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Yau E, Yang L, Chen Y, Umstead TM, Atkins H, Katz ZE, Yewdell JW, Gandhi CK, Halstead ES, Chroneos ZC. Surfactant protein A alters endosomal trafficking of influenza A virus in macrophages. Front Immunol 2023; 14:919800. [PMID: 36960051 PMCID: PMC10028185 DOI: 10.3389/fimmu.2023.919800] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 02/21/2023] [Indexed: 03/09/2023] Open
Abstract
Influenza A virus infection (IAV) often leads to acute lung injury that impairs breathing and can lead to death, with disproportionate mortality in children and the elderly. Surfactant Protein A (SP-A) is a calcium-dependent opsonin that binds a variety of pathogens to help control pulmonary infections by alveolar macrophages. Alveolar macrophages play critical roles in host resistance and susceptibility to IAV infection. The effect of SP-A on IAV infection and antiviral response of macrophages, however, is not understood. Here, we report that SP-A attenuates IAV infection in a dose-dependent manner at the level of endosomal trafficking, resulting in infection delay in a model macrophage cell line. The ability of SP-A to suppress infection was independent of its glycosylation status. Binding of SP-A to hemagglutinin did not rely on the glycosylation status or sugar binding properties of either protein. Incubation of either macrophages or IAV with SP-A slowed endocytic uptake rate of IAV. SP-A interfered with binding to cell membrane and endosomal exit of the viral genome as indicated by experiments using isolated cell membranes, an antibody recognizing a pH-sensitive conformational epitope on hemagglutinin, and microscopy. Lack of SP-A in mice enhanced IFNβ expression, viral clearance and reduced mortality from IAV infection. These findings support the idea that IAV is an opportunistic pathogen that co-opts SP-A to evade host defense by alveolar macrophages. Our study highlights novel aspects of host-pathogen interactions that may lead to better understanding of the local mechanisms that shape activation of antiviral and inflammatory responses to viral infection in the lung.
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Affiliation(s)
- Eric Yau
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Linlin Yang
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Yan Chen
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Todd M. Umstead
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Hannah Atkins
- Department of Comparative Medicine, Pennsylvania State University College of Medicine, PA, Hershey, United States
| | - Zoe E. Katz
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Jonathan W. Yewdell
- Cellular Biology Section, Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, United States
| | - Chintan K. Gandhi
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - E. Scott Halstead
- Department of Pediatrics, Division of Pediatric Critical Care Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Zissis C. Chroneos
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Pulmonary Immunology and Physiology Laboratory, Pennsylvania State University College of Medicine, Hershey, PA, United States
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA, United States
- *Correspondence: Zissis C. Chroneos,
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Decker CH, Rapier-Sharman N, Pickett BE. Mutation in Hemagglutinin Antigenic Sites in Influenza A pH1N1 Viruses from 2015-2019 in the United States Mountain West, Europe, and the Northern Hemisphere. Genes (Basel) 2022; 13:909. [PMID: 35627294 PMCID: PMC9141826 DOI: 10.3390/genes13050909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 05/17/2022] [Accepted: 05/17/2022] [Indexed: 11/17/2022] Open
Abstract
H1N1 influenza A virus is a respiratory pathogen that undergoes antigenic shift and antigenic drift to improve viral fitness. Tracking the evolutionary trends of H1N1 aids with the current detection and the future response to new viral strains as they emerge. Here, we characterize antigenic drift events observed in the hemagglutinin (HA) sequence of the pandemic H1N1 lineage from 2015-2019. We observed the substitutions S200P, K147N, and P154S, together with other mutations in structural, functional, and/or epitope regions in 2015-2019 HA protein sequences from the Mountain West region of the United States, the larger United States, Europe, and other Northern Hemisphere countries. We reconstructed multiple phylogenetic trees to track the relationships and spread of these mutations and tested for evidence of selection pressure on HA. We found that the prevalence of amino acid substitutions at positions 147, 154, 159, 200, and 233 significantly changed throughout the studied geographical regions between 2015 and 2019. We also found evidence of coevolution among a subset of these amino acid substitutions. The results from this study could be relevant for future epidemiological tracking and vaccine prediction efforts. Similar analyses in the future could identify additional sequence changes that could affect the pathogenicity and/or infectivity of this virus in its human host.
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Affiliation(s)
| | | | - Brett E. Pickett
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA; (C.H.D.); (N.R.-S.)
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A Bioinformatics Study of Complete Amino Acid Sequences’ Changes of Hemagglutinin Antigen of H1N1 Influenza Viruses in GenBank From Year 2006 to 2013 in Iran. Jundishapur J Microbiol 2017. [DOI: 10.5812/jjm.44718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Selection Pressure in the Human Adenovirus Fiber Knob Drives Cell Specificity in Epidemic Keratoconjunctivitis. J Virol 2016; 90:9598-9607. [PMID: 27512073 PMCID: PMC5068513 DOI: 10.1128/jvi.01010-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 08/05/2016] [Indexed: 11/20/2022] Open
Abstract
Human adenoviruses (HAdVs) contain seven species (HAdV-A to -G), each associated with specific disease conditions. Among these, HAdV-D includes those viruses associated with epidemic keratoconjunctivitis (EKC), a severe ocular surface infection. The reasons for corneal tropism for some but not all HAdV-Ds are not known. The fiber protein is a major capsid protein; its C-terminal "knob" mediates binding with host cell receptors to facilitate subsequent viral entry. In a comprehensive phylogenetic analysis of HAdV-D capsid genes, fiber knob gene sequences of HAdV-D types associated with EKC formed a unique clade. By proteotyping analysis, EKC virus-associated fiber knobs were uniquely shared. Comparative structural modeling showed no distinct variations in fiber knobs of EKC types but did show variation among HAdV-Ds in a region overlapping with the known CD46 binding site in HAdV-B. We also found signature amino acid positions that distinguish EKC from non-EKC types, and by in vitro studies we showed that corneal epithelial cell tropism can be predicted by the presence of a lysine or alanine at residue 240. This same amino acid residue in EKC viruses shows evidence for positive selection, suggesting that evolutionary pressure enhances fitness in corneal infection, and may be a molecular determinant in EKC pathogenesis. IMPORTANCE Viruses adapt various survival strategies to gain entry into target host cells. Human adenovirus (HAdV) types are associated with distinct disease conditions, yet evidence for connections between genotype and cellular tropism is generally lacking. Here, we provide a structural and evolutionary basis for the association between specific genotypes within HAdV species D and epidemic keratoconjunctivitis, a severe ocular surface infection. We find that HAdV-D fiber genes of major EKC pathogens, specifically the fiber knob gene region, share a distinct phylogenetic clade. Deeper analysis of the fiber gene revealed that evolutionary pressure at crucial amino acid sites has a significant impact on its structural conformation, which is likely important in host cell binding and entry. Specific amino acids in hot spot residues provide a link to ocular cell tropism and possibly to corneal pathogenesis.
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El Rhaffouli H, El Fahime EM, Laraqui A, Bajjou T, Melloul M, Obeid S, Fathallah L, Lahlou-Amine I. Evolution of the hemagglutinin gene of the influenza A(H1N1)pdm09 virus in Morocco during two influenza seasons 2009-2011. Curr Microbiol 2013; 68:372-80. [PMID: 24212335 DOI: 10.1007/s00284-013-0463-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 08/15/2013] [Indexed: 11/30/2022]
Abstract
To study genetic evolution of Moroccan influenza A(H1N1)pdm09 virus strains, we conducted a molecular characterization of the hemagglutinin gene subunit 1 (HA1) of 36 influenza A(H1N1)pdm09 virus strains. The stains were collected from patients in Rabat and Casablanca during two influenza seasons 2009-2010 and 2010-2011. Nucleotide and amino acid sequences of 14 influenza A(H1N1)pdm09 virus strains from 2009 to 2010 were ~97 and 99 %, respectively, similar to the reference strain A/California/07/2009 (H1N1). Phylogenetic analysis of 22 influenza A(H1N1)pdm09 virus strains from 2010 to 2011 revealed a co-circulation of three well-described different genetic groups. Most important, none of the identified groups showed significant changes at the antigenic site of the virus HA1 subunit which may alter the efficacy of California/07/2009 (H1N1) vaccine.
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Affiliation(s)
- Hicham El Rhaffouli
- Biosafety Level 3 and Research Laboratory (LRB-P3), Faculty of Medicine and Pharmacy, Mohammed V Military Teaching Hospital, University Mohammed V-Souissi, Hay Ryade, BP 190, Rabat, Morocco,
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Ruggiero T, De Rosa F, Cerutti F, Pagani N, Allice T, Stella ML, Milia MG, Calcagno A, Burdino E, Gregori G, Urbino R, Di Perri G, Ranieri MV, Ghisetti V. A(H1N1)pdm09 hemagglutinin D222G and D222N variants are frequently harbored by patients requiring extracorporeal membrane oxygenation and advanced respiratory assistance for severe A(H1N1)pdm09 infection. Influenza Other Respir Viruses 2013; 7:1416-26. [PMID: 23927713 PMCID: PMC4634302 DOI: 10.1111/irv.12146] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2013] [Indexed: 12/31/2022] Open
Abstract
Background In patients with A(H1N1)pdm09 infection, severe lung involvement requiring admission to intensive care units (ICU) has been reported. Mutations at the hemagglutinin (HA) receptor binding site (RBS) have been associated with increased virulence and disease severity, representing a potential marker of critical illness. Objectives To assess the contribution of HA‐RBS variability in critically ill patients, A(H1N1)pdm09 virus from adult patients with severe infection admitted to ICU for extracorporeal membrane oxygenation support (ECMO) during influenza season 2009–2011 in Piemonte (4·2 million inhabitants), northwestern Italy, was studied. Patients and methods We retrospectively analyzed HA‐RBS polymorphisms in ICU patients and compared with those from randomly selected inpatients with mild A(H1N1)pdm09 disease and outpatients with influenza from the local surveillance program. Results By HA‐RBS direct sequencing of respiratory specimens, D222G and D222N viral variants were identified in a higher proportion in ICU patients (n = 8/24, 33·3%) than in patients with mild disease (n = 2/34, 6%) or in outpatients (n = 0/44) (Fisher's exact test P < 0·0001; OR 38·5; CI 95% 4·494–329·9). Eleven ICU patients died (42%), three of them carrying the D222G variant, which was associated with RBS mutation S183P in two. D222G and D222N mutants were identified in upper and lower respiratory samples. Conclusions A(H1N1)pdm09 HA substitutions D222G and D222N were harbored in a significantly higher proportion by patients with acute respiratory distress for A(H1N1)pdm09 severe infection requiring ICU admission and ECMO. These data emphasize the importance of monitoring viral evolution for understanding virus–host adaptation aimed at the surveillance of strain circulation and the study of viral correlates of disease severity.
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Affiliation(s)
- Tina Ruggiero
- Department of Infectious Diseases, Laboratory of Microbiology and Virology, Amedeo di Savoia Hospital, Turin, Italy
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Ismail AM, Sharma OP, Kumar MS, Kannangai R, Abraham P. Impact of rtI233V mutation in hepatitis B virus polymerase protein and adefovir efficacy: Homology modeling and molecular docking studies. Bioinformation 2013; 9:121-5. [PMID: 23423477 PMCID: PMC3569598 DOI: 10.6026/97320630009121] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/05/2013] [Indexed: 02/07/2023] Open
Abstract
Adefovir is an adenosine analogue approved by the Food and Drug Administration for the treatment of chronic hepatitis B. Mutations occurring in the hepatitis B virus (HBV) reverse transcriptase (rt) domains are shown to confer resistance to antiviral drugs. The role of the rtI233V mutation and adefovir resistance remains contradictory. In this study, it was attempted to evaluate the impact of putative rtI233V substitution on adefovir action by homology modeling and docking studies. The HBVrt nucleotide sequence containing rtI233V mutation was obtained from the treatment-naive chronic hepatitis B subject. The three dimensional model of HBV polymerase/rt was constructed using the HIV-1rt template (PDB code: 1RTD A) and the model was evaluated by the Ramachandran plot. Autodock was employed to dock the HBV polymerase/rt and adefovir. The modelled structure showed the amino acid rtI233 to be located away from the drug interactory site. The substitution of isoleucine to valine did not appear to affect the catalytic sites of the protein. In addition, it does not alter the conformation of bent structure formed by residues 235 to 240 that stabilizes the binding of dNTPs. Therefore, it was predicted that rtI233V substitution may not independently affect the antiviral action of adefovir and incoming dNTP binding.
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Affiliation(s)
| | - Om Prakash Sharma
- Centre of excellence in Bioinformatics, Pondicherry University, Puducherry -605 014, India
| | - Muthuvel Suresh Kumar
- Centre of excellence in Bioinformatics, Pondicherry University, Puducherry -605 014, India
| | - Rajesh Kannangai
- Departments of Clinical Virology, Christian Medical College, Vellore 632 004, Tamil Nadu, India
| | - Priya Abraham
- Departments of Clinical Virology, Christian Medical College, Vellore 632 004, Tamil Nadu, India
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Zehender G, Pariani E, Piralla A, Lai A, Gabanelli E, Ranghiero A, Ebranati E, Amendola A, Campanini G, Rovida F, Ciccozzi M, Galli M, Baldanti F, Zanetti AR. Reconstruction of the evolutionary dynamics of the A(H1N1)pdm09 influenza virus in Italy during the pandemic and post-pandemic phases. PLoS One 2012; 7:e47517. [PMID: 23152755 PMCID: PMC3494699 DOI: 10.1371/journal.pone.0047517] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/12/2012] [Indexed: 11/28/2022] Open
Abstract
The aim of this study was to reconstruct the evolutionary dynamics of the A(H1N1)pdm09 influenza virus in Italy during two epidemic seasons (2009/2010 and 2010/2011) in the light of the forces driving the evolution of the virus. Nearly six thousands respiratory specimens were collected from patients with influenza-like illness within the framework of the Italian Influenza Surveillance Network, and the A(H1N1)pdm09 hemagglutinin (HA) gene was amplified and directly sequenced from 227 of these. Phylodynamic and phylogeographical analyses were made using a Bayesian Markov Chain Monte Carlo method, and codon-specific positive selection acting on the HA coding sequence was evaluated. The global and local phylogenetic analyses showed that all of the Italian sequences sampled in the post-pandemic (2010/2011) season grouped into at least four highly significant Italian clades, whereas those of the pandemic season (2009/2010) were interspersed with isolates from other countries at the tree root. The time of the most recent common ancestor of the strains circulating in the pandemic season in Italy was estimated to be between the spring and summer of 2009, whereas the Italian clades of the post-pandemic season originated in the spring of 2010 and showed radiation in the summer/autumn of the same year; this was confirmed by a Bayesian skyline plot showing the biphasic growth of the effective number of infections. The local phylogeography analysis showed that the first season of infection originated in Northern Italian localities with high density populations, whereas the second involved less densely populated localities, in line with a gravity-like model of geographical dispersion. Two HA sites, codons 97 and 222, were under positive selection. In conclusion, the A(H1N1)pdm09 virus was introduced into Italy in the spring of 2009 by means of multiple importations. This was followed by repeated founder effects in the post-pandemic period that originated specific Italian clades.
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Affiliation(s)
- Gianguglielmo Zehender
- Dipartimento di Scienze Cliniche e Biomediche Luigi Sacco, Sezione di Malattie Infettive, Università degli Studi di Milano, Milan, Italy.
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Ávila-Arcos MC, Ho SYW, Ishida Y, Nikolaidis N, Tsangaras K, Hönig K, Medina R, Rasmussen M, Fordyce SL, Calvignac-Spencer S, Willerslev E, Gilbert MTP, Helgen KM, Roca AL, Greenwood AD. One hundred twenty years of koala retrovirus evolution determined from museum skins. Mol Biol Evol 2012; 30:299-304. [PMID: 22983950 PMCID: PMC3548305 DOI: 10.1093/molbev/mss223] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Although endogenous retroviruses are common across vertebrate genomes, the koala retrovirus (KoRV) is the only retrovirus known to be currently invading the germ line of its host. KoRV is believed to have first infected koalas in northern Australia less than two centuries ago. We examined KoRV in 28 koala museum skins collected in the late 19th and 20th centuries and deep sequenced the complete proviral envelope region from five northern Australian specimens. Strikingly, KoRV env sequences were conserved among koalas collected over the span of a century, and two functional motifs that affect viral infectivity were fixed across the museum koala specimens. We detected only 20 env polymorphisms among the koalas, likely representing derived mutations subject to purifying selection. Among northern Australian koalas, KoRV was already ubiquitous by the late 19th century, suggesting that KoRV evolved and spread among koala populations more slowly than previously believed. Given that museum and modern koalas share nearly identical KoRV sequences, it is likely that koala populations, for more than a century, have experienced increased susceptibility to diseases caused by viral pathogenesis.
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Affiliation(s)
- María C Ávila-Arcos
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
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Pascalis H, Temmam S, Wilkinson DA, Dsouli N, Turpin M, de Lamballerie X, Dellagi K. Molecular evolutionary analysis of pH1N1 2009 influenza virus in Reunion Island, South West Indian Ocean region: a cohort study. PLoS One 2012; 7:e43742. [PMID: 22952752 PMCID: PMC3428279 DOI: 10.1371/journal.pone.0043742] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 07/23/2012] [Indexed: 01/08/2023] Open
Abstract
Background/Objectives Molecular epidemiology is a powerful tool to decipher the dynamics of viral transmission, quasispecies temporal evolution and origins. Little is known about the pH1N1 molecular dynamics in general population. A prospective study (CoPanFlu-RUN) was carried out in Reunion Island to characterize pH1N1 genetic variability and molecular evolution occurring in population during the pH1N1 Influenza pandemic in 2009. Methodology We directly amplified pH1N1 genomes from 28 different nasal swabs (26 individuals from 21 households). Fifteen strains were fully sequenced and 13 partially. This includes pairs of sequences from different members of 5 separate households; and two pairs from individuals, collected at different times. We assessed the molecular evolution of pH1N1 by genetic variability and phylogenetic analyses. Principal Findings We found that i) Reunion pH1N1 sequences stemmed from global “clade 7” but shaped two phylogenetic sub-clades; ii) D239E mutation was identified in the hemagglutinin protein of all Reunion sequences, a mutation which has been associated elsewhere with mild-, upper-respiratory tract pH1N1 infecting strains; iii) Date estimates from molecular phylogenies predicted clade emergence some time before the first detection of pH1N1 by the epidemiological surveillance system; iv) Phylogenetic relatedness was observed between Reunion pH1N1 viruses and those from other countries in South-western Indian Ocean area; v) Quasispecies populations were observed within households and individuals of the cohort-study. Conclusions Surveillance and/or prevention systems presently based on Influenza virus sequence variation should take into account that the majority of studies of pH1N1 Influenza generate genetic data for the HA/NA viral segments obtained from hospitalized-patients, which is potentially non-representative of the overall viral diversity within whole populations. Our observations highlight the importance of collecting unbiased data at the community level and conducting whole genome analysis to accurately understand viral dynamics.
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Affiliation(s)
- Hervé Pascalis
- GIS CRVOI, Centre de Recherche et de Veille sur maladies émergentes dans l'Océan Indien, Plateforme technologique CYROI, Saint-Denis, La Réunion, France.
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High titer and avidity of nonneutralizing antibodies against influenza vaccine antigen are associated with severe influenza. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1012-8. [PMID: 22573737 DOI: 10.1128/cvi.00081-12] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The importance of neutralizing antibody in protection against influenza virus is well established, but the role of the early antibody response during the initial stage of infection in affecting the severity of disease is unknown. The 2009 influenza pandemic provided a unique opportunity for study because most patients lacked preexisting neutralizing antibody. In this study, we compared the antibody responses of 52 patients with severe or mild disease, using sera collected at admission. A microneutralization (MN) assay was used to detect neutralizing antibody. We also developed an enzyme-linked immunosorbent assay (ELISA) which detects both neutralizing and nonneutralizing antibodies against viral antigens from a split-virion inactivated monovalent influenza virus vaccine. While the MN titers were not significantly different between the two groups (P = 0.764), the ELISA titer and ELISA/MN titer ratio were significantly higher for patients with severe disease than for those with mild disease (P = 0.004 and P = 0.011, respectively). This finding suggested that in patients with severe disease, a larger proportion of serum antibodies were antibodies with no detectable neutralizing activity. The antibody avidity was also significantly higher in patients with severe disease than in those with mild disease (P < 0.05). Among patients with severe disease, those who required positive pressure ventilation (PPV) had significantly higher ELISA titers than those who did not require PPV (P < 0.05). Multivariate analysis showed that the ELISA titer and antibody avidity were independently associated with severe disease. Higher titers of nonneutralizing antibody with higher avidity at the early stage of influenza virus infection may be associated with worse clinical severity and poorer outcomes.
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Cheng VCC, To KKW, Tse H, Hung IFN, Yuen KY. Two years after pandemic influenza A/2009/H1N1: what have we learned? Clin Microbiol Rev 2012; 25:223-63. [PMID: 22491771 PMCID: PMC3346300 DOI: 10.1128/cmr.05012-11] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The world had been anticipating another influenza pandemic since the last one in 1968. The pandemic influenza A H1N1 2009 virus (A/2009/H1N1) finally arrived, causing the first pandemic influenza of the new millennium, which has affected over 214 countries and caused over 18,449 deaths. Because of the persistent threat from the A/H5N1 virus since 1997 and the outbreak of the severe acute respiratory syndrome (SARS) coronavirus in 2003, medical and scientific communities have been more prepared in mindset and infrastructure. This preparedness has allowed for rapid and effective research on the epidemiological, clinical, pathological, immunological, virological, and other basic scientific aspects of the disease, with impacts on its control. A PubMed search using the keywords "pandemic influenza virus H1N1 2009" yielded over 2,500 publications, which markedly exceeded the number published on previous pandemics. Only representative works with relevance to clinical microbiology and infectious diseases are reviewed in this article. A significant increase in the understanding of this virus and the disease within such a short amount of time has allowed for the timely development of diagnostic tests, treatments, and preventive measures. These findings could prove useful for future randomized controlled clinical trials and the epidemiological control of future pandemics.
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Affiliation(s)
- Vincent C C Cheng
- Department of Microbiology, Queen Mary Hospital, Hong Kong Special Administrative Region, China
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To KKW, Yuen KY. The Management of the 2009 pandemic Influenza A H1N1 virus infection. J Thorac Dis 2012; 4:4-6. [PMID: 22295157 DOI: 10.3978/j.issn.2072-1439.2011.11.01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Accepted: 10/29/2011] [Indexed: 11/14/2022]
Affiliation(s)
- Kelvin K W To
- State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, The University of Hong Kong, Hong Kong Special Administrative Region, China
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