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Construction and Immunogenicity Evaluation of Recombinant Influenza A Viruses Containing Chimeric Hemagglutinin Genes Derived from Genetically Divergent Influenza A H1N1 Subtype Viruses.

McCormick K, Jiang Z, Zhu L, Lawson SR, Langenhorst R, Ransburgh R, Brunick C, Tracy MC, Hurtig HR, Mabee LM, Mingo M, Li Y, Webby RJ, Huber VC, Fang Y - PLoS ONE (2015)

Bottom Line: Nine shuffled HA constructs were initially screened for immunogenicity in mice by DNA immunization, and one chimeric HA (HA-129) was expressed on both a A/Puerto Rico/8/34 backbone with mutations associated with a live, attenuated phenotype (PR8LAIV-129) and a A/swine/Texas/4199-2/98 backbone (TX98-129).When delivered to mice, the PR8LAIV-129 induced antibodies against all four parental viruses, which was similar to the breadth of immunity observed when HA-129 was delivered as a DNA vaccine.This study established a platform for creating novel genes of influenza viruses using a molecular breeding approach, which will have important applications toward future development of broadly protective influenza virus vaccines.

View Article: PubMed Central - PubMed

Affiliation: Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota, Vermillion, SD, 57069, United States of America.

ABSTRACT

Background and objectives: Influenza A viruses cause highly contagious diseases in a variety of hosts, including humans and pigs. To develop a vaccine that can be broadly effective against genetically divergent strains of the virus, in this study we employed molecular breeding (DNA shuffling) technology to create a panel of chimeric HA genes.

Methods and results: Each chimeric HA gene contained genetic elements from parental swine influenza A viruses that had a history of zoonotic transmission, and also from a 2009 pandemic virus. Each parental virus represents a major phylogenetic clade of influenza A H1N1 viruses. Nine shuffled HA constructs were initially screened for immunogenicity in mice by DNA immunization, and one chimeric HA (HA-129) was expressed on both a A/Puerto Rico/8/34 backbone with mutations associated with a live, attenuated phenotype (PR8LAIV-129) and a A/swine/Texas/4199-2/98 backbone (TX98-129). When delivered to mice, the PR8LAIV-129 induced antibodies against all four parental viruses, which was similar to the breadth of immunity observed when HA-129 was delivered as a DNA vaccine. This chimeric HA was then tested as a candidate vaccine in a nursery pig model, using inactivated TX98-129 virus as the backbone. The results demonstrate that pigs immunized with HA-129 developed antibodies against all four parental viruses, as well as additional primary swine H1N1 influenza virus field isolates.

Conclusion: This study established a platform for creating novel genes of influenza viruses using a molecular breeding approach, which will have important applications toward future development of broadly protective influenza virus vaccines.

No MeSH data available.


Related in: MedlinePlus

Serum antibody HAI titers from mice inoculated with recombinant virus PR8LAIV-129 vaccine.Balb/c mice (n = 7) were vaccinated intranasally with PR8LAIV-129. Serum antibody titers were analyzed using the HAI assay against the parental viruses and PR8LAIV-129 itself. HAI titers are defined as the reciprocal of the final serum dilution where inhibition of hemagglutination was observed. Serum samples with a titer below the detectable limit of the assay (initial serum dilution of 1:10) were assigned a value of 5 for graphical representation and statistical analyses. HAI titers from vaccinated (color bars) and unvaccinated (black bars) groups are presented for each HA tested (PR8LAIV-129, OH07, TN09, NJ76, and IA06). Reactivity of antibodies induced by PR8LAIV-129 from vaccinated mice was compared with that of unvaccinated mice (n = 7) using Mann Whitney nonparametric test (*p<0.05). Bars represent mean values for the indicated groups, with vertical error bars indicating standard deviation.
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pone.0127649.g005: Serum antibody HAI titers from mice inoculated with recombinant virus PR8LAIV-129 vaccine.Balb/c mice (n = 7) were vaccinated intranasally with PR8LAIV-129. Serum antibody titers were analyzed using the HAI assay against the parental viruses and PR8LAIV-129 itself. HAI titers are defined as the reciprocal of the final serum dilution where inhibition of hemagglutination was observed. Serum samples with a titer below the detectable limit of the assay (initial serum dilution of 1:10) were assigned a value of 5 for graphical representation and statistical analyses. HAI titers from vaccinated (color bars) and unvaccinated (black bars) groups are presented for each HA tested (PR8LAIV-129, OH07, TN09, NJ76, and IA06). Reactivity of antibodies induced by PR8LAIV-129 from vaccinated mice was compared with that of unvaccinated mice (n = 7) using Mann Whitney nonparametric test (*p<0.05). Bars represent mean values for the indicated groups, with vertical error bars indicating standard deviation.

Mentions: Using the PR8LAIV-129 as antigen, HAI assay results show that immune sera from mice inoculated with parental viruses broadly reacted with this chimeric HA-expressing virus (Table 2). To determine whether the PR8LAIV-129 can be used to induce broad immune responses, we thenvaccinated mice with this chimeric HA-expressing virus. Specifically, mice were immunized twice with the PR8LAIV-129, and sera were collected at 21 days post-secondary inoculation. Results from the HAI assay show that antibodies induced by the PR8LAIV-129 react with viruses expressing each of the four parental HAs, with maximal reactivity against the virus expressing the HA-129 itself (Fig 5). This result indicates that HA-129 is immunogenic when expressed within a whole virus, and that antibodies induced can react with all four parental HA proteins.


Construction and Immunogenicity Evaluation of Recombinant Influenza A Viruses Containing Chimeric Hemagglutinin Genes Derived from Genetically Divergent Influenza A H1N1 Subtype Viruses.

McCormick K, Jiang Z, Zhu L, Lawson SR, Langenhorst R, Ransburgh R, Brunick C, Tracy MC, Hurtig HR, Mabee LM, Mingo M, Li Y, Webby RJ, Huber VC, Fang Y - PLoS ONE (2015)

Serum antibody HAI titers from mice inoculated with recombinant virus PR8LAIV-129 vaccine.Balb/c mice (n = 7) were vaccinated intranasally with PR8LAIV-129. Serum antibody titers were analyzed using the HAI assay against the parental viruses and PR8LAIV-129 itself. HAI titers are defined as the reciprocal of the final serum dilution where inhibition of hemagglutination was observed. Serum samples with a titer below the detectable limit of the assay (initial serum dilution of 1:10) were assigned a value of 5 for graphical representation and statistical analyses. HAI titers from vaccinated (color bars) and unvaccinated (black bars) groups are presented for each HA tested (PR8LAIV-129, OH07, TN09, NJ76, and IA06). Reactivity of antibodies induced by PR8LAIV-129 from vaccinated mice was compared with that of unvaccinated mice (n = 7) using Mann Whitney nonparametric test (*p<0.05). Bars represent mean values for the indicated groups, with vertical error bars indicating standard deviation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4465703&req=5

pone.0127649.g005: Serum antibody HAI titers from mice inoculated with recombinant virus PR8LAIV-129 vaccine.Balb/c mice (n = 7) were vaccinated intranasally with PR8LAIV-129. Serum antibody titers were analyzed using the HAI assay against the parental viruses and PR8LAIV-129 itself. HAI titers are defined as the reciprocal of the final serum dilution where inhibition of hemagglutination was observed. Serum samples with a titer below the detectable limit of the assay (initial serum dilution of 1:10) were assigned a value of 5 for graphical representation and statistical analyses. HAI titers from vaccinated (color bars) and unvaccinated (black bars) groups are presented for each HA tested (PR8LAIV-129, OH07, TN09, NJ76, and IA06). Reactivity of antibodies induced by PR8LAIV-129 from vaccinated mice was compared with that of unvaccinated mice (n = 7) using Mann Whitney nonparametric test (*p<0.05). Bars represent mean values for the indicated groups, with vertical error bars indicating standard deviation.
Mentions: Using the PR8LAIV-129 as antigen, HAI assay results show that immune sera from mice inoculated with parental viruses broadly reacted with this chimeric HA-expressing virus (Table 2). To determine whether the PR8LAIV-129 can be used to induce broad immune responses, we thenvaccinated mice with this chimeric HA-expressing virus. Specifically, mice were immunized twice with the PR8LAIV-129, and sera were collected at 21 days post-secondary inoculation. Results from the HAI assay show that antibodies induced by the PR8LAIV-129 react with viruses expressing each of the four parental HAs, with maximal reactivity against the virus expressing the HA-129 itself (Fig 5). This result indicates that HA-129 is immunogenic when expressed within a whole virus, and that antibodies induced can react with all four parental HA proteins.

Bottom Line: Nine shuffled HA constructs were initially screened for immunogenicity in mice by DNA immunization, and one chimeric HA (HA-129) was expressed on both a A/Puerto Rico/8/34 backbone with mutations associated with a live, attenuated phenotype (PR8LAIV-129) and a A/swine/Texas/4199-2/98 backbone (TX98-129).When delivered to mice, the PR8LAIV-129 induced antibodies against all four parental viruses, which was similar to the breadth of immunity observed when HA-129 was delivered as a DNA vaccine.This study established a platform for creating novel genes of influenza viruses using a molecular breeding approach, which will have important applications toward future development of broadly protective influenza virus vaccines.

View Article: PubMed Central - PubMed

Affiliation: Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota, Vermillion, SD, 57069, United States of America.

ABSTRACT

Background and objectives: Influenza A viruses cause highly contagious diseases in a variety of hosts, including humans and pigs. To develop a vaccine that can be broadly effective against genetically divergent strains of the virus, in this study we employed molecular breeding (DNA shuffling) technology to create a panel of chimeric HA genes.

Methods and results: Each chimeric HA gene contained genetic elements from parental swine influenza A viruses that had a history of zoonotic transmission, and also from a 2009 pandemic virus. Each parental virus represents a major phylogenetic clade of influenza A H1N1 viruses. Nine shuffled HA constructs were initially screened for immunogenicity in mice by DNA immunization, and one chimeric HA (HA-129) was expressed on both a A/Puerto Rico/8/34 backbone with mutations associated with a live, attenuated phenotype (PR8LAIV-129) and a A/swine/Texas/4199-2/98 backbone (TX98-129). When delivered to mice, the PR8LAIV-129 induced antibodies against all four parental viruses, which was similar to the breadth of immunity observed when HA-129 was delivered as a DNA vaccine. This chimeric HA was then tested as a candidate vaccine in a nursery pig model, using inactivated TX98-129 virus as the backbone. The results demonstrate that pigs immunized with HA-129 developed antibodies against all four parental viruses, as well as additional primary swine H1N1 influenza virus field isolates.

Conclusion: This study established a platform for creating novel genes of influenza viruses using a molecular breeding approach, which will have important applications toward future development of broadly protective influenza virus vaccines.

No MeSH data available.


Related in: MedlinePlus