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de Boer RJ, Tesselaar K, Borghans JAM. Better safe than sorry: Naive T-cell dynamics in healthy ageing. Semin Immunol 2023; 70:101839. [PMID: 37716048 DOI: 10.1016/j.smim.2023.101839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 09/01/2023] [Accepted: 09/02/2023] [Indexed: 09/18/2023]
Abstract
It is well-known that the functioning of the immune system gradually deteriorates with age, and we are increasingly confronted with its consequences as the life expectancy of the human population increases. Changes in the T-cell pool are among the most prominent features of the changing immune system during healthy ageing, and changes in the naive T-cell pool in particular are generally held responsible for its gradual deterioration. These changes in the naive T-cell pool are thought to be due to involution of the thymus. It is commonly believed that the gradual loss of thymic output induces compensatory mechanisms to maintain the number of naive T cells at a relatively constant level, and induces a loss of diversity in the T-cell repertoire. Here we review the studies that support or challenge this widely-held view of immune ageing and discuss the implications for vaccination strategies.
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Affiliation(s)
- Rob J de Boer
- Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, the Netherlands
| | - Kiki Tesselaar
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - José A M Borghans
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands.
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2
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Derksen LY, Tesselaar K, Borghans JAM. Memories that last: Dynamics of memory T cells throughout the body. Immunol Rev 2023. [PMID: 37114435 DOI: 10.1111/imr.13211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Memory T cells form an essential part of immunological memory, which can last for years or even a lifetime. Much experimental work has shown that the individual cells that make up the memory T-cell pool are in fact relatively short-lived. Memory T cells isolated from the blood of humans, or the lymph nodes and spleen of mice, live about 5-10 fold shorter than naive T cells, and much shorter than the immunological memory they convey. The commonly accepted view is, therefore, that long-term T-cell memory is maintained dynamically rather than by long-lived cells. This view is largely based on memory T cells in the circulation, identified using rather broad phenotypic markers, and on research in mice living in overly clean conditions. We wondered to what extent there may be heterogeneity in the dynamics and lifespans of memory T cells. We here review what is currently known about the dynamics of memory T cells in different memory subsets, locations in the body and conditions of microbial exposure, and discuss how this may be related to immunometabolism and how this knowledge can be used in various clinical settings.
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Affiliation(s)
- Lyanne Y Derksen
- Leukocyte Dynamics Group, Center for Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kiki Tesselaar
- Leukocyte Dynamics Group, Center for Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - José A M Borghans
- Leukocyte Dynamics Group, Center for Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
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3
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Pasternak AO, Berkhout B. HIV persistence: silence or resistance? Curr Opin Virol 2023; 59:101301. [PMID: 36805974 DOI: 10.1016/j.coviro.2023.101301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/05/2022] [Accepted: 12/19/2022] [Indexed: 02/19/2023]
Abstract
Despite decades of suppressive antiretroviral therapy, human immunodeficiency virus (HIV) reservoirs in infected individuals persist and fuel viral rebound once therapy is interrupted. The persistence of viral reservoirs is the main obstacle to achieving HIV eradication or a long-term remission. The last decade has seen a profound change in our understanding of the mechanisms behind HIV persistence, which appears to be much more complex than originally assumed. In addition to the persistence of transcriptionally silent proviruses in a stable latent reservoir that is invisible to the immune system, HIV is increasingly recognized to persist by resistance to the immune clearance, which appears to play a surprisingly prominent role in shaping the reservoir. In this review, we discuss some emerging insights into the mechanisms of HIV persistence, as well as their implications for the development of strategies towards an HIV cure.
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Affiliation(s)
- Alexander O Pasternak
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
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4
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Baliu-Piqué M, Tesselaar K, Borghans JAM. Are homeostatic mechanisms aiding the reconstitution of the T-cell pool during lymphopenia in humans? Front Immunol 2022; 13:1059481. [PMID: 36483556 PMCID: PMC9723355 DOI: 10.3389/fimmu.2022.1059481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/02/2022] [Indexed: 11/23/2022] Open
Abstract
A timely recovery of T-cell numbers following haematopoietic stem-cell transplantation (HSCT) is essential for preventing complications, such as increased risk of infection and disease relapse. In analogy to the occurrence of lymphopenia-induced proliferation in mice, T-cell dynamics in humans are thought to be homeostatically regulated in a cell density-dependent manner. The idea is that T cells divide faster and/or live longer when T-cell numbers are low, thereby helping the reconstitution of the T-cell pool. T-cell reconstitution after HSCT is, however, known to occur notoriously slowly. In fact, the evidence for the existence of homeostatic mechanisms in humans is quite ambiguous, since lymphopenia is often associated with infectious complications and immune activation, which confound the study of homeostatic regulation. This calls into question whether homeostatic mechanisms aid the reconstitution of the T-cell pool during lymphopenia in humans. Here we review the changes in T-cell dynamics in different situations of T-cell deficiency in humans, including the early development of the immune system after birth, healthy ageing, HIV infection, thymectomy and hematopoietic stem cell transplantation (HSCT). We discuss to what extent these changes in T-cell dynamics are a side-effect of increased immune activation during lymphopenia, and to what extent they truly reflect homeostatic mechanisms.
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Affiliation(s)
| | | | - José A. M. Borghans
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
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5
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Anikeeva N, Steblyanko M, Kuri-Cervantes L, Buggert M, Betts MR, Sykulev Y. The immune synapses reveal aberrant functions of CD8 T cells during chronic HIV infection. Nat Commun 2022; 13:6436. [PMID: 36307445 PMCID: PMC9616955 DOI: 10.1038/s41467-022-34157-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 10/14/2022] [Indexed: 02/05/2023] Open
Abstract
Chronic HIV infection causes persistent low-grade inflammation that induces premature aging of the immune system including senescence of memory and effector CD8 T cells. To uncover the reasons of gradually diminished potency of CD8 T cells from people living with HIV, here we expose the T cells to planar lipid bilayers containing ligands for T-cell receptor and a T-cell integrins and analyze the cellular morphology, dynamics of synaptic interface formation and patterns of the cellular degranulation. We find a large fraction of phenotypically naive T cells from chronically infected people are capable to form mature synapse with focused degranulation, a signature of a differentiated T cells. Further, differentiation of aberrant naive T cells may lead to the development of anomalous effector T cells undermining their capacity to control HIV and other pathogens that could be contained otherwise.
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Affiliation(s)
- Nadia Anikeeva
- grid.265008.90000 0001 2166 5843Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA USA
| | - Maria Steblyanko
- grid.265008.90000 0001 2166 5843Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA USA
| | - Leticia Kuri-Cervantes
- grid.25879.310000 0004 1936 8972Department of Microbiology and Institute of Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Marcus Buggert
- grid.25879.310000 0004 1936 8972Department of Microbiology and Institute of Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA ,grid.24381.3c0000 0000 9241 5705Present Address: Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Michael R. Betts
- grid.25879.310000 0004 1936 8972Department of Microbiology and Institute of Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Yuri Sykulev
- grid.265008.90000 0001 2166 5843Departments of Immunology and Medical Oncology, Thomas Jefferson University, Philadelphia, PA USA ,grid.265008.90000 0001 2166 5843Sydney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA USA
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6
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Briceño O, Peralta-Prado A, Garrido-Rodríguez D, Romero-Mora K, Chávez-Torres M, de la Barrera CA, Reyes-Terán G, Ávila-Ríos S. Characterization of CD31 expression in CD4+ and CD8+T cell subpopulations in chronic untreated HIV infection. Immunol Lett 2021; 235:22-31. [PMID: 33852965 DOI: 10.1016/j.imlet.2021.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 03/09/2021] [Accepted: 04/07/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND The platelet endothelial cell adhesion molecule-1 (PECAM-1) or CD31 has been involved in regulation of T-cell tolerance, activation, survival and homing in mice cells. However, there is limited knowledge about the expression pattern and role of this molecule in human T cells, particularly in conditions of chronic immune activation. OBJECTIVES We explored CD31 expression in T cell differentiation subsets of individuals with untreated HIV infection and in non-HIV-infected controls. We also assessed phenotypic differences between CD31+ and CD31- subsets in memory and terminally differentiated (TEMRA) CD4+ and CD8 + T cells. METHODS Forty-one individuals with untreated HIV infection and 34 non-HIV-infected controls were included in the study. We compared the expression of CD31 in CD4+ and CD8 + T cells across stages of differentiation in the two study groups by flow cytometry. We also analyzed the expression of CD57 (a marker of senescence), Ki67 (a marker of cycling cells), PD-1 (a marker of exhaustion), and CD38/HLA-DR (a marker of immune activation) on memory and TEMRA CD31+ and CD31- T cells. RESULTS CD31 expression was significantly higher in CD8 + T cells than in CD4 + T cells, measured as frequency, absolute numbers and median fluorescence intensity (MFI), in both study groups (p < 0.0001 in all cases). Intermediate differentiation subsets of CD4+ and CD8 + T cells expressed higher levels of CD31 in the context of HIV infection (p < 0.001 in all cases). CD31 expression frequency decreased with cellular differentiation of CD4+ and CD8 + T cells in both groups, but this decrease was steeper in individuals without HIV infection (CD4+: p < 0.001 and CD8+: p < 0.0001). As expected, memory and TEMRA CD4+ and CD8 + T cells expressed significantly higher levels of CD57, PD-1, Ki67 and CD38/HLA-DR in HIV-infected compared to non-HIV-infected individuals (p < 0.01 in all cases). CD31 expression was associated with lower activation of memory (but not TEMRA) CD4 + T cells in non-HIV-infected persons, an effect not observed in the HIV-infected group. CD31 expression on memory CD8 + T cells of HIV-infected individuals was associated higher levels of PD-1 (p = 0.0019) and CD38/HLADR (p = 0.0345), and higher PD-1 expression on CD8 + TEMRA (p = 0.0024), an effect not observed in non-HIV-infected individuals. CONCLUSION In the context of HIV-associated chronic immune activation, specifically on memory CD8 + T cells, CD31 expression was associated with higher PD-1 and CD38/HLA-DR co-expression, suggesting that CD31 expression may result from an insufficient attempt to contain T cell exhaustion and activation. CD31-targeted therapies may contribute to modulate these cellular responses.
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Affiliation(s)
- Olivia Briceño
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico.
| | - Amy Peralta-Prado
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Daniela Garrido-Rodríguez
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Karla Romero-Mora
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Monserrat Chávez-Torres
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Claudia-Alvarado de la Barrera
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
| | - Gustavo Reyes-Terán
- Coordinating Commission of the Mexican National Institutes of Health, Mexico City, Mexico
| | - Santiago Ávila-Ríos
- Instituto Nacional de Enfermedades Respiratorias, Centro de Investigación en Enfermedades Infecciosas, México City, Mexico
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7
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Nagaraja P, Gopalan BP, D'Souza RR, Sarkar D, Rajnala N, Dixit NM, Shet A. The within-host fitness of HIV-1 increases with age in ART-naïve HIV-1 subtype C infected children. Sci Rep 2021; 11:2990. [PMID: 33542308 PMCID: PMC7862260 DOI: 10.1038/s41598-021-82293-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/18/2021] [Indexed: 02/07/2023] Open
Abstract
As the immune system develops with age, children combat infections better. HIV-1, however, targets an activated immune system, potentially rendering children increasingly permissive to HIV-1 infection as they grow. How HIV-1 fitness changes with age in children is unknown. Here, we estimated the within-host basic reproductive ratio, R0, a marker of viral fitness, in HIV-1 subtype C-infected children in India, aged between 84 days and 17 years. We measured serial viral load and CD4 T cell counts in 171 children who initiated first-line ART. For 25 children, regular and frequent measurements provided adequate data points for analysis using a mathematical model of viral dynamics to estimate R0. For the rest, we used CD4 counts for approximate estimation of R0. The viral load decline during therapy was biphasic. The mean lifespans of productively and long-lived infected cells were 1.4 and 27.8 days, respectively. The mean R0 was 1.5 in children aged < 5 years, increased with age, and approached 6.0 at 18 years, close to 5.8 estimated previously for adults. The tolerogenic immune environment thus compromises HIV-1 fitness in young children. Early treatment initiation, when the R0 is small, will likely improve viral control, in addition to suppressing the latent reservoir.
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Affiliation(s)
- Pradeep Nagaraja
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Bindu P Gopalan
- Division of Infectious Diseases, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.,The University of Trans Disciplinary Health Sciences and Technology, Bangalore, India
| | - Reena R D'Souza
- Division of Infectious Diseases, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.,University of Oxford, Oxford, UK
| | - Debolina Sarkar
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Niharika Rajnala
- Division of Infectious Diseases, St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India
| | - Narendra M Dixit
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka, 560012, India. .,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore, India.
| | - Anita Shet
- International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, 415 N Washington Street, Baltimore, 21321, USA.
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8
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Ahmed R, Miners KL, Lahoz-Beneytez J, Jones RE, Roger L, Baboonian C, Zhang Y, Wang ECY, Hellerstein MK, McCune JM, Baird DM, Price DA, Macallan DC, Asquith B, Ladell K. CD57 + Memory T Cells Proliferate In Vivo. Cell Rep 2020; 33:108501. [PMID: 33326780 PMCID: PMC7758161 DOI: 10.1016/j.celrep.2020.108501] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/26/2020] [Accepted: 11/18/2020] [Indexed: 01/15/2023] Open
Abstract
A central paradigm in the field of lymphocyte biology asserts that replicatively senescent memory T cells express the carbohydrate epitope CD57. These cells nonetheless accumulate with age and expand numerically in response to persistent antigenic stimulation. Here, we use in vivo deuterium labeling and ex vivo analyses of telomere length, telomerase activity, and intracellular expression of the cell-cycle marker Ki67 to distinguish between two non-exclusive scenarios: (1) CD57+ memory T cells do not proliferate and instead arise via phenotypic transition from the CD57- memory T cell pool; and/or (2) CD57+ memory T cells self-renew via intracompartmental proliferation. Our results provide compelling evidence in favor of the latter scenario and further suggest in conjunction with mathematical modeling that self-renewal is by far the most abundant source of newly generated CD57+ memory T cells. Immunological memory therefore appears to be intrinsically sustainable among highly differentiated subsets of T cells that express CD57.
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Affiliation(s)
- Raya Ahmed
- Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Kelly L Miners
- Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | | | - Rhiannon E Jones
- Division of Cancer and Genetics, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Laureline Roger
- Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Christina Baboonian
- Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Yan Zhang
- Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Eddie C Y Wang
- Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Marc K Hellerstein
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
| | - Joseph M McCune
- HIV Frontiers Program, Global Health Innovative Technology Solutions, Bill & Melinda Gates Foundation, Seattle, WA 98109, USA
| | - Duncan M Baird
- Division of Cancer and Genetics, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - David A Price
- Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK; Systems Immunity Research Institute, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
| | - Derek C Macallan
- Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK; St George's University Hospitals NHS Foundation Trust, London SW17 0QT, UK.
| | - Becca Asquith
- Department of Infectious Disease, Imperial College London, London W2 1PG, UK.
| | - Kristin Ladell
- Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK; Neonatal Unit, Singleton Hospital, Swansea Bay University Health Board, Swansea SA2 8QA, UK.
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9
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Venanzi Rullo E, Pinzone MR, Cannon L, Weissman S, Ceccarelli M, Zurakowski R, Nunnari G, O'Doherty U. Persistence of an intact HIV reservoir in phenotypically naive T cells. JCI Insight 2020; 5:133157. [PMID: 33055422 PMCID: PMC7605525 DOI: 10.1172/jci.insight.133157] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 09/10/2020] [Indexed: 12/25/2022] Open
Abstract
Despite the efficacy of antiretroviral therapy (ART), HIV persists in a latent form and remains a hurdle to eradication. CD4+ T lymphocytes harbor the majority of the HIV reservoir, but the role of individual subsets remains unclear. CD4+ T cells were sorted into central, transitional, effector memory, and naive T cells. We measured HIV DNA and performed proviral sequencing of more than 1900 proviruses in 2 subjects at 2 and 9 years after ART initiation to estimate the contribution of each subset to the reservoir. Although our study was limited to 2 subjects, we obtained comparable findings with publicly available sequences. While the HIV integration levels were lower in naive compared with memory T cells, naive cells were a major contributor to the intact proviral reservoir. Notably, proviral sequences isolated from naive cells appeared to be unique, while those retrieved from effector memory cells were mainly clonal. The number of clones increased as cells differentiated from a naive to an effector memory phenotype, suggesting naive cells repopulate the effector memory reservoir as previously shown for central memory cells. Naive T cells contribute substantially to the intact HIV reservoir and represent a significant hurdle for HIV eradication.
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Affiliation(s)
- Emmanuele Venanzi Rullo
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Clinical and Experimental Medicine, Unit of Infectious Diseases, University of Messina, Messina, Italy
| | - Marilia Rita Pinzone
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - LaMont Cannon
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for the Study of Biological Complexity, Virginia Commonwealth University, Virginia, USA
| | - Sam Weissman
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Manuela Ceccarelli
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Clinical and Experimental Medicine, Unit of Infectious Diseases, University of Messina, Messina, Italy
| | - Ryan Zurakowski
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Giuseppe Nunnari
- Department of Clinical and Experimental Medicine, Unit of Infectious Diseases, University of Messina, Messina, Italy
| | - Una O'Doherty
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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10
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Borghans JAM, Tesselaar K, de Boer RJ. Current best estimates for the average lifespans of mouse and human leukocytes: reviewing two decades of deuterium-labeling experiments. Immunol Rev 2019; 285:233-248. [PMID: 30129193 DOI: 10.1111/imr.12693] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Deuterium is a non-toxic, stable isotope that can safely be administered to humans and mice to study their cellular turnover rates in vivo. It is incorporated into newly synthesized DNA strands during cell division, without interference with the kinetics of cells, and the accumulation and loss of deuterium in the DNA of sorted (sub-)populations of leukocytes can be used to estimate their cellular production rates and lifespans. In the past two decades, this powerful technology has been used to estimate the turnover rates of various types of leukocytes. Although it is the most reliable technique currently available to study leukocyte turnover, there are remarkable differences between the cellular turnover rates estimated by some of these studies. We have recently established that part of this variation is due to (a) difficulties in estimating deuterium availability in some deuterium-labeling studies, and (b) assumptions made by the mathematical models employed to fit the data. Being aware of these two problems, we here aim to approach a consensus on the life expectancies of different types of T cells, B cells, monocytes, and neutrophils in mice and men. We address remaining outstanding problems whenever appropriate and discuss for which immune subpopulations we currently have too little information to draw firm conclusions about their turnover.
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Affiliation(s)
- José A M Borghans
- Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Kiki Tesselaar
- Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Rob J de Boer
- Theoretical Biology & Bioinformatics, Utrecht, The Netherlands
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11
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Abstract
Generating and maintaining a diverse repertoire of naive T cells is essential for protection against pathogens, and developing a mechanistic and quantitative description of the processes involved lies at the heart of our understanding of vertebrate immunity. Here, we review the biology of naive T cells from birth to maturity and outline how the integration of mathematical models and experiments has helped us to develop a full picture of their life histories.
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Affiliation(s)
- Benedict Seddon
- Institute of Immunity and Transplantation, Division of Infection and Immunity, UCL, Royal Free Hospital, London, UK
| | - Andrew J Yates
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
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12
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T-cell and B-cell perturbations identify distinct differences in HIV-2 compared with HIV-1-induced immunodeficiency. AIDS 2019; 33:1131-1141. [PMID: 30845070 DOI: 10.1097/qad.0000000000002184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND For unknown reasons, HIV-2 is less pathogenic than HIV-1, and HIV-2-induced immunodeficiency may be different from that caused by HIV-1. Previous immunological studies have hinted at possible shifts in both T-cell and B-cell subsets, which we aimed to characterize further. METHODS From an HIV clinic in Guinea-Bissau, 63 HIV-2, 83 HIV-1, and 26 HIV-negative participants were included. All HIV-infected participants were ART-naive. The following cell subsets were analysed by flow cytometry; T cells (maturation and activation), regulatory T cells, and B cells (maturation and activation). RESULTS After standardizing for sex, age, and CD4 T-cell count HIV-2 had 0.938 log10 copies/ml lower HIV RNA levels than the HIV-1-infected patients. Whereas T-cell maturation and regulatory T-cell profiles were similar between patients, HIV-2-infected patients had higher proportions of CD8CD28 and lower proportions of CD8PD-1+ T cells than HIV-1-infected patients. This finding was independent of HIV RNA levels. HIV-2 was also associated with a more preserved proportion of naive B cells. CONCLUSION HIV-2 is characterized by lower viral load, and lower T-cell activation, which may account for the slower disease progression.
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13
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Veel E, Westera L, van Gent R, Bont L, Otto S, Ruijsink B, Rabouw HH, Mudrikova T, Wensing A, Hoepelman AIM, Borghans JAM, Tesselaar K. Impact of Aging, Cytomegalovirus Infection, and Long-Term Treatment for Human Immunodeficiency Virus on CD8 + T-Cell Subsets. Front Immunol 2018; 9:572. [PMID: 29619031 PMCID: PMC5871714 DOI: 10.3389/fimmu.2018.00572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/06/2018] [Indexed: 01/09/2023] Open
Abstract
Both healthy aging and human immunodeficiency virus (HIV) infection lead to a progressive decline in naive CD8+ T-cell numbers and expansion of the CD8+ T-cell memory and effector compartments. HIV infection is therefore often considered a condition of premature aging. Total CD8+ T-cell numbers of HIV-infected individuals typically stay increased even after long-term (LT) combination antiretroviral treatment (cART), which is associated with an increased risk of non-AIDS morbidity and mortality. The causes of these persistent changes in the CD8+ T-cell pool remain debated. Here, we studied the impact of age, CMV infection, and LT successful cART on absolute cell numbers in different CD8+ T-cell subsets. While naïve CD8+ T-cell numbers in cART-treated individuals (N = 38) increased to healthy levels, central memory (CM), effector memory (EM), and effector CD8+ T-cell numbers remained higher than in (unselected) age-matched healthy controls (N = 107). Longitudinal analysis in a subset of patients showed that cART did result in a loss of memory CD8+ T-cells, mainly during the first year of cART, after which memory cell numbers remained relatively stable. As CMV infection is known to increase CD8+ T-cell numbers in healthy individuals, we studied whether any of the persistent changes in the CD8+ T-cell pools of cART-treated patients could be a direct reflection of the high CMV prevalence among HIV-infected individuals. We found that EM and effector CD8+ T-cell numbers in CMV+ healthy individuals (N = 87) were significantly higher than in CMV- (N = 170) healthy individuals. As a result, EM and effector CD8+ T-cell numbers in successfully cART-treated HIV-infected individuals did not deviate significantly from those of age-matched CMV+ healthy controls (N = 39). By contrast, CM T-cell numbers were quite similar in CMV+ and CMV- healthy individuals across all ages. The LT expansion of the CM CD8+ T-cell pool in cART-treated individuals could thus not be attributed directly to CMV and was also not related to residual HIV RNA or to the presence of HIV-specific CM T-cells. It remains to be investigated why the CM CD8+ T-cell subset shows seemingly irreversible changes despite years of effective treatment.
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Affiliation(s)
- Ellen Veel
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Liset Westera
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Rogier van Gent
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Louis Bont
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Sigrid Otto
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Bram Ruijsink
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Huib H Rabouw
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Tania Mudrikova
- Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht, Netherlands
| | - Annemarie Wensing
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Andy I M Hoepelman
- Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht, Netherlands
| | - José A M Borghans
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Kiki Tesselaar
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, Netherlands
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14
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Heavy Water Shedding Light on Antigen-Specific T Cell Responses. Trends Immunol 2018; 39:170-172. [DOI: 10.1016/j.it.2018.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 01/11/2018] [Indexed: 01/16/2023]
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15
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Dendritic cell immunotherapy followed by cART interruption during HIV-1 infection induces plasma protein markers of cellular immunity and neutrophil recruitment. PLoS One 2018; 13:e0192278. [PMID: 29389978 PMCID: PMC5794189 DOI: 10.1371/journal.pone.0192278] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/16/2018] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVES To characterize the host response to dendritic cell-based immunotherapy and subsequent combined antiretroviral therapy (cART) interruption in HIV-1-infected individuals at the plasma protein level. DESIGN An autologous dendritic cell (DC) therapeutic vaccine was administered to HIV-infected individuals, stable on cART. The effect of vaccination was evaluated at the plasma protein level during the period preceding cART interruption, during analytical therapy interruption and at viral reactivation. Healthy controls and post-exposure prophylactically treated healthy individuals were included as controls. METHODS Plasma marker ('analyte') levels including cytokines, chemokines, growth factors, and hormones were measured in trial participants and control plasma samples using a multiplex immunoassay. Analyte levels were analysed using principle component analysis, cluster analysis and limma. Blood neutrophil counts were analysed using linear regression. RESULTS Plasma analyte levels of HIV-infected individuals are markedly different from those of healthy controls and HIV-negative individuals receiving post-exposure prophylaxis. Viral reactivation following cART interruption also affects multiple analytes, but cART interruption itself only has only a minor effect. We find that Thyroxine-Binding Globulin (TBG) levels and late-stage neutrophil numbers correlate with the time off cART after DC vaccination. Furthermore, analysis shows that cART alters several regulators of blood glucose levels, including C-peptide, chromogranin-A and leptin. HIV reactivation is associated with the upregulation of CXCR3 ligands. CONCLUSIONS Chronic HIV infection leads to a change in multiple plasma analyte levels, as does virus reactivation after cART interruption. Furthermore, we find evidence for the involvement of TBG and neutrophils in the response to DC-vaccination in the setting of HIV-infection.
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16
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van Hoeven V, Drylewicz J, Westera L, den Braber I, Mugwagwa T, Tesselaar K, Borghans JAM, de Boer RJ. Dynamics of Recent Thymic Emigrants in Young Adult Mice. Front Immunol 2017; 8:933. [PMID: 28824653 PMCID: PMC5545745 DOI: 10.3389/fimmu.2017.00933] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 07/21/2017] [Indexed: 11/13/2022] Open
Abstract
The peripheral naive T-cell pool is generally thought to consist of a subpopulation of recent thymic emigrants (RTEs) and a subpopulation of mature naive (MN) T cells with different dynamics. Thymus transplantation and adoptive transfer studies in mice have provided contradicting results, with some studies suggesting that RTEs are relatively short-lived cells, while another study suggested that RTEs have a survival advantage. We here estimate the death rates of RTE and MN T cells by performing both thymus transplantations and deuterium labeling experiments in mice of at least 12 weeks old, an age at which the size of the T-cell pool has stabilized. For CD4+ T cells, we found the total loss rate from the RTE compartment (by death and maturation) to be fourfold faster than that of MN T cells. We estimate the death rate of CD4+ RTE to be 0.046 per day, which is threefold faster than the total loss rate from the MN T-cell compartment. For CD8+ T cells, we found no evidence for kinetic differences between RTE and MN T cells. Thus, our data support the notion that in young adult mice, CD4+ RTE are relatively short-lived cells within the naive CD4+ T-cell pool.
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Affiliation(s)
- Vera van Hoeven
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Julia Drylewicz
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands.,Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, Netherlands
| | - Liset Westera
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Ineke den Braber
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Tendai Mugwagwa
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, Netherlands
| | - Kiki Tesselaar
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - José A M Borghans
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Rob J de Boer
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, Netherlands
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17
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Döring M, Borrego P, Büch J, Martins A, Friedrich G, Camacho RJ, Eberle J, Kaiser R, Lengauer T, Taveira N, Pfeifer N. A genotypic method for determining HIV-2 coreceptor usage enables epidemiological studies and clinical decision support. Retrovirology 2016; 13:85. [PMID: 27998283 PMCID: PMC5168878 DOI: 10.1186/s12977-016-0320-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/28/2016] [Indexed: 12/31/2022] Open
Abstract
Background CCR5-coreceptor antagonists can be used for treating HIV-2 infected individuals. Before initiating treatment with coreceptor antagonists, viral coreceptor usage should be determined to ensure that the virus can use only the CCR5 coreceptor (R5) and cannot evade the drug by using the CXCR4 coreceptor (X4-capable). However, until now, no online tool for the genotypic identification of HIV-2 coreceptor usage had been available. Furthermore, there is a lack of knowledge on the determinants of HIV-2 coreceptor usage. Therefore, we developed a data-driven web service for the prediction of HIV-2 coreceptor usage from the V3 loop of the HIV-2 glycoprotein and used the tool to identify novel discriminatory features of X4-capable variants. Results Using 10 runs of tenfold cross validation, we selected a linear support vector machine (SVM) as the model for geno2pheno[coreceptor-hiv2], because it outperformed the other SVMs with an area under the ROC curve (AUC) of 0.95. We found that SVMs were highly accurate in identifying HIV-2 coreceptor usage, attaining sensitivities of 73.5% and specificities of 96% during tenfold nested cross validation. The predictive performance of SVMs was not significantly different (p value 0.37) from an existing rules-based approach. Moreover, geno2pheno[coreceptor-hiv2] achieved a predictive accuracy of 100% and outperformed the existing approach on an independent data set containing nine new isolates with corresponding phenotypic measurements of coreceptor usage. geno2pheno[coreceptor-hiv2] could not only reproduce the established markers of CXCR4-usage, but also revealed novel markers: the substitutions 27K, 15G, and 8S were significantly predictive of CXCR4 usage. Furthermore, SVMs trained on the amino-acid sequences of the V1 and V2 loops were also quite accurate in predicting coreceptor usage (AUCs of 0.84 and 0.65, respectively). Conclusions In this study, we developed geno2pheno[coreceptor-hiv2], the first online tool for the prediction of HIV-2 coreceptor usage from the V3 loop. Using our method, we identified novel amino-acid markers of X4-capable variants in the V3 loop and found that HIV-2 coreceptor usage is also influenced by the V1/V2 region. The tool can aid clinicians in deciding whether coreceptor antagonists such as maraviroc are a treatment option and enables epidemiological studies investigating HIV-2 coreceptor usage. geno2pheno[coreceptor-hiv2] is freely available at http://coreceptor-hiv2.geno2pheno.org. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0320-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Matthias Döring
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus, Campus E 1 4, 66123, Saarbrücken, Germany.
| | - Pedro Borrego
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Professor Gama Pinto, 1649-003, Lisbon, Portugal.,Centro de Administração e Políticas Públicas (CAPP), Instituto Superior de Ciências Sociais e Políticas (ISCSP), University of Lisbon, Rua Almerindo Lessa, 1300-663, Lisbon, Portugal
| | - Joachim Büch
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus, Campus E 1 4, 66123, Saarbrücken, Germany
| | - Andreia Martins
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Professor Gama Pinto, 1649-003, Lisbon, Portugal
| | - Georg Friedrich
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus, Campus E 1 4, 66123, Saarbrücken, Germany
| | - Ricardo Jorge Camacho
- Rega Institute for Medical Research, Clinical and Epidemiological Virology, Department of Microbiology and Immunology, KU Leuven-University of Leuven, Minderbroedersstraat 10, 3000, Louvain, Belgium
| | - Josef Eberle
- Department of Virology, Max von Pettenkofer-Institut, Ludwig-Maximilians-University, Pettenkoferstraße 9a, 80336, Munich, Germany
| | - Rolf Kaiser
- Institute for Virology, University of Cologne, Fürst-Pückler-Str. 56, 50935, Cologne, Germany
| | - Thomas Lengauer
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus, Campus E 1 4, 66123, Saarbrücken, Germany
| | - Nuno Taveira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Professor Gama Pinto, 1649-003, Lisbon, Portugal.,Instituto Superior de Ciências da Saúde Egas Moniz (ISCSEM), Campus Universitário, Quinta da Granja, Monte de Caparica, 2829-511, Caparica, Portugal
| | - Nico Pfeifer
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus, Campus E 1 4, 66123, Saarbrücken, Germany.
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18
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Thiébaut R, Lévy Y. Reply to Bordoni et al. Clin Infect Dis 2016; 63:1684-1685. [PMID: 27664240 DOI: 10.1093/cid/ciw642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 09/02/2016] [Indexed: 11/14/2022] Open
Affiliation(s)
- Rodolphe Thiébaut
- INSERM U1219, INRIA Statistics in Systems and Translational Medicine, Bordeaux University
| | - Yves Lévy
- INSERM U955, Université Paris Est, Faculté de médecine.,Vaccine Research Institute.,AP-HP, Hôpital H. Mondor - A. Chenevier, Service d'immunologie clinique et maladies infectieuses, Créteil, France
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19
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Notwithstanding Circumstantial Alibis, Cytotoxic T Cells Can Be Major Killers of HIV-1-Infected Cells. J Virol 2016; 90:7066-7083. [PMID: 27226367 PMCID: PMC4984658 DOI: 10.1128/jvi.00306-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023] Open
Abstract
Several experiments suggest that in the chronic phase of human immunodeficiency virus type 1 (HIV-1) infection, CD8+ cytotoxic T lymphocytes (CTL) contribute very little to the death of productively infected cells. First, the expected life span of productively infected cells is fairly long, i.e., about 1 day. Second, this life span is hardly affected by the depletion of CD8+ T cells. Third, the rate at which mutants escaping a CTL response take over the viral population tends to be slow. Our main result is that all these observations are perfectly compatible with killing rates that are much faster than one per day once we invoke the fact that infected cells proceed through an eclipse phase of about 1 day before they start producing virus. Assuming that the major protective effect of CTL is cytolytic, we demonstrate that mathematical models with an eclipse phase account for the data when the killing is fast and when it varies over the life cycle of infected cells. Considering the steady state corresponding to the chronic phase of the infection, we find that the rate of immune escape and the rate at which the viral load increases following CD8+ T cell depletion should reflect the viral replication rate, ρ. A meta-analysis of previous data shows that viral replication rates during chronic infection vary between 0.5 ≤ ρ ≤ 1 day−1. Balancing such fast viral replication requires killing rates that are several times larger than ρ, implying that most productively infected cells would die by cytolytic effects. IMPORTANCE Most current data suggest that cytotoxic T cells (CTL) mediate their control of human immunodeficiency virus type 1 (HIV-1) infection by nonlytic mechanisms; i.e., the data suggest that CTL hardly kill. This interpretation of these data has been based upon the general mathematical model for HIV infection. Because this model ignores the eclipse phase between the infection of a target cell and the start of viral production by that cell, we reanalyze the same data sets with novel models that do account for the eclipse phase. We find that the data are perfectly consistent with lytic control by CTL and predict that most productively infected cells are killed by CTL. Because the killing rate should balance the viral replication rate, we estimate both parameters from a large set of published experiments in which CD8+ T cells were depleted in simian immunodeficiency virus (SIV)-infected monkeys. This confirms that the killing rate can be much faster than is currently appreciated.
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20
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Abstract
Mathematical and statistical methods enable multidisciplinary approaches that catalyse discovery. Together with experimental methods, they identify key hypotheses, define measurable observables and reconcile disparate results. We collect a representative sample of studies in T-cell biology that illustrate the benefits of modelling–experimental collaborations and that have proven valuable or even groundbreaking. We conclude that it is possible to find excellent examples of synergy between mathematical modelling and experiment in immunology, which have brought significant insight that would not be available without these collaborations, but that much remains to be discovered.
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Affiliation(s)
- Mario Castro
- Universidad Pontificia Comillas , E28015 Madrid , Spain
| | - Grant Lythe
- Department of Applied Mathematics, School of Mathematics , University of Leeds , Leeds LS2 9JT , UK
| | - Carmen Molina-París
- Department of Applied Mathematics, School of Mathematics , University of Leeds , Leeds LS2 9JT , UK
| | - Ruy M Ribeiro
- Los Alamos National Laboratory , Theoretical Biology and Biophysics , Los Alamos, NM 87545 , USA
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21
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Drylewicz J, Vrisekoop N, Mugwagwa T, de Boer AB, Otto SA, Hazenberg MD, Tesselaar K, de Boer RJ, Borghans JAM. Reconciling Longitudinal Naive T-Cell and TREC Dynamics during HIV-1 Infection. PLoS One 2016; 11:e0152513. [PMID: 27010200 PMCID: PMC4806918 DOI: 10.1371/journal.pone.0152513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/15/2016] [Indexed: 12/14/2022] Open
Abstract
Naive T cells in untreated HIV-1 infected individuals have a reduced T-cell receptor excision circle (TREC) content. Previous mathematical models have suggested that this is due to increased naive T-cell division. It remains unclear, however, how reduced naive TREC contents can be reconciled with a gradual loss of naive T cells in HIV-1 infection. We performed longitudinal analyses in humans before and after HIV-1 seroconversion, and used a mathematical model to investigate which processes could explain the observed changes in naive T-cell numbers and TRECs during untreated HIV-1 disease progression. Both CD4+ and CD8+ naive T-cell TREC contents declined biphasically, with a rapid loss during the first year and a much slower loss during the chronic phase of infection. While naive CD8+ T-cell numbers hardly changed during follow-up, naive CD4+ T-cell counts continually declined. We show that a fine balance between increased T-cell division and loss in the peripheral naive T-cell pool can explain the observed short- and long-term changes in TRECs and naive T-cell numbers, especially if T-cell turnover during the acute phase is more increased than during the chronic phase of infection. Loss of thymic output, on the other hand, does not help to explain the biphasic loss of TRECs in HIV infection. The observed longitudinal changes in TRECs and naive T-cell numbers in HIV-infected individuals are most likely explained by a tight balance between increased T-cell division and death, suggesting that these changes are intrinsically linked in HIV infection.
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Affiliation(s)
- Julia Drylewicz
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Nienke Vrisekoop
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Tendai Mugwagwa
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Anne Bregje de Boer
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sigrid A. Otto
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mette D. Hazenberg
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kiki Tesselaar
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rob J. de Boer
- Theoretical Biology & Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - José A. M. Borghans
- Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
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22
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Elevation and persistence of CD8 T-cells in HIV infection: the Achilles heel in the ART era. J Int AIDS Soc 2016; 19:20697. [PMID: 26945343 PMCID: PMC4779330 DOI: 10.7448/ias.19.1.20697] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 01/15/2016] [Accepted: 01/28/2016] [Indexed: 12/18/2022] Open
Abstract
Introduction HIV infection leads to a disturbed T-cell homeostasis, featured by a depletion of CD4 T-cells and a persistent elevation of CD8 T-cells over disease progression. Most effort of managing HIV infection has been focused on CD4 T-cell recovery, while changes in the CD8 compartment were relatively underappreciated in the past. Methods A comprehensive literature review of publications in English language was conducted using major electronic databases. Our search was focused on factors contributing to CD8 T-cell dynamics in HIV infection and following antiretroviral therapy (ART). Discussion Normalization of CD8 counts is seldom observed even with optimal CD4 recovery following long-term treatment. Initiation of ART in primary HIV infection leads to enhanced normalization of CD8 count compared with long-term ART initiated in chronic infection. Importantly, such CD8 elevation in treated HIV infection is associated with an increased risk of inflammatory non-AIDS-related clinical events independent of CD4 T-cell recovery. The mechanisms underlying CD8 persistence remain largely unknown, which may include bystander activation, exhaustion and immunosenescence of CD8 T-cells. The information provided herein will lead to a better understanding of factors associated with CD8 persistence and contribute to the development of strategies aiming at CD8 normalization. Conclusions Persistence of CD8 T-cell elevation in treated HIV-infected patients is associated with an increased risk of non-AIDS-related events. Now that advances in ART have led to decreased AIDS-related opportunistic diseases, more attention has been focused on reducing non-AIDS events and normalizing persistent CD8 T-cell elevation.
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De Boer RJ, Perelson AS, Ribeiro RM. Modelling deuterium labelling of lymphocytes with temporal and/or kinetic heterogeneity. J R Soc Interface 2012; 9:2191-200. [PMID: 22513720 PMCID: PMC3405764 DOI: 10.1098/rsif.2012.0149] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Accepted: 03/27/2012] [Indexed: 12/12/2022] Open
Abstract
To study the kinetics of lymphocytes, models have divided the cell population into subpopulations with different turnover rates. These have been called 'kinetic heterogeneity models' so as to distinguish them from 'temporal heterogeneity models', in which a cell population may have different turnover rates at different times, e.g. when resting versus when activated. We model labelling curves for temporally heterogeneous populations, and predict that they exhibit equal biphasic up- and downslopes. We show when cells divide only once upon activation, these slopes are dominated by the slowest exponent, yielding underestimates of the average turnover rate. When cells undergo more than one division, the labelling curves allow fitting of the two exponential slopes in the temporal heterogeneity model. The same data can also be described with a two-compartment kinetic heterogeneity model. In both instances, the average turnover rate is correctly estimated. Because both models assume a different cell biology but describe the data equally well, the parameters of either model have no simple biological interpretation, as each parameter could reflect a combination of parameters of another biological process. Thus, even if there are sufficient data to reliably estimate all exponentials, one can only accurately estimate an average turnover rate. We illustrate these issues by re-fitting labelling data from healthy and HIV-infected individuals.
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Affiliation(s)
- Rob J De Boer
- Department of Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, The Netherlands.
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