title: Modulation of DNA vaccine-elicited CD8+ T-lymphocyte epitope immunodominance hierarchies.
abstract: Generating broad cellular immune responses against a diversity of viral epitopes is a major goal of current vaccine strategies for human immunodeficiency virus type 1 (HIV-1) and other pathogens. Virus-specific CD8(+) T-lymphocyte responses, however, are often highly focused on a very limited number of immunodominant epitopes. For an HIV-1 vaccine, the breadth of CD8(+) T-lymphocyte responses may prove to be critical as a result of the need to cover a wide diversity of viral isolates in the population and to limit viral escape from dominant epitope-specific T lymphocytes. Here we show that epitope modification strategies can alter CD8(+) T-lymphocyte epitope immunodominance hierarchies elicited by a DNA vaccine in mice. Mice immunized with a DNA vaccine expressing simian immunodeficiency virus Gag lacking the dominant D(b)-restricted AL11 epitope generated a marked and durable augmentation of responses specific for the subdominant D(b)-restricted KV9 epitope. Moreover, anatomic separation strategies and heterologous prime-boost regimens generated codominant responses against both epitopes. These data demonstrate that dominant epitopes can dramatically suppress the immunogenicity of subdominant epitopes in the context of gene-based vaccines and that epitope modification strategies can be utilized to enhance responses to subdominant epitopes.
authors.affiliation: Research East Room 213, Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Liu
authors.forename: Bonnie A
authors.initials: BA
authors.lastname: Ewald
authors.forename: Diana M
authors.initials: DM
authors.lastname: Lynch
authors.forename: Anjali
authors.initials: A
authors.lastname: Nanda
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Sumida
authors.forename: Dan H
authors.initials: DH
authors.lastname: Barouch
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D005260:Female; D015683:Gene Products, gag / Q000276:immunology*; D007111:Immunity, Cellular / Q000235:genetics / Q000276:immunology*; D016056:Immunodominant Epitopes / Q000235:genetics / Q000276:immunology*; D007124:Immunoenzyme Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D018449:SAIDS Vaccines / Q000235:genetics / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology*
chemical_list: D018984:Epitopes, T-Lymphocyte; D015683:Gene Products, gag; D016056:Immunodominant Epitopes; D018449:SAIDS Vaccines