目的 诺如病毒(norovirus,NoV)是导致人类急性胃肠炎的主要病原体之一,目前仍没有获批上市的NoV疫苗,开发安全有效且便于推广的NoV疫苗具有重要意义.本研究基于乳酸菌表达系统构建在体外表达G Ⅱ.2型人诺如病毒(human norovirus,HuNoV)主要衣壳蛋白(viral protein 1,VP1)的重组乳酸乳球菌,并评价其诱导机体产生黏膜免疫和体液免疫的能力.方法 将HuNoV G Ⅱ.2型VP1基因片段无缝克隆至乳酸菌表达系统中,体外诱导表达目的蛋白VP1,并通过正交试验优化蛋白表达条件.对小鼠进行口服免疫后通过ELISA方法测定其血清和组织中的免疫因子水平.结果 构建了一株针对HuNoV G Ⅱ.2型的新型重组乳酸乳球菌疫苗,口服免疫后可诱导小鼠产生NoV特异性IgG和IgA,并诱导产生黏膜免疫系统的主要效应分子sIgA.结论 本研究构建的口服乳酸菌疫苗能够诱导小鼠产生针对NoV的先天性和获得性免疫,并产生对应的免疫分子.与被广泛用于研究的病毒样颗粒(virus-like particle,VLP)疫苗相比,此口服疫苗还具有制备快捷、成本更低、运输方便的优势.
Preparation and immunogenicity evaluation of a recombinant lactic acid bacterium vaccine against human norovirus
Objective Norovirus(NoV)is a major pathogen responsible for acute gastroenteritis in humans.Currently,there is no approved vaccines or therapeutic drugs for NoV,making the development of a safe,effective,and easily deployable NoV vaccine imperative.This study aimed to construct a recombinant Lactococcus lactis expressing the major capsid protein VP1 of G Ⅱ.2 human norovirus(HuNoV)using the nisin-controlled gene expression system and to evaluate its ability to induce mucosal and humoral immune responses.Methods The VP1 gene fragment of GⅡ.2 HuNoV was seamlessly cloned into the Lactococcus lactis expression system.The target protein VP1 was induced for expression in vitro.The protein expression conditions were optimized through orthogonal experiments.After oral immunization of mice,the levels of immune factors in serum and tissues were measured by ELISA.Results A novel recombinant Lactococcus lactis oral vaccine targeting G Ⅱ.2 HuNoV was constructed.Following oral immunization,the vaccine induced the production of NoV-specific IgG and IgA in the host and stimulated the production of the main effector molecule sIgA in the mucosal immune system.Conclusions The oral Lactococcus lactis vaccine constructed in this study is capable of eliciting both innate and acquired immunity against NoV,generating corresponding immune molecules.In addition to its ease of preparation,lower cost and convenient transportation,this oral vaccine holds advantages over virus-like particle(VLP)vaccines widely used in research.
Human norovirusOral vaccineLactic acid bacteriaVP1
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