title: A triclade DNA vaccine designed on the basis of a comprehensive serologic study elicits neutralizing antibody responses against all clades and subclades of highly pathogenic avian influenza H5N1 viruses.
abstract: Because of their rapid evolution, genetic diversity, broad host range, ongoing circulation in birds, and potential human-to-human transmission, H5N1 influenza viruses remain a major global health concern. Their high degree of genetic diversity also poses enormous burdens and uncertainties in developing effective vaccines. To overcome this, we took a new approach, i.e., the development of immunogens based on a comprehensive serologic study. We constructed DNA plasmids encoding codon-optimized hemagglutinin (HA) from 17 representative strains covering all reported clades and subclades of highly pathogenic avian influenza H5N1 viruses. Using DNA plasmids, we generated the corresponding H5N1 pseudotypes and immune sera. We performed an across-the-board pseudotype-based neutralization assay and determined antigenic clusters by cartography. We then designed a triclade DNA vaccine and evaluated its immunogenicity and protection in mice. We report here that (sub)clades 0, 1, 3, 4, 5, 6, 7.1, and 9 were grouped into antigenic cluster 1, (sub)clades 2.1.3.2, 2.3.4, 2.4, 2.5, and 8 were grouped into another antigenic cluster, with subclade 2.2.1 loosely connected to it, and each of subclades 2.3.2.1 and 7.2 was by itself. Importantly, the triclade DNA vaccine encoding HAs of (sub)clades 0, 2.3.2.1, and 7.2 elicited broadly neutralizing antibody responses against all H5 clades and subclades and protected mice against high-lethal-dose heterologous H5N1 challenge. Thus, we conclude that broadly neutralizing antibodies against all H5 clades and subclades can indeed be elicited with immunogens on the basis of a comprehensive serologic study. Further evaluation and optimization of such an approach in ferrets and in humans is warranted.
authors.affiliation: Unit of Anti-Viral Immunity and Genetic Therapy, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhou
authors.forename: Guiqin
authors.initials: G
authors.lastname: Wang
authors.forename: Philippe
authors.initials: P
authors.lastname: Buchy
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Cai
authors.forename: Honglin
authors.initials: H
authors.lastname: Chen
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Chen
authors.forename: Genhong
authors.initials: G
authors.lastname: Cheng
authors.forename: Xiu-Feng
authors.initials: XF
authors.lastname: Wan
authors.forename: Vincent
authors.initials: V
authors.lastname: Deubel
authors.forename: Paul
authors.initials: P
authors.lastname: Zhou
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology*; D002460:Cell Line; D002645:Chickens; D003429:Cross Reactions; D015195:Drug Design; D005260:Female; D005289:Ferrets; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D019444:Vaccines, DNA