of inflammation, RTEs exhibited defects in proliferation, diminished cytokine production, elevated expression of anergy-associated genes, and diminished diabetogenicity. These properties were mirrored in vitro by enhanced RTE susceptibility to regulatory T cell-mediated suppression. In the presence of inflammation, RTEs and mature T cells were, in contrast, equally capable of inducing diabetes, proliferating, and producing cytokines. Thus, recirculating RTEs encounter TRAs during a transitional developmental stage that facilitates tolerance induction, but inflammation converts antigen-exposed, tolerance-prone RTEs into competent effector cells.
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Affiliation(s)
- Travis J Friesen
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Qingyong Ji
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109
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24
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Deets KA, Berkley AM, Bergsbaken T, Fink PJ. Cutting Edge: Enhanced Clonal Burst Size Corrects an Otherwise Defective Memory Response by CD8+ Recent Thymic Emigrants. THE JOURNAL OF IMMUNOLOGY 2016; 196:2450-5. [PMID: 26873989 DOI: 10.4049/jimmunol.1502525] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/21/2016] [Indexed: 12/28/2022]
Abstract
The youngest peripheral T cells (recent thymic emigrants [RTEs]) are functionally distinct from naive T cells that have completed postthymic maturation. We assessed the RTE memory response and found that RTEs produced less granzyme B than their mature counterparts during infection but proliferated more and, therefore, generated equivalent target killing in vivo. Postinfection, RTE numbers contracted less dramatically than those of mature T cells, but RTEs were delayed in their transition to central memory, displaying impaired expression of CD62L, IL-2, Eomesodermin, and CXCR4, which resulted in impaired bone marrow localization. RTE-derived and mature memory cells expanded equivalently during rechallenge, indicating that the robust proliferative capacity of RTEs was maintained independently of central memory phenotype. Thus, the diminished effector function and delayed central memory differentiation of RTE-derived memory cells are counterbalanced by their increased proliferative capacity, driving the efficacy of the RTE response to that of mature T cells.
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Affiliation(s)
- Katherine A Deets
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Amy M Berkley
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Tessa Bergsbaken
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109
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25
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Wissink EM, Smith NL, Spektor R, Rudd BD, Grimson A. MicroRNAs and Their Targets Are Differentially Regulated in Adult and Neonatal Mouse CD8+ T Cells. Genetics 2015; 201:1017-30. [PMID: 26416483 PMCID: PMC4649632 DOI: 10.1534/genetics.115.179176] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 09/18/2015] [Indexed: 11/30/2022] Open
Abstract
Immunological memory, which protects organisms from re-infection, is a hallmark of the mammalian adaptive immune system and the underlying principle of vaccination. In early life, however, mice and other mammals are deficient at generating memory CD8+ T cells, which protect organisms from intracellular pathogens. The molecular basis that differentiates adult and neonatal CD8+ T cells is unknown. MicroRNAs (miRNAs) are both developmentally regulated and required for normal adult CD8+ T cell functions. We used next-generation sequencing to identify mouse miRNAs that are differentially regulated in adult and neonatal CD8+ T cells, which may contribute to the impaired development of neonatal memory cells. The miRNA profiles of adult and neonatal cells were surprisingly similar during infection; however, we observed large differences prior to infection. In particular, miR-29 and miR-130 have significant differential expression between adult and neonatal cells before infection. Importantly, using RNA-Seq, we detected reciprocal changes in expression of messenger RNA targets for both miR-29 and miR-130. Moreover, targets that we validated include Eomes and Tbx21, key genes that regulate the formation of memory CD8+ T cells. Notably, age-dependent changes in miR-29 and miR-130 are conserved in human CD8+ T cells, further suggesting that these developmental differences are biologically relevant. Together, these results demonstrate that miR-29 and miR-130 are likely important regulators of memory CD8+ T cell formation and suggest that neonatal cells are committed to a short-lived effector cell fate prior to infection.
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Affiliation(s)
- Erin M Wissink
- Graduate Field of Biochemistry, Molecular, and Cell Biology, Cornell University, Ithaca, New York 14853
| | - Norah L Smith
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York 14853
| | - Roman Spektor
- Graduate Field of Genetics, Genomics, and Development, Cornell University, Ithaca, New York 14853
| | - Brian D Rudd
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York 14853
| | - Andrew Grimson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
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26
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Gil A, Kenney LL, Mishra R, Watkin LB, Aslan N, Selin LK. Vaccination and heterologous immunity: educating the immune system. Trans R Soc Trop Med Hyg 2015; 109:62-9. [PMID: 25573110 DOI: 10.1093/trstmh/tru198] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This review discusses three inter-related topics: (1) the immaturity of the neonatal and infant immune response; (2) heterologous immunity, where prior infection history with unrelated pathogens alters disease outcome resulting in either enhanced protective immunity or increased immunopathology to new infections, and (3) epidemiological human vaccine studies that demonstrate vaccines can have beneficial or detrimental effects on subsequent unrelated infections. The results from the epidemiological and heterologous immunity studies suggest that the immune system has tremendous plasticity and that each new infection or vaccine that an individual is exposed to during a lifetime will potentially alter the dynamics of their immune system. It also suggests that each new infection or vaccine that an infant receives is not only perturbing the immune system but is educating the immune system and laying down the foundation for all subsequent responses. This leads to the question, is there an optimum way to educate the immune system? Should this be taken into consideration in our vaccination protocols?
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Affiliation(s)
- Anna Gil
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Laurie L Kenney
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Rabinarayan Mishra
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Levi B Watkin
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Nuray Aslan
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Liisa K Selin
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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27
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Zhao C, Marrero I, Narsale A, Moya R, Davies JD. CD4(+) CD44(v.low) cells are unique peripheral precursors that are distinct from recent thymic emigrants and stem cell-like memory cells. Cell Immunol 2015; 296:106-14. [PMID: 25910642 PMCID: PMC4509828 DOI: 10.1016/j.cellimm.2015.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 04/09/2015] [Accepted: 04/11/2015] [Indexed: 01/17/2023]
Abstract
CD4(+) CD44(v.low) cells are peripheral precursor T cells that inhibit lymphopenia by generating a large CD4(+) T cell pool containing balanced numbers of naïve, memory, and regulatory Foxp3(+) cells with a diverse TCR repertoire. Recent thymic emigrants (RTE) and stem cell-like memory T cells (T(SCM)) can also replenish a T cell pool. In this study we formally test whether CD44(v.low) cells are the same population as RTE and T(SCM). Our data show that, in contrast to RTE, CD44(v.low) cells express high levels of CD45RB and low levels of CD24. Moreover, CD44(v.low) cells isolated from mice devoid of RTE retain their capacity to repopulate lymphopenic mice with naïve and memory cells and Foxp3(+) Tregs. In addition, CD44(v.low) cells do not express IL-2Rβ, Sca-1, and CXCR3, the phenotypic hallmarks of T(SCM). Overall, these data demonstrate that CD44(v.low) cells are neither RTE nor T(SCM).
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Affiliation(s)
- Chunfang Zhao
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, U.S.A.
| | - Idania Marrero
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, U.S.A.
| | - Aditi Narsale
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, U.S.A
| | - Rosita Moya
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, U.S.A
| | - Joanna D Davies
- Torrey Pines Institute for Molecular Studies, 3550 General Atomics Court, San Diego, CA 92121, U.S.A.
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28
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Nelson RW, Rajpal MN, Jenkins MK. The Neonatal CD4+ T Cell Response to a Single Epitope Varies in Genetically Identical Mice. THE JOURNAL OF IMMUNOLOGY 2015; 195:2115-21. [PMID: 26179899 DOI: 10.4049/jimmunol.1500405] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/19/2015] [Indexed: 01/16/2023]
Abstract
Neonatal infection is a major cause of morbidity and mortality worldwide. Increased susceptibility to infection in the neonate is attributed in part to defects in T cell-mediated immunity. A peptide:MHC class II tetramer-based cell enrichment method was used to test this hypothesis at the level of a single epitope. We found that naive T cells with TCRs specific for the 2W:I-A(b) epitope were present in the thymuses of 1-d-old CD57BL/6 mice but were barely detectable in the spleen, likely because each mouse contained very few total splenic CD4(+) T cells. By day 7 of life, however, the total number of splenic CD4(+) T cells increased dramatically and the frequency of 2W:I-A(b)-specific naive T cells reached that of adult mice. Injection of 2W peptide in CFA into 1-d-old mice generated a 2W:I-A(b)-specific effector cell population that peaked later than in adult mice and showed more animal-to-animal variation. Similarly, 2W:I-A(b)-specific naive T cells in different neonatal mice varied significantly in generation of Th1, Th2, and follicular Th cells compared with adult mice. These results suggest that delayed effector cell expansion and stochastic variability in effector cell generation due to an initially small naive repertoire contribute to defective peptide:MHC class II-specific immunity in neonates.
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Affiliation(s)
- Ryan W Nelson
- Department of Microbiology and Immunology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455; and
| | - Miriam N Rajpal
- Department of Pediatrics, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Marc K Jenkins
- Department of Microbiology and Immunology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455; and
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Li YP, Yu SL, Huang ZJ, Huang J, Pan J, Feng X, Zhang XG, Wang JH, Wang J. An impaired inflammatory cytokine response to gram-negative LPS in human neonates is associated with the defective TLR-mediated signaling pathway. J Clin Immunol 2015; 35:218-26. [PMID: 25631527 DOI: 10.1007/s10875-015-0128-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 01/12/2015] [Indexed: 11/26/2022]
Abstract
PURPOSE Human neonates are highly susceptible to a wide range of infections, which has been attributed to deficiencies in their innate and adaptive immunity. In contrast to the well-documented immaturity in neonatal adaptive immunity, deficiencies in their innate immunity are less defined. This study examined the inflammatory response of neonatal monocytes to bacterial lipopolysaccharide (LPS) and peptidoglycan (PGN) stimulation and discriminated the underlying Toll-like receptor (TLR)-mediated signal transduction pathways. METHODS Cord blood from 30 healthy newborns of full-term elective cesarean sections and peripheral blood from 25 healthy adult volunteers were collected. Ex vivo production of inflammatory cytokines was assessed by cytometric bead array, and expression of CD14, TLR4, TLR2, phosphorylated NF-κB p65 and p38 on monocytes were detected by FACScan analysis. RESULTS Neonatal whole blood showed significantly decreased ex vivo TNF-α and IL-1β production in response to stimulation with the TLR4 agonist LPS, but not the TLR2 agonist PGN, when compared with adult whole blood. Consistent with the diminished inflammatory cytokine response to LPS stimulation, neonatal monocytes exhibited substantially impaired TLR-mediated signal transduction pathways characterized by down-regulated expression of CD14 and TLR4, and suppressed phosphorylation of NF-κB p65 at Ser536 and p38 following LPS stimulation. In addition, neonates had a significantly lower percentage of TLR4(+)/CD14(+) monocytes than adults. CONCLUSIONS These results indicate that in contrast to the adult, human neonates display deficiencies in innate immunity-associated inflammatory cytokine responses due to their defective TLR signaling pathways, which may render them more susceptible to microbial infection.
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Affiliation(s)
- Yi Ping Li
- Institute of Pediatric Research, Soochow University, Suzhou, 215006, China
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30
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Rane S, Das R, Ranganathan V, Prabhu S, Das A, Mattoo H, Durdik JM, George A, Rath S, Bal V. Peripheral residence of naïve CD4 T cells induces MHC class II-dependent alterations in phenotype and function. BMC Biol 2014; 12:106. [PMID: 25528158 PMCID: PMC4306244 DOI: 10.1186/s12915-014-0106-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 12/05/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND As individual naïve CD4 T lymphocytes circulate in the body after emerging from the thymus, they are likely to have individually varying microenvironmental interactions even in the absence of stimulation via specific target recognition. It is not clear if these interactions result in alterations in their activation, survival and effector programming. Naïve CD4 T cells show unimodal distribution for many phenotypic properties, suggesting that the variation is caused by intrinsic stochasticity, although underlying variation due to subsets created by different histories of microenvironmental interactions remains possible. To explore this possibility, we began examining the phenotype and functionality of naïve CD4 T cells differing in a basic unimodally distributed property, the CD4 levels, as well as the causal origin of these differences. RESULTS We examined separated CD4hi and CD4lo subsets of mouse naïve CD4 cells. CD4lo cells were smaller with higher CD5 levels and lower levels of the dual-specific phosphatase (DUSP)6-suppressing micro-RNA miR181a, and responded poorly with more Th2-skewed outcomes. Human naïve CD4lo and CD4hi cells showed similar differences. Naïve CD4lo and CD4hi subsets of thymic single-positive CD4 T cells did not show differences whereas peripheral naïve CD4lo and CD4hi subsets of T cell receptor (TCR)-transgenic T cells did. Adoptive transfer-mediated parking of naïve CD4 cells in vivo lowered CD4 levels, increased CD5 and reactive oxygen species (ROS) levels and induced hyporesponsiveness in them, dependent, at least in part, on availability of major histocompatibility complex class II (MHCII) molecules. ROS scavenging or DUSP inhibition ameliorated hyporesponsiveness. Naïve CD4 cells from aged mice showed lower CD4 levels and cell sizes, higher CD5 levels, and hyporesponsiveness and Th2-skewing reversed by DUSP inhibition. CONCLUSIONS Our data show that, underlying a unimodally distributed property, the CD4 level, there are subsets of naïve CD4 cells that vary in the time spent in the periphery receiving MHCII-mediated signals and show resultant alteration of phenotype and functionality via ROS and DUSP activity. Our findings also suggest the feasibility of potential pharmacological interventions for improved CD4 T cell responses during vaccination of older people via either anti-oxidant or DUSP inhibitor small molecules.
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Affiliation(s)
- Sanket Rane
- National Institute of Immunology, New Delhi, 110067, India.
| | - Rituparna Das
- National Institute of Immunology, New Delhi, 110067, India. .,Current address: Yale Cancer Center, Sterling Hall of Medicine, New Haven, USA.
| | - Vidya Ranganathan
- National Institute of Immunology, New Delhi, 110067, India. .,Current address: Division of Genetics & Development, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada.
| | - Savit Prabhu
- National Institute of Immunology, New Delhi, 110067, India. .,Current address: Pediatric Biology Centre, Translational Health Sciences and Technology Institute, Gurgaon, India.
| | - Arundhoti Das
- National Institute of Immunology, New Delhi, 110067, India.
| | - Hamid Mattoo
- National Institute of Immunology, New Delhi, 110067, India. .,Current address: MGH Cancer Center, Charlestown, USA.
| | - Jeannine Marie Durdik
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA.
| | - Anna George
- National Institute of Immunology, New Delhi, 110067, India.
| | - Satyajit Rath
- National Institute of Immunology, New Delhi, 110067, India.
| | - Vineeta Bal
- National Institute of Immunology, New Delhi, 110067, India.
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Berkley AM, Fink PJ. Cutting edge: CD8+ recent thymic emigrants exhibit increased responses to low-affinity ligands and improved access to peripheral sites of inflammation. THE JOURNAL OF IMMUNOLOGY 2014; 193:3262-6. [PMID: 25172492 DOI: 10.4049/jimmunol.1401870] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
To explore the TCR sensitivity of recent thymic emigrants (RTEs), we triggered T cells with altered peptide ligands (APLs). Upon peptide stimulation in vitro, RTEs exhibited increased TCR signal transduction, and following infection in vivo with APL-expressing bacteria, CD8 RTEs expanded to a greater extent in response to low-affinity Ags than did their mature T cell counterparts. RTEs skewed to short-lived effector cells in response to all APLs but also were characterized by diminished cytokine production. RTEs responding to infection expressed increased levels of VLA-4, with consequent improved entry into inflamed tissue and pathogen clearance. These positive outcomes were offset by the capacity of RTEs to elicit autoimmunity. Overall, salient features of CD8 RTE biology should inform strategies to improve neonatal vaccination and therapies for cancer and HIV, because RTEs make up a large proportion of the T cells in lymphodepleted environments.
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Affiliation(s)
- Amy M Berkley
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Pamela J Fink
- Department of Immunology, University of Washington, Seattle, WA 98109
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32
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Abstract
Neonates have little immunological memory and a developing immune system, which increases their vulnerability to infectious agents. Recent advances in the understanding of neonatal immunity indicate that both innate and adaptive responses are dependent on precursor frequency of lymphocytes, antigenic dose and mode of exposure. Studies in neonatal mouse models and human umbilical cord blood cells demonstrate the capability of neonatal immune cells to produce immune responses similar to adults in some aspects but not others. This review focuses mainly on the developmental and functional mechanisms of the human neonatal immune system. In particular, the mechanism of innate and adaptive immunity and the role of neutrophils, antigen presenting cells, differences in subclasses of T lymphocytes (Th1, Th2, Tregs) and B cells are discussed. In addition, we have included the recent developments in the neonatal mouse immune system. Understanding neonatal immunity is essential to development of therapeutic vaccines to combat newly emerging infectious agents.
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Affiliation(s)
- Saleem Basha
- Center for Infectious Disease and Immunology, Rochester General Hospital Research Institute, 1425 Portland Avenue, Rochester, NY 14621, USA
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33
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Dowling DJ, Levy O. Ontogeny of early life immunity. Trends Immunol 2014; 35:299-310. [PMID: 24880460 DOI: 10.1016/j.it.2014.04.007] [Citation(s) in RCA: 257] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/29/2014] [Accepted: 04/30/2014] [Indexed: 12/18/2022]
Abstract
The human immune system comprises cellular and molecular components designed to coordinately prevent infection while avoiding potentially harmful inflammation and autoimmunity. Immunity varies with age, reflecting unique age-dependent challenges including fetal gestation, the neonatal phase, and infancy. Here, we review novel mechanistic insights into early life immunity, with an emphasis on emerging models of human immune ontogeny, which may inform age-specific translational development of novel anti-infectives, immunomodulators, and vaccines.
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Affiliation(s)
- David J Dowling
- Department of Medicine, Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Ofer Levy
- Department of Medicine, Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
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34
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Smith NL, Wissink E, Wang J, Pinello JF, Davenport MP, Grimson A, Rudd BD. Rapid proliferation and differentiation impairs the development of memory CD8+ T cells in early life. THE JOURNAL OF IMMUNOLOGY 2014; 193:177-84. [PMID: 24850719 DOI: 10.4049/jimmunol.1400553] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neonates often generate incomplete immunity against intracellular pathogens, although the mechanism of this defect is poorly understood. An important question is whether the impaired development of memory CD8+ T cells in neonates is due to an immature priming environment or lymphocyte-intrinsic defects. In this article, we show that neonatal and adult CD8+ T cells adopted different fates when responding to equal amounts of stimulation in the same host. Whereas adult CD8+ T cells differentiated into a heterogeneous pool of effector and memory cells, neonatal CD8+ T cells preferentially gave rise to short-lived effector cells and exhibited a distinct gene expression profile. Surprisingly, impaired neonatal memory formation was not due to a lack of responsiveness, but instead because neonatal CD8+ T cells expanded more rapidly than adult cells and quickly became terminally differentiated. Collectively, these findings demonstrate that neonatal CD8+ T cells exhibit an imbalance in effector and memory CD8+ T cell differentiation, which impairs the formation of memory CD8+ T cells in early life.
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Affiliation(s)
- Norah L Smith
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853
| | - Erin Wissink
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853; and
| | - Jocelyn Wang
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853
| | - Jennifer F Pinello
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853
| | - Miles P Davenport
- Complex Systems in Biology Group, Centre for Vascular Research, University of New South Wales, Kensington, New South Wales 2052, Australia
| | - Andrew Grimson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853; and
| | - Brian D Rudd
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853;
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35
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Xu X, Ge Q. Maturation and migration of murine CD4 single positive thymocytes and thymic emigrants. Comput Struct Biotechnol J 2014; 9:e201403003. [PMID: 24757506 PMCID: PMC3995209 DOI: 10.5936/csbj.201403003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/18/2014] [Accepted: 03/23/2014] [Indexed: 11/22/2022] Open
Abstract
T lymphopoiesis in the thymus was thought to be completed once they reach the single positive (SP) stage, when they are “fully mature” and wait to be exported at random or follow a “first in-first out” manner. Recently, accumulating evidence has revealed that newly generated SP thymocytes undergo further maturation in the thymic medulla before they follow a tightly regulated emigrating process to become recent thymic emigrants (RTEs). RTEs in the periphery then experience a post-thymic maturation and peripheral tolerance and eventually become licensed as mature naïve T cells. This review summarizes the recent progress in the late stage T cell development in and outside of the thymus. The regulation of this developmental process is also discussed.
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Affiliation(s)
- Xi Xu
- Key Laboratory of Medical Immunology, Ministry of Health. Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100191, P R China
| | - Qing Ge
- Key Laboratory of Medical Immunology, Ministry of Health. Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, 38 Xue Yuan Road, Beijing 100191, P R China
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36
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Rezzani R, Nardo L, Favero G, Peroni M, Rodella LF. Thymus and aging: morphological, radiological, and functional overview. AGE (DORDRECHT, NETHERLANDS) 2014; 36:313-51. [PMID: 23877171 PMCID: PMC3889907 DOI: 10.1007/s11357-013-9564-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 07/01/2013] [Indexed: 05/20/2023]
Abstract
Aging is a continuous process that induces many alterations in the cytoarchitecture of different organs and systems both in humans and animals. Moreover, it is associated with increased susceptibility to infectious, autoimmune, and neoplastic processes. The thymus is a primary lymphoid organ responsible for the production of immunocompetent T cells and, with aging, it atrophies and declines in functions. Universality of thymic involution in all species possessing thymus, including human, indicates it as a long-standing evolutionary event. Although it is accepted that many factors contribute to age-associated thymic involution, little is known about the mechanisms involved in the process. The exact time point of the initiation is not well defined. To address the issue, we report the exact age of thymus throughout the review so that readers can have a nicely pictured synoptic view of the process. Focusing our attention on the different stages of the development of the thymus gland (natal, postnatal, adult, and old), we describe chronologically the morphological changes of the gland. We report that the thymic morphology and cell types are evolutionarily preserved in several vertebrate species. This finding is important in understanding the similar problems caused by senescence and other diseases. Another point that we considered very important is to indicate the assessment of the thymus through radiological images to highlight its variability in shape, size, and anatomical conformation.
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Affiliation(s)
- Rita Rezzani
- Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, Viale Europa 11, 25123, Brescia, Italy,
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37
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Lopes-Carvalho T, Coutinho A. Old dogs and new tricks: defective peripheral regulatory T cell generation in aged mice. Eur J Immunol 2013; 43:2534-7. [PMID: 24122754 DOI: 10.1002/eji.201344029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 08/26/2013] [Accepted: 09/12/2013] [Indexed: 01/21/2023]
Abstract
Tolerance is a developmentally acquired property of the vertebrate immune system, in part ensured by regulatory CD4⁺ lymphocytes (Treg cells) expressing the Foxp3 transcription factor. Recent work has shown that thymic emigrants are the preferential source of peripherally generated Treg cells. A new report in this issue of the European Journal of Immunology [Eur. J. Immunol. 2013. 43: 2598-2604] describes a cell autonomous defect in Foxp3 induction in aged CD4⁺ cells in mice. Immune homeostasis becomes progressively less robust as ontogeny gives way to aging, and a key feature of senescence is thymic involution and the impaired T-cell turnover that follows. In this Commentary, we discuss the implications of these recent findings for our understanding of the induction of tolerance to peripheral antigens in aging.
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38
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Vanden Driessche K, Persson A, Marais BJ, Fink PJ, Urdahl KB. Immune vulnerability of infants to tuberculosis. Clin Dev Immunol 2013; 2013:781320. [PMID: 23762096 PMCID: PMC3666431 DOI: 10.1155/2013/781320] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/30/2013] [Accepted: 03/31/2013] [Indexed: 02/08/2023]
Abstract
One of the challenges faced by the infant immune system is learning to distinguish the myriad of foreign but nonthreatening antigens encountered from those expressed by true pathogens. This balance is reflected in the diminished production of proinflammatory cytokines by both innate and adaptive immune cells in the infant. A downside of this bias is that several factors critical for controlling Mycobacterium tuberculosis infection are significantly restricted in infants, including TNF, IL-1, and IL-12. Furthermore, infant T cells are inherently less capable of differentiating into IFN- γ -producing T cells. As a result, infected infants are 5-10 times more likely than adults to develop active tuberculosis (TB) and have higher rates of severe disseminated disease, including miliary TB and meningitis. Infant TB is a fundamentally different disease than TB in immune competent adults. Immunotherapeutics, therefore, should be specifically evaluated in infants before they are routinely employed to treat TB in this age group. Modalities aimed at reducing inflammation, which may be beneficial for adjunctive therapy of some forms of TB in older children and adults, may be of no benefit or even harmful in infants who manifest much less inflammatory disease.
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Affiliation(s)
- Koen Vanden Driessche
- Centre for Understanding and Preventing Infections in Children, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
- Department of Pediatrics, Laboratory of Pediatric Infectious Diseases, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands
| | - Alexander Persson
- Centre for Understanding and Preventing Infections in Children, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Ben J. Marais
- Sydney Institute for Emerging Infectious Diseases and Biosecurity and The Children's Hospital at Westmead, University of Sydney, Locked Bag 4100, Sydney, NSW 2145, Australia
| | - Pamela J. Fink
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
| | - Kevin B. Urdahl
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
- Seattle Biomedical Research Institute, Seattle, WA 98109, USA
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
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39
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Zhang Q, Coveney AP, Yu S, Liu JH, Li Y, Blankson S, Redmond HP, Wang JH, Wang J. Inefficient antimicrobial functions of innate phagocytes render infant mice more susceptible to bacterial infection. Eur J Immunol 2013; 43:1322-32. [PMID: 23404483 DOI: 10.1002/eji.201243077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 01/16/2013] [Accepted: 02/08/2013] [Indexed: 12/16/2022]
Abstract
Neonates and infants, due to the immaturity in their adaptive immunity, are thought to depend largely on the innate immune system for protection against bacterial infection. However, the innate immunity-mediated antimicrobial response in neonates and infants is incompletely characterized. Here, we report that infant mice were more susceptible to microbial sepsis than adult mice, with significantly reduced bacterial clearance from the circulation and visceral organs. Infant PMNs exhibited less constitutive expression of the chemokine receptor CXCR2, and bacterial infection caused further reduction of PMN CXCR2 in infant mice compared with adult mice. This correlates with diminished in vitro chemotaxis of infant PMNs toward the chemoattractant CXCL2 and impaired in vivo recruitment of infant PMNs into the infectious site. Furthermore, consistent with the reduced antimicrobial response in vivo, infant macrophages displayed an impaired bactericidal activity with a defect in phagosome maturation after ingestion of either gram-positive or gram-negative bacteria. Thus, infant mice exhibit an increased vulnerability to microbial infection with delayed bacterial clearance, which is associated with the inefficiency in their innate phagocyte-associated antimicrobial functions characterized by defects in PMN recruitment and macrophage phagosome maturation during microbial sepsis.
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Affiliation(s)
- Qi Zhang
- Department of Pediatric Surgery, Affiliated Children's Hospital, Soochow University, Suzhou, China
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40
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Affiliation(s)
- Pamela J. Fink
- Department of Immunology, University of Washington, Seattle, Washington 98195;
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41
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Bains I, Yates AJ, Callard RE. Heterogeneity in thymic emigrants: implications for thymectomy and immunosenescence. PLoS One 2013; 8:e49554. [PMID: 23468830 PMCID: PMC3584139 DOI: 10.1371/journal.pone.0049554] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 10/15/2012] [Indexed: 01/19/2023] Open
Abstract
The development of mature, antigen-inexperienced (naive) T cells begins in the thymus and continues after export into the periphery. Post-thymic maturation of naive T cells, in humans, coincides with the progressive loss of markers such as protein tyrosine kinase 7 (PTK7) and platelet endothelial cell adhesion molecule-1 (CD31). As a consequence, subpopulations of naive T cells can be recognised raising questions about the processes that give rise to the loss of these markers and their exact relationship to recent thymic emigrants (RTE). Here, we combine a mathematical survival analysis approach and data from healthy and thymectomised humans to understand the apparent persistence of populations of ‘veteran’ PTK7+T cells in thymectomised individuals. We show that a model of heterogeneity in rates of maturation, possibly linked to natural variation in TCR signalling thresholds or affinity for self-antigens, can explain the data. This model of maturation predicts that the average post-thymic age of PTK7+T cells will increase linearly with the age of the host suggesting that, despite the immature phenotype, PTK7+cells do not necessarily represent a population of RTE. Further, the model predicts an accelerated increase in the average post-thymic age of residual PTK7+T cells following thymectomy and may also explain in part the prematurely aged phenotype of the naive T cell pool in individuals thymectomised early in life.
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Affiliation(s)
- Iren Bains
- Immune Cell Biology, National Institute for Medical Research, Mill Hill, London, United Kingdom.
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42
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Bhaumik S, Giffon T, Bolinger D, Kirkman R, Lewis DB, Weaver CT, Randolph DA. Retinoic acid hypersensitivity promotes peripheral tolerance in recent thymic emigrants. THE JOURNAL OF IMMUNOLOGY 2013; 190:2603-13. [PMID: 23401586 DOI: 10.4049/jimmunol.1200852] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Whereas thymic education eliminates most self-reactive T cells, additional mechanisms to promote tolerance in the periphery are critical to prevent excessive immune responses against benign environmental Ags and some self-Ags. In this study we show that murine CD4(+) recent thymic emigrants (RTEs) are programmed to facilitate tolerance in the periphery. Both in vitro and in vivo, naive RTEs more readily upregulate Foxp3 than do mature naive cells after stimulation under tolerogenic conditions. In RTEs, a relatively high sensitivity to retinoic acid contributes to decreased IFN-γ production, permitting the expression of Foxp3. Conversely, mature naive CD4 cells have a lower sensitivity to retinoic acid, resulting in increased IFN-γ production and subsequent IFN-γ-mediated silencing of Foxp3 expression. Enhanced retinoic acid signaling and Foxp3 induction in RTEs upon Ag encounter in the periphery may serve as form of secondary education that complements thymic education and helps avoid inappropriate immune responses. This mechanism for tolerance may be particularly important in settings where RTEs comprise a large fraction of the peripheral T cell pool, such as in newborns or after umbilical cord blood transplant.
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Affiliation(s)
- Suniti Bhaumik
- Division of Neonatology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35233, USA
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43
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Dong J, Chen Y, Xu X, Jin R, Teng F, Yan F, Tang H, Li P, Sun X, Li Y, Wu H, Zhang Y, Ge Q. Homeostatic properties and phenotypic maturation of murine CD4+ pre-thymic emigrants in the thymus. PLoS One 2013; 8:e56378. [PMID: 23409179 PMCID: PMC3569422 DOI: 10.1371/journal.pone.0056378] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 01/08/2013] [Indexed: 11/24/2022] Open
Abstract
After a tightly regulated developmental program in the thymus, “mature” single positive (SP) thymocytes leave the thymus and enter the periphery. These newly arrived recent thymic emigrants (RTEs) are phenotypically and functionally immature, and will complete a dynamic maturation in the peripheral lymphoid organs before being licensed to be resident naïve T cells. To study the early events occurring in the RTE maturation process, we identified the phenotype of CD4+ pre-RTEs, a population of CD4+ SP thymocytes that have acquired the thymus egress capability. Compared to peripheral naïve T cells, CD4+ pre-RTEs displayed superior survival capability in lymphoreplete mice and faster proliferation under lymphopenic condition. The differences in Bcl2/Bim expression and/or heightened IL-7 signaling pathway may account for the pre-RTEs’ better responsiveness to homeostatic signals. Qa2, the expression of which indicates the phenotypic maturation of SPs and RTEs, was found to be upregulated in CD4+ pre-RTEs in thymic perivascular space. Migratory dendritic cells that surround this region contribute to Qa2 expression in pre-RTEs. The dendritic cell-driven Qa2 induction of CD4+ pre-RTEs is independent of MHC class II and Aire molecules.
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Affiliation(s)
- Jie Dong
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Yu Chen
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Xi Xu
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Rong Jin
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Fei Teng
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Fan Yan
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Hui Tang
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Pingping Li
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Xiuyuan Sun
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Yan Li
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
| | - Hounan Wu
- Peking University Medical and Health Analytical Center, Peking University Health Science Center, Beijing, China
- * E-mail: (QG); (YZ); (HW)
| | - Yu Zhang
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
- * E-mail: (QG); (YZ); (HW)
| | - Qing Ge
- Key Laboratory of Medical Immunology, Ministry of Health, Department of Immunology, Peking University Health Science Center, Beijing, China
- * E-mail: (QG); (YZ); (HW)
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Cai X, Huang W, Qiao Y, Chen Y, Du S, Chen D, Yu S, Che R, Jiang Y. Proteomics identifies differentially expressed proteins in neonatal murine thymus compared with adults. Proteome Sci 2012; 10:65. [PMID: 23134655 PMCID: PMC3583686 DOI: 10.1186/1477-5956-10-65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 11/02/2012] [Indexed: 11/14/2022] Open
Abstract
Background The thymus is an immune organ essential for life and plays a crucial role in the development of T cells. It undergoes a fetal to adult developmental maturation process occurring in mouse during the postnatal months. The molecular modifications underlying these ontogenic changes are essentially unknown. Here we used a differential proteomic-based technique (2D-Difference Gel Electrophoresis) coupled with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry to search for key proteins in the postnatal development of the thymus. Eight different BALB/c mice were used in the study: four mice aged of 1 day (neonatal) and four mice aged of 60 days (adult). Protein samples derived from thymus were labeled and run in 2D-PAGE (Two-Dimensional Polyacrylamide Gel Electrophoresis). One whole-thymus tissue from each mouse was run on gels and each gel containing a pooled sample of the eight mice was run in parallel. The pooled sample was set as the internal pool, containing equal amount of each protein extract used in the experiment. Gels were matched and compared with Difference In-gel Analysis software. Differential spots were picked, in-gel digested and peptide mass fingerprints were obtained. Results Among the differentially regulated proteins in neonatal thymus group, 111 proteins were identified by mass spectrometry, of which 95 proteins were up-regulated and 16 proteins were down-regulated. The identified proteins belong to several functional categories, including cell proliferation, cycle and apoptosis, transcription regulation, signal transduction, nucleotide processing, proteolysis and translation, protein folding, metabolism, oxidoreduction, cytoskeleton, immune response, and embryonic development. The major interaction networks comprised of cellular function and maintenance, cellular assembly and organization, and metabolism were also identified by STRING analysis. Conclusions The demonstrated molecular changes are relevant for understanding thymus development as well as neonatal immune function, and they provide the diagnostic disease markers. Further studies will be required to describe in detail the role of the identified proteins in thymus maturation and in the specific functions of neonatal thymus.
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Affiliation(s)
- Xinze Cai
- Central Laboratory, First Affiliated Hospital of China Medical University, Shenyang, 110001, China.
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Schatorjé EJH, Gemen EFA, Driessen GJA, Leuvenink J, van Hout RWNM, de Vries E. Paediatric reference values for the peripheral T cell compartment. Scand J Immunol 2012; 75:436-44. [PMID: 22420532 DOI: 10.1111/j.1365-3083.2012.02671.x] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Immunophenotyping of blood lymphocyte subpopulations is an important tool in the diagnosis of immunological and haematological diseases. Paediatric age-matched reference values have been determined for the major lymphocyte populations, but reliable reference values for the more recently described T lymphocyte subpopulations, like different types of memory T lymphocytes, recent thymic emigrants, regulatory T cells and CXCR5(+) helper T lymphocytes, are not sufficiently available yet. We determined reference values for the absolute and relative sizes of T lymphocyte subpopulations in healthy children using the lysed whole blood method, which is most often used in diagnostic procedures. When the absolute numbers of some or all T lymphocyte subpopulations fall outside these reference ranges, this may indicate disease. The reference values show the course of T lymphocyte development in healthy children. Absolute T lymphocyte numbers increase 1.4-fold during the first months of life, and after 9-15 months, they decrease threefold to adult values; this is mainly caused by the expansion of recent thymic emigrants and naive cells. Helper and cytotoxic T lymphocytes show the same pattern. Regulatory T cells increase in the first 5 months of life and then gradually decrease to adult values, although the absolute numbers remain small. The relative number of CXCR5(+) cells within the CD4(+) CD45RO(+) T lymphocytes increases during the first 6 months of life and then remains more or less stable around 20%.
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Affiliation(s)
- E J H Schatorjé
- Department of Pediatrics, Jeroen Bosch Hospital, `s-Hertogenbosch, The Netherlands
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Homeostatic signals do not drive post-thymic T cell maturation. Cell Immunol 2012; 274:39-45. [PMID: 22398309 DOI: 10.1016/j.cellimm.2012.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 11/20/2022]
Abstract
Recent thymic emigrants, the youngest T cells in the lymphoid periphery, undergo a 3 week-long period of functional and phenotypic maturation before being incorporated into the pool of mature, naïve T cells. Previous studies indicate that this maturation requires T cell exit from the thymus and access to secondary lymphoid organs, but is MHC-independent. We now show that post-thymic T cell maturation is independent of homeostatic and costimulatory pathways, requiring neither signals delivered by IL-7 nor CD80/86. Furthermore, while CCR7/CCL19,21-regulated homing of recent thymic emigrants to the T cell zones within the secondary lymphoid organs is not required for post-thymic T cell maturation, an intact dendritic cell compartment modulates this process. It is thus clear that, unlike T cell development and homeostasis, post-thymic maturation is focused not on interrogating the T cell receptor or the cell's responsiveness to homeostatic or costimulatory signals, but on some as yet unrecognized property.
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Neonatal T-cell maturation and homing receptor responses to Toll-like receptor ligands differ from those of adult naive T cells: relationship to prematurity. Pediatr Res 2012; 71:136-43. [PMID: 22258123 PMCID: PMC3394681 DOI: 10.1038/pr.2011.26] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Inflammation and infection are associated with premature birth and with activation of the fetal immune system. We hypothesized that exposure to microbial Toll-like receptor (TLR) ligands plays an important role in neonatal T-cell maturation and that early exposure to microbial products may result in early T-cell maturation and a tendency for these matured effector cells to change their homing receptor patterns. RESULTS Expression of the CD45RO marker was induced in term neonatal T cells after in vitro exposure to TLR ligands for 7 days. Interestingly, naive T cells from adult blood were unaffected by TLR ligand exposure. In addition, neonatal T cells had more cells with decreased expression of the α4β7 integrins and increased expression of CCR4 after in vitro exposure of TLR ligands-similar to the expression of these molecules in adult naive T cells. DISCUSSION These findings are relevant for the understanding of neonatal T-cell maturation and may contribute to our understanding of multiorgan inflammatory complications of prematurity. METHODS Cord blood was obtained from term and preterm infants. Using flow cytometry, we identified a mature (CD45RO(+)) phenotype in preterm infant cord blood (CB) T cells that had decreased expression of the α4β7 integrins and increased expression of the C-C chemokine receptor 4 (CCR4) as compared with term infant CB.
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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.
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Affiliation(s)
- Pamela J Fink
- Department of Immunology, University of Washington, Seattle, Washington, USA.
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Adkins B, Contractor N. Immune responses of female BALB/c and C57BL/6 neonatal mice to vaccination or intestinal infection are unaltered by exposure to breast milk lycopene. J Nutr 2011; 141:1326-30. [PMID: 21593356 PMCID: PMC3113289 DOI: 10.3945/jn.110.136762] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Lycopene, a carotenoid produced by some commonly consumed plants such as tomatoes, is not synthesized by animals. Thus, the levels of lycopene found in the breast milk of lactating females reflect the dietary lycopene supply. Lycopene has potent antioxidant activity but has also been implicated in modulating immune function. Therefore, lycopene in breast milk has the potential to affect the development and/or function of the immune system in the suckling pups. Here, we have investigated the impact of breast milk lycopene on systemic and mucosal immunity in mouse neonates. Diets containing 0.3 g/kg lycopene (Lyc) or control (Con) diets were fed to mouse dams beginning at late gestation and continuing throughout lactation. Seven-day-old female BALB/c pups were parenterally immunized with a model vaccine antigen dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH) and then reimmunized as adults. The levels of DNP-KLH-specific IgG in the sera as well as keyhole limpet hemocyanin-specific IFNγ and IL-4 production by splenic CD4(+) cells were similar in the Lyc and Con pups. In addition, female neonatal (d7) C57BL/6 Lyc and Con pups were infected orally with the enteropathogen Yersinia enterocolitica. Breast milk lycopene had no effect on the recruitment of neutrophils to intestinal lymphoid tissues or on bacterial tissue colonization of the intestines, spleens, and livers. Thus, suckling pups exposed to lycopene in breast milk appear to develop normal innate and adaptive responses both systemically and at intestinal mucosal surfaces.
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Affiliation(s)
- Becky Adkins
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
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PrabhuDas M, Adkins B, Gans H, King C, Levy O, Ramilo O, Siegrist CA. Challenges in infant immunity: implications for responses to infection and vaccines. Nat Immunol 2011; 12:189-94. [PMID: 21321588 DOI: 10.1038/ni0311-189] [Citation(s) in RCA: 294] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Mercy PrabhuDas
- Division of Allergy, Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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