title: Immunization of woodchucks with adjuvanted sHDAg (p24): immune response and outcome following challenge.
abstract: The immunogenicity and the protection induced by an hepatitis delta virus (HDV) vaccine consisting of the small nucleoprotein (HDAg) (p24) and adjuvanted with MF59 or Freund's adjuvant (FA) were evaluated in woodchucks chronically infected with woodchuck hepatitis virus (WHV) and challenged with hepatitis delta virus. Humoral and T-cell-mediated responses to HDAg were measured. Anti-HD antibodies appeared earlier in the FA/p24 animals. After challenge, all MF59/p24 vaccinated animals showed a response to HDAg-derived peptides, compared to two of the five FA/p24 animals and one of the control animals. Serum HDV-RNA peak values and persistence were considerably reduced in immunized animals, in comparison to controls. Furthermore, HDV-RNA was absent in autopsy liver tissues of 50% of the MF59/p24 animals, whereas high levels were present in all of the FA/p24 animals and controls. Histological liver analysis performed before and after challenge revealed the presence of acute hepatitis-like lesions only in the controls. Overall, the results suggest that the MF59/p24 vaccine better controls the infection in terms of viral replication and survival.
authors.affiliation: Laboratory of Virology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Emilio
authors.initials: E
authors.lastname: D'Ugo
authors.forename: Marino
authors.initials: M
authors.lastname: Paroli
authors.forename: Giampiero
authors.initials: G
authors.lastname: Palmieri
authors.forename: Roberto
authors.initials: R
authors.lastname: Giuseppetti
authors.forename: Claudio
authors.initials: C
authors.lastname: Argentini
authors.forename: Elena
authors.initials: E
authors.lastname: Tritarelli
authors.forename: Roberto
authors.initials: R
authors.lastname: Bruni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barnaba
authors.forename: Michael
authors.initials: M
authors.lastname: Houghton
authors.forename: Maria
authors.initials: M
authors.lastname: Rapicetta
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D018963:Hepatitis Antigens / Q000276:immunology*; D006509:Hepatitis B / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000032:analysis / Q000096:biosynthesis; D017919:Hepatitis B Virus, Woodchuck / Q000276:immunology*; D008099:Liver / Q000276:immunology / Q000473:pathology / Q000821:virology; D008392:Marmota / Q000276:immunology*; D012367:RNA, Viral / Q000032:analysis / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D018963:Hepatitis Antigens; D006510:Hepatitis B Antibodies; D012367:RNA, Viral; D014614:Vaccines, Synthetic