三种人体带绦虫乳酸脱氢酶基因的结构功能及其在绦、囊虫病防治中的应用研究

Lactate dehydrogenase （LDH）is the terminal enzyme of glycolytic pathway, the reversible reactions of catalyzing acetylformic acid as lactic acid and oxidizing lactic acid as acetylformic acid are important enzymes which affect parasites energy metabolism. The project candidate did early researches and got results as below: LDH of tapeworms had immunogenicity and immunoreactivity, they located at the pellicle of adults and the embryophoric membrane of eggs, and subcellular localization result indicated there were expressions on the cell membrane. Bioinformatics analysis indicated that LDH had three transmembrane domains and they composed channels to run through the inside and outside of cell membranes; a main antigenic epitope which contained key catalytic site located at the outer membrane regions closed to channels. This analysis revealed LDH can directly discharge products of metabolism lactic acid and it was the potential candidate vaccine for tapeworms. For this study, it was based on previous work to improve and perfect the expression levels and tissue localization of LDH to tapeworms at different development stages, so as to understand the energy metabolism effect which played by glycolysis. Then, the LDH structures and physiological functions which could adapt to parasitism of the three kinds of human-carried tapeworms were revealed through the studies of enzymatic characteristics, topological structure, immunological function, etc. Consequently, recombinant bacillus subtilis engineering bacteria of tapeworms LDH were constructed to evaluate the effect and application prospect, so as to clarify the biological significance of LDH to human-carried tapeworms.

乳酸脱氢酶 （lactate dehydrogenase ，LDH）是糖酵解途径的末端酶，催化丙酮酸还原为乳酸及乳酸氧化为丙酮酸的可逆反应，是影响寄生虫能量代谢的重要酶类之一。申请人前期研究结果显示：绦虫LDH具有免疫原性及免疫反应性，定位在成虫表膜和虫卵肧膜上，亚细胞定位揭示在细胞膜上有表达。生物信息学分析绦虫LDH具有三个跨膜区构成贯穿细胞膜内外的通道，一个含有关键催化位点的主要抗原表位位于紧靠通道的膜外区域，揭示LDH可直接排出代谢产物乳酸，是绦虫潜在的候选疫苗。本研究拟在前期工作的基础上，完善对LDH在绦虫发育各期的表达水平及定位研究，以了解糖酵解在绦虫能量代谢中的作用；通过酶学特点、拓扑结构、免疫学功能等的研究，揭示三种绦虫LDH的结构与寄生生活相适应的生理功能；构建绦虫LDH重组枯草芽孢工程菌，评价其免疫保护效果及应用前景，以阐明LDH在人体带绦虫中的生物学意义。

带绦虫是常见的人兽共患寄生虫，人是这三种带绦虫唯一的终宿主，牛和猪是其主要的中间宿主，猪带绦虫（Taenia solium）感染人也可引起后果严重的囊尾蚴病（囊虫病）。我国北部和西部地区是带绦虫病和囊虫病较严重的流行区，尤以滇、黔、桂、川、藏、蒙为甚。研究证实在贵州的都匀地区存在亚洲带绦虫（Taenia asiatica）的流行，从江地区存在牛带绦虫（Taenia saginata）的流行，患者主要是青壮年，对当地的劳动生产危害很大，是严重影响西部欠发达地区社会发展的一个公共卫生问题。针对中间宿主（猪、牛）和终宿主（人）的抗感染疫苗是预防这些寄生虫病的重要策略。.乳酸脱氢酶 （lactate dehydrogenase ，LDH）是糖酵解途径的末端酶，催化丙酮酸还原为乳酸及乳酸氧化为丙酮酸的可逆反应，是影响寄生虫能量代谢的重要酶类之一。申请人前期研究结果显示：绦虫LDH具有免疫原性及免疫反应性，定位在成虫表膜和虫卵肧膜上，亚细胞定位揭示在细胞膜上有表达。生物信息学分析绦虫LDH具有三个跨膜区构成贯穿细胞膜内外的通道，一个含有关键催化位点的主要抗原表位位于紧靠通道的膜外区域，揭示LDH可直接排出代谢产物乳酸，是绦虫潜在的候选疫苗。本研究拟在前期工作的基础上，完善对LDH在绦虫发育各期的表达水平及定位研究，以了解糖酵解在绦虫能量代谢中的作用；通过酶学特点、拓扑结构、免疫学功能等的研究，揭示三种绦虫LDH的结构与寄生生活相适应的生理功能；构建绦虫LDH重组枯草芽孢工程菌，评价其免疫保护效果及应用前景，以阐明LDH在人体带绦虫中的生物学意义。