title: Immunogenicity of recombinant HBsAg/HCV particles in mice pre-immunised with hepatitis B virus-specific vaccine.
abstract: Due to their spatial structure virus-like particles (VLPs) generally induce effective immune responses. VLPs derived from the small envelope protein (HBsAg-S) of hepatitis B virus (HBV) comprise the HBV vaccine. Modified HBsAs-S VLPs, carrying the immunodominant hypervariable region (HVR1) of the hepatitis C virus (HCV) envelope protein E2 within the exposed 'a'-determinant region (HBsAg/HVR1-VLPs), elicited HVR1-specific antibodies in mice. A high percentage of the human population is positive for anti-HBsAg antibodies (anti-HBs), either through vaccination or natural infection. We, therefore, determined if pre-existing anti-HBs could influence immunisation with modified VLPs. Mice were immunised with a commercial HBV vaccine, monitored to ensure an anti-HBs response, then immunised with HBsAg/HVR1-VLPs. The resulting anti-HVR1 antibody titre was similar in mice with or without pre-existing anti-HBs. This suggests that HBsAg/HVR1-VLPs induce a primary immune response to HVR1 in anti-HBs positive mice and, hence, they may be used successfully in individuals already immunised with the HBV vaccine.
authors.affiliation: Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Herston, QLD 4029, Australia. hans.netter@med.monash.edu.au
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Netter
authors.forename: Wai-Ping
authors.initials: WP
authors.lastname: Woo
authors.forename: Robert
authors.initials: R
authors.lastname: Tindle
authors.forename: Roderick I
authors.initials: RI
authors.lastname: Macfarlan
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Gowans
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D000939:Epitopes; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000235:genetics / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D007114:Immunization; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000939:Epitopes; C400562:HVR1 protein, Hepatitis C virus; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D018937:Hepatitis C Antibodies; D014614:Vaccines, Synthetic; D014764:Viral Proteins