Severe Fever with Thrombocytopenia Syndrome (SFTS) is a newly emerging tick-borne disease caused by the SFTS virus (SFTSV), which belongs to the phlebovirus in the Bunyaviridae family. SFTSV is enveloped with a tripartite ambisense RNA genome. The L segment encodes the viral RNA-dependent RNA polymerase, the M segment encodes the two glycoproteins, Gc and Gn, and the S segment encodes the nucleoprotein (NP) and the nonstructural protein (NSs). NP participates in ribonucleoprotein (RNP) packaging and commonly detected early after infection, suggesting that the N protein is possible to be used as a target antigen for early diagnosis of SFTSV infection. In this study, we analyzed a highly immunogenic multi-epitope using GnGc and NP genes from a consensus sequence of SFTSV strain isolated from infected patients in Korea. The selected genes are constructed to the expression vector plasmid pJHL65 and the recombinant plasmid vector was transformed into the Δasd Δlon ΔcpxR Salmonella Typhimurium attenuated strain JOL912 and the expression of these antigens was verified by immunoblotting assay. We observed the significant levels of systemic IgG and mucosal IgM responses against the JOL912-derived antigen in the immunized BALB/c mice. The level of CD3+CD4+, CD3+CD8+ T lymphocyte subpopulation and TNF-α were also highly regulated in splenic T cells re-stimulated in vitro with NP and Gn/Gc multi-epitope selected antigens. Therefore, immunized mice with NP and Gn/GC multi-epitope recombinant proteins of attenuated Salmonella delivery system elicited T cell-related immune response, inducing an effective immune response. In conclusion, the attenuated Salmonella expressing NP-GnGc multi-epitopes could be a novel vaccine candidate against the SFTS virus.

서 론
재료 및 방법
    실험에 사용된 균주, 플라스미드 및 프라이머 정보
    실험동물 및 동물실험 윤리규정
    재조합 항원 발현 플라스미드 및 백신 후보 균주 제작
    동물실험 및 체액성 면역활성 측정
    세포성 면역활성 측정 및 세포생존능 평가
    면역 사이토카인 분석
    중화항체형성능 측정
    통계분석
결 과
    살모넬라 표면 백신 항원 발현 벡터 및 백신 후보 균주제작과 고면역원성 항원 발현
    개발 백신 후보균주의 면역화에 따른 세포성 면역활성평가
    개발 백신 후보균주의 면역화에 따른 체액성 면역활성평가
고 찰
감사의 글
REFERENCES

• John Hwa Lee(Department of Veterinary Public Health, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea) Corresponding author
• Gayeon Won(Department of Veterinary Public Health, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea) Corresponding author
• Jae-Ho Woon(Department of Marine Food Science & Technology, Gangneung-Wonju National University, Gangneung 25457, Korea)
• Ji-Young Park(Department of Veterinary Public Health, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea)