title: DNA immunization of mice and macaques with plasmids encoding hepatitis C virus envelope E2 protein expressed intracellularly and on the cell surface.
abstract: We analyzed the humoral immune response elicited by hepatitis C virus (HCV) E2 protein expressed in vivo after injection of plasmid DNA into mice and rhesus macaques. Three plasmids were used for immunization: a plasmid containing the entire sequence of the E2 and p7 genes (pE2); a plasmid encoding a truncated form of the E2 protein targeted to the cell surface (pE2surf); a control plasmid (pDisplay) lacking an HCV insert. Each plasmid was injected intramuscularly into 5 mice and intraepidermally (via gene gun) into 5 mice. Immunization was repeated three times at three week intervals. Five macaques were injected intramuscularly (two with pE2, two with pE2surf and one with pDisplay) and immunization was repeated after 8 weeks. All mice immunized via gene gun with pE2 or pE2surf developed anti-E2. The animals immunized with pE2surf developed an earlier and stronger humoral immune response than those immunized with pE2. Only 2 of the mice injected by the intramuscular route, both immunized with pE2surf, developed detectable anti-E2. One of the two macaques immunized with pE2 and both macaques immunized with pE2surf developed anti-E2; the humoral immune response was much stronger in the animals immunized with pE2surf. Our results suggest that presentation of HCV E2 on the cell surface may increase its immunogenicity while preserving its ability to react with antibodies generated during a natural infection.
authors.affiliation: Hepatitis Viruses and Molecular Hepatitis Sections, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0740, USA.
authors.forename: X
authors.initials: X
authors.lastname: Forns
authors.forename: S U
authors.initials: SU
authors.lastname: Emerson
authors.forename: G J
authors.initials: GJ
authors.lastname: Tobin
authors.forename: I K
authors.initials: IK
authors.lastname: Mushahwar
authors.forename: R H
authors.initials: RH
authors.lastname: Purcell
authors.forename: J
authors.initials: J
authors.lastname: Bukh
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D019470:Biolistics; D015153:Blotting, Western; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007273:Injections, Intramuscular; D008251:Macaca; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D014162:Transfection; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C091015:glycoprotein E2, Hepatitis C virus