Development of Salmonella vaccines for breast cancer and viruses

癌症疫苗被认为是治疗性的（治疗现有的癌症）或预防性的（防止癌症在健康人中发展）。我们的目标是开发一种治疗乳腺癌的疫苗。乳腺癌转移，当原始肿瘤的细胞扩散到其他器官时，通常会导致患者死亡。这种疫苗将刺激免疫系统发现并摧毁转移细胞。这个项目是与俄克拉荷马州医学研究基金会的Alana Welm博士合作的。Welm博士有几种不同的小鼠体内转移模型，包括一种将人类肿瘤移植到小鼠体内并继续复制与患者相同的转移的模型。我们正在开发一种新的重组减毒沙门氏菌疫苗（RASV）的这个项目。为了测试RASV毒株的功能，在将它们改造为癌症疫苗之前，我们将首先在病毒感染模型中测试它们。拉沙病毒是一种BSL 4级人类病原体，在西非引起严重的发病率和感染。接种疫苗是预防人类疾病的有效方法，但它对环境中病毒的数量几乎没有影响，因为这种人畜共患疾病的天然宿主是啮齿动物，Mastomys natalensis，它在拉沙流行地区普遍存在且高度寄生。作为控制该疾病的人畜共患传播的一种方法，我们将开发一种RASV，以质粒的形式将DNA疫苗递送到Mastomys natalensis中。在过去的两年里，我们一直专注于设计和制造新的RASV菌株。这涉及在沙门氏菌血清型鼠伤寒沙门氏菌（Salmonella Typhimurium）中引入多个减毒突变，这必须依次进行，使得其成为相当费力的过程。我们现在有几个RASV毒株，它们已经被测序并在体外进行了测试，以表明它们可以感染上皮细胞，但在细胞内复制中被减弱，并且能够将重组质粒递送到宿主细胞的胞质溶胶。与我们的合作者凯尔罗森克（病毒学实验室）合作，我们开始在M. natalensis。我们还在寻找优化质粒递送和随后病毒糖蛋白在哺乳动物细胞中表达的方法。

Cancer vaccines are considered either therapeutic (treating an existing cancer) or prophylactic (which prevent cancer from developing in healthy people). Our goal is to develop a therapeutic vaccine for breast cancer. Breast cancer metastasis, when cells from the original tumor spread to other organs, is what usually kills patients. This vaccine would stimulate the immune system to discover and destroy metastatic cells. This project is a collaboration with Dr Alana Welm at the Oklahoma Medical Research Foundation. Dr Welm has several different in vivo models for metastasis in mice, including a model where human tumors can be transplanted into mice and go on to reproduce the same metastasis as seen in the patient. We are developing a novel recombinant attenuated Salmonella vaccine (RASV) for this project. In order to test the functionality of the RASV strains, before adapting them as cancer vaccines, we will first test them in a viral infection model. Lassa virus is an BSL4 level human pathogen that causes significant morbidity and infection in West Africa. Vaccination is an effective way to prevent disease in humans but it has little to no effect on the amount of virus in the environment since the natural host of this zoonotic disease is a rodent, Mastomys natalensis, which is ubiquitous and highly commensal in Lassa endemic areas. As a way to control zoonotic spread of the disease we will develop an RASV to deliver a DNA-vaccine, in the form of a plasmid, into Mastomys natalensis. For the last two years we have focused on designing and making novel RASV strains. This involves introducing multiple attenuating mutations in Salmonella enterica serovar Typhmurium (Salmonella Typhimurium), which must be done sequentially making it a rather laborious process. We now have several RASV strains that have been sequenced and have been tested in vitro, to show that they can infect epithelial cells but are attenuated in intracellular replication and able to deliver the recombinant plasmid to the cytosol of the host cell. Working with our collaborator Kyle Rosenke (Laboratory of Virology) we are starting to test a Lassa RASV in M. natalensis. We are also looking at ways to optimize delivery of the plasmid and subsequent expression of the viral glycoprotein in mammalian cells.