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Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity
Published on: June 25, 2015
DNA immunization followed by a viral vector booster in a Chlamydia pneumoniae mouse model
Tuula Penttilä1, Anne Tammiruusu, Peter Liljeström
1Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland. tuula.penttila@ktl.fi
Abstract:
Vaccination against Chlamydia pneumoniae would be a beneficial strategy for either preventing or controlling infection by this human respiratory pathogen that also causes persistent infections. In the present study, we used recombinant Semliki Forest virus (rSFV) particles for delivering C. pneumoniae antigens major outer membrane protein (MOMP) or outer membrane protein 2 (Omp2) to the mice or applied the prime-boost technique, where mice were first primed with naked DNA and then boosted with the viral vector coding for the same proteins. Partial protection suggested by the reduced number of cultivable bacteria from the lungs of the challenged mice was seen in mice immunized by either method with MOMP expressing constructs. A significant protection was also achieved after DNA/rSFV immunization with Omp2. DNA priming followed by rSFV boosting induced a more prominent IFN-gamma production after challenge at the site of the infection in pulmonary and mediastinal cells.
Insights
Developing a Chlamydia pneumoniae vaccine is crucial for controlling this respiratory pathogen. Immunization with major outer membrane protein (MOMP) or outer membrane protein 2 (Omp2) via DNA/viral vectors showed protective effects and enhanced immune responses in mice.
Area of Science:
- Immunology
- Microbiology
- Vaccine Development
Background:
- Chlamydia pneumoniae is a significant human respiratory pathogen responsible for persistent infections.
- Effective vaccination strategies are needed for prevention and control of C. pneumoniae infections.
Purpose of the Study:
- To evaluate the efficacy of recombinant Semliki Forest virus (rSFV) vectors delivering C. pneumoniae antigens (MOMP or Omp2) for immunization.
- To assess the prime-boost immunization strategy using DNA priming followed by rSFV boosting.
Main Methods:
- Mice were immunized with rSFV particles expressing MOMP or Omp2, or subjected to a DNA prime/rSFV boost regimen.
- Mice were challenged with C. pneumoniae, and protection was assessed by bacterial load and immune responses.
Main Results:
- Partial protection, indicated by reduced cultivable bacteria, was observed in mice immunized with MOMP constructs.
- Significant protection was achieved with Omp2 via DNA/rSFV immunization.
- DNA/rSFV prime-boost induced enhanced IFN-gamma production in pulmonary and mediastinal cells post-challenge.
Conclusions:
- Both rSFV-mediated immunization and DNA/rSFV prime-boost strategies show promise for C. pneumoniae vaccine development.
- Omp2 antigen delivered via DNA/rSFV prime-boost elicited significant protective immunity and robust cellular immune responses.
- Further research into these immunization methods could lead to effective vaccines against C. pneumoniae infections.
