Testing DNA Vaccine Against T. cruzi in Large Animal Model (Dogs)

摘要 由克氏锥虫引起的原虫恰加斯病是#年年轻人死亡的主要原因。 美洲大陆的流行地区，造成50000人死亡，100万新病例和2.74人损失 每年残疾调整数为100万年。恰加斯病主要是一种人畜共患疾病，狗在这种疾病中流行。 作为主要的寄主和吸血的三甲虫是媒介。导致以下目标的战略 减少库区宿主(犬)的克氏毛滴虫感染率和狗对三聚氰胺的感染力将中断 寄生虫传播，以及人类新感染和疾病病例。 该项目的总体目标是测试由以下成分组成的多组分DNA疫苗的效力 克鲁兹毛滴虫编码ASP-2、TcG1、TcG2和TcG4的基因，以及细胞因子佐剂(即IL-12和GM-CSF- 表达构建体)在抑制寄主和昆虫媒介中的寄生虫发展方面。克氏锥虫 选择疫苗鸡尾酒中包含的基因是因为它们具有诱导抗寄生虫保护的潜在能力 免疫反应。IL-12和GM-CSF作为佐剂用于增强和调节血管内皮细胞生长 保护性1型免疫反应。我们的假设是，对狗进行DNA疫苗免疫将 诱导对克氏锥虫的保护性免疫，从而减轻该宿主感染媒介和 保持传输周期。我们将进行免疫学、寄生虫学和心脏功能和 解剖-组织病理学分析来验证我们的假设有两个特定的目的： 目的1.确定多组分疫苗接种后是否产生抗克氏毛滴虫体液 和犬类宿主的细胞免疫。 目的2.确定DNA疫苗诱导的免疫是否对克氏锥虫的感染具有保护作用 和狗的临床疾病，并减少狗对三聚氰胺的传染性。 拟议的研究将建立一种新的犬类疫苗接种和保护免受T。 克鲁兹病毒感染。这将是阻止克氏锥虫通过DNA传播到昆虫媒介的第一次尝试 免疫接种方法。这些研究将为今后侧重于评估 为狗接种疫苗作为有效控制克氏毛滴虫人兽共患和地方性传播的有效性。被克氏锥虫感染会导致人类查格西克心肌病。狗是最重要的 在维持寄生虫在三叶虫媒介和人类中的传播方面的主要宿主。 这个项目的总体目标是确定给狗接种疫苗是否会减少 狗对昆虫媒介的传染性，从而扰乱传播循环。

SUMMARY The protozoan parasite T. cruzi-induced Chagas disease is the prime cause of death in young adults in endemic areas of the American continent and results in >50,000 deaths, 1 million new cases, and loss of 2.74 million disability-adjusted years per year. Chagas disease is principally a zoonotic disease, in which dogs serve as a principal reservoir host and the blood-sucking triatomine insects are the vectors. Strategies leading to reduction of T. cruzi infection in reservoir host (dogs) and dogs' infectivity to triatomines would interrupt parasite transmission, and human cases of new infection and disease. The overall objective of this project is to test the efficacy of a multi-component DNA vaccine constituted of T. cruzi genes encoding ASP-2, TcG1, TcG2 and TcG4; and cytokine adjuvants (i.e. IL-12- and GM-CSF- expression constructs) in inhibiting parasite development in the reservoir host and the insect vector. T. cruzi genes included in the vaccine cocktail are selected for their potential ability to elicit anti-parasite protective immune responses. IL-12 and GM-CSF are selected as adjuvants for the enhancement and regulation of the protective type 1 immune response. Our hypothesis is that immunization of dogs with DNA vaccines would elicit protective immunity against T. cruzi, and thereby, alleviate the ability of this host to infect the vector and maintain the transmission cycle. We will perform immunological, parasitological, and cardiac functional and anatomo-histopathological analyses to test our hypothesis in two specific aims: Aim 1. To determine whether vaccination with the multi-component vaccine elicits anti- T. cruzi humoral and cellular immunity in the canine host. Aim 2. To determine whether DNA vaccination¿induced immunity provides protection from T. cruzi infection and clinical disease in dogs and reduce dogs' infectivity to triatomines. The proposed studies will establish a novel canine model of vaccination and protection from challenge T. cruzi infection. This will be the first attempt to block transmission of T. cruzi to insect vector through a DNA immunization approach. These studies would provide a basis for future field studies focused on evaluating the usefulness of vaccinating dogs as an effective way to control ezootic and enzoonotic transmission of T. cruzi. Infection by Trypanosoma cruzi causes Chagasic cardiomyopathy in humans. Dogs are the principal reservoir host in maintaing parasite transmission in the triatomine vector and humans. The overall objective of this project is to determine whether vaccination of dogs would reduce the infectivity of dogs to the insect vector, and thereby disrupt the transmission cycle.