基于Toll样受体7激动剂的海洛因疫苗构建及其抗海洛因作用研究

Heroin is the most abused drug in China with seriously damaging social consequences. The currently available therapies to treat heroin addiction continue to have many limitations. A vaccine capable of blocking heroin’s effects can provide a long-lasting and sustainable adjunct to heroin addiction therapy. However, most of the reported heroin vaccines produced inadequate antibody titers with poor specificity. In this study, we designed a novel heroin vaccine with a heroin-like hapten, N-aminobutyl-norheroin, conjugated to a carrier of a Toll-like receptor 7 agonist. This design turns heroin hapten into a super antigen and overcome the problems of the large protein carriers producing their own antibodies and affecting the immune recognition of the hapten, thus can dramatically enhance the production of antibodies and their specificities. Moreover, the novel hapten designed in this study is immunochemically dynamic such that multiple haptens are simultaneously presented to the immune system to produce antibodies against heroin, 6-acetylmorphine and morphine. ELISA and Competitive ELISA will be conducted respectively to assess the titers and the selectivity of the antibodies produced by the vaccine. Also, both the antinociceptive effects of heroin and acquisition and reinstatement of heroin self-administration will be evaluated in rats vaccinated using the vaccine.

海洛因是我国流行最广的毒品，危害严重，复吸率极高。现有抗海洛因成瘾疗法存在很多局限。免疫疗法通过接种疫苗，阻断毒品进入中枢发挥作用，在预防复吸方面显示了卓越前景，但现有抗毒疫苗免疫效力弱、特异性差，很难达到临床防复吸效果。本项目拟采用小分子Toll样受体7（TLR7）激动剂为载体，以桥头氮偶联新的海洛因半抗原结构，构建一种动态海洛因疫苗。这一设计属国际首创，TLR7激动剂使海洛因半抗原转化为超级抗原，并克服传统的大分子蛋白载体产生自身抗体、影响半抗原的免疫识别问题，大幅提高疫苗的免疫活性和特异性。同时，特殊半抗原设计和载体连接位点使疫苗能够产生海洛因及其活性代谢物6-乙酰吗啡和吗啡三种抗体，全面且特异性阻断海洛因的作用。在此基础上，采用ELISA和大鼠自身给药模型等对疫苗的免疫活性﹑抗体特异性和抗海洛因作用进行初步评价，以期开发临床经济有效，副作用小的预防复吸，辅助治疗海洛因成瘾的新方法。

海洛因是我国流行最广的毒品，危害严重，复吸率极高。现有抗海洛因成瘾疗法存在很多局限。免疫疗法通过接种疫苗，阻断毒品进入中枢发挥作用，在预防复吸方面显示了卓越前景。本项目采用新型海洛因半抗原结构，利用桥头氮位点偶联Toll样受体7 （TLR7）激动剂，构建抗海洛因疫苗。在此基础上，我们进一步探索了海洛因半抗原偶联多聚赖氨酸（PLL）和Toll样受体7 （TLR7）激动剂的疫苗组成。采用ELISA检测了海洛因疫苗的免疫活性和特异性。动物实验进一步证明，接种疫苗能够阻断海洛因的镇痛作用及海洛因诱导的小鼠条件性位置偏爱。本研究申请国家发明专利2个，已授权1个；发表文章1篇，已投稿文章2篇。培养硕士研究生2名，基本完成了课题申请中的研究任务。 研究合成了新型海洛因半抗原，探索了海洛因半抗原的载体，初步评价了抗海洛因疫苗的免疫活性及其抗海洛因作用，为成功研发新型海洛因疫苗提供了必要的前期准备。