초록 ▼

○ 연구결과
- 본 연구에서는 기존의 DNA 백신의 효능을 향상시키고자 NDV helper T cell epitope, 사이토카인 또는 CpG adjuvant 등의 면역증강효능을 확인 하였다.
- NDV helper T cell epitope 발현 H9N2 AI DNA 백신의 NDV 생독백신 접종계에서의 면역증강 효과를 입증하였다.
- FACs 분석기법을 이용한 닭의 세포성 면역분석법과 real-time PCR을 이용한 닭사이토카인 발현 유전자 정량분석법을 확립하였다.
- T 세포 억제제인 cyclosporin

○ 연구결과
- 본 연구에서는 기존의 DNA 백신의 효능을 향상시키고자 NDV helper T cell epitope, 사이토카인 또는 CpG adjuvant 등의 면역증강효능을 확인 하였다.
- NDV helper T cell epitope 발현 H9N2 AI DNA 백신의 NDV 생독백신 접종계에서의 면역증강 효과를 입증하였다.
- FACs 분석기법을 이용한 닭의 세포성 면역분석법과 real-time PCR을 이용한 닭사이토카인 발현 유전자 정량분석법을 확립하였다.
- T 세포 억제제인 cyclosporin 처리한 시험계를 이용하여 H9N2 LPAI 바이러스의 병원성이 증강되는 원인을 규명하였다.
- H5N2 AI DNA 백신으로 기초백신 (priming)을 한 시험계를 이용하여 H5N2 사독오일 백신의 면역증강 (boosting) 효과를 입증하였다.

Abstract ▼

We surveyed avian influenza (AI) activity in migratory birds in their habitats and in a live bird markets (LBMs) in Korea during winter season in 2003-2007 and September 2006-March 2007, respectively. To identify the possible source of the infection, avian influenza viruses (AIVs) isolated from dome

We surveyed avian influenza (AI) activity in migratory birds in their habitats and in a live bird markets (LBMs) in Korea during winter season in 2003-2007 and September 2006-March 2007, respectively. To identify the possible source of the infection, avian influenza viruses (AIVs) isolated from domestic chicken and duck farms were also genetically characterized. Ninety-five AIVs were isolated from total 7093 fecal specimens of migrating birds, and 28 avian influenza viruses were isolated from total 648 tissues or oropharyngeal swab samples of domestic poultry in LBM during the study. Eleven HA subtypes of AIV (H1 to H12 except H8) were isolated from migratory birds and four HA subtypes of AIV (H9N2, H3N2, H3N8 and H6N2) were isolated from domestic poultry in LBMs. Most recent H9N2 viruses isolated from terrestrial poultry in Korea have low affinity with horse erythrocytes (which exclusively display 2,3-linked SA) and one H9N2 virus isolated from LBMs and the H7N8 virus isolated from migratory birds could replicate in chickens, turkeys as well as BALB/c mice. The isolation of H7N8 from migratory birds raises concern about reservoirs of potentially pathogenic influenza virus for domestic poultry. The low pathogenic H5 viruses of migratory birds clustered separately with highly pathogenic HA genes of H5N1 viruses. The H9N2 AIV isolated from domestic ducks is related to the AIVs isolated from migratory birds. These results suggest that the reassortment events sufficiently occurred not only in migratory birds habitats but also in the LBMs which supplied birds from the chicken and domestic duck farms.
The pathogenesis of and host immune response to H9N2 low pathogenic avian influenza (LPAI) virus in poultry has not been completely elucidated. Therefore, in present experiment, pathogenesis of and host immune responses to low pathogenic avian influenza H9N2 virus in immunosuppressed chicken model were evaluated by virus shedding, clinical signs, histopathology, FACs analysis and real-time quantitative RT-PCR for cytokine gene expression. We demonstrated that pathogenicity of H9N2 low pathogenic avian influenza (LPAI) virus was more enhanced in cyclosporine A (CsA) treated SPF chickens than cyclophosphamide (CY) - treated or immunocompetent SPF chickens. Furthermore, immune responses to the H9N2 LPAI virus in CsA-treated SPF chickens were determined. The proportion of CD8+ T cells and expression of mRNA for IFN-γ dramatically increased in immunocompetent chickens at 5 days post infection. However, those of CsA-treated chickens significantly decreased. CsA treatment induced increased PI value and mortality (1.225 PI value and 25% mortality) as well as significantly increased virus shedding after infection. These results suggest that T cells and T-cell-mediated responses may be important in viral clearance and promoting recovery from H9N2 LPAI virus infection. Our data provide insights into the molecular interaction of this virus, candidate for pandemic influenza, with immunocomprimised human by immunosuppressants.

목차 Contents

• 표지 ... 1
• 제출문 ... 3
• 요약문 ... 4
• SUMMARY ... 6
• CONTENTS ... 9
• 목차 ... 11
• 제1장 연구개발과제의 개요 ... 12
• 제1절 연구개발의 필요성 ... 12
• 제2절 연구개발의 목표 및 내용 ... 18
• 제3절 연구개발 방법 및 설계 ... 23
• 제2장 국내외 기술개발 현황 ... 27
• 제1절 국내.외 관련기술의 현황과 문제점 ... 27
• 제2절 앞으로의 전망 ... 28
• 제3장 연구개발수행 내용 및 결과 ... 30
• 제1절 저병원성 조류인플루엔자 바이러스의 H9 항원을 효과적으로 발현하고 전달하는 재조합 DNA 백신 및 subunit 백신의 개발 ... 30
• 제2절 DNA 백신의 효능을 향상시키는 사이토카인, 콜레라톡신 및 CpG adjuvant의 개발 ... 37
• 제3절 저병원성 조류인플루엔자 바이러스의 병원성을 증대시키는 cofactor의 확인을 통한 새로운 질병방제기법의 개발 ... 44
• 제4절 고병원성 조류인플루엔자 바이러스의 H5 항원을 효과적으로 발현 하고 전달하는 재조합 DNA 백신 및 subunit 백신의 개발 ... 63
• 제4장 목표달성도 및 관련분야에의 기여도 ... 82
• 제5장 연구개발결과의 활용계획 ... 83
• 제6장 연구개발과정에서 수집한 해외과학기술정보 ... 84
• 제7장 참고문헌 ... 85
• 끝페이지 ... 87