Human studies of Listeria monocytogenes vectors

描述：（由申请人提供）单核细胞增生李斯特菌为革兰氏阳性 刺激细胞免疫反应的细胞内细菌， 这是消除病毒所必需的。工程湖单核细胞增多症有效 用于在动物中递送病毒和肿瘤抗原的疫苗载体。两 治疗和预防方法在动物中是成功的。李斯特菌 spp.存在于食物中，通过肠道进入人体， 传播引起严重感染，并趋向中枢神经系统 系统和胎盘。因此，安全性是使用L的主要考虑因素。 单核细胞增多症作为人类的载体。我以我所知， 第一个安全性研究的活减毒L.单核细胞增多症载体生物 人类志愿者一种高度减毒的L.单核细胞增生10403S 正在研究删除毒力元件actA和plcB。已经 迄今为止，在18名接受单次给药的志愿者中没有发生严重不良事件。 口服递增剂量的该减毒株（10E5至10E9菌落形成 单位）。该提案提出了一个正在进行的李斯特菌评价计划 细菌作为人类疫苗载体。减毒L.单核细胞增多症将是 经工程改造以表达分泌的确定的甲型流感和HIV Gag表位 鲎溶血素的融合蛋白。将对构建的菌株进行评价 细菌学上，在小鼠和组织培养系统中。有前途的菌株 将在设计的小型住院临床研究中进行评价 评价安全性、散毒和人免疫原性。当代 将使用四聚体、FACS和ELISPOT技术进行免疫学研究， 用于确定离散的人细胞免疫应答是否对载体化的 在这些研究之后，可以在人类中检测到病毒抗原， 免疫接种。这些研究将提供关于可行性的重要数据， 在人类中使用单核细胞增生李斯特菌载体的效用。

DESCRIPTION: (Provided by Applicant) Listeria monocytogenes are Gram-positive intracellular bacteria which stimulate cellular immune responses, those necessary for elimination of viruses. Engineered L. monocytogenes are effective vaccine vectors for delivery of both viral and tumor antigens in animals. Both therapeutic and prophylactic approaches are successful in animals. Listeria spp. Are present in foods, enter the body through the intestine and may disseminate to cause serious infection with a tropism for the central nervous system and placenta. Safety is therefore a major consideration in use of L. monocytogenes as a vector in humans. We have initiated (to our knowledge) the first safety study of a live attenuated L. monocytogenes vector organism in human volunteers. A highly attenuated derivative of L. monocytogenes 10403S deleted for the virulence elements actA and plcB is being studied. There have been no serious adverse events to date in 18 volunteers who received single oral escalating doses of this attenuated strain (10E5 to 10E9 colony forming units). This proposal sets forth a plan for ongoing evaluation of Listeria bacteria as vaccine vectors in humans. Attenuated L. monocytogenes will be engineered to express defined influenza A and HIV Gag epitopes as secreted fusion proteins of listeriolysin. Strains constructed will be evaluated bacteriologically, in mice and in tissue culture systems. Promising strains will be carried on for evaluation in small inpatient clinical studies designed to evaluate safety, shedding and human immunogenicity. Contemporary immunological studies using tetramer, FACS and ELISPOT technologies will be used to determine whether discrete human cellular immune responses to vectored viral antigens can be detected in humans after these investigational immunizations. These studies will provide important data on the feasibility and utility of using Listeria monocytogenes vectors in humans.