마우스에서 살모넬라 감염증 예방을 위한 신개념 Salmonella Typhimurium 불활화 사균체에 최적 adjuvant 선택을 위한 효능 비교 시험

This study was carried out to examine a novel inactivated Salmonella Typhimurium (S. Typhimurium) vaccine candidate for protection of mice against salmonellosis by immunization of BALB/c mice using various type adjuvant. The novel type-inactivated vaccine candidate was constructed by adding Chlorhexidine digluconate solution. BALB/c mice were divided into 6 groups of 15 mice apiece. The mice were intramuscularly (IM) primed at 6 weeks of age and were IM boosted 8 weeks of age. Groups A and B mice were injected with sterile phosphate-buffered saline as controls; group C mice were inoculated with 5×108 cells/100 μL of formalin-inactivated S. Typhimurium cells and adjuvant ISA70; groups D∼F mice were immunized with 5×108 cells/100 μL of the inactivated vaccine candidate and adjuvant ISA70, adjuvant IMS1313 and adjuvant IMS1313 containing 30 μg/mL of GI24, respectively. All mice (except group A mice) were orally challenged with a virulent S. Typhimurium strain at 10 weeks of age. Mice from groups C-F had significantly increased IgG levels compared to control groups (A-B) mice. The levels of splenocyte IFN-γ and IL-4 in mice of all groups were measured by ELISA, resulting in increased immunity in group F mice compared to those of groups A-E mice. These data suggested that systemic and cell-mediated immune responses were highly induced by IM immunization with the vaccine candidate and adjuvant IMS1313 containing GI24. Furthermore, clinical signs such as death were observed in only 20% of group F mice after virulent Salmonella strain challenge, however, groups B and C (100%), and groups D and E (60%) mice died. This data suggested that mice immunized by intramuscular prime and booster with this vaccine candidate and adjuvant IMS1313 containing GI24 effectively protected mice from salmonellosis.