RESUMO
Seasonal human influenza virus continues to cause morbidity and mortality annually, and highly pathogenic avian influenza (HPAI) viruses along with other emerging influenza viruses continue to pose pandemic threats. Vaccination is considered the most effective measure for controlling influenza; however, current strategies rely on a precise vaccine match with currently circulating virus strains for efficacy, requiring constant surveillance and regular development of matched vaccines. Current vaccines focus on eliciting specific antibody responses against the hemagglutinin (HA) surface glycoprotein; however, the diversity of HAs across species and antigenic drift of circulating strains enable the evasion of virus-inhibiting antibody responses, resulting in vaccine failure. The neuraminidase (NA) surface glycoprotein, while diverse, has a conserved enzymatic site and presents an appealing target for priming broadly effective antibody responses. Here we show that vaccination with parainfluenza virus 5 (PIV5), a promising live viral vector expressing NA from avian (H5N1) or pandemic (H1N1) influenza virus, elicited NA-specific antibody and T cell responses, which conferred protection against homologous and heterologous influenza virus challenges. Vaccination with PIV5-N1 NA provided cross-protection against challenge with a heterosubtypic (H3N2) virus. Experiments using antibody transfer indicate that antibodies to NA have an important role in protection. These findings indicate that PIV5 expressing NA may be effective as a broadly protective vaccine against seasonal influenza and emerging pandemic threats.IMPORTANCE Seasonal influenza viruses cause considerable morbidity and mortality annually, while emerging viruses pose potential pandemic threats. Currently licensed influenza virus vaccines rely on the antigenic match of hemagglutinin (HA) for vaccine strain selection, and most vaccines rely on HA inhibition titers to determine efficacy, despite the growing awareness of the contribution of neuraminidase (NA) to influenza virus vaccine efficacy. Although NA is immunologically subdominant to HA, and clinical studies have shown variable NA responses to vaccination, in this study, we show that vaccination with a parainfluenza virus 5 recombinant vaccine candidate expressing NA (PIV5-NA) from a pandemic influenza (pdmH1N1) virus or highly pathogenic avian influenza (H5N1) virus elicits robust, cross-reactive protection from influenza virus infection in two animal models. New vaccination strategies incorporating NA, including PIV5-NA, could improve seasonal influenza virus vaccine efficacy and provide protection against emerging influenza viruses.
Assuntos
Proteção Cruzada , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Neuraminidase/imunologia , Vírus da Parainfluenza 5/genética , Animais , Anticorpos Antivirais/administração & dosagem , Anticorpos Antivirais/sangue , Reações Cruzadas , Vetores Genéticos/administração & dosagem , Humanos , Imunização Passiva , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/patogenicidade , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/patogenicidade , Vacinas contra Influenza/genética , Influenza Humana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/genética , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Pandemias/prevenção & controle , Vacinas Sintéticas/imunologiaRESUMO
New approaches for vaccination to prevent influenza virus infection are needed. Emerging viruses, such as the H5N1 highly pathogenic avian influenza (HPAI) virus, pose not only pandemic threats but also challenges in vaccine development and production. Parainfluenza virus 5 (PIV5) is an appealing vector for vaccine development, and we have previously shown that intranasal immunization with PIV5 expressing the hemagglutinin from influenza virus was protective against influenza virus challenge (S. M. Tompkins, Y. Lin, G. P. Leser, K. A. Kramer, D. L. Haas, E. W. Howerth, J. Xu, M. J. Kennett, J. E. Durbin, R. A. Tripp, R. A. Lamb, and B. He, Virology 362:139-150, 2007). While intranasal immunization is an appealing approach, PIV5 may have the potential to be utilized in other formats, prompting us to test the efficacy of rPIV5-H5, which encodes the HA from H5N1 HPAI virus, in different vaccination schemes. In the BALB/c mouse model, a single intramuscular or intranasal immunization with a live rPIV5-H5 (ZL46) rapidly induced robust neutralizing serum antibody responses and protected against HPAI challenge, although mucosal IgA responses primed by intranasal immunization more effectively controlled virus replication in the lung. The rPIV5-H5 vaccine incorporated the H5 HA into the virion, so we tested the efficacy of an inactivated form of the vaccine. Inactivated rPIV5-H5 primed neutralizing serum antibody responses and controlled H5N1 virus replication; however, similar to other H5 antigen vaccines, it required a booster immunization to prime protective immune responses. Taken together, these results suggest that rPIV5-HA vaccines and H5-specific vaccines in particular can be utilized in multiple formats and by multiple routes of administration. This could avoid potential contraindications based on intranasal administration alone and provide opportunities for broader applications with the use of a single vaccine vector.
Assuntos
Vetores Genéticos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Paramyxoviridae/genética , Administração Intranasal , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Modelos Animais de Doenças , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/genética , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Injeções Intramusculares , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/imunologia , Análise de Sobrevida , Vacinação/métodosRESUMO
Parainfluenza virus 5 (PIV5) is a promising viral vector for vaccine development. PIV5 is safe, stable, efficacious, cost-effective to produce and, most interestingly, it overcomes preexisting antivector immunity. We have recently reported that PIV5 expressing the hemagglutinin (HA) from highly pathogenic avian influenza (HPAI) virus H5N1 (PIV5-H5) provides sterilizing immunity against lethal doses of HPAI H5N1 infection in mice. It is thought that induction of apoptosis can lead to enhanced antigen presentation. Previously, we have shown that deleting the SH gene and the conserved C terminus of the V gene in PIV5 results in mutant viruses (PIV5ΔSH and PIV5VΔC) that enhance induction of apoptosis. In this study, we inserted the HA gene of H5N1 into PIV5ΔSH (PIV5ΔSH-H5) or PIV5VΔC (PIV5VΔC-H5) and compared their efficacies as vaccine candidates to PIV5-H5. We have found that PIV5ΔSH-H5 induced the highest levels of anti-HA antibodies, the strongest T cell responses, and the best protection against an H5N1 lethal challenge in mice. These results suggest that PIV5ΔSH is a better vaccine vector than wild-type PIV5.
Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/imunologia , Vírus da Parainfluenza 5/genética , Rubulavirus/genética , Animais , Anticorpos Antivirais/biossíntese , Apresentação de Antígeno , Apoptose , Chlorocebus aethiops , Feminino , Genes Virais , Vetores Genéticos/imunologia , Virus da Influenza A Subtipo H5N1/patogenicidade , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vírus da Parainfluenza 5/imunologia , Rubulavirus/imunologia , Linfócitos T/imunologia , Células VeroRESUMO
Influenza viruses often evade host immunity via antigenic drift and shift despite previous influenza virus infection and/or vaccination. Vaccines that match circulating virus strains are needed for optimal protection. Development of a universal influenza virus vaccine providing broadly cross-protective immunity will be of great importance. The nucleoprotein (NP) of influenza A virus is highly conserved among all strains of influenza A viruses and has been explored as an antigen for developing a universal influenza virus vaccine. In this work, we generated a recombinant parainfluenza virus 5 (PIV5) containing NP from H5N1 (A/Vietnam/1203/2004), a highly pathogenic avian influenza (HPAI) virus, between HN and L (PIV5-NP-HN/L) and tested its efficacy. PIV5-NP-HN/L induced humoral and T cell responses in mice. A single inoculation of PIV5-NP-HN/L provided complete protection against lethal heterosubtypic H1N1 challenge and 50% protection against lethal H5N1 HPAI virus challenge. To improve efficacy, NP was inserted into different locations within the PIV5 genome. Recombinant PIV5 containing NP between F and SH (PIV5-NP-F/SH) or between SH and HN (PIV5-NP-SH/HN) provided better protection against H5N1 HPAI virus challenge than did PIV5-NP-HN/L. These results suggest that PIV5 expressing NP from H5N1 has the potential to be utilized as a universal influenza virus vaccine.
Assuntos
Proteção Cruzada , Vetores Genéticos , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Paramyxoviridae/genética , Proteínas de Ligação a RNA/imunologia , Proteínas do Core Viral/imunologia , Animais , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Feminino , Vírus da Influenza A Subtipo H1N1/patogenicidade , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/patogenicidade , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Camundongos , Camundongos Endogâmicos BALB C , Proteínas do Nucleocapsídeo , Infecções por Orthomyxoviridae/virologia , Proteínas de Ligação a RNA/genética , Análise de Sobrevida , Linfócitos T/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Core Viral/genéticaRESUMO
A safe and effective vaccine is the best way to prevent large-scale highly pathogenic avian influenza virus (HPAI) H5N1 outbreaks in the human population. The current FDA-approved H5N1 vaccine has serious limitations. A more efficacious H5N1 vaccine is urgently needed. Parainfluenza virus 5 (PIV5), a paramyxovirus, is not known to cause any illness in humans. PIV5 is an attractive vaccine vector. In our studies, a single dose of a live recombinant PIV5 expressing a hemagglutinin (HA) gene of H5N1 (rPIV5-H5) from the H5N1 subtype provided sterilizing immunity against lethal doses of HPAI H5N1 infection in mice. Furthermore, we have examined the effect of insertion of H5N1 HA at different locations within the PIV5 genome on the efficacy of a PIV5-based vaccine. Interestingly, insertion of H5N1 HA between the leader sequence, the de facto promoter of PIV5, and the first viral gene, nucleoprotein (NP), did not lead to a viable virus. Insertion of H5N1 HA between NP and the next gene, V/phosphorprotein (V/P), led to a virus that was defective in growth. We have found that insertion of H5N1 HA at the junction between the small hydrophobic (SH) gene and the hemagglutinin-neuraminidase (HN) gene gave the best immunity against HPAI H5N1 challenge: a dose as low as 1,000 PFU was sufficient to protect against lethal HPAI H5N1 challenge in mice. The work suggests that recombinant PIV5 expressing H5N1 HA has great potential as an HPAI H5N1 vaccine.
Assuntos
Vetores Genéticos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Paramyxoviridae/genética , Animais , Modelos Animais de Doenças , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/genética , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Camundongos , Camundongos Endogâmicos BALB C , Mutagênese Insercional , Infecções por Orthomyxoviridae/imunologia , Recombinação Genética , Análise de Sobrevida , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologiaRESUMO
Influenza A viruses continue to emerge and re-emerge, causing outbreaks, epidemics and occasionally pandemics. While the influenza vaccines licensed for public use are generally effective against seasonal influenza, issues arise with production, immunogenicity, and efficacy in the case of vaccines against pandemic and emerging influenza viruses, and highly pathogenic avian influenza virus in particular. Thus, there is need of improved influenza vaccines and vaccination strategies. This review discusses advances in alternative influenza vaccines, touching briefly on licensed vaccines and vaccine antigens; then reviewing recombinant subunit vaccines, virus-like particle vaccines and DNA vaccines, with the main focus on virus-vectored vaccine approaches.