폐렴구균 DNA 백신의 면역병리학적 측면에서의 안전성 평가

Evaluation of Safety of Streptococcus pneumoniae DNA Vaccine in Immunopathological Aspect

We have previously reported the minimum criteria that can be applied to evaluate efficacy and safety of a DNA vaccine with use of Streptococcus pneumoniae DNA vaccne (SPDNA). The SPDNA was formulated by inserting the DAN sequences that are codons specific for the carbohydrate epitope in the capsule of S. penumoniae by phage display peptide library. Administration of the SPDNA into mice induced both humoral and cell-mediated immunities. The induction was protective even in the absence of CD4+ T lymphocyte in mice. Profiles of cytokine and isotyping of antibody displayed tendency of the Th1. In continuation of these studies, we examined if the efficacy of the SPNDA was provoked by the peptide recognized by codons specific for the capsule. Results showed that the peptide vaccine formulae (SPP) induced protective antibody in mice as did the SPDNA. Involvement of the cell-mediated immunity was also determined. Possible side effects of autoimmune diseases such as myositis and C3a production and tumor-formation were undetectable in mice given 7 times of SPDAN vaccination during entire of 92 days. Even after the frequent immunization, immunogenicity of the SPDNA was observed as determined for antibody production, suggesting that there was no immunotolerance provoked. All together, these examining factors would be applied to measurement of DNA vaccine safety regarding the immunopathological aspect.