title: An hsp70 fusion protein vaccine potentiates the immune response against Japanese encephalitis virus.
abstract: To evaluate the possibility of developing an effective subunit vaccine against Japanese encephalitis virus (JEV), mice were intraperitoneally immunized with either a neutralizing epitope (a 27-amino-acid region of the JEV E protein), or with a fusion protein between this region and a Mycobacterium tuberculosis hsp70. Both antigens were heterologously expressed in Escherichia coli as fusion proteins with thioredoxin. The fusion protein antigen elicited a higher titer of anti-thioredoxin-neutralizing epitope antibodies and a stronger proliferation of lymphocytes than did either the neutralizing epitope (irrespective of the presence of mineral oil as an adjuvant), or the conventional JEV SA14-14-2 vaccine. Assays of antibody isotype and IFN-gamma and IL-4 content in post-immunization serum showed that the fusion protein elicited a higher IgG2a titer and higher levels of IFN-gamma suggesting a potentiation of the Th1 immune response. The fusion protein antigen elicited a long-lived immune response, and the antibodies were able to neutralize JEV in vitro more strongly than did those elicited by the JEV SA14-14-2 vaccine. Immunization with the fusion protein generated both humoral and cellular immune responses to JEV, and the fusion protein appeared to be a more efficient protectant than the JEV SA14-14-2 vaccine.
authors.affiliation: Key Laboratory of Animal Disease Diagnosis and Immunology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, PR China.
authors.forename: F-F
authors.initials: FF
authors.lastname: Ge
authors.forename: Y-F
authors.initials: YF
authors.lastname: Qiu
authors.forename: Y-W
authors.initials: YW
authors.lastname: Yang
authors.forename: P-Y
authors.initials: PY
authors.lastname: Chen
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000235:genetics; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000008:administration & dosage / Q000235:genetics; D001426:Bacterial Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D004664:Encephalitis Virus, Japanese / Q000235:genetics / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000276:immunology* / Q000517:prevention & control*; D000939:Epitopes / Q000008:administration & dosage / Q000235:genetics; D018840:HSP70 Heat-Shock Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000097:blood; D007274:Injections, Intraperitoneal; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D000956:Antigens, Viral; D001426:Bacterial Proteins; D016207:Cytokines; D000939:Epitopes; D018840:HSP70 Heat-Shock Proteins; C444642:HSP70 protein, Mycobacterium tuberculosis; D007074:Immunoglobulin G; D022321:Japanese Encephalitis Vaccines; D011993:Recombinant Fusion Proteins; D022223:Vaccines, Subunit