豬鏈球菌(Streptococcus suis, S. suis)主要引起豬的腦膜炎、敗血症,亦為一種人畜共通傳染病。溶血素(suilysin , Sly)是豬鏈球菌關鍵的毒力因子,會與細胞膜上膽固醇結合進而穿孔,再與其他毒力因子合作造成細胞裂解。研究指出,Sly在豬鏈球菌感染與炎症反應中起重要作用,低濃度Sly會刺激細胞激素分泌使嗜中性球和巨噬細胞,自然殺手細胞和細胞毒性T細胞的活化,引發TH1和TH2免疫反應,可以作為一種候選佐劑。本研究已成功使用原核系統表現重組Sly蛋白,確認蛋白質產物大小及抗原性,並完成Sly重組蛋白純化,搭配本實驗室已構築重組巴氏桿菌抗原製成疫苗免疫仔豬,利用流式細胞儀測定CD4+與CD8+ T細胞數量、酵素連結免疫分析抗體、Real-time PCR測定細胞激素表現量及攻毒試驗,藉此評估佐劑效力。
Streptococcus suis (S. suis) causes meningitis septicemia of swine and it is also a zoonotic disease. Suilysin (Sly) is an essential virulence factors of streptococcus suis and creates transmembrane pores in cholesterol-containing membranes thereby causing cell lysis. Sly plays an important role in S. suis infection and inflammation. Low concentration sly can stimulate cytokine secretion, neutrophil, macrophage, natural killer cell and cytotoxic T cell, causing TH1 and TH2 immune response as a candidate adjuvant. We have constructed a gene fragment that removes toxicity and confirmed the size and antigenicity of the recombinant sly protein product. The sly recombinant protein has been purified successfully, combined with constructed rPMT-NC, and prepared as vaccine. Piglet were then immunized with the vaccine. We will evaluate adjuvant efficacy by ELISA analysis, and cytokine production by Real-time PCR. We will measure CD4+ and CD8+ T cells percentages by flow cytometry. We will perform challenge tests to evaluate vaccine protection rate.