Pushko, P, Tumpey, TM, Bu, F, Knell, J, Robinson, R and Smith, G. Influenza virus-like particles comprised of the HA, NA, and M1 proteins of H9N2 influenza virus induce protective immune responses in BALB/c mice. Vaccine 23: 5751-5759

Novavax, Inc., Vaccine Technologies, 1 Taft Court, Rockville, MD 20850, USA.
Vaccine (Impact Factor: 3.62). 01/2006; 23(50):5751-9. DOI: 10.1016/j.vaccine.2005.07.098
Source: PubMed


Avian influenza viruses represent a growing threat for an influenza pandemic. To develop recombinant vaccine for avian influenza of the H9N2 subtype, we expressed in insect cells virus-like particles (VLPs) consisting of three structural proteins of influenza A/Hong Kong/1073/99 (H9N2) virus. Upon infection of Sf9 cells with recombinant baculoviruses, the hemagglutinin (HA), neuraminidase (NA), and matrix (M1) proteins were co-expressed in the infected cells, self-assembled, and released into the culture medium as VLPs of 80-120nm in diameter. VLPs exhibited functional characteristics of influenza virus including hemagglutination and neuraminidase activities. In BALB/c mice, VLPs elicited serum antibodies specific for influenza A/Hong Kong/1073/99 (H9N2) virus and inhibited replication of the influenza virus after challenge. Thus, VLPs represent a potential strategy for the development of human vaccines against avian influenza H9N2 viruses.

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Available from: Gale Smith, Oct 13, 2014
    • "The protein concentration of culture supernatants was not determined. silver stain, Coomassie stain and Western blot analysis as described by Pushko et al. (Pushko et al., 2005). Total VLP protein amounts of 10 g, 2.5 g and 0.6 g were loaded into the gel and transferred onto a PVDF membrane using a Mini Trans-Blot (Bio-Rad, CA). "
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    ABSTRACT: The highly pathogenic avian influenza (HPAI) H5N1 virus has become highly enzootic since 2003 and has dynamically evolved to undergo substantial evolution. Clades and 2.3.4 have become the most dominant lineage in recent years, and H5N8 avian influenza outbreaks have been reported Asia. The current approach to generate influenza virus vaccines uses embryonated chicken eggs for large-scale production, although such vaccines have been poorly immunogenic to heterologous virus challenge. In the current study, virus-like particles (VLP) based on A/meerkat/Shanghai/SH-1/2012 (clade and comprising hemagglutinin (HA), neuraminidase (NA), and matrix (M1) were produced using a baculovirus expression system to develop effective protection for different H5 HPAI clade challenges. Mice immunized with VLP demonstrated stronger humoral and cellular immune responses than mice immunized with whole influenza virus (WIV), with 20-fold higher IgG antibody titers against A/meerkat/Shanghai/SH-1/2012 after boost. Notably, the WIV vaccine group showed partial protection (80% survival) to homologous challenge, little protection (40% survival) to heterologous challenge, and 20% survival to H5N8 challenge, whereas all mice in the VLP+CFA group survived. These results provide insight for the development of effective prophylactic vaccines based on VLPs with cross-clade protection for the control of current H5 HPAI outbreaks in humans. Copyright © 2015. Published by Elsevier B.V.
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    • "Influenza VLPs have been generated by co-infecting insect cells with recombinant baculoviruses expressing structural influenza proteins of matrix 1 (M1)/hemagglutinin (HA), HA/neuraminidase (NA)/M1, or HA/NA/M1/matrix 2 (M2). [14,15,21,28,33]. Influenza VLPs have been found to induce protective immunity in preclinical and clinical studies [20]. "
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    ABSTRACT: Infectious bronchitis virus (IBV) poses a severe threat to poultry industry and causes heavy economic losses worldwide. Vaccination is the most effective ways of preventing the infection and controlling the spread of IBV, but the currently available inactivated and attenuated virus vaccines have some disadvantages. We have developed a chimeric virus-like particle (VLP)-based candidate vaccine for IBV protection. The chimeric VLP was composed of M1 protein from avian influenza H5N1 virus and a fusion protein NA/S1 that was generated by fusing IBV S1 protein to the cytoplasmic and transmembrane domains of NA protein of avian influenza H5N1 virus. The chimeric VLPs elicited significant higher S1-specific antibody responses in intramuscularly immunized mice and chickens than inactivated IBV viruses. Furthermore, the chimeric VLPs induced significantly higher neutralization antibody levels than inactivated H120 virus in SPF chickens. In addition, the chimeric VLPs induced significantly higher IL-4 production in mice. These results demonstrated that the chimeric VLPs have the potential for further development of vaccines against IBV infection.
    Full-text · Article · Dec 2013 · Journal of veterinary science (Suwŏn-si, Korea)
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    • "Recent studies have demonstrated that H5N1, H3N2 and H9N2 VLP vaccines comprised of only three influenza virus proteins, hemagglutinin (HA), neuraminidase (NA), and matrix 1 (M1) can be expressed in insect cells. These vaccines elicited high-titer antibodies and protected against challenge with lethal viruses (Bright et al., 2007, 2008; Pushko et al., 2005). In addition, VLPs containing the influenza glycoprotein HA and the influenza matrix protein M1 induced high titers of virus-specific antibodies in vaccinated mice or ferrets and provided immunized animals with protection against otherwise lethal experimental infections (Ross et al., 2009). "
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    ABSTRACT: Avian influenza virus (AIV) and Newcastle disease virus (NDV) are both important pathogens in poultry worldwide. The protection of poultry from avian influenza and Newcastle disease can be achieved through vaccination. We embarked on the development of a bivalent vaccine that would allow for a single immunization against both avian influenza and Newcastle disease. We constructed a chimeric virus-like particle (VLP) that is composed of the M1 protein and HA protein of avian influenza virus and a chimeric protein containing the cytoplasmic and transmembrane domains of AIV neuraminidase protein (NA) and the ectodomain of the NDV hemagglutinin-neuraminidase (HN) protein (NA/HN). The single immunization of chickens with the chimeric VLP vaccine induced both AIV H5- and NDV-specific antibodies. The HI titers and specific antibodies elicited by the chimeric VLPs were statistically similar to those elicited in animals vaccinated with the corresponding commercial monovalent vaccines. Chickens vaccinated with chimeric VLP vaccine and then challenged with the Newcastle disease F48E9 virus displayed complete protection. Overall, the chimeric VLP vaccine elicits strong immunity and can protect against Newcastle disease virus challenge.
    Full-text · Article · Sep 2013 · Virus Research
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