出版年:

研究生:

陳彥伶

研究生(英文姓名):

Yen-Ling Chen

論文名稱:

以沙門氏桿菌攜帶假性狂犬病病毒醣蛋白gp50基因免疫小鼠所引起之免疫反應

英文論文名稱:

The immune responses of mice immunized with live Salmonella carrying the pseudorabies virus gp50 gene

指導教授:

蕭 璦 莉

指導教授(英文姓名):

Ai-Li Shiau

學位類別:

碩士

校院名稱:

國立成功大學　

系所名稱:

微生物暨免疫學研究所

學號:

S46851110

學年度:

87

語文別:

中文

論文頁數:

87

關鍵詞:

沙門氏桿菌 ; 假性狂犬病 ; 病毒醣蛋白 ; 免疫反應 ; 前胸腺激素

英文關鍵詞:

live Salmonella ; pseudorabies virus ;
gp50 gene ; PrV ; Salmonella choleraesuis subsp.choleraesuis

被引用次數:

0

[ 摘要 ]

假性狂犬病( pseudorabies )是由屬於泡疹病毒的假性狂犬病毒( pseudorabies virus PrV )所引起。一般認為PrV之自然宿主為豬，傳播方式以口、鼻直接接觸為主。PrV對哺乳仔豬及離乳幼豬有高熱、呼吸困難、嘔吐、下痢、食慾不振及身軀麻痺、迴旋運動等顯著的中樞神經症狀，死亡率高達100﹪。另外，沙門氏桿菌Salmonella choleraesuis ( S.C. )對豬而言，亦是嚴重致病菌，會引起豬腸胃消化道的疾病，例如豬的副傷寒即是由S.C.所引起，傳播方式與PrV相同，都是以口、鼻直接接觸為主，對本省密集式養豬事業是一大威脅。
在PrV的醣蛋白中，gp50與病毒之穿透力有關，且為病毒複製所必須，並且含有二個可誘發中和抗體的抗原決定區，因此選擇gp50作為研發DNA疫苗的目標。前胸腺激素a ( prothymosin a, ProTa )可促進T細胞之成熟與分化，而有免疫增強效果。本篇論文，選擇減毒的沙門氏桿菌(Salmonella choleraesuis subsp.choleraesuis; S.C.S.C.)為疫苗載體，內載有以真核細胞啟動子調控可表現gp50或ProTa之質體DNA，以小鼠為動物模式，進行免疫反應及保護力的研究。由結果顯示出，以口服方式給予小鼠二次含有gp50基因的重組疫苗載體比只給予一次有較高的存活率。在T細胞增殖方面，經gp50基因重組疫苗載體餵食的小鼠，其脾臟淋巴細胞對PrV有增殖的現象，若加上ProTa基因，則T細胞增殖的現象會提升。小鼠亦產生抗PrV和抗S.C.S.C.抗體。小鼠餵食gp50基因重組疫苗載體後，可誘發PrV特異性CTL毒殺作用。總之本研究給予小鼠攜帶PrV gp50基因之重組疫苗載體可增強其對PrV之抵抗力，而ProTa則沒有明顯免疫增強作用。至於重組疫苗載體的形式、投予途徑、投予劑量及次數、重組基因的有效進入寄主細胞並被表現等方面，則需再進一步探討。

[ 英文摘要 ]

Pseudorabies virus (PrV) is one of the most significant viral pathogens for swine. It causes Aujeszky''s disease, which results in severe, even lethal diseases in young pigs, leading to severe financial losses. An other important pathogen is Salmonella choleraesuis, which causes swine paratyphoid. The PrV gp50 glycoprotein mediates adsorption and penetration of PrV and represents a major target for neutralizing antibodies, which may protect mice and swine from the PrV disease. A plasmid encoding the PrV gp50 glycoprotein was used as a DNA vaccine candidate. Attenuated strains of enteropathogenic species, such as Salmonella, represent useful carriers for the delivery of heterologous recombinant antigens to the immune system for eliciting both mucosal and systemic immunities. In our previous study, vaccination with DNA encoding the PrV gp50 under the control of an eukaryotic promoter confers partial protection to mice against PrV challenge. The gp50 plasmid DNA may be delivered by avirulent E. coli strains. In addition, coexpression of prothymosin a (ProTa) enhances the immunogenicity and efficacy of DNA vaccines. In this study, a variety of expression vectors for PrV gp50 and ProTa were constructed in an attempt to explore the feasibility of using attenuated Salmonella as a DNA delivery vehicle for PrV DNA vaccination. Attenuated Salmonella choleraesuis strains transformed with gp50 or ProTa or both plasmids were used for oral vaccination to mice. To compare the efficacy of these oral vaccine vectors, survival rate, antibody production, splenocyte proliferation, and cytotoic T lymphocytes (CTL) of mice were examined.
The results show that mice orally receiving two doses of the recombinant S.C.S.C. containing the gp50 plasmid were protected from PrV challenge. Mice immunized with recombinant S.C.S.C. carrying the gp50 gene developed anti-PrV and anti-Salmonella antibodies, T-cell proliferation to PrV and gp50-specific cytotoxic T lymphocyte responses. Although ProTa enhanced PrV-specific T-cell responses, it did not increase the efficacy of the recombinant S.C.S.C. carrying the gp50 gene. Taken together, these results demonstrate that the PrV gp50 gene delivered through Salmonella by the oral route may be a feasible approach in the development of pseudorabies vaccines.