Limits...
A critical HA1 neutralizing domain of H5N1 influenza in an optimal conformation induces strong cross-protection.

Du L, Zhao G, Sun S, Zhang X, Zhou X, Guo Y, Li Y, Zhou Y, Jiang S - PLoS ONE (2013)

Bottom Line: Consequently, the design of an effective and safe anti-H5N1 vaccine is essential.We then constructed three additional recombinants fused with Fd plus His tag (HA-13-263-Fd-His), Fc only (HA-13-263-Fc), and His tag only (HA-13-263-His), respectively.These results suggest that the oligomeric form of the CND containing the RBD can be further developed as an effective and safe vaccine for cross-protection against divergent strains of H5N1 viruses.

View Article: PubMed Central - PubMed

Affiliation: Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America.

ABSTRACT
The highly pathogenic avian influenza (HPAI) H5N1 viruses, especially the laboratory-generated H5N1 mutants, have demonstrated the potential to cross the species barrier and infect mammals and humans. Consequently, the design of an effective and safe anti-H5N1 vaccine is essential. We previously demonstrated that the full-length hemagglutinin 1 (HA1) could induce significant neutralizing antibody response and protection. Here, we intended to identify the critical neutralizing domain (CND) in an optimal conformation that can elicit strong cross-neutralizing antibodies and protection against divergent H5N1 strains. We thus constructed six recombinant proteins covering different regions of HA1 of A/Anhui/1/2005(H5N1), each of which was fused with foldon (Fd) and Fc of human IgG. We found that the critical fragment fused with Fd/Fc (HA-13-263-Fdc, H5 numbering) that could elicit the strongest neutralizing antibody response is located in the N-terminal region of HA1 (residues 13-263), which covers the receptor-binding domain (RBD, residues 112-263). We then constructed three additional recombinants fused with Fd plus His tag (HA-13-263-Fd-His), Fc only (HA-13-263-Fc), and His tag only (HA-13-263-His), respectively. We found that the HA-13-263-Fdc, which formed an oligomeric conformation, induced the strongest neutralizing antibody response and cross-protection against challenges of two tested H5N1 virus strains covering clade 1: A/VietNam/1194/2004 (VN/1194) or clade 2.3.4: A/Shenzhen/406H/06 (SZ/406H), while HA-13-263-Fc dimer and HA-13-263-Fd-His trimer elicited higher neutralizing antibody response and protection than HA-13-263-His monomer. These results suggest that the oligomeric form of the CND containing the RBD can be further developed as an effective and safe vaccine for cross-protection against divergent strains of H5N1 viruses.

Show MeSH

Related in: MedlinePlus

Comparison of neutralizing antibodies in sera of mice vaccinated with HA-13–263 proteins.Sera were collected at 10 days post-last vaccination. PBS was used as the negative control. (A) Neutralizing antibody titers against HA of homologous AH-HA strain (clade 2.3.4) and heterologous A/Hong Kong/156/97 (HK-HA, clade 0) and A/VietNam/1194/2004 (1194-HA, clade 1) strains of H5N1 pseudovirus. The data are presented as mean NT50± SD from five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for the three H5N1 pseudoviruses. (B) Neutralizing antibody titers against heterologous strains of A/VietNam/1194/2004 (VN/1194, clade 1) and A/Shenzhen/406H/06 (SZ/406H, clade 2.3.4) H5N1 live viruses. The titers of neutralizing antibodies are presented as mean ± SD of five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for both VN/1194 and SZ/406H viruses. The dotted line shows the limit of detection.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3539987&req=5

pone-0053568-g007: Comparison of neutralizing antibodies in sera of mice vaccinated with HA-13–263 proteins.Sera were collected at 10 days post-last vaccination. PBS was used as the negative control. (A) Neutralizing antibody titers against HA of homologous AH-HA strain (clade 2.3.4) and heterologous A/Hong Kong/156/97 (HK-HA, clade 0) and A/VietNam/1194/2004 (1194-HA, clade 1) strains of H5N1 pseudovirus. The data are presented as mean NT50± SD from five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for the three H5N1 pseudoviruses. (B) Neutralizing antibody titers against heterologous strains of A/VietNam/1194/2004 (VN/1194, clade 1) and A/Shenzhen/406H/06 (SZ/406H, clade 2.3.4) H5N1 live viruses. The titers of neutralizing antibodies are presented as mean ± SD of five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for both VN/1194 and SZ/406H viruses. The dotted line shows the limit of detection.

Mentions: Further evaluation of the neutralizing activity of these proteins in vaccinated mouse sera revealed that all HA-13–263 proteins with Fd and/or Fc were able to induce a significantly higher level of neutralizing antibodies than HA-13–263-His against homologous (AH-HA) and heterologous (HK-HA and 1194-HA) H5N1 pseudoviruses. Specifically, HA-13–263-Fdc and HA-13–263-His induced the highest and lowest neutralizing antibody responses, respectively, against all three H5N1 strains, while HA-13–263-Fc elicited a significantly higher level of neutralizing antibodies than HA-13–263-Fd-His. However, PBS control did not induce neutralizing antibodies against any tested pseudoviruses (Fig. 7A).


A critical HA1 neutralizing domain of H5N1 influenza in an optimal conformation induces strong cross-protection.

Du L, Zhao G, Sun S, Zhang X, Zhou X, Guo Y, Li Y, Zhou Y, Jiang S - PLoS ONE (2013)

Comparison of neutralizing antibodies in sera of mice vaccinated with HA-13–263 proteins.Sera were collected at 10 days post-last vaccination. PBS was used as the negative control. (A) Neutralizing antibody titers against HA of homologous AH-HA strain (clade 2.3.4) and heterologous A/Hong Kong/156/97 (HK-HA, clade 0) and A/VietNam/1194/2004 (1194-HA, clade 1) strains of H5N1 pseudovirus. The data are presented as mean NT50± SD from five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for the three H5N1 pseudoviruses. (B) Neutralizing antibody titers against heterologous strains of A/VietNam/1194/2004 (VN/1194, clade 1) and A/Shenzhen/406H/06 (SZ/406H, clade 2.3.4) H5N1 live viruses. The titers of neutralizing antibodies are presented as mean ± SD of five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for both VN/1194 and SZ/406H viruses. The dotted line shows the limit of detection.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539987&req=5

pone-0053568-g007: Comparison of neutralizing antibodies in sera of mice vaccinated with HA-13–263 proteins.Sera were collected at 10 days post-last vaccination. PBS was used as the negative control. (A) Neutralizing antibody titers against HA of homologous AH-HA strain (clade 2.3.4) and heterologous A/Hong Kong/156/97 (HK-HA, clade 0) and A/VietNam/1194/2004 (1194-HA, clade 1) strains of H5N1 pseudovirus. The data are presented as mean NT50± SD from five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for the three H5N1 pseudoviruses. (B) Neutralizing antibody titers against heterologous strains of A/VietNam/1194/2004 (VN/1194, clade 1) and A/Shenzhen/406H/06 (SZ/406H, clade 2.3.4) H5N1 live viruses. The titers of neutralizing antibodies are presented as mean ± SD of five mice per group. * indicates significant difference (P<0.05), respectively, between HA-13–263-Fdc, HA-13–263-Fc, or HA-13–263-Fd-His vaccination groups and HA-13–263-His group or PBS control for both VN/1194 and SZ/406H viruses. The dotted line shows the limit of detection.
Mentions: Further evaluation of the neutralizing activity of these proteins in vaccinated mouse sera revealed that all HA-13–263 proteins with Fd and/or Fc were able to induce a significantly higher level of neutralizing antibodies than HA-13–263-His against homologous (AH-HA) and heterologous (HK-HA and 1194-HA) H5N1 pseudoviruses. Specifically, HA-13–263-Fdc and HA-13–263-His induced the highest and lowest neutralizing antibody responses, respectively, against all three H5N1 strains, while HA-13–263-Fc elicited a significantly higher level of neutralizing antibodies than HA-13–263-Fd-His. However, PBS control did not induce neutralizing antibodies against any tested pseudoviruses (Fig. 7A).

Bottom Line: Consequently, the design of an effective and safe anti-H5N1 vaccine is essential.We then constructed three additional recombinants fused with Fd plus His tag (HA-13-263-Fd-His), Fc only (HA-13-263-Fc), and His tag only (HA-13-263-His), respectively.These results suggest that the oligomeric form of the CND containing the RBD can be further developed as an effective and safe vaccine for cross-protection against divergent strains of H5N1 viruses.

View Article: PubMed Central - PubMed

Affiliation: Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America.

ABSTRACT
The highly pathogenic avian influenza (HPAI) H5N1 viruses, especially the laboratory-generated H5N1 mutants, have demonstrated the potential to cross the species barrier and infect mammals and humans. Consequently, the design of an effective and safe anti-H5N1 vaccine is essential. We previously demonstrated that the full-length hemagglutinin 1 (HA1) could induce significant neutralizing antibody response and protection. Here, we intended to identify the critical neutralizing domain (CND) in an optimal conformation that can elicit strong cross-neutralizing antibodies and protection against divergent H5N1 strains. We thus constructed six recombinant proteins covering different regions of HA1 of A/Anhui/1/2005(H5N1), each of which was fused with foldon (Fd) and Fc of human IgG. We found that the critical fragment fused with Fd/Fc (HA-13-263-Fdc, H5 numbering) that could elicit the strongest neutralizing antibody response is located in the N-terminal region of HA1 (residues 13-263), which covers the receptor-binding domain (RBD, residues 112-263). We then constructed three additional recombinants fused with Fd plus His tag (HA-13-263-Fd-His), Fc only (HA-13-263-Fc), and His tag only (HA-13-263-His), respectively. We found that the HA-13-263-Fdc, which formed an oligomeric conformation, induced the strongest neutralizing antibody response and cross-protection against challenges of two tested H5N1 virus strains covering clade 1: A/VietNam/1194/2004 (VN/1194) or clade 2.3.4: A/Shenzhen/406H/06 (SZ/406H), while HA-13-263-Fc dimer and HA-13-263-Fd-His trimer elicited higher neutralizing antibody response and protection than HA-13-263-His monomer. These results suggest that the oligomeric form of the CND containing the RBD can be further developed as an effective and safe vaccine for cross-protection against divergent strains of H5N1 viruses.

Show MeSH
Related in: MedlinePlus