scholarly journals Hemagglutinin stalk domain from H5N1 strain as a potentially universal antigen.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Karolina Uranowska ◽  
Jolanta Tyborowska ◽  
Anna Jurek ◽  
Bogusław Szewczyk ◽  
Beata Gromadzka
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Virus Antigen ◽  
Cross Reactivity ◽  
Influenza Viruses ◽  
Health Concern ◽  
Stalk Domain ◽  
Major Surface

Influenza A virus infections are the major public health concern and cause significant morbidity and mortality each year worldwide. Vaccination is the main strategy of influenza epidemic prevention. However, seasonal vaccines induce strain-specific immunity and must be reformulated annually based on prediction of the strains that will circulate in the next season. Thus, it is essential to develop vaccines that would induce broad and persistent immunity to influenza viruses. Hemagglutinin is the major surface antigen of the influenza virus. Recent studies revealed the importance of HA stalk-specific antibodies in neutralization of different influenza virus strains. Therefore, it is important to design an immunogen that would focus the immune response on the HA stalk domain in order to elicit neutralizing antibodies. In the present study, we report characterization of a conserved truncated protein, potentially a universal influenza virus antigen from the H5N1 Highly Pathogenic Avian Influenza A virus strain. Our results indicate that exposure of the HA stalk domain containing conserved epitopes results in cross reactivity with different antibodies (against group 1 and 2 HAs). Additionally, we conclude that HA stalk domain contains not only conformational epitopes recognized by universal FI6 antibody, but also linear epitopes recognized by other antibodies.

scholarly journals Structure and Receptor Binding Preferences of Recombinant Hemagglutinins from Avian and Human H6 and H10 Influenza A Virus Subtypes

2015 ◽  
Vol 89 (8) ◽  
pp. 4612-4623 ◽  
Author(s):  
Hua Yang ◽  
Paul J. Carney ◽  
Jessie C. Chang ◽  
Julie M. Villanueva ◽  
James Stevens
Keyword(s):  
Influenza A Virus ◽  
Receptor Binding ◽  
Influenza A ◽  
Influenza Viruses ◽  
Surface Glycoprotein ◽  
Health Concern ◽  
Glycan Microarray ◽  
Detailed Structural Analysis ◽  
Major Surface ◽  
Human Infections

ABSTRACTDuring 2013, three new avian influenza A virus subtypes, A(H7N9), A(H6N1), and A(H10N8), resulted in human infections. While the A(H7N9) virus resulted in a significant epidemic in China across 19 provinces and municipalities, both A(H6N1) and A(H10N8) viruses resulted in only a few human infections. This study focuses on the major surface glycoprotein hemagglutinins from both of these novel human viruses. The detailed structural and glycan microarray analyses presented here highlight the idea that both A(H6N1) and A(H10N8) virus hemagglutinins retain a strong avian receptor binding preference and thus currently pose a low risk for sustained human infections.IMPORTANCEHuman infections with zoonotic influenza virus subtypes continue to be a great public health concern. We report detailed structural analysis and glycan microarray data for recombinant hemagglutinins from A(H6N1) and A(H10N8) viruses, isolated from human infections in 2013, and compare them with hemagglutinins of avian origin. This is the first structural report of an H6 hemagglutinin, and our results should further the understanding of these viruses and provide useful information to aid in the continuous surveillance of these zoonotic influenza viruses.

scholarly journals A single dose vaccination with an elastase-dependent H1N1 live attenuated swine influenza virus protects pigs from challenge with 2009 pandemic H1N1 virus

2014 ◽  
Vol 64 (1) ◽  
pp. 10-23
Author(s):  
Aleksandar Mašić ◽  
Niziti Woldeab ◽  
Carissa Embury-Hyatt ◽  
Yan Zhou ◽  
Shawn Babiuk
Keyword(s):  
Influenza Virus ◽  
Single Dose ◽  
Influenza A Virus ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Swine Influenza Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Virus Infections ◽  
Intranasal Route

Abstract The 2009 outbreak of H1N1 influenza A viruses in humans underscored the importance of pigs in influenza A virus evolution and the emergence of novel viruses with pandemic potential. In addition, influenza A virus infections continued to cause production losses in the agricultural industry resulting in a significant drop of profit. The primary method to control influenza A virus infections in pigs is through vaccination. Previously we demonstrated that two doses of an elastase-dependent live attenuated swine influenza virus administered by either the intratracheal or intranasal route can provide a high degree of protection in pigs against challenge with both homologous and different heterologous swine influenza viruses. Here we report the protection efficacy of a single dose elastase-dependent live attenuated swine influenza virus administered by the intranasal route against challenge with homologous subtypic H1N1 2009 pandemic swine-like influenza virus. Protection was observed in the absence of neutralizing antibodies specific for H1N1 2009 in sera.

scholarly journals Evaluation of Influenza Virus A/H3N2 and B Vaccines on the Basis of Cross-Reactivity of Postvaccination Human Serum Antibodies against Influenza Viruses A/H3N2 and B Isolated in MDCK Cells and Embryonated Hen Eggs

2012 ◽  
Vol 19 (6) ◽  
pp. 897-908 ◽  
Author(s):  
Noriko Kishida ◽  
Seiichiro Fujisaki ◽  
Masaru Yokoyama ◽  
Hironori Sato ◽  
Reiko Saito ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Human Serum ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Geometric Mean ◽  
Cross Reactivity ◽  
Influenza Viruses ◽  
Serum Antibodies ◽  
Influenza Virus A ◽  
The Cross

ABSTRACTThe vaccine strains against influenza virus A/H3N2 for the 2010-2011 season and influenza virus B for the 2009-2010 and 2010-2011 seasons in Japan are a high-growth reassortant A/Victoria/210/2009 (X-187) strain and an egg-adapted B/Brisbane/60/2008 (Victoria lineage) strain, respectively. Hemagglutination inhibition (HI) tests with postinfection ferret antisera indicated that the antisera raised against the X-187 and egg-adapted B/Brisbane/60/2008 vaccine production strains poorly inhibited recent epidemic isolates of MDCK-grown A/H3N2 and B/Victoria lineage viruses, respectively. The low reactivity of the ferret antisera may be attributable to changes in the hemagglutinin (HA) protein of production strains during egg adaptation. To evaluate the efficacy of A/H3N2 and B vaccines, the cross-reactivities of postvaccination human serum antibodies against A/H3N2 and B/Victoria lineage epidemic isolates were assessed by a comparison of the geometric mean titers (GMTs) of HI and neutralization (NT) tests. Serum antibodies elicited by the X-187 vaccine had low cross-reactivity to both MDCK- and egg-grown A/H3N2 isolates by HI test and narrow cross-reactivity by NT test in all age groups. On the other hand, the GMTs to B viruses detected by HI test were below the marginal level, so the cross-reactivity was assessed by NT test. The serum neutralizing antibodies elicited by the B/Brisbane/60/2008 vaccine reacted well with egg-grown B viruses but exhibited remarkably low reactivity to MDCK-grown B viruses. The results of these human serological studies suggest that the influenza A/H3N2 vaccine for the 2010-2011 season and B vaccine for the 2009-2010 and 2010-2011 seasons may possess insufficient efficacy and low efficacy, respectively.

scholarly journals Thapsigargin Is a Broad-Spectrum Inhibitor of Major Human Respiratory Viruses: Coronavirus, Respiratory Syncytial Virus and Influenza A Virus

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 234
Author(s):  
Sarah Al-Beltagi ◽  
Cristian Alexandru Preda ◽  
Leah V. Goulding ◽  
Joe James ◽  
Juan Pu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Respiratory Syncytial Virus ◽  
Influenza A Virus ◽  
Broad Spectrum ◽  
Influenza A ◽  
Respiratory Viruses ◽  
Influenza Viruses ◽  
Virus Challenge ◽  
2009 H1n1 ◽  
Syncytial Virus

The long-term control strategy of SARS-CoV-2 and other major respiratory viruses needs to include antivirals to treat acute infections, in addition to the judicious use of effective vaccines. Whilst COVID-19 vaccines are being rolled out for mass vaccination, the modest number of antivirals in use or development for any disease bears testament to the challenges of antiviral development. We recently showed that non-cytotoxic levels of thapsigargin (TG), an inhibitor of the sarcoplasmic/endoplasmic reticulum (ER) Ca2+ ATPase pump, induces a potent host innate immune antiviral response that blocks influenza A virus replication. Here we show that TG is also highly effective in blocking the replication of respiratory syncytial virus (RSV), common cold coronavirus OC43, SARS-CoV-2 and influenza A virus in immortalized or primary human cells. TG’s antiviral performance was significantly better than remdesivir and ribavirin in their respective inhibition of OC43 and RSV. Notably, TG was just as inhibitory to coronaviruses (OC43 and SARS-CoV-2) and influenza viruses (USSR H1N1 and pdm 2009 H1N1) in separate infections as in co-infections. Post-infection oral gavage of acid-stable TG protected mice against a lethal influenza virus challenge. Together with its ability to inhibit the different viruses before or during active infection, and with an antiviral duration of at least 48 h post-TG exposure, we propose that TG (or its derivatives) is a promising broad-spectrum inhibitor against SARS-CoV-2, OC43, RSV and influenza virus.

scholarly journals Development of Neuraminidase Subtype-Specific Reference Antisera by Recombinant Protein Expressed in Baculovirus

2012 ◽  
Vol 20 (2) ◽  
pp. 140-145 ◽  
Author(s):  
Kyu-Jun Lee ◽  
Jun-Gu Choi ◽  
Hyun-Mi Kang ◽  
Kwang-Il Kim ◽  
Choi-Kyu Park ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Influenza A Virus ◽  
Diagnostic Tests ◽  
Influenza A ◽  
Recombinant Baculovirus ◽  
Cross Reactivity ◽  
Specific Reference ◽  
Simple Method ◽  
Avian Influenza A Virus

ABSTRACTOutbreaks of avian influenza A virus infection, particularly the H5N1 strains that have affected birds and some humans for the past 15 years, have highlighted the need for increased surveillance and disease control. Such measures require diagnostic tests to detect and characterize the different subtypes of influenza virus. In the current study, a simple method for producing reference avian influenza virus antisera to be used in diagnostic tests was developed. Antisera of nine avian influenza A virus neuraminidases (NA) used for NA subtyping were produced using a recombinant baculovirus. The recombinant NA (rNA) proteins were expressed in Sf9 insect cells and inoculated intramuscularly into specific-pathogen-free chickens with the ISA70 adjuvant. The NA inhibition antibody titers of the rNA antiserum were in the ranges of 5 to 8 and 6 to 9 log2units after the primary and boost immunizations, respectively. The antisera were subtype specific, showing low cross-reactivity against every other NA subtype using the conventional thiobarbituric acid NA inhibition assay. These results suggest that this simple method for producing reference NA antisera without purification may be useful for the diagnosis and surveillance of influenza virus.

scholarly journals Functional Analysis of PA Binding by Influenza A Virus PB1: Effects on Polymerase Activity and Viral Infectivity

2001 ◽  
Vol 75 (17) ◽  
pp. 8127-8136 ◽  
Author(s):  
Daniel R. Perez ◽  
Ruben O. Donis
Keyword(s):  
Amino Acids ◽  
Influenza Virus ◽  
Amino Acid ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Influenza Viruses ◽  
Virus Growth ◽  
Transcription And Replication

ABSTRACT Influenza A virus expresses three viral polymerase (P) subunits—PB1, PB2, and PA—all of which are essential for RNA and viral replication. The functions of P proteins in transcription and replication have been partially elucidated, yet some of these functions seem to be dependent on the formation of a heterotrimer for optimal viral RNA transcription and replication. Although it is conceivable that heterotrimer subunit interactions may allow a more efficient catalysis, direct evidence of their essentiality for viral replication is lacking. Biochemical studies addressing the molecular anatomy of the P complexes have revealed direct interactions between PB1 and PB2 as well as between PB1 and PA. Previous studies have shown that the N-terminal 48 amino acids of PB1, termed domain α, contain the residues required for binding PA. We report here the refined mapping of the amino acid sequences within this small region of PB1 that are indispensable for binding PA by deletion mutagenesis of PB1 in a two-hybrid assay. Subsequently, we used site-directed mutagenesis to identify the critical amino acid residues of PB1 for interaction with PA in vivo. The first 12 amino acids of PB1 were found to constitute the core of the interaction interface, thus narrowing the previous boundaries of domain α. The role of the minimal PB1 domain α in influenza virus gene expression and genome replication was subsequently analyzed by evaluating the activity of a set of PB1 mutants in a model reporter minigenome system. A strong correlation was observed between a functional PA binding site on PB1 and P activity. Influenza viruses bearing mutant PB1 genes were recovered using a plasmid-based influenza virus reverse genetics system. Interestingly, mutations that rendered PB1 unable to bind PA were either nonviable or severely growth impaired. These data are consistent with an essential role for the N terminus of PB1 in binding PA, P activity, and virus growth.

scholarly journals A Host-Restricted Self-Attenuated Influenza Virus Provides Broad Pan-Influenza A Protection in a Mouse Model

2021 ◽  
Vol 12 ◽  
Author(s):  
Minjin Kim ◽  
Yucheol Cheong ◽  
Jinhee Lee ◽  
Jongkwan Lim ◽  
Sanguine Byun ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Mouse Model ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Protective Efficacy ◽  
Influenza Viruses ◽  
Cross Protection ◽  
Infection Model ◽  
Wild Type ◽  
Group 1

Influenza virus infections can cause a broad range of symptoms, form mild respiratory problems to severe and fatal complications. While influenza virus poses a global health threat, the frequent antigenic change often significantly compromises the protective efficacy of seasonal vaccines, further increasing the vulnerability to viral infection. Therefore, it is in great need to employ strategies for the development of universal influenza vaccines (UIVs) which can elicit broad protection against diverse influenza viruses. Using a mouse infection model, we examined the breadth of protection of the caspase-triggered live attenuated influenza vaccine (ctLAIV), which was self-attenuated by the host caspase-dependent cleavage of internal viral proteins. A single vaccination in mice induced a broad reactive antibody response against four different influenza viruses, H1 and rH5 (HA group 1) and H3 and rH7 subtypes (HA group 2). Notably, despite the lack of detectable neutralizing antibodies, the vaccination provided heterosubtypic protection against the lethal challenge with the viruses. Sterile protection was confirmed by the complete absence of viral titers in the lungs and nasal turbinates after the challenge. Antibody-dependent cellular cytotoxicity (ADCC) activities of non-neutralizing antibodies contributed to cross-protection. The cross-protection remained robust even after in vivo depletion of T cells or NK cells, reflecting the strength and breadth of the antibody-dependent effector function. The robust mucosal secretion of sIgA reflects an additional level of cross-protection. Our data show that the host-restricted designer vaccine serves an option for developing a UIV, providing pan-influenza A protection against both group 1 and 2 influenza viruses. The present results of potency and breadth of protection from wild type and reassortant viruses addressed in the mouse model by single immunization merits further confirmation and validation, preferably in clinically relevant ferret models with wild type challenges.

scholarly journals Epitope specificity plays a critical role in regulating antibody-dependent cell-mediated cytotoxicity against influenza A virus

2016 ◽  
Vol 113 (42) ◽  
pp. 11931-11936 ◽  
Author(s):  
Wenqian He ◽  
Gene S. Tan ◽  
Caitlin E. Mullarkey ◽  
Amanda J. Lee ◽  
Mannie Man Wai Lam ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Critical Role ◽  
Host Cells ◽  
Viral Glycoprotein ◽  
Effector Functions ◽  
Dependent Cell

The generation of strain-specific neutralizing antibodies against influenza A virus is known to confer potent protection against homologous infections. The majority of these antibodies bind to the hemagglutinin (HA) head domain and function by blocking the receptor binding site, preventing infection of host cells. Recently, elicitation of broadly neutralizing antibodies which target the conserved HA stalk domain has become a promising “universal” influenza virus vaccine strategy. The ability of these antibodies to elicit Fc-dependent effector functions has emerged as an important mechanism through which protection is achieved in vivo. However, the way in which Fc-dependent effector functions are regulated by polyclonal influenza virus-binding antibody mixtures in vivo has never been defined. Here, we demonstrate that interactions among viral glycoprotein-binding antibodies of varying specificities regulate the magnitude of antibody-dependent cell-mediated cytotoxicity induction. We show that the mechanism responsible for this phenotype relies upon competition for binding to HA on the surface of infected cells and virus particles. Nonneutralizing antibodies were poor inducers and did not inhibit antibody-dependent cell-mediated cytotoxicity. Interestingly, anti-neuraminidase antibodies weakly induced antibody-dependent cell-mediated cytotoxicity and enhanced induction in the presence of HA stalk-binding antibodies in an additive manner. Our data demonstrate that antibody specificity plays an important role in the regulation of ADCC, and that cross-talk among antibodies of varying specificities determines the magnitude of Fc receptor-mediated effector functions.

scholarly journals Rewiring the RNAs of influenza virus to prevent reassortment

2009 ◽  
Vol 106 (37) ◽  
pp. 15891-15896 ◽  
Author(s):  
Qinshan Gao ◽  
Peter Palese
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Nonstructural Protein ◽  
Influenza Viruses ◽  
Ha Gene ◽  
Ns Gene ◽  
Virus Rna ◽  
Reassortant Viruses ◽  
Packaging Signals

Influenza viruses contain segmented, negative-strand RNA genomes. Genome segmentation facilitates reassortment between different influenza virus strains infecting the same cell. This phenomenon results in the rapid exchange of RNA segments. In this study, we have developed a method to prevent the free reassortment of influenza A virus RNAs by rewiring their packaging signals. Specific packaging signals for individual influenza virus RNA segments are located in the 5′ and 3′ noncoding regions as well as in the terminal regions of the ORF of an RNA segment. By putting the nonstructural protein (NS)-specific packaging sequences onto the ORF of the hemagglutinin (HA) gene and mutating the packaging regions in the ORF of the HA, we created a chimeric HA segment with the packaging identity of an NS gene. By the same strategy, we made an NS gene with the packaging identity of an HA segment. This rewired virus had the packaging signals for all eight influenza virus RNAs, but it lost the ability to independently reassort its HA or NS gene. A similar approach can be applied to the other influenza A virus segments to diminish their ability to form reassortant viruses.

scholarly journals Evaluation of Live Attenuated Influenza A Virus H6 Vaccines in Mice and Ferrets

2008 ◽  
Vol 83 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Zhongying Chen ◽  
Celia Santos ◽  
Amy Aspelund ◽  
Laura Gillim-Ross ◽  
Hong Jin ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Neutralizing Antibodies ◽  
Influenza A ◽  
Serum Antibody ◽  
Cross Reactivity ◽  
Phenotypic Properties ◽  
Vaccine Candidates ◽  
Virus Challenge ◽  
Avian Influenza A Virus ◽  
Internal Gene

ABSTRACT Avian influenza A virus A/teal/HK/W312/97 (H6N1) possesses seven gene segments that are highly homologous to those of highly pathogenic human influenza H5N1 viruses, suggesting that a W312-like H6N1 virus might have been involved in the generation of the A/HK/97 H5N1 viruses. The continuous circulation and reassortment of influenza H6 subtype viruses in birds highlight the need to develop an H6 vaccine to prevent potential influenza pandemics caused by the H6 viruses. Based on the serum antibody cross-reactivity data obtained from 14 different H6 viruses from Eurasian and North American lineages, A/duck/HK/182/77, A/teal/HK/W312/97, and A/mallard/Alberta/89/85 were selected to produce live attenuated H6 candidate vaccines. Each of the H6 vaccine strains is a 6:2 reassortant ca virus containing HA and NA gene segments from an H6 virus and the six internal gene segments from cold-adapted A/Ann Arbor/6/60 (AA ca), the master donor virus that is used to make live attenuated influenza virus FluMist (intranasal) vaccine. All three H6 vaccine candidates exhibited phenotypic properties of temperature sensitivity (ts), ca, and attenuation (att) conferred by the internal gene segments from AA ca. Intranasal administration of a single dose of the three H6 ca vaccine viruses induced neutralizing antibodies in mice and ferrets and fully protected mice and ferrets from homologous wild-type (wt) virus challenge. Among the three H6 vaccine candidates, the A/teal/HK/W312/97 ca virus provided the broadest cross-protection against challenge with three antigenically distinct H6 wt viruses. These data support the rationale for further evaluating the A/teal/HK/W312/97 ca vaccine in humans.

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