title: Rational design of a multiepitope vaccine encoding T-lymphocyte epitopes for treatment of chronic hepatitis B virus infections.
abstract: Protein sequences from multiple hepatitis B virus (HBV) isolates were analyzed for the presence of amino acid motifs characteristic of cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes with the goal of identifying conserved epitopes suitable for use in a therapeutic vaccine. Specifically, sequences bearing HLA-A1, -A2, -A3, -A24, -B7, and -DR supertype binding motifs were identified, synthesized as peptides, and tested for binding to soluble HLA. The immunogenicity of peptides that bound with moderate to high affinity subsequently was assessed using HLA transgenic mice (CTL) and HLA cross-reacting H-2(bxd) (BALB/c x C57BL/6J) mice (HTL). Through this process, 30 CTL and 16 HTL epitopes were selected as a set that would be the most useful for vaccine design, based on epitope conservation among HBV sequences and HLA-based predicted population coverage in diverse ethnic groups. A plasmid DNA-based vaccine encoding the epitopes as a single gene product, with each epitope separated by spacer residues to enhance appropriate epitope processing, was designed. Immunogenicity testing in mice demonstrated the induction of multiple CTL and HTL responses. Furthermore, as a complementary approach, mass spectrometry allowed the identification of correctly processed and major histocompatibility complex-presented epitopes from human cells transfected with the DNA plasmid. A heterologous prime-boost immunization with the plasmid DNA and a recombinant MVA gave further enhancement of the immune responses. Thus, a multiepitope therapeutic vaccine candidate capable of stimulating those cellular immune responses thought to be essential for controlling and clearing HBV infection was successfully designed and evaluated in vitro and in HLA transgenic mice.
authors.affiliation: GENimmune NV (Innogenetics NV), Ghent, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Depla
authors.forename: Annegret
authors.initials: A
authors.lastname: Van der Aa
authors.forename: Brian D
authors.initials: BD
authors.lastname: Livingston
authors.forename: Claire
authors.initials: C
authors.lastname: Crimi
authors.forename: Koen
authors.initials: K
authors.lastname: Allosery
authors.forename: Veronique
authors.initials: V
authors.lastname: De Brabandere
authors.forename: Jonathan
authors.initials: J
authors.lastname: Krakover
authors.forename: Sidharta
authors.initials: S
authors.lastname: Murthy
authors.forename: Manley
authors.initials: M
authors.lastname: Huang
authors.forename: Scott
authors.initials: S
authors.lastname: Power
authors.forename: Lilia
authors.initials: L
authors.lastname: Babé
authors.forename: Carol
authors.initials: C
authors.lastname: Dahlberg
authors.forename: Denise
authors.initials: D
authors.lastname: McKinney
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sette
authors.forename: Scott
authors.initials: S
authors.lastname: Southwood
authors.forename: Ramilla
authors.initials: R
authors.lastname: Philip
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Newman
authors.forename: Lydie
authors.initials: L
authors.lastname: Meheus
mesh_terms: D000818:Animals; D018984:Epitopes, T-Lymphocyte / Q000235:genetics* / Q000276:immunology*; D005260:Female; D017325:Hepatitis B Vaccines / Q000235:genetics* / Q000276:immunology* / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000276:immunology*; D007117:Immunization, Secondary; D007167:Immunotherapy / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010957:Plasmids / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology
chemical_list: D018984:Epitopes, T-Lymphocyte; D017325:Hepatitis B Vaccines; D019444:Vaccines, DNA; D014765:Viral Vaccines