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Batty CJ, Pena ES, Amouzougan EA, Moore KM, Ainslie KM, Bachelder EM. Humoral Response to the Acetalated Dextran M2e Vaccine is Enhanced by Antigen Surface Conjugation. Bioconjug Chem 2023; 34:1447-1458. [PMID: 37458383 DOI: 10.1021/acs.bioconjchem.3c00223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
The influenza A virus causes substantial morbidity and mortality worldwide every year and poses a constant threat of an emergent pandemic. Seasonal influenza vaccination strategies fail to provide complete protection against infection due to antigenic drift and shift. A universal vaccine targeting a conserved influenza epitope could substantially improve current vaccination strategies. The ectodomain of the matrix 2 protein (M2e) of influenza is a highly conserved epitope between virus strains but is also poorly immunogenic. Administration of M2e and the immunostimulatory stimulator of interferon genes (STING) agonist 3'3'-cyclic guanosine-adenosine monophosphate (cGAMP) encapsulated in microparticles made of acetalated dextran (Ace-DEX) has previously been shown to be effective for increasing the immunogenicity of M2e, primarily through T-cell-mediated responses. Here, the immunogenicity of Ace-DEX MPs delivering M2e was further improved by conjugating the M2e peptide to the particle surface in an effort to affect B-cell responses more directly. Conjugated or encapsulated M2e co-administered with Ace-DEX MPs containing cGAMP were used to vaccinate mice, and it was shown that two or three vaccinations could fully protect against a lethal influenza challenge, while only the surface-conjugated antigen constructs could provide some protection against lethal challenge with only one vaccination. Additionally, the use of a reducible linker augmented the T-cell response to the antigen. These results show the utility of conjugating M2e to the surface of a particle carrier to increase its immunogenicity for use as the antigen in a universal influenza vaccine.
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Affiliation(s)
- Cole J Batty
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Erik S Pena
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina 27599, United States
| | - Eva A Amouzougan
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Kathryn M Moore
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina 27599, United States
| | - Kristy M Ainslie
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina 27599, United States
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Eric M Bachelder
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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Liu T, Wang Y, Tan TJC, Wu NC, Brooke CB. The evolutionary potential of influenza A virus hemagglutinin is highly constrained by epistatic interactions with neuraminidase. Cell Host Microbe 2022; 30:1363-1369.e4. [PMID: 36150395 PMCID: PMC9588755 DOI: 10.1016/j.chom.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/27/2022] [Accepted: 09/02/2022] [Indexed: 11/03/2022]
Abstract
Antigenic evolution of the influenza A virus (IAV) hemagglutinin (HA) gene limits efforts to effectively control the spread of the virus in the population. Efforts to understand the mechanisms governing HA antigenic evolution typically examine the HA gene in isolation. This can ignore the importance of balancing HA receptor binding activities with the receptor-destroying activities of the viral neuraminidase (NA) to maintain viral fitness. We hypothesize that the need to maintain functional balance with NA significantly constrains the evolutionary potential of the HA. We use deep mutational scanning and show that variation in NA activity significantly reshapes the HA fitness landscape by modulating the overall mutational robustness of HA. Consistent with this, we observe that different NA backgrounds support the emergence of distinct repertoires of HA escape variants under neutralizing antibody pressure. Our results reveal a critical role for intersegment epistasis in influencing the evolutionary potential of the HA gene.
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Affiliation(s)
- Tongyu Liu
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yiquan Wang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Timothy J C Tan
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Nicholas C Wu
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Christopher B Brooke
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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3
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Abstract
Most currently used conventional influenza vaccines are based on 1940s technology. Advances in vaccine immunogen design and delivery emerging over the last decade promise new options for improving influenza vaccines. In addition, new technologies for immune profiling provide better-defined immune correlates of protection and precise surrogate biomarkers for vaccine evaluations. Major technological advances include single-cell analysis, high-throughput antibody discovery, next-generation sequencing of antibody gene transcripts, antibody ontogeny, structure-guided immunogen design, nanoparticle display, delivery and formulation options, and better adjuvants. In this review, we provide our prospective outlook for improved influenza vaccines in the foreseeable future.
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Affiliation(s)
- Masaru Kanekiyo
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Barney S Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Sangesland M, Lingwood D. Antibody Focusing to Conserved Sites of Vulnerability: The Immunological Pathways for 'Universal' Influenza Vaccines. Vaccines (Basel) 2021; 9:vaccines9020125. [PMID: 33562627 PMCID: PMC7914524 DOI: 10.3390/vaccines9020125] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 01/31/2023] Open
Abstract
Influenza virus remains a serious public health burden due to ongoing viral evolution. Vaccination remains the best measure of prophylaxis, yet current seasonal vaccines elicit strain-specific neutralizing responses that favor the hypervariable epitopes on the virus. This necessitates yearly reformulations of seasonal vaccines, which can be limited in efficacy and also shortchange pandemic preparedness. Universal vaccine development aims to overcome these deficits by redirecting antibody responses to functionally conserved sites of viral vulnerability to enable broad coverage. However, this is challenging as such antibodies are largely immunologically silent, both following vaccination and infection. Defining and then overcoming the immunological basis for such subdominant or ‘immuno-recessive’ antibody targeting has thus become an important aspect of universal vaccine development. This, coupled with structure-guided immunogen design, has led to proof-of-concept that it is possible to rationally refocus humoral immunity upon normally ‘unseen’ broadly neutralizing antibody targets on influenza virus.
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Identification of Antibodies Targeting the H3N2 Hemagglutinin Receptor Binding Site following Vaccination of Humans. Cell Rep 2020; 29:4460-4470.e8. [PMID: 31875553 PMCID: PMC6953393 DOI: 10.1016/j.celrep.2019.11.084] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/26/2019] [Accepted: 11/20/2019] [Indexed: 11/26/2022] Open
Abstract
Antibodies targeting the receptor binding site (RBS) of the influenza virus hemagglutinin (HA) protein are usually not broadly reactive because their footprints are typically large and extend to nearby variable HA residues. Here, we identify several human H3N2 HA RBS-targeting monoclonal antibodies (mAbs) that are sensitive to substitutions in conventional antigenic sites and are therefore not broadly reactive. However, we also identify an H3N2 HA RBS-targeting mAb that is exceptionally broadly reactive despite being sensitive to substitutions in residues outside of the RBS. We show that similar antibodies are present at measurable levels in the sera of some individuals but that they are inefficiently elicited by conventional vaccines. Our data indicate that HA RBS-targeting antibodies can be effective against variable viral strains even when they are somewhat sensitive to substitutions in HA residues adjacent to the RBS. Zost et al. show that most antibodies targeting the RBS of the H3N2 HAs are not broadly reactive. They identify one broadly reactive H3 HA RBS antibody that is tolerant of substitutions in adjacent antigenic sites but show that these types of antibodies are not efficiently elicited by vaccination.
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Ellebedy AH. Immunizing the Immune: Can We Overcome Influenza's Most Formidable Challenge? Vaccines (Basel) 2018; 6:vaccines6040068. [PMID: 30248996 PMCID: PMC6313899 DOI: 10.3390/vaccines6040068] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 12/14/2022] Open
Abstract
The first human influenza virus was isolated more than 85 years ago, and several vaccine candidates were developed and tested soon after. Yet, controlling infections mediated by this respiratory pathogen continues to present a formidable challenge. Development of an effective influenza vaccine has been undermined by the dynamic nature of influenza viruses: these viruses have the unique capacity to escape pre-existing immunity. In this perspective, I highlight pre-existing immunity as a different, but related, hurdle that may actually lessen the effectiveness of influenza vaccine-induced immune responses. Specifically, I discuss the impact of pre-existing immunity on the generation of de novo B cell responses to influenza vaccination. As the influenza virus changes its major antigenic determinants, it creates new ones in the process. Our immune system adapts by targeting the new determinants. However, pre-existing antibodies and memory B cells interfere with the generation of de novo responses against these newly formed epitopes, rendering vaccines less effective. Overcoming such interference is essential for the development of more effective influenza vaccines.
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Affiliation(s)
- Ali H Ellebedy
- Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
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Sera from Individuals with Narrowly Focused Influenza Virus Antibodies Rapidly Select Viral Escape Mutations In Ovo. J Virol 2018; 92:JVI.00859-18. [PMID: 30045982 DOI: 10.1128/jvi.00859-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/19/2018] [Indexed: 02/05/2023] Open
Abstract
Influenza viruses use distinct antibody escape mechanisms depending on the overall complexity of the antibody response that is encountered. When grown in the presence of a hemagglutinin (HA) monoclonal antibody, influenza viruses typically acquire a single HA mutation that reduces the binding of that specific monoclonal antibody. In contrast, when confronted with mixtures of HA monoclonal antibodies or polyclonal sera that have antibodies that bind several HA epitopes, influenza viruses acquire mutations that increase HA binding to host cells. Recent data from our laboratory and others suggest that some humans possess antibodies that are narrowly focused on HA epitopes that were present in influenza virus strains that they were likely exposed to in childhood. Here, we completed a series of experiments to determine if humans with narrowly focused HA antibody responses are able to select for influenza virus antigenic escape variants in ovo We identified three human donors that possessed HA antibody responses that were heavily focused on a single HA antigenic site. Sera from all three of these donors selected single HA escape mutations during in ovo passage experiments, similar to what has been previously reported for single monoclonal antibodies. These single HA mutations directly reduced binding of serum antibodies used for selection. We propose that new antigenic variants of influenza viruses might originate in individuals who produce antibodies that are narrowly focused on HA epitopes that were present in viral strains that they encountered in childhood.IMPORTANCE Influenza vaccine strains must be updated frequently since circulating viral strains continuously change in antigenically important epitopes. Our previous studies have demonstrated that some individuals possess antibody responses that are narrowly focused on epitopes that were present in viral strains that they encountered during childhood. Here, we show that influenza viruses rapidly escape this type of polyclonal antibody response when grown in ovo by acquiring single mutations that directly prevent antibody binding. These studies improve our understanding of how influenza viruses evolve when confronted with narrowly focused polyclonal human antibodies.
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Hsp90 shapes protein and RNA evolution to balance trade-offs between protein stability and aggregation. Nat Commun 2018; 9:1781. [PMID: 29725062 PMCID: PMC5934419 DOI: 10.1038/s41467-018-04203-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/10/2018] [Indexed: 01/16/2023] Open
Abstract
Acquisition of mutations is central to evolution; however, the detrimental effects of most mutations on protein folding and stability limit protein evolvability. Molecular chaperones, which suppress aggregation and facilitate polypeptide folding, may alleviate the effects of destabilizing mutations thus promoting sequence diversification. To illuminate how chaperones can influence protein evolution, we examined the effect of reduced activity of the chaperone Hsp90 on poliovirus evolution. We find that Hsp90 offsets evolutionary trade-offs between protein stability and aggregation. Lower chaperone levels favor variants of reduced hydrophobicity and protein aggregation propensity but at a cost to protein stability. Notably, reducing Hsp90 activity also promotes clusters of codon-deoptimized synonymous mutations at inter-domain boundaries, likely to facilitate cotranslational domain folding. Our results reveal how a chaperone can shape the sequence landscape at both the protein and RNA levels to harmonize competing constraints posed by protein stability, aggregation propensity, and translation rate on successful protein biogenesis.
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Contemporary H3N2 influenza viruses have a glycosylation site that alters binding of antibodies elicited by egg-adapted vaccine strains. Proc Natl Acad Sci U S A 2017; 114:12578-12583. [PMID: 29109276 PMCID: PMC5703309 DOI: 10.1073/pnas.1712377114] [Citation(s) in RCA: 395] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
H3N2 viruses continuously acquire mutations in the hemagglutinin (HA) glycoprotein that abrogate binding of human antibodies. During the 2014-2015 influenza season, clade 3C.2a H3N2 viruses possessing a new predicted glycosylation site in antigenic site B of HA emerged, and these viruses remain prevalent today. The 2016-2017 seasonal influenza vaccine was updated to include a clade 3C.2a H3N2 strain; however, the egg-adapted version of this viral strain lacks the new putative glycosylation site. Here, we biochemically demonstrate that the HA antigenic site B of circulating clade 3C.2a viruses is glycosylated. We show that antibodies elicited in ferrets and humans exposed to the egg-adapted 2016-2017 H3N2 vaccine strain poorly neutralize a glycosylated clade 3C.2a H3N2 virus. Importantly, antibodies elicited in ferrets infected with the current circulating H3N2 viral strain (that possesses the glycosylation site) and humans vaccinated with baculovirus-expressed H3 antigens (that possess the glycosylation site motif) were able to efficiently recognize a glycosylated clade 3C.2a H3N2 virus. We propose that differences in glycosylation between H3N2 egg-adapted vaccines and circulating strains likely contributed to reduced vaccine effectiveness during the 2016-2017 influenza season. Furthermore, our data suggest that influenza virus antigens prepared via systems not reliant on egg adaptations are more likely to elicit protective antibody responses that are not affected by glycosylation of antigenic site B of H3N2 HA.
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10
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Pulmonary immunity to viruses. Clin Sci (Lond) 2017; 131:1737-1762. [PMID: 28667071 DOI: 10.1042/cs20160259] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/31/2017] [Accepted: 04/06/2017] [Indexed: 12/28/2022]
Abstract
Mucosal surfaces, such as the respiratory epithelium, are directly exposed to the external environment and therefore, are highly susceptible to viral infection. As a result, the respiratory tract has evolved a variety of innate and adaptive immune defenses in order to prevent viral infection or promote the rapid destruction of infected cells and facilitate the clearance of the infecting virus. Successful adaptive immune responses often lead to a functional state of immune memory, in which memory lymphocytes and circulating antibodies entirely prevent or lessen the severity of subsequent infections with the same virus. This is also the goal of vaccination, although it is difficult to vaccinate in a way that mimics respiratory infection. Consequently, some vaccines lead to robust systemic immune responses, but relatively poor mucosal immune responses that protect the respiratory tract. In addition, adaptive immunity is not without its drawbacks, as overly robust inflammatory responses may lead to lung damage and impair gas exchange or exacerbate other conditions, such as asthma or chronic obstructive pulmonary disease (COPD). Thus, immune responses to respiratory viral infections must be strong enough to eliminate infection, but also have mechanisms to limit damage and promote tissue repair in order to maintain pulmonary homeostasis. Here, we will discuss the components of the adaptive immune system that defend the host against respiratory viral infections.
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11
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Takanashi K, Dan K, Kanzaki S, Hasegawa H, Watanabe K, Ogawa K. Hochuekkito, a Japanese Herbal Medicine, Restores Metabolic Homeostasis between Mitochondrial and Glycolytic Pathways Impaired by Influenza A Virus Infection. Pharmacology 2017; 99:240-249. [PMID: 28147362 DOI: 10.1159/000455918] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/09/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND Hochuekkito (HKT), a traditional Japanese herbal medicine (Kampo), has been used to treat symptoms of several diseases. In a recent clinical study, HKT was shown to be protective against the influenza virus infection. However, the underlying mechanism of the prophylactic effect is not clear. Mitochondrial and glycolytic pathways play important roles in cellular energy metabolism to maintain biological functions. These metabolic pathways are affected by the influenza virus infection. In this study, we examined the relationship between the preventive effects of HKT against the influenza virus infection and cellular energy metabolism in mitochondria and glycolysis using Madin-Darby canine kidney cells and influenza A/PR/8/34 (H1N1) virus (IAV). METHODS Mitochondrial and glycolytic metabolic pathways were evaluated on the basis of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), respectively, using the XF24 Extracellular Analyzer. RESULTS The OCR/ECAR ratio in IAV-infected cells was lower than that in control cells. Cells that were treated with HKT before IAV infection showed a metabolic pattern similar to that in the control cells (increase in both OCR and ECAR). CONCLUSIONS Our results suggest that HKT not only activates both mitochondrial and glycolytic energy metabolism in IAV-infected cells but also helps maintain metabolic homeostasis similar to that in noninfected cells.
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Affiliation(s)
- Keita Takanashi
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
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12
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Deconstructing the Antiviral Neutralizing-Antibody Response: Implications for Vaccine Development and Immunity. Microbiol Mol Biol Rev 2016; 80:989-1010. [PMID: 27784796 DOI: 10.1128/mmbr.00024-15] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The antibody response plays a key role in protection against viral infections. While antiviral antibodies may reduce the viral burden via several mechanisms, the ability to directly inhibit (neutralize) infection of cells has been extensively studied. Eliciting a neutralizing-antibody response is a goal of many vaccine development programs and commonly correlates with protection from disease. Considerable insights into the mechanisms of neutralization have been gained from studies of monoclonal antibodies, yet the individual contributions and dynamics of the repertoire of circulating antibody specificities elicited by infection and vaccination are poorly understood on the functional and molecular levels. Neutralizing antibodies with the most protective functionalities may be a rare component of a polyclonal, pathogen-specific antibody response, further complicating efforts to identify the elements of a protective immune response. This review discusses advances in deconstructing polyclonal antibody responses to flavivirus infection or vaccination. Our discussions draw comparisons to HIV-1, a virus with a distinct structure and replication cycle for which the antibody response has been extensively investigated. Progress toward deconstructing and understanding the components of polyclonal antibody responses identifies new targets and challenges for vaccination strategies.
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13
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Zarnitsyna VI, Ellebedy AH, Davis C, Jacob J, Ahmed R, Antia R. Masking of antigenic epitopes by antibodies shapes the humoral immune response to influenza. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0248. [PMID: 26194761 DOI: 10.1098/rstb.2014.0248] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The immune responses to influenza, a virus that exhibits strain variation, show complex dynamics where prior immunity shapes the response to the subsequent infecting strains. Original antigenic sin (OAS) describes the observation that antibodies to the first encountered influenza strain, specifically antibodies to the epitopes on the head of influenza's main surface glycoprotein, haemagglutinin (HA), dominate following infection with new drifted strains. OAS suggests that responses to the original strain are preferentially boosted. Recent studies also show limited boosting of the antibodies to conserved epitopes on the stem of HA, which are attractive targets for a 'universal vaccine'. We develop multi-epitope models to explore how pre-existing immunity modulates the immune response to new strains following immunization. Our models suggest that the masking of antigenic epitopes by antibodies may play an important role in describing the complex dynamics of OAS and limited boosting of antibodies to the stem of HA. Analysis of recently published data confirms model predictions for how pre-existing antibodies to an epitope on HA decrease the magnitude of boosting of the antibody response to this epitope following immunization. We explore strategies for boosting of antibodies to conserved epitopes and generating broadly protective immunity to multiple strains.
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Affiliation(s)
| | - Ali H Ellebedy
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA Emory Vaccine Center, Atlanta, GA 30322, USA
| | - Carl Davis
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA Emory Vaccine Center, Atlanta, GA 30322, USA
| | - Joshy Jacob
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA Emory Vaccine Center, Atlanta, GA 30322, USA
| | - Rafi Ahmed
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA Emory Vaccine Center, Atlanta, GA 30322, USA
| | - Rustom Antia
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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14
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Chambers BS, Parkhouse K, Ross TM, Alby K, Hensley SE. Identification of Hemagglutinin Residues Responsible for H3N2 Antigenic Drift during the 2014-2015 Influenza Season. Cell Rep 2015; 12:1-6. [PMID: 26119736 DOI: 10.1016/j.celrep.2015.06.005] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/22/2015] [Accepted: 06/01/2015] [Indexed: 01/09/2023] Open
Abstract
Influenza vaccines must be updated regularly because influenza viruses continuously acquire mutations in antibody binding sites of hemagglutinin (HA). The majority of H3N2 strains circulating in the Northern Hemisphere during the 2014-2015 season are antigenically mismatched to the A/Texas/50/2012 H3N2 vaccine strain. Recent H3N2 strains possess several new HA mutations, and it is unknown which of these mutations contribute to the 2014-2015 vaccine mismatch. Here, we use reverse genetics to demonstrate that mutations in HA antigenic site B are primarily responsible for the current mismatch. Sera isolated from vaccinated humans and infected ferrets and sheep had reduced hemagglutination inhibition and in vitro neutralization titers against reverse-genetics-derived viruses possessing mutations in the HA antigenic site B. These data provide an antigenic explanation for the low influenza vaccine efficacy observed during the 2014-2015 influenza season. Furthermore, our data support the World Health Organization's decision to update the H3N2 component of future vaccine formulations.
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Affiliation(s)
- Benjamin S Chambers
- Wistar Institute, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Ted M Ross
- Department of Vaccine and Viral Immunity, Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987, USA
| | - Kevin Alby
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Scott E Hensley
- Wistar Institute, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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15
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Chiu C, Openshaw PJ. Antiviral B cell and T cell immunity in the lungs. Nat Immunol 2015; 16:18-26. [PMID: 25521681 PMCID: PMC7097128 DOI: 10.1038/ni.3056] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 11/14/2014] [Indexed: 12/13/2022]
Abstract
Respiratory viruses are frequent causes of repeated common colds, bronchitis and pneumonia, which often occur unpredictably as epidemics and pandemics. Despite those decimating effects on health and decades of intensive research, treatments remain largely supportive. The only commonly available vaccines are against influenza virus, and even these need improvement. The lung shares some features with other mucosal sites, but preservation of its especially delicate anatomical structures necessitates a fine balance of pro- and anti-inflammatory responses; well-timed, appropriately placed and tightly regulated T cell and B cell responses are essential for protection from infection and limitation of symptoms, whereas poorly regulated inflammation contributes to tissue damage and disease. Recent advances in understanding adaptive immunity should facilitate vaccine development and reduce the global effect of respiratory viruses.
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Affiliation(s)
- Christopher Chiu
- Centre for Respiratory Infection, National Heart and Lung Institute, Imperial College London, London, UK
| | - Peter J Openshaw
- Centre for Respiratory Infection, National Heart and Lung Institute, Imperial College London, London, UK
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16
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Induction of broadly cross-reactive antibody responses to the influenza HA stem region following H5N1 vaccination in humans. Proc Natl Acad Sci U S A 2014; 111:13133-8. [PMID: 25157133 DOI: 10.1073/pnas.1414070111] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The emergence of pandemic influenza viruses poses a major public health threat. Therefore, there is a need for a vaccine that can induce broadly cross-reactive antibodies that protect against seasonal as well as pandemic influenza strains. Human broadly neutralizing antibodies directed against highly conserved epitopes in the stem region of influenza virus HA have been recently characterized. However, it remains unknown what the baseline levels are of antibodies and memory B cells that are directed against these conserved epitopes. More importantly, it is also not known to what extent anti-HA stem B-cell responses get boosted in humans after seasonal influenza vaccination. In this study, we have addressed these two outstanding questions. Our data show that: (i) antibodies and memory B cells directed against the conserved HA stem region are prevalent in humans, but their levels are much lower than B-cell responses directed to variable epitopes in the HA head; (ii) current seasonal influenza vaccines are efficient in inducing B-cell responses to the variable HA head region but they fail to boost responses to the conserved HA stem region; and (iii) in striking contrast, immunization of humans with the avian influenza virus H5N1 induced broadly cross-reactive HA stem-specific antibodies. Taken together, our findings provide a potential vaccination strategy where heterologous influenza immunization could be used for increasing the levels of broadly neutralizing antibodies and for priming the human population to respond quickly to emerging pandemic influenza threats.
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17
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Challenges of selecting seasonal influenza vaccine strains for humans with diverse pre-exposure histories. Curr Opin Virol 2014; 8:85-9. [PMID: 25108824 DOI: 10.1016/j.coviro.2014.07.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 11/21/2022]
Abstract
Seasonal influenza vaccine strains are routinely updated when influenza viruses acquire mutations in exposed regions of the hemagglutinin and neuraminidase glycoproteins. Ironically, although thousands of viral isolates are sequenced each year, today's influenza surveillance community places less emphasis on viral genetic information and more emphasis on classical serological assays when choosing vaccine strains. Here, I argue that these classical serological assays are oversimplified and that they fail to detect influenza mutations that facilitate escape of particular types of human antibodies. I propose that influenza vaccine strains should be updated more frequently even when classical serological assays fail to detect significant antigenic alterations.
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Recent H3N2 influenza virus clinical isolates rapidly acquire hemagglutinin or neuraminidase mutations when propagated for antigenic analyses. J Virol 2014; 88:10986-9. [PMID: 24991002 DOI: 10.1128/jvi.01077-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Prior to serological testing, influenza viruses are typically propagated in eggs or cell culture. Recent human H3N2 strains bind to cells with low avidity. Here, we isolated nine primary H3N2 viral isolates from respiratory secretions of children. Upon propagation in vitro, five of these isolates acquired hemagglutinin or neuraminidase mutations that increased virus binding to cell surfaces. These mutations can potentially confound serological assays commonly used to identify antigenically novel influenza viruses.
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Abstract
Influenza A viruses (IAV) are significant pathogens able to repeatedly switch hosts to infect multiple avian and mammalian species, including humans. The unpredictability of IAV evolution and interspecies movement creates continual public health challenges, such as the emergence of the 2009 pandemic H1N1 virus from swine, as well as pandemic threats from the ongoing H5N1 and the recent H7N9 epizootics. In the last decade there has been increased concern about the “dual use” nature of microbiology, and a set of guidelines covering “dual use research of concern” includes seven categories of potentially problematic scientific experiments. In this Perspective, we consider how in nature IAV continually undergo “dual use experiments” as a matter of evolution and selection, and we conclude that studying these properties of IAV is critical for mitigating and preventing future epidemics and pandemics.
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20
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Influenza A virus hemagglutinin trimerization completes monomer folding and antigenicity. J Virol 2013; 87:9742-53. [PMID: 23824811 DOI: 10.1128/jvi.00471-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Influenza A virus (IAV) remains an important human pathogen largely because of antigenic drift, the rapid emergence of antibody escape mutants that precludes durable vaccination. The most potent neutralizing antibodies interact with cognate epitopes in the globular "head" domain of hemagglutinin (HA), a homotrimeric glycoprotein. The H1 HA possesses five distinct regions defined by a large number of mouse monoclonal antibodies (MAbs), i.e., Ca1, Ca2, Cb, Sa, and Sb. Ca1-Ca2 sites require HA trimerization to attain full antigenicity, consistent with their locations on opposite sides of the trimer interface. Here, we show that full antigenicity of Cb and Sa sites also requires HA trimerization, as revealed by immunofluorescence microscopy of IAV-infected cells and biochemically by pulse-chase radiolabeling experiments. Surprisingly, epitope antigenicity acquired by HA trimerization persists following acid triggering of the globular domains dissociation and even after proteolytic release of monomeric heads from acid-treated HA. Thus, the requirement for HA trimerization by trimer-specific MAbs mapping to the Ca, Cb, and Sa sites is not dependent upon the bridging of adjacent monomers in the native HA trimer. Rather, complete antigenicity of HA (and, by inference, immunogenicity) requires a final folding step that accompanies its trimerization. Once this conformational change occurs, HA trimers themselves would not necessarily be required to induce a highly diverse neutralizing response to epitopes in the globular domain.
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21
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McKinstry KK, Dutton RW, Swain SL, Strutt TM. Memory CD4 T cell-mediated immunity against influenza A virus: more than a little helpful. Arch Immunol Ther Exp (Warsz) 2013; 61:341-53. [PMID: 23708562 DOI: 10.1007/s00005-013-0236-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 05/13/2013] [Indexed: 12/22/2022]
Abstract
Recent observations have uncovered multiple pathways whereby CD4 T cells can contribute to protective immune responses against microbial threats. Incorporating the generation of memory CD4 T cells into vaccine strategies thus presents an attractive approach toward improving immunity against several important human pathogens, especially those against which antibody responses alone are inadequate to confer long-term immunity. Here, we review how memory CD4 T cells provide protection against influenza viruses. We discuss the complexities of protective memory CD4 T cell responses observed in animal models and the potential challenges of translating these observations into the clinic. Specifically, we concentrate on how better understanding of organ-specific heterogeneity of responding cells and defining multiple correlates of protection might improve vaccine-generated memory CD4 T cells to better protect against seasonal, and more importantly, pandemic influenza.
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Affiliation(s)
- K Kai McKinstry
- Department of Pathology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA, 01583, USA,
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22
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Das SR, Hensley SE, Ince WL, Brooke CB, Subba A, Delboy MG, Russ G, Gibbs JS, Bennink JR, Yewdell JW. Defining influenza A virus hemagglutinin antigenic drift by sequential monoclonal antibody selection. Cell Host Microbe 2013; 13:314-23. [PMID: 23498956 PMCID: PMC3747226 DOI: 10.1016/j.chom.2013.02.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 12/04/2012] [Accepted: 02/20/2013] [Indexed: 12/21/2022]
Abstract
Human influenza A virus (IAV) vaccination is limited by "antigenic drift," rapid antibody-driven escape reflecting amino acid substitutions in the globular domain of hemagglutinin (HA), the viral attachment protein. To better understand drift, we used anti-hemagglutinin monoclonal Abs (mAbs) to sequentially select IAV escape mutants. Twelve selection steps, each resulting in a single amino acid substitution in the hemagglutinin globular domain, were required to eliminate antigenicity defined by monoclonal or polyclonal Abs. Sequential mutants grow robustly, showing the structural plasticity of HA, although several hemagglutinin substitutions required an epistatic substitution in the neuraminidase glycoprotein to maximize growth. Selecting escape mutants from parental versus sequential variants with the same mAb revealed distinct escape repertoires, attributed to contextual changes in antigenicity and the mutation landscape. Since each hemagglutinin mutation potentially sculpts future mutation space, drift can follow many stochastic paths, undermining its unpredictability and underscoring the need for drift-insensitive vaccines.
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Affiliation(s)
- Suman R. Das
- Laboratory of Viral Diseases, NIAID, Bethesda, MD 20892, USA
- Infectious Diseases Group, J. Craig Venter Institute, Rockville, MD 20850, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | | | - William L. Ince
- Laboratory of Viral Diseases, NIAID, Bethesda, MD 20892, USA
| | | | - Anju Subba
- Infectious Diseases Group, J. Craig Venter Institute, Rockville, MD 20850, USA
| | - Mark G. Delboy
- Infectious Diseases Group, J. Craig Venter Institute, Rockville, MD 20850, USA
| | - Gustav Russ
- Institute of Virology, Slovak Academy of Sciences, 84505 Bratislava, Slovak Republic
| | - James S. Gibbs
- Laboratory of Viral Diseases, NIAID, Bethesda, MD 20892, USA
| | - Jack R. Bennink
- Laboratory of Viral Diseases, NIAID, Bethesda, MD 20892, USA
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23
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Wikramaratna PS, Sandeman M, Recker M, Gupta S. The antigenic evolution of influenza: drift or thrift? Philos Trans R Soc Lond B Biol Sci 2013; 368:20120200. [PMID: 23382423 PMCID: PMC3678325 DOI: 10.1098/rstb.2012.0200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
It is commonly assumed that antibody responses against the influenza virus are polarized in the following manner: strong antibody responses are directed at highly variable antigenic epitopes, which consequently undergo 'antigenic drift', while weak antibody responses develop against conserved epitopes. As the highly variable epitopes are in a constant state of flux, current antibody-based vaccine strategies are focused on the conserved epitopes in the expectation that they will provide some level of clinical protection after appropriate boosting. Here, we use a theoretical model to suggest the existence of epitopes of low variability, which elicit a high degree of both clinical and transmission-blocking immunity. We show that several epidemiological features of influenza and its serological and molecular profiles are consistent with this model of 'antigenic thrift', and that identifying the protective epitopes of low variability predicted by this model could offer a more viable alternative to regularly update the influenza vaccine than exploiting responses to weakly immunogenic conserved regions.
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Cargnelutti DE, Sánchez MV, Mattion NM, Scodeller EA. Development of a universal CTL-based vaccine for influenza. Bioengineered 2013; 4:374-8. [PMID: 23337287 DOI: 10.4161/bioe.23573] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In pursuit of better influenza vaccines, many strategies are being studied worldwide. An attractive alternative is the generation of a broadly cross-reactive vaccine based on the induction of cytotoxic T-lymphocytes (CTL) directed against conserved internal antigens of influenza A virus. The feasibility of this approach using recombinant viral vectors has recently been demonstrated in mice and humans by several research groups. However, similar results might also be achieved through immunization with viral proteins expressed in a prokaryotic system formulated with the appropriate adjuvants and delivery systems. This approach would be much simpler and less expensive. Recent results from several laboratories seem to confirm this is as a valid option to be considered.
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Affiliation(s)
- Diego Esteban Cargnelutti
- Institute of Experimental Medicine and Biology of Cuyo (IMBECU-CONICET); Mendoza, Argentina; Animal Virology Center; Institute of Science and Technology Dr César Milstein; CONICET; Buenos Aires, Argentina
| | - María Victoria Sánchez
- Institute of Experimental Medicine and Biology of Cuyo (IMBECU-CONICET); Mendoza, Argentina
| | - Nora Marta Mattion
- Animal Virology Center; Institute of Science and Technology Dr César Milstein; CONICET; Buenos Aires, Argentina
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25
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Koutsonanos DG, Compans RW, Skountzou I. Targeting the skin for microneedle delivery of influenza vaccine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 785:121-32. [PMID: 23456844 PMCID: PMC6525635 DOI: 10.1007/978-1-4614-6217-0_13] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Influenza infection represents a major socioeconomic burden worldwide. Skin represents a new target that has gained much attention in recent years for delivery of influenza vaccine as an alternative to the conventional intramuscular route of immunization. In this review we describe different microneedle vaccination approaches used in vivo, including metal and dissolving microneedle patches that have demonstrated promising results. Additionally we analyze the immunological basis for microneedle skin immunization and targeting of the skin's dense population of antigen presenting cells, their role, characterization, and function. Additionally we analyze the importance of inflammatory signaling in the skin after microneedle delivery.
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Affiliation(s)
- Dimitrios G. Koutsonanos
- Department of Microbiology & Immunology and Emory Vaccine Center, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322
| | - Richard W. Compans
- Department of Microbiology & Immunology and Emory Vaccine Center, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322
| | - Ioanna Skountzou
- Department of Microbiology & Immunology and Emory Vaccine Center, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322
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26
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Age profile of immunity to influenza: effect of original antigenic sin. Theor Popul Biol 2011; 81:102-12. [PMID: 22209755 DOI: 10.1016/j.tpb.2011.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 12/13/2011] [Accepted: 12/14/2011] [Indexed: 11/19/2022]
Abstract
When multiple infections are possible during an individual's lifetime, as with influenza, a host's history of infection and immunity will determine the result of future exposures. In turn, the suite of varying individual infection histories will shape the population level dynamics of the disease. Exploring the consequences of precisely how immunity is acquired using mathematical models has proven challenging though: if n strains have circulated previously, there are 2(n) combinations of past infection to consider. However, by using an age-structured mathematical model of a disease with multiple strains, we can examine the population immune profile without explicitly keeping track of all possible infection histories. This framework allows previously unknown consequences of assumptions about immune acquisition to be observed. In particular, we see that 'original antigenic sin' can reduce immunity in some age groups: these immune blind spots could be responsible for the unexpectedly high severity of certain past influenza epidemics.
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