scholarly journals A Replication-Defective Influenza Virus Harboring H5 and H7 Hemagglutinins Provides Protection against H5N1 and H7N9 Infection in Mice

2020 ◽  
Author(s):  
Xingui Tian ◽  
Shelby Landreth ◽  
Yao Lu ◽  
Kannupriya Pandey ◽  
Yan Zhou
Keyword(s):  
Avian Influenza ◽  
Immune Responses ◽  
Vaccine Candidate ◽  
Mortality Rates ◽  
Influenza Viruses ◽  
Effective Vaccine ◽  
H7n9 Virus ◽  
Complete Protection ◽  
Virus Challenge ◽  
Ha Gene

The recent highly pathogenic avian influenza (HPAI) H5N1 and H7N9 viruses have caused hundreds of human infections with high mortality rates. Although H5N1 and H7N9 viruses have been mainly limited to avian species, there is high potential for these viruses to acquire human-to-human transmission and initiate a pandemic. A highly safe and effective vaccine is needed to protect against a potential H5N1 or H7N9 influenza pandemic. Here, we report the generation and evaluation of two reassortant influenza viruses, PR8-H5-H7NA and PR8-H7-H5NA. These viruses contain six internal segments from A/Puerto Rico/8/1934 (PR8), the HA segment from either A/Alberta/01/2014 (H5N1) [AB14 (H5N1)] or A/British Columbia/01/2015 (H7N9) [BC15 (H7N9)], and a chimeric NA segment with either the BC15 (H7N9) HA gene or the AB14 (H5N1) HA gene flanked by the NA packaging signals of PR8. These viruses expressed both H5 and H7 HAs in infected cells, replicated to high titres when exogenous NA was added to the culture medium in vitro, and were replication-defective and non-virulent when administered intranasally in mice. Moreover, intranasal vaccination with PR8-H5-H7NA elicited robust immune responses to both H5 and H7 viruses, conferring complete protection against both AB14 (H5N1) and BC15 (H7N9) challenges in mice. Conversely, vaccination with PR8-H7-H5NA only elicited robust immune responses towards the H7 virus, which conferred complete protection against BC15 (H7N9) but not against AB14 (H5N1) in mice. Therefore, PR8-H5-H7NA has strong potential to serve as a vaccine candidate against both H5 and H7 subtypes of influenza viruses. Importance Avian influenza H5N1 and H7N9 viruses infected human with high mortality rates. A highly safe and effective vaccine is needed to protect against a potential pandemic. We generated and evaluated two reassortant influenza viruses, PR8-H5-H7NA and PR8-H7-H5NA as vaccine candidates. Each virus contains one type of HA in segment 4 and the other subtype of HA in segment 6, thus expressing both H5 and H7 subtypes of HA molecule. The viruses’ replication is dependent in the addition of exogenous NA in cell culture, and are replication-defective in vivo. Vaccination of PR8-H5-H7NA virus confers protection to both H5N1 and H7N9 virus challenge; conversely, vaccination of PR8-H7-H5NA only provides protection to H7N9 virus challenge. Our data revealed when engineering such virus, the H5 or H7 HA in segment 6 affects the immunogenicity. PR8-H5-H7NA has strong potential to serve as a vaccine candidate against both H5 and H7 subtypes of influenza viruses.

scholarly journals Virus-Like Particle Vaccine Induces Protective Immunity against Homologous and Heterologous Strains of Influenza Virus

2007 ◽  
Vol 81 (7) ◽  
pp. 3514-3524 ◽  
Author(s):  
Fu-Shi Quan ◽  
Chunzi Huang ◽  
Richard W. Compans ◽  
Sang-Moo Kang
Keyword(s):  
Influenza Virus ◽  
Immune Responses ◽  
Protective Immunity ◽  
Protective Efficacy ◽  
High Serum ◽  
Influenza Viruses ◽  
Effective Vaccine ◽  
Lethal Challenge ◽  
Virus Challenge ◽  
Vaccine Approach

ABSTRACT Recurrent outbreaks of highly pathogenic avian influenza virus pose the threat of pandemic spread of lethal disease and make it a priority to develop safe and effective vaccines. Influenza virus-like particles (VLPs) have been suggested to be a promising vaccine approach. However, VLP-induced immune responses, and their roles in inducing memory immune responses and cross-protective immunity have not been investigated. In this study, we developed VLPs containing influenza virus A/PR8/34 (H1N1) hemagglutinin (HA) and matrix (M1) proteins and investigated their immunogenicity, long-term cross-protective efficacy, and effects on lung proinflammatory cytokines in mice. Intranasal immunization with VLPs containing HA induced high serum and mucosal antibody titers and neutralizing activity against PR8 and A/WSN/33 (H1N1) viruses. Mice immunized with VLPs containing HA showed little or no proinflammatory lung cytokines and were protected from a lethal challenge with mouse-adapted PR8 or WSN viruses even 5 months postimmunization. Influenza VLPs induced mucosal immunoglobulin G and cellular immune responses, which were reactivated rapidly upon virus challenge. Long-lived antibody-secreting cells were detected in the bone marrow of immunized mice. Immune sera administered intranasally were able to confer 100% protection from a lethal challenge with PR8 or WSN, which provides further evidence that anti-HA antibodies are primarily responsible for preventing infection. Taken together, these results indicate that nonreplicating influenza VLPs represent a promising strategy for the development of a safe and effective vaccine to control the spread of lethal influenza viruses.

scholarly journals Enhancing Protective Efficacy of Poultry Vaccines through Targeted Delivery of Antigens to Antigen-Presenting Cells

Vaccines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 75 ◽  
Author(s):  
Angita Shrestha ◽  
Jean-Remy Sadeyen ◽  
Munir Iqbal
Keyword(s):  
B Cells ◽  
Avian Influenza ◽  
Targeted Delivery ◽  
Vaccine Development ◽  
Antigen Presenting Cells ◽  
Influenza Viruses ◽  
Effective Vaccine ◽  
Capture Process ◽  
Selective Delivery ◽  
Antigen Presenting

Avian viral diseases including avian influenza, Marek’s disease and Newcastle disease are detrimental to economies around the world that depend on the poultry trade. A significant zoonotic threat is also posed by avian influenza viruses. Vaccination is an important and widely used method for controlling these poultry diseases. However, the current vaccines do not provide full protection or sterile immunity. Hence, there is a need to develop improved vaccines. The major aim of developing improved vaccines is to induce strong and specific humoral and cellular immunity in vaccinated animals. One strategy used to enhance the immunogenicity of vaccines is the selective delivery of protective antigens to antigen-presenting cells (APCs) including dendritic cells, macrophages and B cells. APCs have a central role in the initiation and maintenance of immune responses through their ability to capture, process and present antigens to T and B cells. Vaccine technology that selectively targets APCs has been achieved by coupling antigens to monoclonal antibodies or ligands that are targeted by APCs. The aim of this review is to discuss existing strategies of selective delivery of antigens to APCs for effective vaccine development in poultry.

scholarly journals Genetic Characterization and Pathogenicity of H7N7 and H7N9 Avian Influenza Viruses Isolated from South Korea

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2057
Author(s):  
Eun-Jee Na ◽  
Young-Sik Kim ◽  
Yoon-Ji Kim ◽  
Jun-Soo Park ◽  
Jae-Ku Oem
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
South Korea ◽  
Influenza Viruses ◽  
The Body ◽  
Avian Influenza Viruses ◽  
Receptor Binding Site ◽  
Phylogenetic Tree Analysis ◽  
Pathogenic Avian Influenza ◽  
Ha Gene

H7 low pathogenic avian influenza viruses (LPAIVs) can mutate into highly pathogenic avian influenza viruses (HPAIVs). In addition to avian species, H7 avian influenza viruses (AIVs) also infect humans. In this study, two AIVs, H7N9 (20X-20) and H7N7 (34X-2), isolated from the feces of wild birds in South Korea in 2021, were genetically analyzed. The HA cleavage site of the two H7 Korean viruses was confirmed to be ELPKGR/GLF, indicating they are LPAIVs. There were no amino acid substitutions at the receptor-binding site of the HA gene of two H7 Korean viruses compared to that of A/Anhui/1/2013 (H7N9), which prefer human receptors. In the phylogenetic tree analysis, the HA gene of the two H7 Korean viruses shared the highest nucleotide similarity with the Korean H7 subtype AIVs. In addition, the HA gene of the two H7 Korean viruses showed high nucleotide similarity to that of the A/Jiangsu/1/2018(H7N4) virus, which is a human influenza virus originating from avian influenza virus. Most internal genes (PB2, PB1, PA, NP, NA, M, and NS) of the two H7 Korean viruses belonged to the Eurasian lineage, except for the M gene of 34X-2. This result suggests that active reassortment occurred among AIVs. In pathogenicity studies of mice, the two H7 Korean viruses replicated in the lungs of mice. In addition, the body weight of mice infected with 34X-2 decreased 7 days post-infection (dpi) and inflammation was observed in the peribronchiolar and perivascular regions of the lungs of mice. These results suggest that mammals can be infected with the two H7 Korean AIVs. Our data showed that even low pathogenic H7 AIVs may infect mammals, including humans, as confirmed by the A/Jiangsu/1/2018(H7N4) virus. Therefore, continuous monitoring and pathogenicity assessment of AIVs, even of LPAIVs, are required.

scholarly journals Amino Acid Residue 217 in the Hemagglutinin Glycoprotein Is a Key Mediator of Avian Influenza H7N9 Virus Antigenicity

2018 ◽  
Vol 93 (1) ◽  
Author(s):  
Pengxiang Chang ◽  
Joshua E. Sealy ◽  
Jean-Remy Sadeyen ◽  
Munir Iqbal
Keyword(s):  
Amino Acid ◽  
Avian Influenza ◽  
Immune Escape ◽  
Influenza Viruses ◽  
Single Mutation ◽  
H7n9 Virus ◽  
Avian Influenza Viruses ◽  
Antigenic Analysis ◽  
Neutralizing Capacity ◽  
High Pathogenicity

ABSTRACTAvian influenza viruses continue to evolve and acquire mutations that facilitate antigenic drift and virulence change. In 2017, low-pathogenicity H7N9 avian influenza viruses evolved to a high-pathogenicity phenotype in China. Comparative antigenic analysis of the low- and high-pathogenicity virus strains showed marked variability. In order to identify residues that may be linked to the antigenic change among the H7N9 viruses, we serially passaged the viruses in the presence of homologous ferret antiserum. Progeny viruses able to overcome the neutralizing capacity of the antiserum were sequenced. The analysis showed that the emergent immune escape viruses contained mutations A125T, A151T, and L217Q in the hemagglutinin (HA) glycoprotein as early as passage 5 and that these mutations persisted until passage 10. The results revealed that a single mutation, L217Q, in the HA of H7N9 virus led to 23- and 8-fold reductions in hemagglutination inhibition (HI) titer with ferret and chicken antisera, respectively. Further analysis showed that this change also contributed to antigenic differences between the low- and high-pathogenicity H7N9 viruses, thus playing a major role in their antigenic diversification. Therefore, evolutionary changes at amino acid position 217 in the H7N9 viruses can serve as a genetic marker for virus antigenic diversity during vaccine seed matching and selection. Thein vitroimmune escape mutant selection method used in this study could also aid in the prediction of emerging antigenic variants in naturally infected or immunized animals.IMPORTANCEAvian influenza H7N9 viruses circulating in poultry and wild birds continue to evolve and acquire important phenotypic changes. Mutations to the virus hemagglutinin (HA) glycoprotein can modulate virus antigenicity and facilitate virus escape from natural or vaccine-induced immunity. The focus of this study was to identify evolutionary markers in the HA of H7N9 that drive escape from antibody-based immunity. To achieve this, we propagated low-pathogenicity H7N9 virus in the presence of polyclonal antiserum derived from ferrets infected with the same strain of virus (homologous antiserum). This selection process was repeated 10 times. The HA gene sequences of viruses recovered after the fifth passage showed that the viruses readily acquired mutations at three different amino acid positions (A125T, A151T, and L217Q). Further functional analysis of these mutations confirmed that the mutation at residue 217 in the HA was responsible for mediating changes to the immunological properties of the H7N9 virus.

scholarly journals Pathogenicity and Vaccine Efficacy of Different Clades of Asian H5N1 Avian Influenza A Viruses in Domestic Ducks

2008 ◽  
Vol 82 (22) ◽  
pp. 11374-11382 ◽  
Author(s):  
Jeong-Ki Kim ◽  
Patrick Seiler ◽  
Heather L. Forrest ◽  
Alexey M. Khalenkov ◽  
John Franks ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Influenza A ◽  
Preventive Strategy ◽  
Complete Protection ◽  
Influenza A Viruses ◽  
Symptomatic Infection ◽  
Domestic Ducks ◽  
Virus Challenge ◽  
H5n1 Influenza

ABSTRACT Waterfowl represent the natural reservoir of all subtypes of influenza A viruses, including H5N1. Ducks are especially considered major contributors to the spread of H5N1 influenza A viruses because they exhibit diversity in morbidity and mortality. Therefore, as a preventive strategy against endemic as well as pandemic influenza, it is important to reduce the spread of H5N1 influenza A viruses in duck populations. Here, we describe the pathogenicity of dominant clades (clades 1 and 2) of H5N1 influenza A viruses circulating in birds in Asia. Four representatives of dominant clades of the viruses cause symptomatic infection but lead to different profiles of lethality in domestic ducks. We also demonstrate the efficacy, cross-protectiveness, and immunogenicity of three different inactivated oil emulsion whole-virus H5 influenza vaccines (derived by implementing reverse genetics) to the viruses in domestic ducks. A single dose of the vaccines containing 1 μg of hemagglutinin protein provides complete protection against a lethal A/Duck/Laos/25/06 (H5N1) influenza virus challenge, with no evidence of morbidity, mortality, or shedding of the challenge virus. Moreover, two of the three vaccines achieved complete cross-clade or cross-subclade protection against the heterologous avian influenza virus challenge. Interestingly, the vaccines induce low or undetectable titers of hemagglutination inhibition (HI), cross-HI, and/or virus neutralization antibodies. The mechanism of complete protection in the absence of detectable antibody responses remains an open question.

scholarly journals The pandemic potential of avian influenza A(H7N9) virus: a review

2015 ◽  
Vol 143 (16) ◽  
pp. 3359-3374 ◽  
Author(s):  
W. D. TANNER ◽  
D. J. A. TOTH ◽  
A. V. GUNDLAPALLI
Keyword(s):  
Avian Influenza ◽  
Disease Transmission ◽  
Human Disease ◽  
Influenza A ◽  
Influenza Viruses ◽  
Assessment Tools ◽  
World Health ◽  
H7n9 Virus ◽  
Transmission Potential ◽  
Modelling Studies

SummaryIn March 2013 the first cases of human avian influenza A(H7N9) were reported to the World Health Organization. Since that time, over 650 cases have been reported. Infections are associated with considerable morbidity and mortality, particularly within certain demographic groups. This rapid increase in cases over a brief time period is alarming and has raised concerns about the pandemic potential of the H7N9 virus. Three major factors influence the pandemic potential of an influenza virus: (1) its ability to cause human disease, (2) the immunity of the population to the virus, and (3) the transmission potential of the virus. This paper reviews what is currently known about each of these factors with respect to avian influenza A(H7N9). Currently, sustained human-to-human transmission of H7N9 has not been reported; however, population immunity to the virus is considered very low, and the virus has significant ability to cause human disease. Several statistical and geographical modelling studies have estimated and predicted the spread of the H7N9 virus in humans and avian species, and some have identified potential risk factors associated with disease transmission. Additionally, assessment tools have been developed to evaluate the pandemic potential of H7N9 and other influenza viruses. These tools could also hypothetically be used to monitor changes in the pandemic potential of a particular virus over time.

ANALYSIS OF AVIAN INFLUENZA A (H7N9) MODEL BASED ON THE LOW PATHOGENICITY IN POULTRY

2017 ◽  
Vol 25 (02) ◽  
pp. 279-294 ◽  
Author(s):  
SHU-MIN GUO ◽  
JUAN WANG ◽  
MINI GHOSH ◽  
XUE-ZHI LI
Keyword(s):  
Avian Influenza ◽  
Equilibrium Point ◽  
High Mortality ◽  
Influenza A ◽  
Influenza Viruses ◽  
H7n9 Virus ◽  
Global Concern ◽  
Reported Data ◽  
High Pathogenic ◽  
Stability Results

The avian influenza A (H7N9) virus is one subtype of influenza viruses, which has previously been isolated only in birds. Recently, an outbreak of a new avian influenza (H7N9) in China has resulted in numerous infections and high mortality in the humans. The H7N9 virus is low pathogenic in poultry and high pathogenic in human and that is critically different from other avian influenza viruses. An increasing number of the new H7N9 cases and the high mortality have caused a serious global concern. Here, based on the reported data, we propose and analyze an SE-SEIS avian–human influenza model. We prove the global stability results for both the disease-free equilibrium point and the endemic equilibrium point by using a general Bendixson–Dulac theorem. Our reported theoretical results of this paper are expected to help in exploring the development of efficient methods to controlling the spread of avian influenza A(H7N9).

scholarly journals Pathogenesis of Influenza A(H7N9) Virus in Aged Nonhuman Primates

2020 ◽  
Vol 222 (7) ◽  
pp. 1155-1164 ◽  
Author(s):  
Satoshi Fukuyama ◽  
Kiyoko Iwatsuki-Horimoto ◽  
Maki Kiso ◽  
Noriko Nakajima ◽  
Robert W Gregg ◽  
...  
Keyword(s):  
Virus Infection ◽  
Immune Responses ◽  
Influenza A ◽  
Nonhuman Primates ◽  
The Elderly ◽  
Mortality Rates ◽  
H7n9 Virus ◽  
Aged Animal ◽  
Chemokine Production ◽  
Mechanistic Basis

Abstract The avian influenza A(H7N9) virus has caused high mortality rates in humans, especially in the elderly; however, little is known about the mechanistic basis for this. In the current study, we used nonhuman primates to evaluate the effect of aging on the pathogenicity of A(H7N9) virus. We observed that A(H7N9) virus infection of aged animals (defined as age 20–26 years) caused more severe symptoms than infection of young animals (defined as age 2–3 years). In aged animals, lung inflammation was weak and virus infection was sustained. Although cytokine and chemokine expression in the lungs of most aged animals was lower than that in the lungs of young animals, 1 aged animal showed severe symptoms and dysregulated proinflammatory cytokine and chemokine production. These results suggest that attenuated or dysregulated immune responses in aged animals are responsible for the severe symptoms observed among elderly patients infected with A(H7N9) virus.

scholarly journals Contribution of Segment 3 to the Acquisition of Virulence in Contemporary H9N2 Avian Influenza Viruses

2020 ◽  
Vol 94 (20) ◽  
Author(s):  
Anabel L. Clements ◽  
Joshua E. Sealy ◽  
Thomas P. Peacock ◽  
Jean-Remy Sadeyen ◽  
Saira Hussain ◽  
...  
Keyword(s):  
Middle East ◽  
Avian Influenza ◽  
Mortality Rates ◽  
Influenza Viruses ◽  
H9n2 Virus ◽  
Morbidity And Mortality ◽  
Single Amino Acid ◽  
Economic Damage ◽  
Poultry Production ◽  
Avian Influenza Viruses

ABSTRACT H9N2 avian influenza viruses (AIVs) circulate in poultry throughout much of Asia, the Middle East, and Africa. These viruses cause huge economic damage to poultry production systems and pose a zoonotic threat both in their own right and in the generation of novel zoonotic viruses, for example, H7N9. In recent years, it has been observed that H9N2 viruses have further adapted to gallinaceous poultry, becoming more highly transmissible and causing higher morbidity and mortality. Here, we investigate the molecular basis for this increased virulence, comparing a virus from the 1990s and a contemporary field strain. The modern virus replicated to higher titers in various systems, and this difference mapped to a single amino acid polymorphism at position 26 of the endonuclease domain shared by the PA and PA-X proteins. This change was responsible for increased replication and higher morbidity and mortality rates along with extended tissue tropism seen in chickens. Although the PA K26E change correlated with increased host cell shutoff activity of the PA-X protein in vitro, it could not be overridden by frameshift site mutations that block PA-X expression and therefore increased PA-X activity could not explain the differences in replication phenotype. Instead, this indicates that these differences are due to subtle effects on PA function. This work gives insight into the ongoing evolution and poultry adaptation of H9N2 and other avian influenza viruses and helps us understand the striking morbidity and mortality rates in the field, as well as the rapidly expanding geographical range seen in these viruses. IMPORTANCE Avian influenza viruses, such as H9N2, cause huge economic damage to poultry production worldwide and are additionally considered potential pandemic threats. Understanding how these viruses evolve in their natural hosts is key to effective control strategies. In the Middle East and South Asia, an older H9N2 virus strain has been replaced by a new reassortant strain with greater fitness. Here, we take representative viruses and investigate the genetic basis for this “fitness.” A single mutation in the virus was responsible for greater fitness, enabling high growth of the contemporary H9N2 virus in cells, as well as in chickens. The genetic mutation that modulates this change is within the viral PA protein, a part of the virus polymerase gene that contributes to viral replication as well as to virus accessory functions—however, we find that the fitness effect is specifically due to changes in the protein polymerase activity.

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