Protective immunization against murine cytomegalovirus infection using adenoviruses and poxviruses expressing hepatitis B virus chimeras

Authors

  • Ricardo T. Gazzinelli Department of Biochemistry and Immunology, Institute for Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Institute René Rachou, Fiocruz, Belo Horizonte, MG, Brazil
  • Margarita Del Val National Center for Fundamental Biology, Carlos III Health Institute, Madrid, Spain
  • Oscar Bruna-Romero Department of Microbiology, Institute for Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Institute René Rachou, Fiocruz, Belo Horizonte, MG, Brazil

Keywords:

cytomegalovirus recombinant adenovirus, vaccines, prime-boost immunization, cellular immunity

Abstract

Recombinant adenoviruses, poxviruses, and plasmid DNA vaccines encoding different hepatitis B virus (HBV)/murine cytomegalovirus (MCMV) protein chimeras were used to immunize mice. Processing of the chimeras resulted in presentation of a protective Ld/CD8+ T-cell epitope of the immediate early 1 protein pp89 (IE1 pp89) of MCMV to the immune system. Different levels of immunogenicity were observed depending on: (i) the type of viral vector used, (ii) whether the antigens were included in the cellular secretion pathway, and (iii) the location of the protective epitope within the chimeric protein. An adenovirus expressing a secretory HBV core protein with the MCMV epitope in its C-terminus induced the highest immune response. When the most immunogenic adenovirus and vaccinia virus were used in a heterologous prime-boost immunization protocol, even higher levels of epitope-specific T cells were obtained. Furthermore, responses were protective against a challenge with MCMV, inducing up to a 96% reduction of viral load in immunized animals, as determined by a sensitive real-time PCR assay. Together, these results confirmed previous observations of the efficient use of adenoviral and poxviral vectors in prime-boost protocols for immunization against diseases whose resolution depends on cellular immunity, as well as the aptness of correctly designed chimeric carrier proteins to facilitate this goal. [Int Microbiol 2007; 10(4):261-269]

Author Biographies

Ricardo T. Gazzinelli, Department of Biochemistry and Immunology, Institute for Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Institute René Rachou, Fiocruz, Belo Horizonte, MG, Brazil

Department of Biochemistry and Immunology, Institute for Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Institute René Rachou, Fiocruz, Belo Horizonte, MG, Brazil

Margarita Del Val, National Center for Fundamental Biology, Carlos III Health Institute, Madrid, Spain

National Center for Fundamental Biology, Carlos III Health Institute, Madrid, Spain

Oscar Bruna-Romero, Department of Microbiology, Institute for Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Institute René Rachou, Fiocruz, Belo Horizonte, MG, Brazil

Department of Microbiology, Institute for Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Institute René Rachou, Fiocruz, Belo Horizonte, MG, Brazil

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Published

2010-01-21

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Section

Research Articles