title: Identification of vaccinia virus epitope-specific HLA-A*0201-restricted T cells and comparative analysis of smallpox vaccines.
abstract: Despite worldwide eradication of naturally occurring variola virus, smallpox remains a potential threat to both civilian and military populations. New, safe smallpox vaccines are being developed, and there is an urgent need for methods to evaluate vaccine efficacy after immunization. Here we report the identification of an immunodominant HLA-A*0201-restricted epitope that is recognized by cytotoxic CD8(+) T cells and conserved among Orthopoxvirus species including variola virus. This finding has permitted analysis and monitoring of epitope-specific T cell responses after immunization and demonstration of the identified T cell specificity in an A*0201-positive human donor. Vaccination of transgenic mice allowed us to compare the immunogenicity of several vaccinia viruses including highly attenuated, replication-deficient modified vaccinia virus Ankara (MVA). MVA vaccines elicited levels of CD8(+) T cell responses that were comparable to those induced by the replication-competent vaccinia virus strains. Finally, we demonstrate that MVA vaccination is fully protective against a lethal respiratory challenge with virulent vaccinia virus strain Western Reserve. Our data provide a basis to rationally estimate immunogenicity of safe, second-generation poxvirus vaccines and suggest that MVA may be a suitable candidate.
authors.affiliation: GSF-Institut für Molekulare Virologie, Institut für Virologie, Technische Universität München (TUM), Trogerstrasse 4 b, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Drexler
authors.forename: Caroline
authors.initials: C
authors.lastname: Staib
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kastenmuller
authors.forename: Stefan
authors.initials: S
authors.lastname: Stevanović
authors.forename: Burkhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: François A
authors.initials: FA
authors.lastname: Lemonnier
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Rammensee
authors.forename: Dirk H
authors.initials: DH
authors.lastname: Busch
authors.forename: Helga
authors.initials: H
authors.lastname: Bernhard
authors.forename: Volker
authors.initials: V
authors.lastname: Erfle
authors.forename: Gerd
authors.initials: G
authors.lastname: Sutter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000032:analysis; D000939:Epitopes / Q000276:immunology; D015234:HLA-A Antigens / Q000276:immunology*; D015789:HLA-A2 Antigen; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D023421:Models, Animal; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012900:Smallpox Vaccine / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology; D014616:Vaccinia virus / Q000276:immunology*
chemical_list: D016207:Cytokines; D000939:Epitopes; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D012900:Smallpox Vaccine