1
|
Boulton S, Poutou J, Gill R, Alluqmani N, He X, Singaravelu R, Crupi MJ, Petryk J, Austin B, Angka L, Taha Z, Teo I, Singh S, Jamil R, Marius R, Martin N, Jamieson T, Azad T, Diallo JS, Ilkow CS, Bell JC. A T cell-targeted multi-antigen vaccine generates robust cellular and humoral immunity against SARS-CoV-2 infection. Mol Ther Methods Clin Dev 2023; 31:101110. [PMID: 37822719 PMCID: PMC10562195 DOI: 10.1016/j.omtm.2023.101110] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
SARS-CoV-2, the etiological agent behind the coronavirus disease 2019 (COVID-19) pandemic, has continued to mutate and create new variants with increased resistance against the WHO-approved spike-based vaccines. With a significant portion of the worldwide population still unvaccinated and with waning immunity against newly emerging variants, there is a pressing need to develop novel vaccines that provide broader and longer-lasting protection. To generate broader protective immunity against COVID-19, we developed our second-generation vaccinia virus-based COVID-19 vaccine, TOH-VAC-2, encoded with modified versions of the spike (S) and nucleocapsid (N) proteins as well as a unique poly-epitope antigen that contains immunodominant T cell epitopes from seven different SARS-CoV-2 proteins. We show that the poly-epitope antigen restimulates T cells from the PBMCs of individuals formerly infected with SARS-CoV-2. In mice, TOH-VAC-2 vaccination produces high titers of S- and N-specific antibodies and generates robust T cell immunity against S, N, and poly-epitope antigens. The immunity generated from TOH-VAC-2 is also capable of protecting mice from heterologous challenge with recombinant VSV viruses that express the same SARS-CoV-2 antigens. Altogether, these findings demonstrate the effectiveness of our versatile vaccine platform as an alternative or complementary approach to current vaccines.
Collapse
Affiliation(s)
- Stephen Boulton
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Joanna Poutou
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Rida Gill
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Nouf Alluqmani
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Xiaohong He
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Ragunath Singaravelu
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Mathieu J.F. Crupi
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Julia Petryk
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Bradley Austin
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Leonard Angka
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Zaid Taha
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Iris Teo
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Siddarth Singh
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Rameen Jamil
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Ricardo Marius
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Nikolas Martin
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Taylor Jamieson
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Taha Azad
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Faculty of Medicine and Health Sciences, Department of Microbiology and Infectious Diseases, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
- Centre de Recherche du CHUS, Sherbrooke, QC J1H 5N4, Canada
| | - Jean-Simon Diallo
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Carolina S. Ilkow
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - John C. Bell
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| |
Collapse
|
2
|
Boulton S, Poutou J, Martin NT, Azad T, Singaravelu R, Crupi MJF, Jamieson T, He X, Marius R, Petryk J, Tanese de Souza C, Austin B, Taha Z, Whelan J, Khan ST, Pelin A, Rezaei R, Surendran A, Tucker S, Fekete EEF, Dave J, Diallo JS, Auer R, Angel JB, Cameron DW, Cailhier JF, Lapointe R, Potts K, Mahoney DJ, Bell JC, Ilkow CS. Single-dose replicating poxvirus vector-based RBD vaccine drives robust humoral and T cell immune response against SARS-CoV-2 infection. Mol Ther 2022; 30:1885-1896. [PMID: 34687845 PMCID: PMC8527104 DOI: 10.1016/j.ymthe.2021.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/24/2021] [Accepted: 10/10/2021] [Indexed: 02/01/2023] Open
Abstract
The coronavirus disease 2019 (COVID-19) pandemic requires the continued development of safe, long-lasting, and efficacious vaccines for preventive responses to major outbreaks around the world, and especially in isolated and developing countries. To combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we characterize a temperature-stable vaccine candidate (TOH-Vac1) that uses a replication-competent, attenuated vaccinia virus as a vector to express a membrane-tethered spike receptor binding domain (RBD) antigen. We evaluate the effects of dose escalation and administration routes on vaccine safety, efficacy, and immunogenicity in animal models. Our vaccine induces high levels of SARS-CoV-2 neutralizing antibodies and favorable T cell responses, while maintaining an optimal safety profile in mice and cynomolgus macaques. We demonstrate robust immune responses and protective immunity against SARS-CoV-2 variants after only a single dose. Together, these findings support further development of our novel and versatile vaccine platform as an alternative or complementary approach to current vaccines.
Collapse
Affiliation(s)
- Stephen Boulton
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Joanna Poutou
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Nikolas T Martin
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Taha Azad
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Ragunath Singaravelu
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Mathieu J F Crupi
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Taylor Jamieson
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Xiaohong He
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Ricardo Marius
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Julia Petryk
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Christiano Tanese de Souza
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Bradley Austin
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Zaid Taha
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jack Whelan
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Sarwat T Khan
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Adrian Pelin
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Reza Rezaei
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Abera Surendran
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Sarah Tucker
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Emily E F Fekete
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jaahnavi Dave
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jean-Simon Diallo
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Rebecca Auer
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jonathan B Angel
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Medicine, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada
| | - D William Cameron
- Division of Infectious Disease, Department of Medicine, University of Ottawa at The Ottawa Hospital/ Research Institute, Ottawa, ON K1H 8L6, Canada
| | | | - Réjean Lapointe
- Institut du Cancer de Montréal, Montréal, Québec H2X 0A9, Canada
| | - Kyle Potts
- Arnie Charbonneau Cancer Institute, Calgary, AB T2N 4Z6, Canada; Alberta Children's Hospital Research Institute, Calgary, AB T2N 6A8, Canada; Department of Microbiology, Immunology and Infectious Disease, Cumming School of Medicine, University of Calgary, Calgary, AB T2T 1N4, Canada
| | - Douglas J Mahoney
- Arnie Charbonneau Cancer Institute, Calgary, AB T2N 4Z6, Canada; Alberta Children's Hospital Research Institute, Calgary, AB T2N 6A8, Canada; Department of Microbiology, Immunology and Infectious Disease, Cumming School of Medicine, University of Calgary, Calgary, AB T2T 1N4, Canada
| | - John C Bell
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Carolina S Ilkow
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| |
Collapse
|
3
|
Abstract
Immunoinformatics is a discipline that applies methods of computer science to study and model the immune system. A fundamental question addressed by immunoinformatics is how to understand the rules of antigen presentation by MHC molecules to T cells, a process that is central to adaptive immune responses to infections and cancer. In the modern era of personalized medicine, the ability to model and predict which antigens can be presented by MHC is key to manipulating the immune system and designing strategies for therapeutic intervention. Since the MHC is both polygenic and extremely polymorphic, each individual possesses a personalized set of MHC molecules with different peptide-binding specificities, and collectively they present a unique individualized peptide imprint of the ongoing protein metabolism. Mapping all MHC allotypes is an enormous undertaking that cannot be achieved without a strong bioinformatics component. Computational tools for the prediction of peptide-MHC binding have thus become essential in most pipelines for T cell epitope discovery and an inescapable component of vaccine and cancer research. Here, we describe the development of several such tools, from pioneering efforts to the current state-of-the-art methods, that have allowed for accurate predictions of peptide binding of all MHC molecules, even including those that have not yet been characterized experimentally.
Collapse
Affiliation(s)
- Morten Nielsen
- Department of Health Technology, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, CP 1650 San Martin, Buenos Aires, Argentina
| | - Massimo Andreatta
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, CP 1650 San Martin, Buenos Aires, Argentina
| | - Bjoern Peters
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, California 92037, USA
- Department of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Søren Buus
- Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| |
Collapse
|
4
|
Loo CP, Nelson NA, Lane RS, Booth JL, Loprinzi Hardin SC, Thomas A, Slifka MK, Nolz JC, Lund AW. Lymphatic Vessels Balance Viral Dissemination and Immune Activation following Cutaneous Viral Infection. Cell Rep 2018; 20:3176-3187. [PMID: 28954233 DOI: 10.1016/j.celrep.2017.09.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 06/28/2017] [Accepted: 08/31/2017] [Indexed: 01/22/2023] Open
Abstract
Lymphatic vessels lie at the interface between peripheral sites of pathogen entry, adaptive immunity, and the systemic host. Though the paradigm is that their open structure allows for passive flow of infectious particles from peripheral tissues to lymphoid organs, virus applied to skin by scarification does not spread to draining lymph nodes. Using cutaneous infection by scarification, we analyzed the effect of viral infection on lymphatic transport and evaluated its role at the host-pathogen interface. We found that, in the absence of lymphatic vessels, canonical lymph-node-dependent immune induction was impaired, resulting in exacerbated pathology and compensatory, systemic priming. Furthermore, lymphatic vessels decouple fluid and cellular transport in an interferon-dependent manner, leading to viral sequestration while maintaining dendritic cell transport for immune induction. In conclusion, we found that lymphatic vessels balance immune activation and viral dissemination and act as an "innate-like" component of tissue host viral defense.
Collapse
Affiliation(s)
- Christopher P Loo
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Nicholas A Nelson
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Ryan S Lane
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jamie L Booth
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Sofia C Loprinzi Hardin
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Archana Thomas
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA
| | - Mark K Slifka
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA; Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jeffrey C Nolz
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA; Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA; Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Amanda W Lund
- Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, OR 97239, USA; Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA; Knight Cancer Institute, Oregon Health and Science University, Portland, OR 97239, USA.
| |
Collapse
|
5
|
Ryerson MR, Shisler JL. Characterizing the effects of insertion of a 5.2 kb region of a VACV genome, which contains known immune evasion genes, on MVA immunogenicity. Virus Res 2018; 246:55-64. [PMID: 29341877 DOI: 10.1016/j.virusres.2018.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/11/2018] [Accepted: 01/12/2018] [Indexed: 01/07/2023]
Abstract
Modified Vaccinia virus Ankara (MVA) is an attenuated Vaccinia virus (VACV) that is a popular vaccine vector candidate against many different pathogens. Its replication-restricted nature makes it a safe vaccine. However, higher doses or multiple boosts of MVA are necessary to elicit an immune response similar to wild-type VACV. Multiple strategies have been used to create modified MVA viruses that remain safe, but have increased immunogenicity. For example, one common strategy is to delete MVA immunomodulatory proteins in hopes of increasing the host immune response. Here, we take the opposite approach and examine, for the first time, how re-introduction of a 5.2 kb region of VACV DNA (that codes for multiple immunomodulatory proteins) into MVA alters viral immunogenicity. Since antigen presenting cells (APCs) are critical connectors between the innate and adaptive immune system, we examined the effect of MVA/5.2 kb infection in these cells in vitro. MVA/5.2 kb infection decreased virus-induced apoptosis and virus-induced NF-κB activation. MVA.5.2 kb infection decreased TNF production. However, MVA/5.2 kb infection did not alter APC maturation or IL-6 and IL-8 production in vitro. We further explored MVA/5.2 kb immunogenicity in vivo. VACV-specific CD8+ T cells were decreased after in vivo infection with MVA/5.2 kb versus MVA, suggesting that the MVA/5.2 kb construct is less immunogenic than MVA. These results demonstrate the limitations of in vitro studies for predicting the effects of genetic manipulation of MVA on immunogenicity. Although MVA/5.2 kb did not enhance MVA's immunogenicity, this study examined an unexplored strategy for optimizing MVA, and the insight gained from these results can help direct how to modify MVA in the future.
Collapse
Affiliation(s)
- Melissa R Ryerson
- Department of Microbiology, B103 Chemical and Life Science Building, 601 South Goodwin Avenue, University of Illinois, Urbana, IL 61801, USA
| | - Joanna L Shisler
- Department of Microbiology, B103 Chemical and Life Science Building, 601 South Goodwin Avenue, University of Illinois, Urbana, IL 61801, USA.
| |
Collapse
|
6
|
Modeling the effect of boost timing in murine irradiated sporozoite prime-boost vaccines. PLoS One 2018; 13:e0190940. [PMID: 29329308 PMCID: PMC5766151 DOI: 10.1371/journal.pone.0190940] [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: 09/13/2017] [Accepted: 12/22/2017] [Indexed: 11/29/2022] Open
Abstract
Vaccination with radiation-attenuated sporozoites has been shown to induce CD8+ T cell-mediated protection against pre-erythrocytic stages of malaria. Empirical evidence suggests that successive inoculations often improve the efficacy of this type of vaccines. An initial dose (prime) triggers a specific cellular response, and subsequent inoculations (boost) amplify this response to create a robust CD8+ T cell memory. In this work we propose a model to analyze the effect of T cell dynamics on the performance of prime-boost vaccines. This model suggests that boost doses and timings should be selected according to the T cell response elicited by priming. Specifically, boosting during late stages of clonal contraction would maximize T cell memory production for vaccines using lower doses of irradiated sporozoites. In contrast, single-dose inoculations would be indicated for higher vaccine doses. Experimental data have been obtained that support theoretical predictions of the model.
Collapse
|
7
|
Flesch IEA, Hollett NA, Wong YC, Quinan BR, Howard D, da Fonseca FG, Tscharke DC. Extent of Systemic Spread Determines CD8+ T Cell Immunodominance for Laboratory Strains, Smallpox Vaccines, and Zoonotic Isolates of Vaccinia Virus. THE JOURNAL OF IMMUNOLOGY 2015. [PMID: 26195812 DOI: 10.4049/jimmunol.1402508] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
CD8(+) T cells that recognize virus-derived peptides presented on MHC class I are vital antiviral effectors. Such peptides presented by any given virus vary greatly in immunogenicity, allowing them to be ranked in an immunodominance hierarchy. However, the full range of parameters that determine immunodominance and the underlying mechanisms remain unknown. In this study, we show across a range of vaccinia virus strains, including the current clonal smallpox vaccine, that the ability of a strain to spread systemically correlated with reduced immunodominance. Reduction in immunodominance was observed both in the lymphoid system and at the primary site of infection. Mechanistically, reduced immunodominance was associated with more robust priming and especially priming in the spleen. Finally, we show this is not just a property of vaccine and laboratory strains of virus, because an association between virulence and immunodominance was also observed in isolates from an outbreak of zoonotic vaccinia virus that occurred in Brazil.
Collapse
Affiliation(s)
- Inge E A Flesch
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Natasha A Hollett
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Yik Chun Wong
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Bárbara Resende Quinan
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia; Laboratório de Virologia Básica e Aplicada, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; and
| | - Debbie Howard
- John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Flávio G da Fonseca
- Laboratório de Virologia Básica e Aplicada, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; and
| | - David C Tscharke
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia; John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| |
Collapse
|
8
|
Gilchuk P, Hill TM, Wilson JT, Joyce S. Discovering protective CD8 T cell epitopes--no single immunologic property predicts it! Curr Opin Immunol 2015; 34:43-51. [PMID: 25660347 PMCID: PMC5023008 DOI: 10.1016/j.coi.2015.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 01/19/2015] [Accepted: 01/19/2015] [Indexed: 01/25/2023]
Abstract
Once a burgeoning field of study, over the past decade or so, T cell epitope discovery has lost some luster. The contributory factors perchance are the general notion that any newly discovered epitope will reveal very little about an immune response and that knowledge of epitopes are less critical for vaccine design. Despite these notions, the breadth and depth of T cell epitopes derived from clinically important microbial agents of human diseases largely remain ill defined. We review here a flurry of recent reports that have rebirthed the field. These reports reveal that epitope discovery is an essential step toward rational vaccine design and critical for monitoring vaccination efficacy. The new findings also indicate that neither immunogenicity nor immunodominance predict protective immunity. Hence, an immunogenic epitope is but a peptide unless proven protective against disease.
Collapse
Affiliation(s)
- Pavlo Gilchuk
- Veterans Administration Tennessee Valley Healthcare System, Vanderbilt University, Nashville, TN 37332, USA; Department of Pathology, Microbiology and Immunology, School of Medicine, Vanderbilt University, Nashville, TN 37332, USA
| | - Timothy M Hill
- Department of Pathology, Microbiology and Immunology, School of Medicine, Vanderbilt University, Nashville, TN 37332, USA
| | - John T Wilson
- Department of Chemical & Biomolecular Engineering, School of Engineering, Vanderbilt University, Nashville, TN 37332, USA
| | - Sebastian Joyce
- Veterans Administration Tennessee Valley Healthcare System, Vanderbilt University, Nashville, TN 37332, USA; Department of Pathology, Microbiology and Immunology, School of Medicine, Vanderbilt University, Nashville, TN 37332, USA.
| |
Collapse
|
9
|
Nelson RW, Beisang D, Tubo NJ, Dileepan T, Wiesner DL, Nielsen K, Wüthrich M, Klein BS, Kotov DI, Spanier JA, Fife BT, Moon JJ, Jenkins MK. T cell receptor cross-reactivity between similar foreign and self peptides influences naive cell population size and autoimmunity. Immunity 2015; 42:95-107. [PMID: 25601203 DOI: 10.1016/j.immuni.2014.12.022] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 10/25/2014] [Accepted: 12/22/2014] [Indexed: 01/06/2023]
Abstract
T cell receptor (TCR) cross-reactivity between major histocompatibility complex II (MHCII)-binding self and foreign peptides could influence the naive CD4(+) T cell repertoire and autoimmunity. We found that nonamer peptides that bind to the same MHCII molecule only need to share five amino acids to cross-react on the same TCR. This property was biologically relevant because systemic expression of a self peptide reduced the size of a naive cell population specific for a related foreign peptide by deletion of cells with cross-reactive TCRs. Reciprocally, an incompletely deleted naive T cell population specific for a tissue-restricted self peptide could be triggered by related microbial peptides to cause autoimmunity. Thus, TCR cross-reactivity between similar self and foreign peptides can reduce the size of certain foreign peptide-specific T cell populations and might allow T cell populations specific for tissue-restricted self peptides to cause autoimmunity after infection.
Collapse
|
10
|
Ni PP, Wang Y, Allen PM. Both positive and negative effects on immune responses by expression of a second class II MHC molecule. Mol Immunol 2014; 62:199-208. [PMID: 25016574 PMCID: PMC4157116 DOI: 10.1016/j.molimm.2014.06.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 06/19/2014] [Accepted: 06/20/2014] [Indexed: 12/24/2022]
Abstract
It is perplexing why vertebrates express a limited number of major histocompatibility complex (MHC) molecules when theoretically, having a greater repertoire of MHC molecules would increase the number of epitopes presented, thereby enhancing thymic selection and T cell response to pathogens. It is possible that any positive effects would either be neutralized or outweighed by negative selection restricting the T cell repertoire. We hypothesize that the limit on MHC number is due to negative consequences arising from expressing additional MHC. We compared T cell responses between B6 mice (I-A(+)) and B6.E(+) mice (I-A(+), I-E(+)), the latter expressing a second class II MHC molecule, I-E(b), due to a monomorphic Eα(k) transgene that pairs with the endogenous I-Eβ(b) chain. First, the naive T cell Vβ repertoire was altered in B6.E(+) thymi and spleens, potentially mediating different outcomes in T cell reactivity. Although the B6 and B6.E(+) responses to hen egg-white lysozyme (HEL) protein immunization remained similar, other immune models yielded differences. For viral infection, the quality of the T cell response was subtly altered, with diminished production of certain cytokines by B6.E(+) CD4(+) T cells. In alloreactivity, the B6.E(+) T cell response was significantly dampened. Finally, we observed markedly enhanced susceptibility to experimental autoimmune encephalomyelitis (EAE) in B6.E(+) mice. This correlated with decreased percentages of nTreg cells, supporting the concept of Tregs exhibiting differential susceptibility to negative selection. Altogether, our data suggest that expressing an additional class II MHC can produce diverse effects, with more severe autoimmunity providing a compelling explanation for limiting the expression of MHC molecules.
Collapse
Affiliation(s)
- Peggy P Ni
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Box 8118, St. Louis, MO 63110, United States
| | - Yaming Wang
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Box 8118, St. Louis, MO 63110, United States
| | - Paul M Allen
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Box 8118, St. Louis, MO 63110, United States.
| |
Collapse
|
11
|
Kim S, Pinto AK, Myers NB, Hawkins O, Doll K, Kaabinejadian S, Netland J, Bevan MJ, Weidanz JA, Hildebrand WH, Diamond MS, Hansen TH. A novel T-cell receptor mimic defines dendritic cells that present an immunodominant West Nile virus epitope in mice. Eur J Immunol 2014; 44:1936-46. [PMID: 24723377 DOI: 10.1002/eji.201444450] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/18/2014] [Accepted: 04/02/2014] [Indexed: 12/22/2022]
Abstract
We used a newly generated T-cell receptor mimic monoclonal antibody (TCRm MAb) that recognizes a known nonself immunodominant peptide epitope from West Nile virus (WNV) NS4B protein to investigate epitope presentation after virus infection in C57BL/6 mice. Previous studies suggested that peptides of different length, either SSVWNATTAI (10-mer) or SSVWNATTA (9-mer) in complex with class I MHC antigen H-2D(b) , were immunodominant after WNV infection. Our data establish that both peptides are presented on the cell surface after WNV infection and that CD8(+) T cells can detect 10- and 9-mer length variants similarly. This result varies from the idea that a given T-cell receptor (TCR) prefers a single peptide length bound to its cognate class I MHC. In separate WNV infection studies with the TCRm MAb, we show that in vivo the 10-mer was presented on the surface of uninfected and infected CD8α(+) CD11c(+) dendritic cells, which suggests the use of direct and cross-presentation pathways. In contrast, CD11b(+) CD11c(-) cells bound the TCRm MAb only when they were infected. Our study demonstrates that TCR recognition of peptides is not limited to certain peptide lengths and that TCRm MAbs can be used to dissect the cell-type specific mechanisms of antigen presentation in vivo.
Collapse
Affiliation(s)
- Sojung Kim
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Russell TA, Tscharke DC. Strikingly poor CD8+ T-cell immunogenicity of vaccinia virus strain MVA in BALB/c mice. Immunol Cell Biol 2014; 92:466-9. [PMID: 24566805 PMCID: PMC4037371 DOI: 10.1038/icb.2014.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 02/02/2014] [Accepted: 02/02/2014] [Indexed: 01/24/2023]
Abstract
Vaccinia virus (VACV) strain MVA is a highly attenuated vector for
vaccines that is being explored in clinical trials. We compared the
CD8+ T cell immunogenicity of MVA with that of a virulent
laboratory strain of VACV (strain WR) in BALB/c mice by examining
epitope-specific responses as well as estimating the total number of activated
CD8+ T cells, irrespective of specificity. We found that
MVA elicited total CD8+ T cell responses that were reduced by
at least 20-fold compared with strain WR in BALB/c mice. In C57Bl/6 mice we also
found a substantial difference in immunogenicity between these VACV strains, but
it was more modest at around 5-fold. Of note, the size of responses to the
virulent WR virus were similar in both strains of mice suggesting that BALB/c
mice can mount robust CD8+ T cell responses to VACV. While
the data for total responses clearly showed that MVA overall is poorly
immunogenic in BALB/c mice, we found one epitope for which strong responses were
made irrespective of virus strain. Therefore in the context of a vaccine, some
recombinant epitopes may have similar immunogenicity when expressed from MVA and
other strains of VACV, but we would expect these to be exceptions. These data
show clearly the substantial difference in immunogenicity between MVA and
virulent VACV strains and suggest that the impact of host genetics on responses
to attenuated vaccine vectors like MVA requires more consideration.
Collapse
Affiliation(s)
- Tiffany A Russell
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - David C Tscharke
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| |
Collapse
|
13
|
Systemic toll-like receptor ligation and selective killing of dendritic cell subsets fail to dissect priming pathways for anti-vaccinia virus CD8⁺ T cells. J Virol 2013; 87:11978-86. [PMID: 23986587 DOI: 10.1128/jvi.01835-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
CD8⁺ T cell responses can be generated by direct or cross-priming mechanisms, and several mouse models have been used to reveal which of these is the most important pathway for various viruses. Among these models is systemic treatment of mice with a CpG-containing oligodeoxynucleotide (CpG) to mature all dendritic cells (DCs), rendering them incapable of cross-presentation. A second is the use of cytochrome c (cytc) as a selective poison of the subsets of DCs able to cross-present antigen. In this study, using two vaccinia virus (VACV) strains, namely, WR and MVA, we found that the CpG and cytc methods gave conflicting data. Moreover, we show for both strains of VACV that treatment of mice with CpG and cytc inhibited CD8⁺ T cell responses to antigens designed to prime exclusively by direct presentation. Further investigation of the CpG method found that the extent to which priming is inhibited depends on the antigen examined, immunization route, replication ability of the virus, and, crucially, immunization dose. We suggest that greater caution is required when interpreting data using these methods and that priming pathways for antiviral CD8⁺ T cells are not simply separated according to DC subsets or their maturation state.
Collapse
|
14
|
Bacher P, Scheffold A. Flow-cytometric analysis of rare antigen-specific T cells. Cytometry A 2013; 83:692-701. [PMID: 23788442 DOI: 10.1002/cyto.a.22317] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/09/2013] [Accepted: 05/14/2013] [Indexed: 12/20/2022]
Abstract
The cytometric enumeration and characterization of antigen-specific lymphocytes, as introduced about 15 years ago, has contributed significantly to our understanding of adaptive immune responses in health and disease. Despite the development of several technologies, allowing to directly or indirectly analyze many aspects of lymphocyte specificity and function, several unresolved issues remain, due to the low frequency of certain antigen-specific lymphocyte subsets and the complexity of T cell antigen recognition. This is especially true for CD4(+) conventional as well as regulatory T cells, which bring major contributions to immune protection and pathology. Here we review the current technologies for the analysis of antigen specific T cells within the physiologic T cell repertoire and with a special focus on recent technologies addressing the analysis of rare antigen-specific T cell populations including naive and regulatory T cells.
Collapse
Affiliation(s)
- Petra Bacher
- Miltenyi Biotec GmbH, Bergisch Gladbach, Germany
| | | |
Collapse
|
15
|
Lin LCW, Flesch IEA, Tscharke DC. Immunodomination during peripheral vaccinia virus infection. PLoS Pathog 2013; 9:e1003329. [PMID: 23633956 PMCID: PMC3635974 DOI: 10.1371/journal.ppat.1003329] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 03/14/2013] [Indexed: 11/20/2022] Open
Abstract
Immunodominance is a fundamental property of CD8(+) T cell responses to viruses and vaccines. It had been observed that route of administration alters immunodominance after vaccinia virus (VACV) infection, but only a few epitopes were examined and no mechanism was provided. We re-visited this issue, examining a panel of 15 VACV epitopes and four routes, namely intradermal (i.d.), subcutaneous (s.c.), intraperitoneal (i.p.) and intravenous (i.v.) injection. We found that immunodominance is sharpened following peripheral routes of infection (i.d. and s.c.) compared with those that allow systemic virus dissemination (i.p. and i.v.). This increased immunodominance was demonstrated with native epitopes of VACV and with herpes simplex virus glycoprotein B when expressed from VACV. Responses to some subdominant epitopes were altered by as much as fourfold. Tracking of virus, examination of priming sites, and experiments restricting virus spread showed that priming of CD8(+) T cells in the spleen was necessary, but not sufficient to broaden responses. Further, we directly demonstrated that immunodomination occurs more readily when priming is mainly in lymph nodes. Finally, we were able to reduce immunodominance after i.d., but not i.p. infection, using a VACV expressing the costimulators CD80 (B7-1) and CD86 (B7-2), which is notable because VACV-based vaccines incorporating these molecules are in clinical trials. Taken together, our data indicate that resources for CD8(+) T cell priming are limiting in local draining lymph nodes, leading to greater immunodomination. Further, we provide evidence that costimulation can be a limiting factor that contributes to immunodomination. These results shed light on a possible mechanism of immunodomination and highlight the need to consider multiple epitopes across the spectrum of immunogenicities in studies aimed at understanding CD8(+) T cell immunity to viruses.
Collapse
Affiliation(s)
- Leon C. W. Lin
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Inge E. A. Flesch
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - David C. Tscharke
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| |
Collapse
|
16
|
Gilchuk P, Spencer CT, Conant SB, Hill T, Gray JJ, Niu X, Zheng M, Erickson JJ, Boyd KL, McAfee KJ, Oseroff C, Hadrup SR, Bennink JR, Hildebrand W, Edwards KM, Crowe JE, Williams JV, Buus S, Sette A, Schumacher TNM, Link AJ, Joyce S. Discovering naturally processed antigenic determinants that confer protective T cell immunity. J Clin Invest 2013; 123:1976-87. [PMID: 23543059 DOI: 10.1172/jci67388] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 02/07/2013] [Indexed: 12/15/2022] Open
Abstract
CD8+ T cells (TCD8) confer protective immunity against many infectious diseases, suggesting that microbial TCD8 determinants are promising vaccine targets. Nevertheless, current T cell antigen identification approaches do not discern which epitopes drive protective immunity during active infection - information that is critical for the rational design of TCD8-targeted vaccines. We employed a proteomics-based approach for large-scale discovery of naturally processed determinants derived from a complex pathogen, vaccinia virus (VACV), that are presented by the most frequent representatives of four major HLA class I supertypes. Immunologic characterization revealed that many previously unidentified VACV determinants were recognized by smallpox-vaccinated human peripheral blood cells in a variegated manner. Many such determinants were recognized by HLA class I-transgenic mouse immune TCD8 too and elicited protective TCD8 immunity against lethal intranasal VACV infection. Notably, efficient processing and stable presentation of immune determinants as well as the availability of naive TCD8 precursors were sufficient to drive a multifunctional, protective TCD8 response. Our approach uses fundamental insights into T cell epitope processing and presentation to define targets of protective TCD8 immunity within human pathogens that have complex proteomes, suggesting that this approach has general applicability in vaccine sciences.
Collapse
Affiliation(s)
- Pavlo Gilchuk
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Hickman HD, Reynoso GV, Ngudiankama BF, Rubin EJ, Magadán JG, Cush SS, Gibbs J, Molon B, Bronte V, Bennink JR, Yewdell JW. Anatomically restricted synergistic antiviral activities of innate and adaptive immune cells in the skin. Cell Host Microbe 2013; 13:155-68. [PMID: 23414756 PMCID: PMC3591514 DOI: 10.1016/j.chom.2013.01.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 11/30/2012] [Accepted: 01/09/2013] [Indexed: 12/14/2022]
Abstract
Despite extensive ex vivo investigation, the spatiotemporal organization of immune cells interacting with virus-infected cells in tissues remains uncertain. To address this, we used intravital multiphoton microscopy to visualize immune cell interactions with virus-infected cells following epicutaneous vaccinia virus (VV) infection of mice. VV infects keratinocytes in epidermal foci and numerous migratory dermal inflammatory monocytes that outlie the foci. We observed Ly6G(+) innate immune cells infiltrating and controlling foci, while CD8(+) T cells remained on the periphery killing infected monocytes. Most antigen-specific CD8(+) T cells in the skin did not interact with virus-infected cells. Blocking the generation of reactive nitrogen species relocated CD8(+) T cells into foci, modestly reducing viral titers. Depletion of Ly6G(+) and CD8(+) cells dramatically increased viral titers, consistent with their synergistic but spatially segregated viral clearance activities. These findings highlight previously unappreciated differences in the anatomic specialization of antiviral immune cell subsets.
Collapse
Affiliation(s)
- Heather D Hickman
- Laboratory of Viral Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Croft NP, Smith SA, Wong YC, Tan CT, Dudek NL, Flesch IEA, Lin LCW, Tscharke DC, Purcell AW. Kinetics of antigen expression and epitope presentation during virus infection. PLoS Pathog 2013; 9:e1003129. [PMID: 23382674 PMCID: PMC3561264 DOI: 10.1371/journal.ppat.1003129] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 11/26/2012] [Indexed: 01/20/2023] Open
Abstract
Current knowledge about the dynamics of antigen presentation to T cells during viral infection is very poor despite being of fundamental importance to our understanding of anti-viral immunity. Here we use an advanced mass spectrometry method to simultaneously quantify the presentation of eight vaccinia virus peptide-MHC complexes (epitopes) on infected cells and the amounts of their source antigens at multiple times after infection. The results show a startling 1000-fold range in abundance as well as strikingly different kinetics across the epitopes monitored. The tight correlation between onset of protein expression and epitope display for most antigens provides the strongest support to date that antigen presentation is largely linked to translation and not later degradation of antigens. Finally, we show a complete disconnect between the epitope abundance and immunodominance hierarchy of these eight epitopes. This study highlights the complexity of viral antigen presentation by the host and demonstrates the weakness of simple models that assume total protein levels are directly linked to epitope presentation and immunogenicity. A major mechanism for the detection of virus infection is the recognition by T cells of short peptide fragments (epitopes) derived from the degradation of intracellular proteins presented at the cell surface in a complex with class I MHC. Whilst the mechanics of antigen degradation and the loading of peptides onto MHC are now well understood, the kinetics of epitope presentation have only been studied for individual model antigens. We addressed this issue by studying vaccinia virus, best known as the smallpox vaccine, using advanced mass spectrometry. Precise and simultaneous quantification of multiple peptide-MHC complexes showed that the surface of infected cells provides a surprisingly dynamic landscape from the point of view of anti-viral T cells. Further, concurrent measurement of virus protein levels demonstrated that in most cases, peak presentation of epitopes occurs at the same time or precedes the time of maximum protein build up. Finally, we found a complete disconnect between the abundance of epitopes on infected cells and the size of the responding T cell populations. These data provide new insights into how virus infected cells are seen by T cells, which is crucial to our understanding of anti-viral immunity and development of vaccines.
Collapse
Affiliation(s)
- Nathan P. Croft
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Stewart A. Smith
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Yik Chun Wong
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Chor Teck Tan
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Nadine L. Dudek
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Inge E. A. Flesch
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Leon C. W. Lin
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - David C. Tscharke
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
- * E-mail: (DCT); (AWP)
| | - Anthony W. Purcell
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
- * E-mail: (DCT); (AWP)
| |
Collapse
|
19
|
Ecological analysis of antigen-specific CTL repertoires defines the relationship between naive and immune T-cell populations. Proc Natl Acad Sci U S A 2013; 110:1839-44. [PMID: 23319654 DOI: 10.1073/pnas.1222149110] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ecology is typically thought of as the study of interactions organisms have with each other and their environment and is focused on the distribution and abundance of organisms both within and between environments. On a molecular level, the capacity to probe analogous questions in the field of T-cell immunology is imperative as we acquire substantial datasets both on epitope-specific T-cell populations through high-resolution analyses of T-cell receptor (TCR) use and on global T-cell populations analyzed via high-throughput DNA sequencing. Here, we present the innovative application of existing statistical measures (used typically in the field of ecology), together with unique statistical analyses, to comprehensively assess how the naïve epitope-specific CD8(+) cytotoxic T lymphocyte (CTL) repertoire translates to that found following an influenza-virus-specific immune response. Such interrogation of our extensive, cumulated TCR CDR3β sequence datasets, derived from both naïve and immune CD8(+) T-cell populations specific for four different influenza-derived epitopes (D(b)NP(366), influenza nucleoprotein amino acid residues 366-374; D(b)PA(224), influenza acid polymerase amino acid residues 224-233; D(b)PB1-F2(62), influenza polymerase B 1 reading frame 2 amino acid residues 62-70; K(b)NS2(114), and influenza nonstructural protein 2 amino acid residues 114-121), demonstrates that epitope-specific TCR use in an antiviral immune response is the consequence of a complex interplay between the intrinsic characteristics of the naïve cytotoxic T lymphocyte precursor pool and extrinsic (likely antigen driven) influences, the contribution of which varies in an epitope-specific fashion.
Collapse
|
20
|
Townsend MB, Keckler MS, Patel N, Davies DH, Felgner P, Damon IK, Karem KL. Humoral immunity to smallpox vaccines and monkeypox virus challenge: proteomic assessment and clinical correlations. J Virol 2013; 87:900-11. [PMID: 23135728 PMCID: PMC3554095 DOI: 10.1128/jvi.02089-12] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/25/2012] [Indexed: 11/20/2022] Open
Abstract
Despite the eradication of smallpox, orthopoxviruses (OPV) remain public health concerns. Efforts to develop new therapeutics and vaccines for smallpox continue through their evaluation in animal models despite limited understanding of the specific correlates of protective immunity. Recent monkeypox virus challenge studies have established the black-tailed prairie dog (Cynomys ludovicianus) as a model of human systemic OPV infections. In this study, we assess the induction of humoral immunity in humans and prairie dogs receiving Dryvax, Acam2000, or Imvamune vaccine and characterize the proteomic profile of immune recognition using enzyme-linked immunosorbent assays (ELISA), neutralization assays, and protein microarrays. We confirm anticipated similarities of antigenic protein targets of smallpox vaccine-induced responses in humans and prairie dogs and identify several differences. Subsequent monkeypox virus intranasal infection of vaccinated prairie dogs resulted in a significant boost in humoral immunity characterized by a shift in reactivity of increased intensity to a broader range of OPV proteins. This work provides evidence of similarities between the vaccine responses in prairie dogs and humans that enhance the value of the prairie dog model system as an OPV vaccination model and offers novel findings that form a framework for examining the humoral immune response induced by systemic orthopoxvirus infection.
Collapse
Affiliation(s)
- M B Townsend
- Centers for Disease Control and Prevention, Division of High Consequence Pathogens and Pathology, Poxvirus and Rabies Branch, Atlanta, GA, USA.
| | | | | | | | | | | | | |
Collapse
|
21
|
Nayak JL, Sant AJ. Loss in CD4 T-cell responses to multiple epitopes in influenza due to expression of one additional MHC class II molecule in the host. Immunology 2012; 136:425-36. [PMID: 22747522 DOI: 10.1111/j.1365-2567.2012.03599.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
An understanding of factors controlling CD4 T-cell immunodominance is needed to pursue CD4 T-cell epitope-driven vaccine design, yet our understanding of this in humans is limited by the complexity of potential MHC class II molecule expression. In the studies described here, we took advantage of genetically restricted, well-defined mouse strains to better understand the effect of increasing MHC class II molecule diversity on the CD4 T-cell repertoire and the resulting anti-influenza immunodominance hierarchy. Interferon-γ ELISPOT assays were implemented to directly quantify CD4 T-cell responses to I-A(b) and I-A(s) restricted peptide epitopes following primary influenza virus infection in parental and F(1) hybrid strains. We found striking and asymmetric declines in the magnitude of many peptide-specific responses in F(1) animals. These declines could not be accounted for by the lower surface density of MHC class II on the cell or by antigen-presenting cells failing to stimulate T cells with lower avidity T-cell receptors. Given the large diversity of MHC class II expressed in humans, these findings have important implications for the rational design of peptide-based vaccines that are based on the premise that CD4 T-cell epitope specificity can be predicted by a simple cataloguing of an individual's MHC class II genotype.
Collapse
Affiliation(s)
- Jennifer L Nayak
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | | |
Collapse
|
22
|
Flesch IEA, Hollett NA, Wong YC, Tscharke DC. Linear fidelity in quantification of anti-viral CD8+ T cells. PLoS One 2012; 7:e39533. [PMID: 22745779 PMCID: PMC3379996 DOI: 10.1371/journal.pone.0039533] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 05/23/2012] [Indexed: 11/19/2022] Open
Abstract
Enumeration of anti-viral CD8(+) T cells to make comparisons between mice, viruses and vaccines is a frequently used approach, but controversy persists as to the most appropriate methods. Use of peptide-MHC tetramers (or variants) and intracellular staining for cytokines, in particular IFNγ, after a short ex vivo stimulation are now common, as are a variety of cytotoxicity assays, but few direct comparisons have been made. It has been argued that use of tetramers leads to the counting of non-functional T cells and that measurement of single cytokines will fail to identify cells with alternative functions. Further, the linear range of these methods has not been tested and this is required to give confidence that relative quantifications can be compared across samples. Here we show for two acute virus infections and CD8(+) T cells activated in vitro that DimerX (a tetramer variant) and intracellular staining for IFNγ, alone or in combination with CD107 to detect degranulation, gave comparable results at the peak of the response. Importantly, these methods were highly linear over nearly two orders of magnitude. In contrast, in vitro and in vivo assays for cytotoxicity were not linear, suffering from high background killing, plateaus in maximal killing and substantial underestimation of differences in magnitude of responses.
Collapse
Affiliation(s)
- Inge E. A. Flesch
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
| | - Natasha A. Hollett
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
| | - Yik Chun Wong
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
| | - David C. Tscharke
- Division of Biomedical Science and Biochemistry, Research School of Biology, The Australian National University, Canberra, Australia
- * E-mail:
| |
Collapse
|
23
|
Jenkins MK, Moon JJ. The role of naive T cell precursor frequency and recruitment in dictating immune response magnitude. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2012; 188:4135-40. [PMID: 22517866 PMCID: PMC3334329 DOI: 10.4049/jimmunol.1102661] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent advances in technology have led to the realization that the populations of naive T cells specific for different foreign peptide:MHC (p:MHC) ligands vary in size. This variability is due, in part, to the fact that certain peptides contain amino acids that engage in particularly favorable interactions with TCRs. In addition, deletion of clones with cross-reactivity for self-p:MHC ligands may reduce the size of some naive populations. In many cases, the magnitude of the immune response to individual p:MHC epitopes correlates with the size of the corresponding naive populations. However, this simple relationship may be complicated by variability in the efficiency of T cell recruitment into the immune response. The knowledge that naive population size can predict immune response magnitude may create opportunities for production of more effective subunit vaccines.
Collapse
Affiliation(s)
- Marc K Jenkins
- Department of Microbiology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| | | |
Collapse
|
24
|
Immunodominance: a pivotal principle in host response to viral infections. Clin Immunol 2012; 143:99-115. [PMID: 22391152 DOI: 10.1016/j.clim.2012.01.015] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/25/2012] [Accepted: 01/28/2012] [Indexed: 11/24/2022]
Abstract
We encounter pathogens on a daily basis and our immune system has evolved to mount an immune response following an infection. An interesting phenomenon that has evolved in response to clearing bacterial and viral infections is called immunodominance. Immunodominance refers to the phenomenon that, despite co-expression of multiple major histocompatibility complex class I alleles by host cells and the potential generation of hundreds of distinct antigenic peptides for recognition following an infection, a large portion of the anti-viral cytotoxic T lymphocyte population targets only some peptide/MHC class I complexes. Here we review the main factors contributing to immunodominance in relation to influenza A and HIV infection. Of special interest are the factors contributing to immunodominance in humans and rodents following influenza A infection. By critically reviewing these findings, we hope to improve understanding of the challenges facing the discovery of new factors enabling better anti-viral vaccine strategies in the future.
Collapse
|
25
|
Greene JM, Wiseman RW, Lank SM, Bimber BN, Karl JA, Burwitz BJ, Lhost JJ, Hawkins OE, Kunstman KJ, Broman KW, Wolinsky SM, Hildebrand WH, O'Connor DH. Differential MHC class I expression in distinct leukocyte subsets. BMC Immunol 2011; 12:39. [PMID: 21762519 PMCID: PMC3155488 DOI: 10.1186/1471-2172-12-39] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 07/15/2011] [Indexed: 11/16/2022] Open
Abstract
Background MHC class I proteins are partly responsible for shaping the magnitude and focus of the adaptive cellular immune response. In humans, conventional wisdom suggests that the HLA-A, -B, and -C alleles are equally expressed on the majority of cell types. While we currently have a thorough understanding of how total MHC class I expression varies in different tissues, it has been difficult to examine expression of single MHC class I alleles due to the homogeneity of MHC class I sequences. It is unclear how cDNA species are expressed in distinct cell subsets in humans and particularly in macaques which transcribe upwards of 20 distinct MHC class I alleles at variable levels. Results We examined MHC gene expression in human and macaque leukocyte subsets. In humans, while we detected overall differences in locus transcription, we found that transcription of MHC class I genes was consistent across the leukocyte subsets we studied with only small differences detected. In contrast, transcription of certain MHC cDNA species in macaques varied dramatically by up to 45% between different subsets. Although the Mafa-B*134:02 RNA is virtually undetectable in CD4+ T cells, it represents over 45% of class I transcripts in CD14+ monocytes. We observed parallel MHC transcription differences in rhesus macaques. Finally, we analyzed expression of select MHC proteins at the cell surface using fluorescent peptides. This technique confirmed results from the transcriptional analysis and demonstrated that other MHC proteins, known to restrict SIV-specific responses, are also differentially expressed among distinct leukocyte subsets. Conclusions We assessed MHC class I transcription and expression in human and macaque leukocyte subsets. Until now, it has been difficult to examine MHC class I allele expression due to the similarity of MHC class I sequences. Using two novel techniques we showed that expression varies among distinct leukocyte subsets of macaques but does not vary dramatically in the human cell subsets we examined. These findings suggest pathogen tropism may have a profound impact on the shape and focus of the MHC class I restricted CD8+ T cell response in macaques.
Collapse
Affiliation(s)
- Justin M Greene
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, 53706 Wisconsin, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Day EB, Charlton KL, La Gruta NL, Doherty PC, Turner SJ. Effect of MHC class I diversification on influenza epitope-specific CD8+ T cell precursor frequency and subsequent effector function. THE JOURNAL OF IMMUNOLOGY 2011; 186:6319-28. [PMID: 21536802 DOI: 10.4049/jimmunol.1000883] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Earlier studies of influenza-specific CD8(+) T cell immunodominance hierarchies indicated that expression of the H2K(k) MHC class I allele greatly diminishes responses to the H2D(b)-restriced D(b)PA(224) epitope (acid polymerase, residues 224-233 complexed with H2D(b)). The results suggested that the presence of H2K(k) during thymic differentiation led to the deletion of a prominent Vβ7(+) subset of D(b)PA(224)-specific TCRs. The more recent definition of D(b)PA(224)-specific TCR CDR3β repertoires in H2(b) mice provides a new baseline for looking again at this possible H2K(k) effect on D(b)PA(224)-specific TCR selection. We found that immune responses to several H2D(b)- and H2K(b)-restricted influenza epitopes were indeed diminished in H2(bxk) F(1) versus homozygous mice. In the case of D(b)PA(224), lower numbers of naive precursors were part of the explanation, though a similar decrease in those specific for the D(b)NP(366) epitope did not affect response magnitude. Changes in precursor frequency were not associated with any major loss of TCR diversity and could not fully account for the diminished D(b)PA(224)-specific response. Further functional and phenotypic characterization of influenza-specific CD8(+) T cells suggested that the expansion and differentiation of the D(b)PA(224)-specific set is impaired in the H2(bxk) F(1) environment. Thus, the D(b)PA(224) response in H2(bxk) F(1) mice is modulated by factors that affect the generation of naive epitope-specific precursors and the expansion and differentiation of these T cells during infection, rather than clonal deletion of a prominent Vβ7(+) subset. Such findings illustrate the difficulties of predicting and defining the effects of MHC class I diversification on epitope-specific responses.
Collapse
Affiliation(s)
- E Bridie Day
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010, Australia
| | | | | | | | | |
Collapse
|
27
|
Woodworth JS, Shin D, Volman M, Nunes-Alves C, Fortune SM, Behar SM. Mycobacterium tuberculosis directs immunofocusing of CD8+ T cell responses despite vaccination. THE JOURNAL OF IMMUNOLOGY 2010; 186:1627-37. [PMID: 21178003 DOI: 10.4049/jimmunol.1002911] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Vaccines that elicit T cell responses try to mimic protective memory T cell immunity after infection by increasing the frequency of Ag-specific T cells in the immune repertoire. However, the factors that determine immunodominance during infection and after vaccination and the relation between immunodominance and protection are incompletely understood. We previously identified TB10.4(20-28) as an immunodominant epitope recognized by H2-K(d)-restricted CD8(+) T cells after M. tuberculosis infection. Here we report a second epitope, EspA(150-158), that is recognized by a substantial number of pulmonary CD8(+) T cells. The relative abundance of these T cells in the naive repertoire only partially predicts their relative frequency after M. tuberculosis infection. Furthermore, although vaccination with recombinant vaccinia virus expressing these epitopes changes their relative immunodominance in the preinfection T cell repertoire, this change is transient after challenge with M. tuberculosis. We speculate that factors intrinsic to the chronic nature of M. tuberculosis infection establishes the hierarchy of immunodominance and may explain the failure of some vaccines to provide protection.
Collapse
Affiliation(s)
- Joshua S Woodworth
- Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | |
Collapse
|
28
|
Yuen TJ, Flesch IEA, Hollett NA, Dobson BM, Russell TA, Fahrer AM, Tscharke DC. Analysis of A47, an immunoprevalent protein of vaccinia virus, leads to a reevaluation of the total antiviral CD8+ T cell response. J Virol 2010; 84:10220-9. [PMID: 20668091 PMCID: PMC2937773 DOI: 10.1128/jvi.01281-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 07/19/2010] [Indexed: 11/20/2022] Open
Abstract
Vaccinia virus (VACV) is the prototypic orthopoxvirus and was the live vaccine used to eradicate smallpox. In addition, VACV is a possible vector for recombinant vaccines. Despite these reasons for study, the roles of many VACV genes are unknown, and some fundamental aspects, such as the total size of immune responses, remain poorly characterized. VACV gene A47L is of interest because it is highly transcribed, has no sequence similarity to any nonpoxvirus gene, and contains a larger-than-expected number of CD8(+) T cell epitopes. Here it is shown that A47L is not required for growth in vitro and does not contribute to virulence in mice. However, we confirmed that this one protein primes CD8(+) T cells to three different epitopes in C57BL/6 mice. In the process, one of these epitopes was redefined and shown to be the most dominant in A47 and one of the more highly ranked in VACV as a whole. The relatively high immunogenicity of this epitope led to a reevaluation of the total CD8(+) T cell response to VACV. By the use of two methods, the true size of the response was found to be around double previous estimates and at its peak is on the order of 60% of all CD8(+) T cells. We speculate that more CD8(+) T cell epitopes remain to be mapped for VACV and that underestimation of responses is unlikely to be unique to VACV, so there would be merit in revisiting this issue for other viruses.
Collapse
Affiliation(s)
- Tracy J. Yuen
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| | - Inge E. A. Flesch
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| | - Natasha A. Hollett
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| | - Bianca M. Dobson
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| | - Tiffany A. Russell
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| | - Aude M. Fahrer
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| | - David C. Tscharke
- Division of Biomedical Science and Biochemistry, Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Canberra, ACT, Australia
| |
Collapse
|
29
|
Coverage of related pathogenic species by multivalent and cross-protective vaccine design: arenaviruses as a model system. Microbiol Mol Biol Rev 2010; 74:157-70. [PMID: 20508245 DOI: 10.1128/mmbr.00045-09] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The arenaviruses are a family of negative-sense RNA viruses that cause severe human disease ranging from aseptic meningitis to hemorrhagic fever syndromes. There are currently no FDA-approved vaccines for the prevention of arenavirus disease, and therapeutic treatment is limited to the use of ribavirin and/or immune plasma for a subset of the pathogenic arenaviruses. The considerable genetic variability observed among the seven arenaviruses that are pathogenic for humans illustrates one of the major challenges for vaccine development today, namely, to overcome pathogen heterogeneity. Over the past 5 years, our group has tested several strategies to overcome pathogen heterogeneity, utilizing the pathogenic arenaviruses as a model system. Because T cells play a prominent role in protective immunity following arenavirus infection, we specifically focused on the development of human vaccines that would induce multivalent and cross-protective cell-mediated immune responses. To facilitate our vaccine development and testing, we conducted large-scale major histocompatibility complex (MHC) class I and class II epitope discovery on murine, nonhuman primate, and human backgrounds for each of the pathogenic arenaviruses, including the identification of protective HLA-restricted epitopes. Finally, using the murine model of lymphocytic choriomeningitis virus infection, we studied the phenotypic characteristics associated with immunodominant and protective T cell epitopes. This review summarizes the findings from our studies and discusses their application to future vaccine design.
Collapse
|
30
|
Ruckwardt TJ, Luongo C, Malloy AMW, Liu J, Chen M, Collins PL, Graham BS. Responses against a subdominant CD8+ T cell epitope protect against immunopathology caused by a dominant epitope. THE JOURNAL OF IMMUNOLOGY 2010; 185:4673-80. [PMID: 20833834 DOI: 10.4049/jimmunol.1001606] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8(+) T cell responses are critical for the control of virus infections. Following infection, epitope-specific responses establish an unpredictable but reproducible pattern of dominance that is dictated by a large number of both positive and negative factors. Immunodomination, or diminution of subdominant epitope-specific responses by dominant epitopes, can play a substantial role in the establishment of epitope hierarchy. To determine the role of a dominant (K(d)M2(82-90)) and a subdominant (D(b)M(187-195)) epitope of respiratory syncytial virus in viral control and immunodomination, MHC-binding anchor residues in the two epitopes were mutated individually in recombinant infectious viruses, greatly reducing or deleting the epitope-specific CD8(+) T cell responses. Neither mutation negatively affected viral clearance in mice, and compensation by the unmutated epitope was seen in both cases, whereas compensation by five other subdominant epitopes was minimal. Mutation of the dominant K(d)M2(82-90) response resulted in effective viral clearance by the subdominant epitope with less illness, whereas mutation of the subdominant D(b)M(187-195) response resulted in overcompensation of the already dominant K(d)M2(82-90) epitope, and increased severity of illness. Increased illness was associated with poor functionality of the abundant population of CD8(+) T cells specific to the dominant K(d)M2(82-90) epitope, as measured by the percentage and magnitude of IFN-γ production. These data demonstrate efficient viral clearance, and a protective effect of subdominant CD8(+) T cell responses.
Collapse
Affiliation(s)
- Tracy J Ruckwardt
- Vaccine Research Center, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Meseda CA, Weir JP. Third-generation smallpox vaccines: challenges in the absence of clinical smallpox. Future Microbiol 2010; 5:1367-82. [DOI: 10.2217/fmb.10.98] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Smallpox, a disease caused by variola virus, is estimated to have killed hundreds of millions to billions of people before it was certified as eradicated in 1980. However, there has been renewed interest in smallpox vaccine development due in part to zoonotic poxvirus infections and the possibility of a re-emergence of smallpox, as well as the fact that first-generation smallpox vaccines are associated with relatively rare, but severe, adverse reactions in some vaccinees. An understanding of the immune mechanisms of vaccine protection and the use of suitable animal models for vaccine efficacy assessment are paramount to the development of safer and effective smallpox vaccines. This article focuses on studies aimed at understanding the immune responses elicited by vaccinia virus and the various animal models that can be used to evaluate smallpox vaccine efficacy. Harnessing this information is necessary to assess the effectiveness and potential usefulness of new-generation smallpox vaccines.
Collapse
Affiliation(s)
| | - Jerry P Weir
- Division of Viral Products, Center for Biologics Evaluation & Research, USFDA, 1401 Rockville Pike, HFM-457, Rockville, MD 20852, USA
| |
Collapse
|