Development of Salmonella vaccines for breast cancer and viruses

癌症疫苗被认为要么是治疗性的(治疗现有的癌症)，要么是预防性的(防止癌症在健康人身上发展)。我们的目标是开发一种乳腺癌治疗性疫苗。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医学研究基金会的阿拉娜·韦尔姆博士合作完成的。韦尔姆博士有几种不同的小鼠转移体内模型，其中包括一个模型，在该模型中，人类肿瘤可以移植到小鼠体内，然后继续复制与患者相同的转移。我们正在为这个项目开发一种新型的重组减毒沙门氏菌疫苗(RASV)。为了测试RASV毒株的功能，在将它们改造成癌症疫苗之前，我们将首先在病毒感染模型中测试它们。拉萨病毒是一种BSL4级人类病原体，在西非造成严重的发病率和感染。接种疫苗是预防人类疾病的一种有效方法，但它对环境中的病毒量几乎没有影响，因为这种人畜共患病的自然宿主是啮齿动物，在拉萨流行区普遍存在，并高度共生。作为一种控制人畜共患传播疾病的方法，我们将开发一种RASV，将DNA疫苗以质粒的形式输送到纳塔尔沼虾中。在过去的两年里，我们一直专注于设计和制造新的RASV毒株。这涉及在鼠伤寒沙门氏菌血清型(鼠伤寒沙门氏菌)中引入多种减毒突变，这必须按顺序进行，使其成为一个相当费力的过程。我们现在有几个RASV毒株已经被测序和体外测试，表明它们可以感染上皮细胞，但在细胞内复制减弱，并能够将重组质粒运送到宿主细胞的胞浆中。与我们的合作者凯尔·罗森克(病毒学实验室)合作，我们开始在纳塔尔分枝杆菌中测试拉萨RASV。我们还在寻找优化质粒递送和随后在哺乳动物细胞中表达病毒糖蛋白的方法。

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.