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Norton NJ, Holder KA, Ings DP, Harnum DOA, Russell RS, Grant MD. Cellular Immune Responses to SARS-CoV-2 in Exposed Seronegative Individuals. Viruses 2023; 15:v15040996. [PMID: 37112977 PMCID: PMC10144856 DOI: 10.3390/v15040996] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/30/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Some SARS-CoV-2-exposed individuals develop immunity without overt infection. We identified 11 individuals who were negative by nucleic acid testing during prolonged close contact and with no serological diagnosis of infection. As this could reflect natural immunity, cross-reactive immunity from previous coronavirus exposure, abortive infection due to de novo immune responses, or other factors, our objective was to characterize immunity against SARS-CoV-2 in these individuals. Blood was processed into plasma and peripheral blood mononuclear cells (PBMC) and screened for IgG, IgA, and IgM antibodies (Ab) against SARS-CoV-2 and common β-coronaviruses OC43 and HKU1. Receptor blocking activity and interferon-alpha (IFN-α) in plasma were also measured. Circulating T cells against SARS-CoV-2 were enumerated and CD4+ and CD8+ T cell responses discriminated after in vitro stimulation. Exposed uninfected individuals were seronegative against SARS-CoV-2 spike (S) and selectively reactive against OC43 nucleocapsid protein (N), suggesting common β-coronavirus exposure induced Ab cross-reactive against SARS-CoV-2 N. There was no evidence of protection from circulating angiotensin-converting enzyme (ACE2) or IFN-α. Six individuals had T cell responses against SARS-CoV-2, with four involving CD4+ and CD8+ T cells. We found no evidence of protection from SARS-CoV-2 through innate immunity or immunity induced by common β-coronaviruses. Cellular immune responses against SARS-CoV-2 were associated with time since exposure, suggesting that rapid cellular responses may contain SARS-CoV-2 infection below the thresholds required for a humoral response.
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Affiliation(s)
- Natasha J Norton
- Immunology and Infectious Diseases Program, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland and Labrador, St. John's, NL A1B 3V6, Canada
| | - Kayla A Holder
- Immunology and Infectious Diseases Program, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland and Labrador, St. John's, NL A1B 3V6, Canada
| | - Danielle P Ings
- Immunology and Infectious Diseases Program, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland and Labrador, St. John's, NL A1B 3V6, Canada
| | - Debbie O A Harnum
- Eastern Regional Health Authority, Department of Health and Community Services, St. John's, NL A1B 3V6, Canada
| | - Rodney S Russell
- Immunology and Infectious Diseases Program, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland and Labrador, St. John's, NL A1B 3V6, Canada
| | - Michael D Grant
- Immunology and Infectious Diseases Program, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland and Labrador, St. John's, NL A1B 3V6, Canada
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2
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Swadling L, Maini MK. Can T Cells Abort SARS-CoV-2 and Other Viral Infections? Int J Mol Sci 2023; 24:4371. [PMID: 36901802 PMCID: PMC10002440 DOI: 10.3390/ijms24054371] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
Despite the highly infectious nature of the SARS-CoV-2 virus, it is clear that some individuals with potential exposure, or even experimental challenge with the virus, resist developing a detectable infection. While a proportion of seronegative individuals will have completely avoided exposure to the virus, a growing body of evidence suggests a subset of individuals are exposed, but mediate rapid viral clearance before the infection is detected by PCR or seroconversion. This type of "abortive" infection likely represents a dead-end in transmission and precludes the possibility for development of disease. It is, therefore, a desirable outcome on exposure and a setting in which highly effective immunity can be studied. Here, we describe how early sampling of a new pandemic virus using sensitive immunoassays and a novel transcriptomic signature can identify abortive infections. Despite the challenges in identifying abortive infections, we highlight diverse lines of evidence supporting their occurrence. In particular, expansion of virus-specific T cells in seronegative individuals suggests abortive infections occur not only after exposure to SARS-CoV-2, but for other coronaviridae, and diverse viral infections of global health importance (e.g., HIV, HCV, HBV). We discuss unanswered questions related to abortive infection, such as: 'Are we just missing antibodies? Are T cells an epiphenomenon? What is the influence of the dose of viral inoculum?' Finally, we argue for a refinement of the current paradigm that T cells are only involved in clearing established infection; instead, we emphasise the importance of considering their role in terminating early viral replication by studying abortive infections.
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Affiliation(s)
- Leo Swadling
- Division of Infection and Immunity, Institute of Immunity and Transplantation, University College London, Pears Building, London WC1E 6BT, UK
| | - Mala K. Maini
- Division of Infection and Immunity, Institute of Immunity and Transplantation, University College London, Pears Building, London WC1E 6BT, UK
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3
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Tanaka S, Umezawa J, Yamaji T, Abe SK, Hamada A, Kobayashi O, Ushijima T, Inoue M. SARS-CoV-2 Antibody Response to Symptoms Indicative of COVID-19 in a Non-Infected Population in Japan: a Cross-Sectional Study. Jpn J Infect Dis 2023; 76:46-54. [PMID: 36184396 DOI: 10.7883/yoken.jjid.2022.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study was aimed at investigating differences in antibody titers indicative of the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between those who had experienced symptoms of coronavirus disease 2019 (COVID-19) and those who had not. We used data from a cross-sectional survey conducted at the National Cancer Center, Japan, of 434 individuals with no previous COVID-19 infection. The participants self-reported symptoms from the start of 2020. A generalized linear model was used to compare the mean SARS-CoV-2-specific IgG nucleocapsid protein (N-IgG) titer with estimated confidence intervals according to the onset of symptoms indicative of COVID-19. We observed a tendency toward an association between higher mean N-IgG titers and occurrence of high fever within the past 8 months (P = 0.053). The mean N-IgG titer was higher in those with prior symptoms (P = 0.03) and those with over three symptoms (P < 0.01) than in those without symptoms. The mean N-IgG titer was higher in those with symptoms and those with more symptoms that might indicate COVID-19 relative to those without symptoms, suggesting that transient but contained SARS-CoV-2 infection had occurred.
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Affiliation(s)
- Shiori Tanaka
- Division of Prevention, National Cancer Center, Japan
| | - Jun Umezawa
- Division of Cohort Research, National Cancer Center, Japan
| | - Taiki Yamaji
- Division of Epidemiology, Institute for Cancer Control, National Cancer Center, Japan
| | - Sarah K Abe
- Division of Prevention, National Cancer Center, Japan
| | - Akinobu Hamada
- Division of Molecular Pharmacology, National Cancer Center, Japan
| | - Osamu Kobayashi
- Department of Infectious Diseases, National Cancer Center, Japan
| | | | - Manami Inoue
- Division of Prevention, National Cancer Center, Japan
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4
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Jay C, Ratcliff J, Turtle L, Goulder P, Klenerman P. Exposed seronegative: Cellular immune responses to SARS-CoV-2 in the absence of seroconversion. Front Immunol 2023; 14:1092910. [PMID: 36776841 PMCID: PMC9909393 DOI: 10.3389/fimmu.2023.1092910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/16/2023] [Indexed: 01/27/2023] Open
Abstract
The factors determining whether infection will occur following exposure to SARS-CoV-2 remain elusive. Certain SARS-CoV-2-exposed individuals mount a specific T-cell response but fail to seroconvert, representing a population that may provide further clarity on the nature of infection susceptibility and correlates of protection against SARS-CoV-2. Exposed seronegative individuals have been reported in patients exposed to the blood-borne pathogens Human Immunodeficiency virus and Hepatitis C virus and the sexually transmitted viruses Hepatitis B virus and Herpes Simplex virus. By comparing the quality of seronegative T-cell responses to SARS-CoV-2 with seronegative cellular immunity to these highly divergent viruses, common patterns emerge that offer insights on the role of cellular immunity against infection. For both SARS-CoV-2 and Hepatitis C, T-cell responses in exposed seronegatives are consistently higher than in unexposed individuals, but lower than in infected, seropositive patients. Durability of T-cell responses to Hepatitis C is dependent upon repeated exposure to antigen - single exposures do not generate long-lived memory T-cells. Finally, exposure to SARS-CoV-2 induces varying degrees of immune activation, suggesting that exposed seronegative individuals represent points on a spectrum rather than a discrete group. Together, these findings paint a complex landscape of the nature of infection but provide clues as to what may be protective early on in SARS-CoV-2 disease course. Further research on this phenomenon, particularly through cohort studies, is warranted.
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Affiliation(s)
- Cecilia Jay
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Jeremy Ratcliff
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Lance Turtle
- National Institute for Health and Care Research Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool, United Kingdom
| | - Philip Goulder
- Peter Medawar Building for Pathogen Research, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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5
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Sugrue JA, Posseme C, Tan Z, Pou C, Charbit B, Bondet V, Bourke NM, Brodin P, Duffy D, O'Farrelly C. Enhanced TLR3 responsiveness in hepatitis C virus resistant women from the Irish anti-D cohort. Cell Rep Med 2022; 3:100804. [PMID: 36334594 PMCID: PMC9729829 DOI: 10.1016/j.xcrm.2022.100804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 08/03/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
Abstract
Natural resistance to infection is an overlooked outcome after hepatitis C virus (HCV) exposure. Between 1977 and 1979, 1,200 Rhesus D-negative Irish women were exposed to HCV-contaminated anti-D immunoglobulin. Here, we investigate why some individuals appear to resist infection despite exposure (exposed seronegative [ESN]). We screen HCV-resistant and -susceptible donors for anti-HCV adaptive immune responses using ELISpots and VirScan to profile antibodies against all know human viruses. We perform standardized ex vivo whole blood stimulation (TruCulture) assays with antiviral ligands and assess antiviral responses using NanoString transcriptomics and Luminex proteomics. We describe an enhanced TLR3-type I interferon response in ESNs compared with seropositive women. We also identify increased inflammatory cytokine production in response to polyIC in ESNs compared with seropositive women. These enhanced responses may have contributed to innate immune protection against HCV infection in our cohort.
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Affiliation(s)
- Jamie A Sugrue
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Céline Posseme
- Translational Immunology Unit, Institut Pasteur, Paris, France
| | - Ziyang Tan
- Science for Life Laboratory, Department of Women's and Children Health, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Christian Pou
- Science for Life Laboratory, Department of Women's and Children Health, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Bruno Charbit
- Cytometry and Biomarkers UTechS, CRT, Institut Pasteur, Paris, France
| | - Vincent Bondet
- Translational Immunology Unit, Institut Pasteur, Paris, France
| | - Nollaig M Bourke
- Discipline of Medical Gerontology, School of Medicine, Trinity Translational Medicine Institute, Trinity College Dublin, Dublin, Ireland
| | - Petter Brodin
- Science for Life Laboratory, Department of Women's and Children Health, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Darragh Duffy
- Translational Immunology Unit, Institut Pasteur, Paris, France; Cytometry and Biomarkers UTechS, CRT, Institut Pasteur, Paris, France
| | - Cliona O'Farrelly
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland; School of Medicine, Trinity College Dublin, Dublin, Ireland.
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6
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Sugrue JA, O’Farrelly C. Uncovering Resistance to Hepatitis C Virus Infection: Scientific Contributions and Unanswered Questions in the Irish Anti-D Cohort. Pathogens 2022; 11:pathogens11030306. [PMID: 35335630 PMCID: PMC8953313 DOI: 10.3390/pathogens11030306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/20/2022] [Accepted: 02/24/2022] [Indexed: 02/04/2023] Open
Abstract
Infections caused inadvertently during clinical intervention provide valuable insight into the spectrum of human responses to viruses. Delivery of hepatitis C virus (HCV)-contaminated blood products in the 70s (before HCV was identified) have dramatically increased our understanding of the natural history of HCV infection and the role that host immunity plays in the outcome to viral infection. In Ireland, HCV-contaminated anti-D immunoglobulin (Ig) preparations were administered to approximately 1700 pregnant Irish rhesus-negative women in 1977–1979. Though tragic in nature, this outbreak (alongside a smaller episode in 1993) has provided unique insight into the host factors that influence outcomes after HCV exposure and the subsequent development of disease in an otherwise healthy female population. Despite exposure to highly infectious batches of anti-D, almost 600 of the HCV-exposed women have never shown any evidence of infection (remaining negative for both viral RNA and anti-HCV antibodies). Detailed analysis of these individuals may shed light on innate immune pathways that effectively block HCV infection and potentially inform us more generally about the mechanisms that contribute to viral resistance in human populations.
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Affiliation(s)
- Jamie A. Sugrue
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, D02R590 Dublin, Ireland
- Correspondence: (J.A.S.); (C.O.)
| | - Cliona O’Farrelly
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, D02R590 Dublin, Ireland
- School of Medicine, Trinity College Dublin, D02R590 Dublin, Ireland
- Correspondence: (J.A.S.); (C.O.)
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7
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Swadling L, Diniz MO, Schmidt NM, Amin OE, Chandran A, Shaw E, Pade C, Gibbons JM, Le Bert N, Tan AT, Jeffery-Smith A, Tan CCS, Tham CYL, Kucykowicz S, Aidoo-Micah G, Rosenheim J, Davies J, Johnson M, Jensen MP, Joy G, McCoy LE, Valdes AM, Chain BM, Goldblatt D, Altmann DM, Boyton RJ, Manisty C, Treibel TA, Moon JC, van Dorp L, Balloux F, McKnight Á, Noursadeghi M, Bertoletti A, Maini MK. Pre-existing polymerase-specific T cells expand in abortive seronegative SARS-CoV-2. Nature 2022; 601:110-117. [PMID: 34758478 PMCID: PMC8732273 DOI: 10.1038/s41586-021-04186-8] [Citation(s) in RCA: 248] [Impact Index Per Article: 124.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/27/2021] [Indexed: 12/15/2022]
Abstract
Individuals with potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) do not necessarily develop PCR or antibody positivity, suggesting that some individuals may clear subclinical infection before seroconversion. T cells can contribute to the rapid clearance of SARS-CoV-2 and other coronavirus infections1-3. Here we hypothesize that pre-existing memory T cell responses, with cross-protective potential against SARS-CoV-2 (refs. 4-11), would expand in vivo to support rapid viral control, aborting infection. We measured SARS-CoV-2-reactive T cells, including those against the early transcribed replication-transcription complex (RTC)12,13, in intensively monitored healthcare workers (HCWs) who tested repeatedly negative according to PCR, antibody binding and neutralization assays (seronegative HCWs (SN-HCWs)). SN-HCWs had stronger, more multispecific memory T cells compared with a cohort of unexposed individuals from before the pandemic (prepandemic cohort), and these cells were more frequently directed against the RTC than the structural-protein-dominated responses observed after detectable infection (matched concurrent cohort). SN-HCWs with the strongest RTC-specific T cells had an increase in IFI27, a robust early innate signature of SARS-CoV-2 (ref. 14), suggesting abortive infection. RNA polymerase within RTC was the largest region of high sequence conservation across human seasonal coronaviruses (HCoV) and SARS-CoV-2 clades. RNA polymerase was preferentially targeted (among the regions tested) by T cells from prepandemic cohorts and SN-HCWs. RTC-epitope-specific T cells that cross-recognized HCoV variants were identified in SN-HCWs. Enriched pre-existing RNA-polymerase-specific T cells expanded in vivo to preferentially accumulate in the memory response after putative abortive compared to overt SARS-CoV-2 infection. Our data highlight RTC-specific T cells as targets for vaccines against endemic and emerging Coronaviridae.
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Affiliation(s)
- Leo Swadling
- Division of Infection and Immunity, University College London, London, UK.
| | - Mariana O Diniz
- Division of Infection and Immunity, University College London, London, UK
| | - Nathalie M Schmidt
- Division of Infection and Immunity, University College London, London, UK
| | - Oliver E Amin
- Division of Infection and Immunity, University College London, London, UK
| | - Aneesh Chandran
- Division of Infection and Immunity, University College London, London, UK
| | - Emily Shaw
- Division of Infection and Immunity, University College London, London, UK
| | - Corinna Pade
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Joseph M Gibbons
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Nina Le Bert
- Emerging Infectious Diseases Program, Duke-NUS Medical School, Singapore, Singapore
| | - Anthony T Tan
- Emerging Infectious Diseases Program, Duke-NUS Medical School, Singapore, Singapore
| | - Anna Jeffery-Smith
- Division of Infection and Immunity, University College London, London, UK
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Cedric C S Tan
- UCL Genetics Institute, University College London, London, UK
| | - Christine Y L Tham
- Emerging Infectious Diseases Program, Duke-NUS Medical School, Singapore, Singapore
| | | | | | - Joshua Rosenheim
- Division of Infection and Immunity, University College London, London, UK
| | - Jessica Davies
- Division of Infection and Immunity, University College London, London, UK
| | - Marina Johnson
- Great Ormond Street Institute of Child Health NIHR Biomedical Research Centre, University College London, London, UK
| | - Melanie P Jensen
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
- Department of Cellular Pathology, Northwest London Pathology, Imperial College London NHS Trust, London, UK
| | - George Joy
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Laura E McCoy
- Division of Infection and Immunity, University College London, London, UK
| | - Ana M Valdes
- Academic Rheumatology, Clinical Sciences, Nottingham City Hospital, Nottingham, UK
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, UK
| | - Benjamin M Chain
- Division of Infection and Immunity, University College London, London, UK
| | - David Goldblatt
- Great Ormond Street Institute of Child Health NIHR Biomedical Research Centre, University College London, London, UK
| | - Daniel M Altmann
- Department of Immunology and Inflammation, Imperial College London, London, UK
| | - Rosemary J Boyton
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Lung Division, Royal Brompton & Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Charlotte Manisty
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Thomas A Treibel
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - James C Moon
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Lucy van Dorp
- UCL Genetics Institute, University College London, London, UK
| | | | - Áine McKnight
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Mahdad Noursadeghi
- Division of Infection and Immunity, University College London, London, UK
| | - Antonio Bertoletti
- Emerging Infectious Diseases Program, Duke-NUS Medical School, Singapore, Singapore
- Singapore Immunology Network, A*STAR, Singapore, Singapore
| | - Mala K Maini
- Division of Infection and Immunity, University College London, London, UK.
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8
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Where to Next? Research Directions after the First Hepatitis C Vaccine Efficacy Trial. Viruses 2021; 13:v13071351. [PMID: 34372558 PMCID: PMC8310243 DOI: 10.3390/v13071351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/03/2021] [Accepted: 07/08/2021] [Indexed: 11/17/2022] Open
Abstract
Thirty years after its discovery, the hepatitis C virus (HCV) remains a leading cause of liver disease worldwide. Given that many countries continue to experience high rates of transmission despite the availability of potent antiviral therapies, an effective vaccine is seen as critical for the elimination of HCV. The recent failure of the first vaccine efficacy trial for the prevention of chronic HCV confirmed suspicions that this virus will be a challenging vaccine target. Here, we examine the published data from this first efficacy trial along with the earlier clinical and pre-clinical studies of the vaccine candidate and then discuss three key research directions expected to be important in ongoing and future HCV vaccine development. These include the following: 1. design of novel immunogens that generate immune responses to genetically diverse HCV genotypes and subtypes, 2. strategies to elicit broadly neutralizing antibodies against envelope glycoproteins in addition to cytotoxic and helper T cell responses, and 3. consideration of the unique immunological status of individuals most at risk for HCV infection, including those who inject drugs, in vaccine platform development and early immunogenicity trials.
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9
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Spike is the most recognized antigen in the whole-blood platform in both acute and convalescent COVID-19 patients. Int J Infect Dis 2021; 106:338-347. [PMID: 33864921 PMCID: PMC8045417 DOI: 10.1016/j.ijid.2021.04.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES To identify the best experimental approach to detect a SARS-CoV-2-specific T cell response using a whole-blood platform. METHODS Whole-blood from 56 COVID-19 and 23 "NO-COVID-19" individuals were stimulated overnight with different concentrations (0.1 or 1 μg/mL) of SARS-CoV-2 PepTivator® Peptide Pools, including spike (pool S), nucleocapsid (pool N), membrane (pool M), and a MegaPool (MP) of these three peptide pools. ELISA was used to analyse interferon (IFN)-γ levels. RESULTS The IFN-γ-response to every SARS-CoV-2 peptide pool was significantly increased in COVID-19 patients compared with NO-COVID-19 individuals. Pool S and MegaPool were the most potent immunogenic stimuli (median: 0.51, IQR: 0.14-2.17; and median: 1.18, IQR: 0.27-4.72, respectively) compared with pools N and M (median: 0.22, IQR: 0.032-1.26; and median: 0.22, IQR: 0.01-0.71, respectively). The whole-blood test based on pool S and MegaPool showed a good sensitivity of 77% and a high specificity of 96%. The IFN-γ-response was mediated by both CD4+ and CD8+ T cells, and independently detected of clinical parameters in both hospitalized and recovered patients. CONCLUSIONS This easy-to-use assay for detecting SARS-CoV-2-specific T cell responses may be implemented in clinical laboratories as a powerful diagnostic tool.
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10
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Gallais F, Velay A, Nazon C, Wendling MJ, Partisani M, Sibilia J, Candon S, Fafi-Kremer S. Intrafamilial Exposure to SARS-CoV-2 Associated with Cellular Immune Response without Seroconversion, France. Emerg Infect Dis 2020; 27. [PMID: 33261718 PMCID: PMC7774579 DOI: 10.3201/eid2701.203611] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We investigated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific antibodies and T-cell responses against SARS-CoV-2 and human coronavirus (HCoV) 229E and OC43 in 11 SARS-CoV-2 serodiscordant couples in Strasbourg, France, in which 1 partner had evidence of mild coronavirus disease (COVID-19) and in 10 unexposed healthy controls. Patients with confirmed COVID-19 were considered index patients and their partners close contacts. All index patients displayed positive SARS-CoV-2–specific antibody and T-cell responses that lasted up to 102 days after symptom onset. All contacts remained seronegative for SARS-CoV-2; however, 6 reported COVID-19 symptoms within a median of 7 days after their partners, and 4 of those showed a positive SARS-CoV-2–specific T-cell response against 3 or 4 SARS-CoV-2 antigens that lasted up to 93 days after symptom onset. The 11 couples and controls displayed positive T-cell responses against HCoV-229E or HCoV-OC43. These data suggest that exposure to SARS-CoV-2 can induce virus-specific T-cell responses without seroconversion.
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11
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Shawa IT, Felmlee DJ, Hegazy D, Sheridan DA, Cramp ME. Exploration of potential mechanisms of hepatitis C virus resistance in exposed uninfected intravenous drug users. J Viral Hepat 2017; 24:1082-1088. [PMID: 28475247 DOI: 10.1111/jvh.12720] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022]
Abstract
A rare outcome following exposure to hepatitis C virus (HCV) is a lack of observable infection as clinically measured by HCV RNA- or HCV-recognizing antibodies. The population who exhibit this trait is termed exposed uninfected (EU). Increasing evidence has refined characterization of these individuals, distinct from those who become infected but spontaneously clear HCV. Study of the EU population is highly pertinent for the discovery of antiviral mechanisms of resistance that can reveal antiviral therapeutic strategies. This review provides an overview of similarities and differences of the EU population relative to spontaneous resolvers and the majority whom develop chronic HCV infection, and focusses on possible mechanisms of resistance including innate and adaptive immunity, genetics and lipid interactions.
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Affiliation(s)
- I T Shawa
- Hepatology Research Group, Institute of Translational and Stratified Medicine, , Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK
| | - D J Felmlee
- Hepatology Research Group, Institute of Translational and Stratified Medicine, , Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK
| | - D Hegazy
- Hepatology Research Group, Institute of Translational and Stratified Medicine, , Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK
| | - D A Sheridan
- Hepatology Research Group, Institute of Translational and Stratified Medicine, , Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK
| | - M E Cramp
- Hepatology Research Group, Institute of Translational and Stratified Medicine, , Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK
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Naggie S, Holland DP, Sulkowski MS, Thomas DL. Hepatitis C Virus Postexposure Prophylaxis in the Healthcare Worker: Why Direct-Acting Antivirals Don't Change a Thing. Clin Infect Dis 2017; 64:92-99. [PMID: 27682067 PMCID: PMC5159603 DOI: 10.1093/cid/ciw656] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/05/2016] [Indexed: 12/27/2022] Open
Abstract
Currently, 380 000-400 000 occupational exposures to blood-borne pathogens occur annually in the United States. The management for occupational HIV or hepatitis B virus exposures includes postexposure prophylaxis (PEP) when necessary; however, PEP is not recommended for hepatitis C virus (HCV) exposures. Recent approval of HCV direct-acting antivirals (DAAs) has renewed discussions as to whether these therapies could be used to prevent infection after exposure. There are no published studies addressing this question, but the prescribing of DAAs for PEP has been reported. We will discuss the differences in transmission of the 3 most common blood-borne pathogens, the natural history of early HCV infection, and the scientific rationale for PEP. In particular, we will discuss how the low feasibility of conducting an adequately powered clinical trial of DAA use for PEP and the low cost-effectiveness of such an intervention is not supportive of targeting limited resources for such use.
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Affiliation(s)
- Susanna Naggie
- Duke Clinical Research Institute
- Duke University School of Medicine, Durham, North Carolina
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13
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Cellular immune correlates analysis of an HIV-1 preexposure prophylaxis trial. Proc Natl Acad Sci U S A 2015; 112:8379-84. [PMID: 26100867 DOI: 10.1073/pnas.1501443112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
HIV-1-specific T-cell responses in exposed seronegative subjects suggest that a viral breach of the exposure site is more common than current transmission rates would suggest and that host immunity can extinguish subsequent infection foci. The Preexposure Prophylaxis Initiative (iPrEx) chemoprophylaxis trial provided an opportunity to rigorously investigate these responses in a case-control immunology study; 84 preinfection peripheral blood mononuclear cell samples from individuals enrolled in the iPrEx trial who later seroconverted were matched with 480 samples from enrolled subjects who remained seronegative from both the placebo and active treatment arms. T-cell responses to HIV-1 Gag, Protease, Integrase, Reverse Transcriptase, Vif, and Nef antigens were quantified for all subjects in an IFN-γ enzyme-linked immunospot (ELISpot) assay. IFN-γ responses varied in magnitude and frequency across subjects. A positive response was more prevalent in those who remained persistently HIV-1-negative for Gag (P = 0.007), Integrase (P < 0.001), Vif (P < 0.001), and Nef (P < 0.001). When correlated with outcomes in the iPrEx trial, Vif- and Integrase-specific T-cell responses were associated with reduced HIV-1 infection risk [hazard ratio (HR) = 0.36, 95% confidence interval (95% CI) = 0.19-0.66 and HR = 0.52, 95% CI = 0.28-0.96, respectively]. Antigen-specific responses were independent of emtricitabine/tenofovir disoproxil fumarate use. IFN-γ secretion in the ELISpot was confirmed using multiparametric flow cytometry and largely attributed to effector memory CD4+ or CD8+ T cells. Our results show that HIV-1-specific T-cell immunity can be detected in exposed but uninfected individuals and that these T-cell responses can differentiate individuals according to infection outcomes.
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14
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Abstract
BACKGROUND Acute hepatitis C (AHCV) provides a diagnostic challenge with diverse clinical presentations. GOALS This study was aimed to examine the clinical and demographic features as well as outcomes in AHCV patients identified from inpatient and outpatient hospital settings. STUDY Patients with suspected AHCV were recruited from Philadelphia VA Medical Center, Hospital of University of Pennsylvania and Brooklyn VA Medical Center between 2000 and 2010. AHCV was diagnosed by acute serum alanine aminotransferase elevation with anti-hepatitis C virus (HCV) seroconversion, HCV-RNA fluctuations above 1 log, and/or recent high-risk exposure without prior HCV infection, excluding those with human immunodeficiency virus infection. Clinical and therapeutic outcomes were monitored for at least 6 months. RESULTS A total of 40 AHCV patients were enrolled with a median follow-up of 129 weeks. They were mostly men (68%) and whites (73%) with median age of 43 years, diverse risk factors (33% injection drugs, 20% health care-associated, 3% sexual, and 45% unknown), and wide variations in peak alanine aminotransferase (143 to 3435 U/L) and total bilirubin levels (0.4 to 19.3 mg/dL). Viremia resolved spontaneously in 23% and persisted without therapy in 27%, whereas 50% received interferon α-based therapy with 90% cure (18/20). Distinct clinical scenarios included: (1) wide viremic fluctuations >1 log (65%) and intermittent HCV-RNA negativity; (2) autoantibodies (25% antinuclear antibodies, 69% antismooth muscle antibodies) or autoimmune features; (3) delayed spontaneous viral clearance in 2 patients; (4) rapid cirrhosis progression in 2 patients. CONCLUSIONS AHCV is a heterogenous disease that requires careful monitoring. The lack of apparent risk factor in high proportion of patients and its diverse presentations warrant diagnostic vigilance.
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Resistance to hepatitis C virus: potential genetic and immunological determinants. THE LANCET. INFECTIOUS DISEASES 2015; 15:451-60. [PMID: 25703062 DOI: 10.1016/s1473-3099(14)70965-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Studies of individuals who were highly exposed but seronegative (HESN) for HIV infection led to the discovery that homozygosity for the Δ32 deletion mutation in the CCR5 gene prevents viral entry into target cells, and is associated with resistance to infection. Additionally, evidence for protective immunity has been noted in some HESN groups, such as sex workers in The Gambia. Population studies of individuals at high risk for hepatitis C virus infection suggest that an HESN phenotype exists. The body of evidence, which suggests that protective immunity allows clearance of hepatitis C virus without seroconversion is growing. Furthermore, proof-of-principle evidence from in-vitro studies shows that genetic polymorphisms can confer resistance to establishment of infection. This Review discusses the possibility that genetic mutations confer resistance against hepatitis C virus, and also explores evidence for protective immunity, including via genetically programmed variations in host responses. The data generally strengthens the notion that investigations of naturally arising polymorphisms within the hepatitis C virus interactome, and genetic association studies of well characterised HESN individuals, could identify potential targets for vaccine design and inform novel therapies.
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16
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Veerapu NS, Park SH, Tully DC, Allen TM, Rehermann B. Trace amounts of sporadically reappearing HCV RNA can cause infection. J Clin Invest 2014; 124:3469-78. [PMID: 25003189 DOI: 10.1172/jci73104] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 05/29/2014] [Indexed: 12/20/2022] Open
Abstract
Successful hepatitis C virus (HCV) treatment is defined as the absence of viremia 6 months after therapy cessation. We previously reported that trace amounts of HCV RNA, below the sensitivity of the standard clinical assay, can reappear sporadically in treatment responders. Here, we assessed the infectivity of this RNA and infused 3 chimpanzees sequentially at 9-week intervals with plasma or PBMCs from patients who tested positive for trace amounts of HCV RNA more than 6 months after completing pegylated IFN-α/ribavirin therapy. A fourth chimpanzee received HCV RNA-negative plasma and PBMCs from healthy blood donors. The 3 experimental chimpanzees, but not the control chimpanzee, generated HCV-specific T cell responses against nonstructural and structural HCV sequences 6-10 weeks after the first infusion of patient plasma and during subsequent infusions. In 1 chimpanzee, T cell responses declined, and this animal developed high-level viremia at week 27. Deep sequencing of HCV demonstrated transmission of a minor HCV variant from the first infusion donor that persisted in the chimpanzee for more than 6 months despite undetectable systemic viremia. Collectively, these results demonstrate that trace amounts of HCV RNA, which appear sporadically in successfully treated patients, can be infectious; furthermore, transmission can be masked in the recipient by an extended eclipse phase prior to establishing high-level viremia.
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Abdel-Hakeem MS, Shoukry NH. Protective immunity against hepatitis C: many shades of gray. Front Immunol 2014; 5:274. [PMID: 24982656 PMCID: PMC4058636 DOI: 10.3389/fimmu.2014.00274] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 05/27/2014] [Indexed: 12/11/2022] Open
Abstract
The majority of individuals who become acutely infected with hepatitis C virus (HCV) develop chronic infection and suffer from progressive liver damage while approximately 25% are able to eliminate the virus spontaneously. Despite the recent introduction of new direct-acting antivirals, there is still no vaccine for HCV. As a result, new infections and reinfections will remain a problem in developing countries and among high risk populations like injection drug users who have limited access to treatment and who continue to be exposed to the virus. The outcome of acute HCV is determined by the interplay between the host genetics, the virus, and the virus-specific immune response. Studies in humans and chimpanzees have demonstrated the essential role of HCV-specific CD4 and CD8 T cell responses in protection against viral persistence. Recent data suggest that antibody responses play a more important role than what was previously thought. Individuals who spontaneously resolve acute HCV infection develop long-lived memory T cells and are less likely to become persistently infected upon reexposure. New studies examining high risk cohorts are identifying correlates of protection during real life exposures and reinfections. In this review, we discuss correlates of protective immunity during acute HCV and upon reexposure. We draw parallels between HCV and the current knowledge about protective memory in other models of chronic viral infections. Finally, we discuss some of the yet unresolved questions about key correlates of protection and their relevance for vaccine development against HCV.
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Affiliation(s)
- Mohamed S Abdel-Hakeem
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) , Montréal, QC , Canada ; Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal , Montréal, QC , Canada ; Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University , Cairo , Egypt
| | - Naglaa H Shoukry
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) , Montréal, QC , Canada ; Département de Médecine, Faculté de Médecine, Université de Montréal , Montréal, QC , Canada
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18
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An archived serum sample as a clue for identifying the primary source of a nosocomial hepatitis C virus outbreak in a haemodialysis unit. Arch Virol 2014; 159:2207-12. [DOI: 10.1007/s00705-014-2074-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/27/2014] [Indexed: 11/30/2022]
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19
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Park SH, Rehermann B. Immune responses to HCV and other hepatitis viruses. Immunity 2014; 40:13-24. [PMID: 24439265 DOI: 10.1016/j.immuni.2013.12.010] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 12/30/2013] [Indexed: 02/08/2023]
Abstract
Five human hepatitis viruses cause most of the acute and chronic liver disease worldwide. Over the past 25 years, hepatitis C virus (HCV) in particular has received much interest because of its ability to persist in most immunocompetent adults and because of the lack of a protective vaccine. Here we examine innate and adaptive immune responses to HCV infection. Although HCV activates an innate immune response, it employs an elaborate set of mechanisms to evade interferon (IFN)-based antiviral immunity. By comparing innate and adaptive immune responses to HCV with those to hepatitis A and B viruses, we suggest that prolonged innate immune activation by HCV impairs the development of successful adaptive immune responses. Comparative immunology provides insights into the maintenance of immune protection. We conclude by discussing prospects for an HCV vaccine and future research needs for the hepatitis viruses.
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Affiliation(s)
- Su-Hyung Park
- Immunology Section, Liver Diseases Branch, NIDDK, National Institutes of Health, DHHS, Bethesda, MD 20892, USA
| | - Barbara Rehermann
- Immunology Section, Liver Diseases Branch, NIDDK, National Institutes of Health, DHHS, Bethesda, MD 20892, USA.
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Influence of frequent infectious exposures on general and varicella-zoster virus-specific immune responses in pediatricians. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:417-26. [PMID: 24429070 DOI: 10.1128/cvi.00818-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Reexposure to viruses is assumed to strengthen humoral and cellular immunity via the secondary immune response. We studied the effects of frequent exposure to viral infectious challenges on immunity. Furthermore, we assessed whether repetitive exposures to varicella-zoster virus (VZV) elicited persistently high immune responses. Blood samples from 11 pediatricians and matched controls were assessed at 3 time points and 1 time point, respectively. Besides the assessment of general immunity by means of measuring T-cell subset percentages, antibody titers and gamma interferon (IFN-γ)/interleukin 2 (IL-2)-producing T-cell percentages against adenovirus type 5 (AdV-5), cytomegalovirus (CMV), tetanus toxin (TT), and VZV were determined. Pediatricians had lower levels of circulating CD4(+)-naive T cells and showed boosting of CD8(+) effector memory T cells. Although no effect on humoral immunity was seen, repetitive exposures to VZV induced persistently higher percentages of IFN-γ-positive T cells against all VZV antigens tested (VZV glycoprotein E [gE], VZV intermediate-early protein 62 [IE62], and VZV IE63) than in controls. T cells directed against latency-associated VZV IE63 benefitted the most from natural exogenous boosting. Although no differences in cellular or humoral immunity were found between the pediatricians and controls for AdV-5 or TT, we did find larger immune responses against CMV antigens in pediatricians. Despite the high infectious burden, we detected a robust and diverse immune system in pediatricians. Repetitive exposures to VZV have been shown to induce a stable increased level of VZV-specific cellular but not humoral immunity. Based on our observations, VZV IE63 can be considered a candidate for a zoster vaccine.
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Flynn JK, Sacks-Davis R, Higgs P, Aitken C, Moneer S, Suppiah V, Tracy L, Ffrench R, Bowden S, Drummer H, George J, Bharadwaj M, Hellard M. Detection of HCV-Specific IFN-γ Responses in HCV Antibody and HCV RNA Negative Injecting Drug Users. HEPATITIS MONTHLY 2014; 14:e14678. [PMID: 24497881 PMCID: PMC3909641 DOI: 10.5812/hepatmon.14678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/13/2013] [Accepted: 11/21/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Detectable HCV-specific cellular immune responses in HCV antibody and RNA negative people who inject drugs (PWID) raise the question of whether some are resistant to HCV infection. Immune responses from people who have been exposed to hepatitis C virus (HCV) and remain anti-HCV negative are of interest for HCV vaccine development; however, limited research addresses this area. OBJECTIVES In a cohort of HCV antibody and RNA negative PWID, we assessed whether the presence of HCV-specific IFN-γ responses or genetic associations provide any evidence of protection from HCV infection. PATIENTS AND METHODS One hundred and ninety-eight participants were examined longitudinally for clinical, behavioral, social, environmental and genetic characteristics (IFNL3 genotype [formally IL-28B] and HLA type). Sixty-one of the 198 participants were HCV antibody and RNA negative, with 53 able to be examined longitudinally for HCV-specific IFN-γ ELISpot T cell responses. RESULTS Ten of the 53 HCV antibody and RNA negative participants had detectable HCV-specific IFN-γ responses at baseline (18%). The magnitude of IFN-γ responses averaged 131 +/- 96 SFC/106 PBMC and the breadth was mean 1 +/- 1 pool positive. The specificity of responses were mainly directed to E2, NS4b and NS5b. Participants with (10) and without (43) HCV-specific IFN-γ responses did not differ in behavioral, clinical or genetic characteristics (P > 0.05). There was a larger proportion sharing needles (with 70%, without 49%, P = 0.320) and a higher incidence of HCV (with 35.1 per 100 py, 95% CI 14.6, 84.4, without 16.0 per 100 py, 95% CI 7.2, 35.6, P = 0.212) in those with IFN-γ responses, although not statistically significant. Half the participants with baseline IFN-γ responses became HCV RNA positive (5/10), with one of these participants spontaneously clearing HCV. The spontaneous clearer had high magnitude and broad Th1 responses, favorable IFNL3 genotype and favorable HLA types. CONCLUSIONS This study demonstrated the detection of HCV-specific IFN-γ responses in HCV antibody and RNA negative individuals, with a tendency for HCV-specific IFN-γ responses to be associated with HCV exposure. The potential role of HCV-specific IFN-γ responses in those who remained HCV RNA negative is of value for the development of novel HCV therapeutics.
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Affiliation(s)
- Jacqueline K Flynn
- Centre for Biomedicine, Burnet Institute, Melbourne, Australia
- Department of Infectious Diseases, Monash University, Melbourne, Australia
- Corresponding Author: Jacqueline K Flynn, Centre for Biomedicine, Burnet Institute, 3001 Victoria, G.P.O. Box: 2284, Melbourne, Australia. Tel: +61-392822109, Fax: +61-392822100, E-mail:
| | - Rachel Sacks-Davis
- Centre for Population Health, Burnet Institute, Melbourne, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Peter Higgs
- Centre for Population Health, Burnet Institute, Melbourne, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
- National Drug Research Institute, Faculty of Health Sciences, Curtin University, Melbourne, Australia
| | - Campbell Aitken
- Centre for Population Health, Burnet Institute, Melbourne, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Sarah Moneer
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Vijay Suppiah
- Storr Liver Unit, Westmead Millennium Institute, University of Sydney, Sydney, Australia
- School of Pharmacy, University of South Australia, Adelaide, Australia
| | - Lilly Tracy
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Australia
| | - Rosemary Ffrench
- Centre for Biomedicine, Burnet Institute, Melbourne, Australia
- Department of Immunology, Monash University, Melbourne, Australia
| | - Scott Bowden
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Australia
| | - Heidi Drummer
- Centre for Biomedicine, Burnet Institute, Melbourne, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
- Department of Microbiology, Monash University, Clayton, Australia
| | - Jacob George
- Storr Liver Unit, Westmead Millennium Institute, University of Sydney, Sydney, Australia
| | - Mandvi Bharadwaj
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Margaret Hellard
- Centre for Population Health, Burnet Institute, Melbourne, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
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Park SH, Veerapu NS, Shin EC, Biancotto A, McCoy JP, Capone S, Folgori A, Rehermann B. Subinfectious hepatitis C virus exposures suppress T cell responses against subsequent acute infection. Nat Med 2013; 19:1638-42. [PMID: 24270546 PMCID: PMC4196667 DOI: 10.1038/nm.3408] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/22/2013] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) is endemic in many countries due to its high propensity to establish persistence1. The presence of HCV–specific T cells in repeatedly HCV–exposed subjects who test for HCV RNA and antibodies and do not have any history of HCV infection has been interpreted as T cell–mediated protection2-5. Here, we show in nonhuman primates that repeated exposure to human plasma with trace amounts of HCV induced HCV–specific T cells without seroconversion and systemic viremia, but did not protect upon subsequent HCV challenge. Rather, HCV–specific recall and de novo T cell responses as well as intrahepatic T cell recruitment and IFN-γ production were suppressed upon HCV challenge, concomitant to quantitative and qualitative changes in regulatory T (Treg) cells that began after subinfectious HCV exposure and increased after HCV challenge. In vitro Treg cell depletion restored HCV–specific T cell responses. Thus, T cells primed by trace amounts of HCV do not generate effective recall responses upon subsequent HCV infection. Subinfectious HCV exposure predisposes to Treg cell expansion, which suppresses effector T cells during subsequent infection. Strategies to reverse this exposure–induced suppression should be examined to aid the development of T cell–based vaccines against HCV and other endemic pathogens.
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Affiliation(s)
- Su-Hyung Park
- Immunology Section, Liver Diseases Branch, NIDDK, National Institutes of Health (NIH), Department of Health and Human Services, Bethesda, Maryland, USA
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