title: Characterization of immune responses induced by immunization with the HA DNA vaccines of two antigenically distinctive H5N1 HPAIV isolates.
abstract: The evolution of the H5N1 highly pathogenic avian influenza virus (HPAIV) has resulted in high sequence variations and diverse antigenic properties in circulating viral isolates. We investigated immune responses induced by HA DNA vaccines of two contemporary H5N1 HPAIV isolates, A/bar-headed goose/Qinghai/3/2005 (QH) and A/chicken/Shanxi/2/2006 (SX) respectively, against the homologous as well as the heterologous virus isolate for comparison. Characterization of antibody responses induced by immunization with QH-HA and SX-HA DNA vaccines showed that the two isolates are antigenically distinctive. Interestingly, after immunization with the QH-HA DNA vaccine, subsequent boosting with the SX-HA DNA vaccine significantly augmented antibody responses against the QH isolate but only induced low levels of antibody responses against the SX isolate. Conversely, after immunization with the SX-HA DNA vaccine, subsequent boosting with the QH-HA DNA vaccine significantly augmented antibody responses against the SX isolate but only induced low levels of antibody responses against the QH isolate. In contrast to the antibody responses, cross-reactive T cell responses are readily detected between these two isolates at similar levels. These results indicate the existence of original antigenic sin (OAS) between concurrently circulating H5N1 HPAIV strains, which may need to be taken into consideration in vaccine development against the potential H5N1 HPAIV pandemic.
authors.affiliation: National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Gao
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Wen
authors.forename: Ke
authors.initials: K
authors.lastname: Dong
authors.forename: Gongxun
authors.initials: G
authors.lastname: Zhong
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wang
authors.forename: Zhigao
authors.initials: Z
authors.lastname: Bu
authors.forename: Hualan
authors.initials: H
authors.lastname: Chen
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.forename: Chinglai
authors.initials: C
authors.lastname: Yang
mesh_terms: D056704:Adaptive Immunity; D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D002645:Chickens; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology; D005260:Female; D005777:Geese; D006367:HeLa Cells; D006389:Hemagglutinins, Viral / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D013601:T-Lymphocytes / Q000276:immunology; D014611:Vaccination; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte; D006389:Hemagglutinins, Viral; D007252:Influenza Vaccines; D019444:Vaccines, DNA