Long-Term and Memory Immune Responses in Mice against Newcastle Disease Virus-Like Particles Containing Respiratory Syncytial Virus Glycoprotein Ectodomains

Department of Microbiology and Physiological Systems/Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Journal of Virology (Impact Factor: 4.44). 08/2012; 86(21):11654-62. DOI: 10.1128/JVI.01510-12
Source: PubMed


Although respiratory syncytial virus (RSV) is a significant human pathogen, no RSV vaccines are available. We have reported that a virus-like particle (VLP) RSV vaccine candidate stimulated, in mice, robust, protective anti-RSV glycoprotein T(H)1 biased immune responses without enhanced respiratory disease upon RSV challenge. We report here an analysis of long-term responses to these VLPs. BALB/c mice immunized, without adjuvant, with VLPs or with infectious RSV generated anti-F and anti-G protein serum antibody responses that were stable over 14 months. Neutralizing antibody titers stimulated by VLPs were robust and durable for 14 months, whereas those of RSV-immunized animals declined significantly by 3 months. F protein-specific antibody-secreting cells were detected in the bone marrows of VLP-immunized mice but not in the marrows of RSV-immunized mice. Adoptive transfer of enriched splenic B cells from VLP-immunized mice into immunodeficient rag(-/-) mice resulted in anti-F and anti-G protein serum IgG antibody responses, in recipient mice, that were protective upon RSV challenge. In contrast, transfer of splenic B cells from RSV-immunized mice produced no detectable serum antibody in the recipients, nor could these mice inhibit RSV replication upon virus challenge. Immunization with VLPs stimulated the formation of germinal center GL7(+) B cells in normal mice. VLP immunization of TCR βδ(-/-) T-cell-deficient mice did not induce anti-RSV IgG antibodies, results consistent with T-cell-dependent immune responses. These results demonstrate that VLPs are effective in stimulating long-lived RSV-specific, T-cell-dependent neutralizing antibody-secreting cells and RSV-specific memory responses.

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    • "To assess the protective efficacy of recombinant PR8/RSV.HA-F vaccine, groups of mice were challenged with RSV A2 (2 Â 10 5 PFU/mouse) at 8 weeks after immunization. We chose a dose of 2 Â 10 5 PFU that was recently reported to be sufficient to assess the efficacy of RSV vaccines (Garg et al., 2014; Johnson et al., 2014; Kim et al., 2014; Murata and Catherman, 2012; Nguyen et al., 2012; Schmidt et al., 2012). We also found that the PBS or PR8 WT group of mice that were infected with 2 Â 10 5 PFU RSV showed a high titer of approximately up to 10 4 PFU from lungs at day 5 post infection (Fig. 3A). "
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    ABSTRACT: Respiratory syncytial virus (RSV) is the leading cause of viral bronchiolitis in both children and the elderly. There is no vaccine available for the prevention of RSV infection. Here, we generated recombinant influenza virus (PR8/RSV.HA-F) expressing an RSV F243-294 neutralizing epitope in the hemagglutinin (HA) as a chimeric protein. Neutralizing antibodies specific for both RSV and influenza virus were induced by a single intranasal immunization of mice with PR8/RSV.HA-F. Mice that were immunized with PR8/RSV.HA-F were protected against RSV infection comparable with live RSV as evidenced by significant reduction of RSV lung viral loads, as well as the absence of lung eosinophilia and RSV-specific cellular immune responses. In contrast, formalin-inactivated RSV-immunized mice showed severe disease and high cellular immune responses in lungs after RSV infection. These findings support a concept that recombinant influenza virus carrying the RSV F243-294 neutralizing epitope can be developed as a promising RSV vaccine candidate which induces protective neutralizing antibodies but avoids lung immunopathology. Copyright © 2014 Elsevier B.V. All rights reserved.
    Antiviral Research 12/2014; 115. DOI:10.1016/j.antiviral.2014.12.009 · 3.94 Impact Factor
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    • "Higher titers of RSV were detected in lungs from unvaccinated naive mice at day 5 post RSV challenge (Fig. 4). Unimmunized naïve mice showed highest levels of lung viral titers with an average of 3.5 log10, which is similar to those reported in previous studies (McGinnes et al., 2011; Schmidt et al., 2012 "
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    ABSTRACT: This study demonstrates that immunization with non-replicating virus-like particle (FFG VLP) containing RSV F and G glycoproteins together with RSV F DNA induced T helper type 1 antibody responses to RSV F similar to live RSV infection. Upon RSV challenge 21 weeks after immunization, FFG VLP vaccination induced protection against RSV infection as shown by clearance of lung viral loads, and the absence of eosinophil infiltrates, and did not cause lung pathology. In contrast, formalin-inactivated RSV (FI-RSV) vaccination showed significant pulmonary eosinophilia, severe mucus production, and extensive histopathology resulting in a hallmark of pulmonary pathology. Substantial lung pathology was also observed in mice with RSV re-infections. High levels of systemic and local inflammatory cytokine-secreting cells were induced in mice with FI-RSV but not with FFG VLP immunization after RSV challenge. Therefore, the results provide evidence that recombinant RSV FFG VLP vaccine can confer long-term protection against RSV without causing lung pathology.
    Antiviral Research 10/2014; 110. DOI:10.1016/j.antiviral.2014.07.016 · 3.94 Impact Factor
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    ABSTRACT: Virus-like particles (VLPs) are large particles, the size of viruses, composed of repeating structures that mimic those of infectious virus. Since their structures are similar to that of viruses, they have been used to study the mechanisms of virus assembly. They are also in development for delivery of molecules to cells and in studies of the immunogenicity of particle-associated antigens. However, they have been most widely used for development of vaccines and vaccine candidates. VLPs can form upon the expression of the structural proteins of many different viruses. This chapter describes the generation and purification of VLPs formed with the structural proteins, M, NP, F, and HN proteins, of Newcastle disease virus (NDV). Newcastle disease virus-like particles (ND VLPs) have also been developed as a platform for assembly into VLPs of glycoproteins from other viruses. This chapter describes the methods for this use of ND VLPs. Curr. Protoc. Microbiol. 30:18.2.1-18.2.21. © 2013 by John Wiley & Sons, Inc.
    Current protocols in microbiology 01/2013; 30:18.2.1-18.2.21. DOI:10.1002/9780471729259.mc1802s30
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