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Petkau G, Mitchell TJ, Chakraborty K, Bell SE, D Angeli V, Matheson L, Turner DJ, Saveliev A, Gizlenci O, Salerno F, Katsikis PD, Turner M. The timing of differentiation and potency of CD8 effector function is set by RNA binding proteins. Nat Commun 2022; 13:2274. [PMID: 35477960 PMCID: PMC9046422 DOI: 10.1038/s41467-022-29979-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 03/30/2022] [Indexed: 01/08/2023] Open
Abstract
CD8+ T cell differentiation into effector cells is initiated early after antigen encounter by signals from the T cell antigen receptor and costimulatory molecules. The molecular mechanisms that establish the timing and rate of differentiation however are not defined. Here we show that the RNA binding proteins (RBP) ZFP36 and ZFP36L1 limit the rate of differentiation of activated naïve CD8+ T cells and the potency of the resulting cytotoxic lymphocytes. The RBP function in an early and short temporal window to enforce dependency on costimulation via CD28 for full T cell activation and effector differentiation by directly binding mRNA of NF-κB, Irf8 and Notch1 transcription factors and cytokines, including Il2. Their absence in T cells, or the adoptive transfer of small numbers of CD8+ T cells lacking the RBP, promotes resilience to influenza A virus infection without immunopathology. These findings highlight ZFP36 and ZFP36L1 as nodes for the integration of the early T cell activation signals controlling the speed and quality of the CD8+ T cell response.
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Affiliation(s)
- Georg Petkau
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Twm J Mitchell
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Krishnendu Chakraborty
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Sarah E Bell
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Vanessa D Angeli
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Louise Matheson
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - David J Turner
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Alexander Saveliev
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Ozge Gizlenci
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Fiamma Salerno
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Peter D Katsikis
- Department of Immunology, Erasmus University Medical Center, P.O. Box 2040, 3000CA, Rotterdam, Netherlands
| | - Martin Turner
- Immunology Programme, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK.
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2
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Mohammed RN, Wehenkel SC, Galkina EV, Yates EK, Preece G, Newman A, Watson HA, Ohme J, Bridgeman JS, Durairaj RRP, Moon OR, Ladell K, Miners KL, Dolton G, Troeberg L, Kashiwagi M, Murphy G, Nagase H, Price DA, Matthews RJ, Knäuper V, Ager A. ADAM17-dependent proteolysis of L-selectin promotes early clonal expansion of cytotoxic T cells. Sci Rep 2019; 9:5487. [PMID: 30940840 PMCID: PMC6445073 DOI: 10.1038/s41598-019-41811-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 03/12/2019] [Indexed: 01/15/2023] Open
Abstract
L-selectin on T-cells is best known as an adhesion molecule that supports recruitment of blood-borne naïve and central memory cells into lymph nodes. Proteolytic shedding of the ectodomain is thought to redirect activated T-cells from lymph nodes to sites of infection. However, we have shown that activated T-cells re-express L-selectin before lymph node egress and use L-selectin to locate to virus-infected tissues. Therefore, we considered other roles for L-selectin proteolysis during T cell activation. In this study, we used T cells expressing cleavable or non-cleavable L-selectin and determined the impact of L-selectin proteolysis on T cell activation in virus-infected mice. We confirm an essential and non-redundant role for ADAM17 in TCR-induced proteolysis of L-selectin in mouse and human T cells and show that L-selectin cleavage does not regulate T cell activation measured by CD69 or TCR internalisation. Following virus infection of mice, L-selectin proteolysis promoted early clonal expansion of cytotoxic T cells resulting in an 8-fold increase over T cells unable to cleave L-selectin. T cells unable to cleave L-selectin showed delayed proliferation in vitro which correlated with lower CD25 expression. Based on these results, we propose that ADAM17-dependent proteolysis of L-selectin should be considered a regulator of T-cell activation at sites of immune activity.
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Affiliation(s)
- Rebar N Mohammed
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
- College of Veterinary Medicine, University of Sulaimani, Sulaimani, Kurdistan, Iraq
| | - Sophie C Wehenkel
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Elena V Galkina
- Francis Crick Institute, London, NW1 1AT, UK
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA, 23507, USA
| | | | | | - Andrew Newman
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - H Angharad Watson
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Julia Ohme
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - John S Bridgeman
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Ruban R P Durairaj
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Owen R Moon
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Kristin Ladell
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Kelly L Miners
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Garry Dolton
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Linda Troeberg
- Norwich Medical School, University of East Anglia, Norwich, NR4 7UQ, UK
| | | | - Gillian Murphy
- University of Cambridge Depratment of Oncology, Cancer Research UK Cambridge Insitute, Li Ka Shing Centre, Cambridge, CB2 0RE, UK
| | - Hideaki Nagase
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, OX3 7FY, UK
| | - David A Price
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
- Systems Immunity Research Institute, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - R James Matthews
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Vera Knäuper
- School of Dentistry, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Ann Ager
- Divsion of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK.
- Systems Immunity Research Institute, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK.
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3
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Moseman EA, Wu T, de la Torre JC, Schwartzberg PL, McGavern DB. Type I interferon suppresses virus-specific B cell responses by modulating CD8
+
T cell differentiation. Sci Immunol 2016; 1. [DOI: 10.1126/sciimmunol.aah3565] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- E. Ashley Moseman
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tuoqi Wu
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Pamela L. Schwartzberg
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Dorian B. McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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4
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Nikolich-Žugich J, Li G, Uhrlaub JL, Renkema KR, Smithey MJ. Age-related changes in CD8 T cell homeostasis and immunity to infection. Semin Immunol 2012; 24:356-64. [PMID: 22554418 DOI: 10.1016/j.smim.2012.04.009] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 04/13/2012] [Indexed: 01/10/2023]
Abstract
Studies of CD8 T cell responses to vaccination or infection with various pathogens in both animal models and human subjects have revealed a markedly consistent array of age-related defects. In general, recent work shows that aged CD8 T cell responses are decreased in magnitude, and show poor differentiation into effector cells, with a reduced arsenal of effector functions. Here we review potential mechanisms underlying these defects. We specifically address phenotypic and numeric changes to the naïve CD8 T cell precursor pool, the impact of persistent viral infection(s) and inflammation, and contributions of the aging environment in which these cells are activated.
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Affiliation(s)
- Janko Nikolich-Žugich
- Department of Immunobiology and the Arizona Center on Aging, University of Arizona College of Medicine, Tucson, AZ 85724, United States.
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5
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Olson MR, Russ BE, Doherty PC, Turner SJ. The role of epigenetics in the acquisition and maintenance of effector function in virus-specific CD8 T cells. IUBMB Life 2010; 62:519-26. [PMID: 20552633 DOI: 10.1002/iub.351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CD8(+) T cells are critical for protecting the body from infectious disease. To achieve this protection, CD8(+) T cells must undergo a highly involved process of differentiation that involves the activation of naïve/quiescent cells followed by robust rounds of cell division and the acquisition of effector functions that mediate viral clearance. After the pathogen is eliminated, a small number of these cells survive into long-lived memory and maintain the capacity to respond rapidly and reacquire effector function after secondary exposure to their cognate antigen. This review focuses on how CD8(+) T cells acquire and regulate effector functions and how the capacity to produce effector molecules is maintained into memory.
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Affiliation(s)
- Matthew R Olson
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC, Australia.
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6
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Olson M, Russ B, Doherty P, Turner S, Stambas J. Influenza A virus-specific CD8 T-cell responses: from induction to function. Future Virol 2010; 5:175-183. [PMID: 21544256 DOI: 10.2217/fvl.10.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Seasonal influenza virus infection is a leading cause of illness and mortality in young children and the elderly each year. Current influenza vaccines generate protective antibody responses; however, these must be given annually to provide protection against serologically distinct viruses. By contrast, CD8(+) T cells are capable of recognizing conserved antigenic determinants within the influenza virion and, as such, may provide protection against a number of variant strains of the virus. CD8(+) T cells play a critical key role in controlling and resolving influenza virus infections via the production of cytokines and cytolytic mediators. This article focuses on the induction of the influenza-specific CD8(+) T-cell response and how these cells acquire and maintain effector function after induction. Moreover, we discuss how cytotoxic T-lymphocyte function correlates with protection following vaccination.
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Affiliation(s)
- Mr Olson
- Department of Microbiology & Immunology, University of Melbourne, Parkville, VIC, 3010, Australia
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7
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Moffat JM, Gebhardt T, Doherty PC, Turner SJ, Mintern JD. Granzyme A expression reveals distinct cytolytic CTL subsets following influenza A virus infection. Eur J Immunol 2009; 39:1203-10. [PMID: 19404988 DOI: 10.1002/eji.200839183] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
CTL mediate anti-viral immunity via targeted exocytosis of cytolytic granules containing perforin and members of the granzyme (grz) serine protease family. Here, we provide the first analysis of grzA protein expression by murine anti-viral CTL. During the progression of influenza A virus infection, CTL expressed two divergent cytolytic phenotypes: grzA(-)B(+) and grzA(+)B(+). CTL lacked grzA expression during the initial rounds of antigen-driven division. High levels of grzA were expressed by influenza-specific CTL early post infection (day 6), particularly in tissues associated with the infected respiratory tract (bronchoalveolar lavage, lung). Following resolution of influenza infection, a small population of memory CTL expressed grzA. Interestingly, individual influenza A virus-derived epitope-specific CTL expressed different levels of grzA. The grzA expression hierarchy was determined to be K(b)PB1(703)=D(b)F2(62)=K(b)NS2(114)>D(b)NP(366)=D(b)PA(224) and inversely correlated with CTL magnitude. Therefore following influenza infection, a CTL cytolytic hierarchy was established relating to the different profiles of antigen expression and relative immunodominance. Analysis of CTL grzA expression during influenza virus immunity has enabled a more detailed insight into the cytolytic mechanisms of virus elimination.
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Affiliation(s)
- Jessica M Moffat
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia
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8
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Palmowski MJ, Parker M, Choudhuri K, Chiu C, Callan MFC, van der Merwe PA, Cerundolo V, Gould KG. A single-chain H-2Db molecule presenting an influenza virus nucleoprotein epitope shows enhanced ability at stimulating CD8+ T cell responses in vivo. THE JOURNAL OF IMMUNOLOGY 2009; 182:4565-71. [PMID: 19342630 DOI: 10.4049/jimmunol.0803893] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have generated a construct encoding a single-chain H-2D(b) mouse MHC class I molecule in which an influenza virus nucleoprotein (NP) epitope, amino acid sequence ASNENMDAM, is fused to mouse beta(2)-microglobulin and the D(b) H chain via flexible linker sequences. This single-chain trimer (SCT) was efficiently expressed at the cell surface independently of TAP and endogenous beta(2)-microglobulin, and it was recognized directly and efficiently by specific T cells in vitro. A recombinant vaccinia virus encoding the D(b) NP SCT primed a CD8(+) T cell response in C57BL/6 mice 4-fold greater than an equivalent virus expressing the NP epitope as a minigene, as shown by tetramer staining, whether or not the minigene was directed into the endoplasmic reticulum by a signal sequence. This response was functional as shown by in vivo lysis assays with peptide-pulsed target cells, and it was greatly expanded following secondary challenge in vivo with influenza virus. The SCT was also significantly more immunostimulatory for CD8(+) cells than the NP minigene in adoptive transfer experiments using F5 TCR transgenic spleen cells, in which the magnitude of the T cell response was much greater. Our results extend previous DNA vaccination studies using SCTs, which demonstrated that such molecules are capable of generating functional CD8(+) T cell responses. We have shown that class I SCTs are more immunogenic than even preprocessed Ag in the form of an epitope minigene, and they therefore should be considered for use when the generation of optimal CD8(+) T cell responses is required.
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Affiliation(s)
- Michael J Palmowski
- Tumour Immunology Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
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9
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Abstract
Despite recent advances in immunology, several key parameters determining virus dynamics in infected hosts remain largely unknown. For example, the rate at which specific effector and memory CD8 T cells clear virus-infected cells in vivo is hardly known for any viral infection. We propose a framework to quantify T-cell-mediated killing of infected or peptide-pulsed target cells using the widely used in vivo cytotoxicity assay. We have reanalyzed recently published data on killing of peptide-pulsed splenocytes by cytotoxic T lymphocytes and memory CD8 T cells specific to NP396 and GP276 epitopes of lymphocytic choriomeningitis virus (LCMV) in the mouse spleen. Because there are so many effector CD8 T cells in spleens of mice at the peak of the immune response, NP396- and GP276-pulsed targets are estimated to have very short half-lives of 2 and 14 min, respectively. After the effector numbers have diminished, i.e., in LCMV-immune mice, the half-lives become 48 min and 2.8 h for NP396- and GP276-expressing targets, respectively. Analysis of several alternative models demonstrates that the estimates of half-life times of peptide-pulsed targets are not affected when changes are made in the model assumptions. Our report provides a unifying framework to compare killing efficacies of CD8 T-cell responses specific to different viral and bacterial infections in vivo, which may be used to compare efficacies of various cytotoxic-T-lymphocyte-based vaccines.
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10
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Fuse S, Usherwood E. Simultaneous analysis of in vivo CD8+ T cell cytotoxicity against multiple epitopes using multicolor flow cytometry. Immunol Invest 2008; 36:829-45. [PMID: 18161531 DOI: 10.1080/08820130701683753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
CD8+ T cells play a critical role in host defense against infections and tumors. Analysis of cytotoxic function of antigen-specific CD8+ T cells in animal models would be important in optimizing vaccine design against infections and tumors. In vivo cytotoxicity assays using fluorescent cellular dyes have been used as a popular alternative to traditionally used in vitro (51)Cr-release assays. With the identification of multiple epitopes in various pathogen models, methods to simultaneously analyze cytotoxicity of CD8+ T cells to multiple epitopes in vivo would assist studies which aim to generate protective CD8+ T cell immunity to multiple epitopes. In this study, we evaluate the use of multiple fluorescent cellular dyes for the in vivo cytotoxicity assay. The use of 3 dyes allowed us to analyze the cytotoxicity of antigen-specific CD8+ T cell populations to multiple epitopes generated by virus infections, as well as their functional avidity, in vivo. Our studies extend the use of in vivo cytotoxicity assays to allow direct comparisons of cytotoxicity to various epitopes in the same animal and may also be applicable to assessment of in vitro cytotoxicity of human CD8+ T cells specific for multiple viral or tumor antigens in clinical settings.
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Affiliation(s)
- Shinichiro Fuse
- Department of Microbiology and Immunology, Dartmouth Medical School, Lebanon, New Hampshire, USA
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11
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Speiser DE, Baumgaertner P, Voelter V, Devevre E, Barbey C, Rufer N, Romero P. Unmodified self antigen triggers human CD8 T cells with stronger tumor reactivity than altered antigen. Proc Natl Acad Sci U S A 2008; 105:3849-54. [PMID: 18319339 PMCID: PMC2268830 DOI: 10.1073/pnas.0800080105] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Indexed: 11/18/2022] Open
Abstract
Human cancer vaccines are often prepared with altered "analog" or "heteroclitic" antigens that have been optimized for HLA class I binding, resulting in enhanced immunogenicity. Here, we take advantage of CpG oligodeoxynucleotides as powerful vaccine adjuvants and demonstrate the induction of high T cell frequencies in melanoma patients, despite the use of natural (unmodified) tumor antigenic peptide. Compared with vaccination with analog peptide, natural peptide induced T cell frequencies that were approximately twofold lower. However, T cells showed superior tumor reactivity because of (i) increased functional avidity for natural antigen and (ii) enhancement of T cell activation and effector function. Thus, novel vaccine formulations comprising potent immune stimulators may allow to circumvent the need for modified antigens and can induce highly functional T cells with precise antigen specificity.
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Affiliation(s)
- Daniel E Speiser
- Division of Clinical Onco-Immunology, Ludwig Institute for Cancer Research and University of Lausanne, and Multidisciplinary Oncology Center, Centre Hospitalier Universitaire Vaudois, 1001 Lausanne, Switzerland.
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12
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Xiao Z, Mescher MF, Jameson SC. Detuning CD8 T cells: down-regulation of CD8 expression, tetramer binding, and response during CTL activation. ACTA ACUST UNITED AC 2007; 204:2667-77. [PMID: 17954566 PMCID: PMC2118473 DOI: 10.1084/jem.20062376] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CD8 is critical for T cell recognition of peptide/class I major histocompatability complex ligands, yet is down-regulated during activation of CD8 T cells. We report that loss of CD8 expression early during in vivo responses to vaccinia virus or Listeria monocytogenes (LM) correlates with decreased T cell staining with specific class I/peptide tetramers and reduced CD8 T cell sensitivity for antigen. Loss of CD8 cell surface expression occurs despite sustained mRNA expression, and CD8 levels return to normal levels during differentiation of memory cells, indicating a transient effect. We determined that during response to LM, CD8 down-regulation is regulated by T cell reactivity to type I interferon (IFN-I) because CD8 loss was averted on IFN-I receptor-deficient T cells. IFN-I alone was not sufficient to drive CD8 down-regulation, however, as antigen was also required for CD8 loss. These results suggest that CD8 effector T cell differentiation involves a transient down-regulation of antigen sensitivity (CTL "detuning"), via reduced CD8 expression, a feature that may focus the effector response on target cells expressing high levels of antigen (e.g., infected cells), while limiting collateral damage to bystander cells.
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Affiliation(s)
- Zhengguo Xiao
- Center for Immunology and 2Department of Laboratory Medicine and Pathology, Medical School, University of Minnesota, Minneapolis, MN 55455
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13
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Ganusov VV, Milutinović D, De Boer RJ. IL-2 regulates expansion of CD4+ T cell populations by affecting cell death: insights from modeling CFSE data. THE JOURNAL OF IMMUNOLOGY 2007; 179:950-7. [PMID: 17617586 DOI: 10.4049/jimmunol.179.2.950] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
It is generally accepted that IL-2 influences the dynamics of populations of T cells in vitro and in vivo. However, which parameters for cell division and/or death are affected by IL-2 is not well understood. To get better insights into the potential ways of how IL-2 may influence the population dynamics of T cells, we analyze data on the dynamics of CFSE-labeled polyclonal CD4(+) T lymphocytes in vitro after anti-CD3 stimulation at different concentrations of exogenous IL-2. Inferring cell division and death rates from CFSE-delabeling experiments is not straightforward and requires the use of mathematical models. We find that to adequately describe the dynamics of T cells at low concentrations of exogenous IL-2, the death rate of divided cells has to increase with the number of divisions cells have undergone. IL-2 hardly affects the average interdivision time. At low IL-2 concentrations 1) fewer cells are recruited into the response and successfully complete their first division; 2) the stochasticity of cell division is increased; and 3) the rate, at which the death rate increases with the division number, increases. Summarizing, our mathematical reinterpretation suggests that the main effect of IL-2 on the in vitro dynamics of naive CD4(+) T cells occurs by affecting the rate of cell death and not by changing the rate of cell division.
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Affiliation(s)
- Vitaly V Ganusov
- Theoretical Biology, Utrecht University, Utrecht, The Netherlands.
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14
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Jenkins MR, Kedzierska K, Doherty PC, Turner SJ. Heterogeneity of effector phenotype for acute phase and memory influenza A virus-specific CTL. THE JOURNAL OF IMMUNOLOGY 2007; 179:64-70. [PMID: 17579022 DOI: 10.4049/jimmunol.179.1.64] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ag-specific, CD8+ CTLs clear influenza A viruses from the lung via granzyme (Gzm) and perforin-dependent mechanisms. Ex vivo analysis of perforin-Gzm mRNA profiles demonstrated substantial heterogeneity in patterns of effector mRNA transcription of CD8+ D(b)NP(366)- or D(b)PA(224)-specific CTL. The only difference between the two epitope-specific sets was apparent very early after infection with similar molecular profiles seen in peak primary and secondary responses and in long-term memory. Surprisingly, memory T cells also expressed a diverse pattern of effector mRNA profile with an emphasis on GzmB and, surprisingly, GzmK. This analysis thus defines how naive, effector, and memory T cells differ in cytotoxic potential and provides novel insight into the molecular signatures of effector molecules observed at various stages after infection.
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Affiliation(s)
- Misty R Jenkins
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
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