SALMONELLA VACCINES THAT DELIVER BOTH ANTIGEN & CYTOKINE

沙门氏菌的减毒菌株已被用作异源微生物的载体。 用于人类和动物疫苗接种的抗原。在小鼠中，S.鼠伤寒通常 感染肠道派伊尔集合淋巴结中的巨噬细胞， 肝脏和脾脏我们将比较小鼠口服的免疫反应- 接种S.表达两种模型抗原之一的鼠伤寒沙门氏菌： (l)猴免疫缺陷病毒gag蛋白（SIV gag）和（2）B 志贺样毒素I型（SLT-I）和SLT-II的亚基来自 肠出血性大肠杆菌杆菌其中一种菌株，旨在增强 对抗原的细胞免疫应答，将递送编码IL-1的DNA 2细胞因子和SIV gag蛋白直接进入巨噬细胞， 适当地转录、翻译和加工这些蛋白质。做 因此，沙门氏菌菌株将包含两组原核基因， 在严格调节的启动子下，吞噬后将1）释放 从吞噬体进入巨噬细胞的细胞质， 然后2）裂解细菌，从而释放原核/真核 穿梭载体携带细胞因子和病毒DNA进入细胞质， 巨噬细胞那些感染了沙门氏菌的巨噬细胞 将处理抗原并共表达特异性细胞因子， 有针对性的增强免疫反应另一 设计用于增强粘膜免疫的菌株将共表达IL-5， 增加slgA产生的细胞因子，连同抗肿瘤保护因子， 抗原最后，我们将使用沙门氏菌疫苗系统来评估 对异源抗原产生的T细胞应答类型， 通过疫苗株直接递送至抗原的细胞质 呈递细胞这些研究结果可直接应用于 生产有效的疫苗，可以特异性地调节 免疫系统产生针对细胞内和 细胞外病原体

Attenuated strains of Salmonella have been used as carriers of heterologous antigens for human and animal vaccination. in mice, S. typhimurium normally infects macrophages in the Peyer's patches of the gut and also cells of the liver and the spleen. We will compare the immune response of mice orally- inoculated with S. typhimurium which expresses one of two model antigens: (l) Simian immunodeficiency virus gag protein (SIV gag) and (2) the B subunits of Shiga-like toxin type l (SLT-l) and SLT-ll from Enterohemorragic E. coli. One of these strains, designed to enhance a cellular immune response to an antigen, will deliver DNA encoding the IL-1 2 cytokine and the SIV gag protein directly to macrophages which will then appropriately transcribe, translate, and process these proteins. To do this, the Salmonella strain will contain two sets of prokaryotic genes under a tightly regulated promoter that after phagocytosis will 1) liberate the bacteria from the phagosome into the cytoplasm of a macrophage, and then 2) lyse the bacterium thereby releasing a prokaryotic/eukaryotic shuttle vector carrying cytokine and viral DNA into the cytoplasm of the macrophage. Those macrophages infected with the Salmonella carrier strains will process the antigen and co-express specific cytokines thus resulting in a targeted and specific enhanced immune response. One of the other strains, designed to augment a mucosal immunity, will co-express IL-5, a cytokine that augments slgA production, together with the SLT protective antigens. finally, we will use the Salmonella vaccine system to evaluate the type of T cell response generated to a heterologous antigen that is delivered via a vaccine strain directly to the cytoplasm of an antigen presenting cell. The results from these studies have direct application to the production of effective vaccines that can specifically modulate the immune system to develop a protective response against intracellular and extracellular pathogens.