Innate Immune Responses to Pro-Apoptotic BCG

摘要 目前的结核病疫苗，卡介苗(BCG)，对肺部传染性结核病的保护不足。几个研究小组正在试图制造更有效的结核病疫苗。在过去的几年里，最有希望的技术被AERAS全球结核病疫苗基金会(www.Aeras.org)获得，该基金会是一个由该法案支持的非营利性基金会 和梅琳达·盖茨基金会。AERS计划在10年内开发、测试、制造和分发至少一种新的结核病疫苗，并支持Prime-Boost策略，即在出生时给予表现出增强免疫原性的转基因卡介苗，然后在14周时给予异种亚单位增强。卡介苗起源于牛分枝杆菌的一种强毒株，它保留了牛分枝杆菌的许多免疫逃避特征。 致命的分枝杆菌。我们已经对卡介苗进行了改造，以减少其介导免疫逃避的酶的产生和分泌。这种名为促凋亡卡介苗(PaBCG)的改良疫苗比卡介苗对小鼠具有更强的保护作用，并能诱导更强的CD4+和CD8+T细胞反应。AERAS已经获得了这项技术的许可，目前正在构建GMP版本的疫苗，可能会与其他技术相结合。AERAS拥有疫苗生产设施，每年可生产1.5亿剂疫苗。在目前的应用中，构建paBCG(DK和MB)的研究人员加入了他们机构在抗原提呈细胞和淋巴细胞(JT和SK)方面的专业知识的同事的行列。我们建议探索导致增强T细胞反应和保护的先天免疫反应。具体目标是： 1.比较卡介苗和paBCG对人单核细胞感染的免疫应答 2.比较卡介苗和paBCG免疫小鼠后的NK细胞应答、细胞因子极化和体内基因表达 3.检测表达布氏杆菌鲁马津合成酶(BLS)的4dBCG疫苗诱导的BLS特异性T细胞应答 总而言之，paBCG疫苗技术是在SERCEB成员机构开发的，并有望成为取代当前BCG疫苗的可交付产品的一部分。该项目将探索与抗原呈递相关的细胞信号机制，以更好地了解与卡介苗相比，在paBCG接种期间暴露出来的免疫反应。这将有助于设计针对其他疾病的疫苗 在设计针对早期宿主反应的佐剂策略方面，我们的研究重点是细胞内的细菌病原体。

Abstract The current vaccine against tuberculosis, Bacillus Calmette Guerin (BCG), provides inadequate protection against the pulmonary, contagious form of TB. Several groups of investigators are trying to make a more effective TB vaccine ¿ in the past couple of years the most promising technologies have been acquired by the Aeras Global TB Vaccine Foundation (www.aeras.org), a not-for-profit foundation supported by the Bill and Melinda Gates Foundation. Aeras plans to develop, test, manufacture and distribute at least one new TB vaccine within 10 years and favors a prime-boost strategy in which a genetically-modified BCG exhibiting enhanced immunogenicity is given at birth followed by a heterologous subunit boost at 14 weeks. BCG originated from a virulent strain of M. bovis and retains many of the immune-evasive characteristics of virulent mycobacteria. We have modified BCG to reduce its production and secretion of enzymes that mediate immune evasion. The modified vaccine, called ¿pro-apoptotic BCG¿ (paBCG), is more protective than BCG as a vaccine in mice and induces stronger CD4+ and CD8+ T-cell responses. Aeras has licensed this technology and is currently constructing a GMP version of the vaccine, possibly in combination with other technologies. Aeras has a vaccine production facility with capacity to make 150 million doses annually. In the current application, the investigators who built paBCG (DK and MB) have joined colleagues from their institutions with expertise in antigen-presenting cells and lymphocytes (JT and SK). We propose to explore the innate immune responses that lead to enhanced T-cell responses and protection. The specific aims are: 1. To compare the immune response of human monocytes to infection with BCG and paBCG 2. To compare NK cell responses, cytokine polarization, and in vivo gene expression in mice after vaccination with BCG and paBCG 3. To determine BLS-specific T cell responses induced by vaccination with 4dBCG expressing recombinant Brucella lumazine synthase (BLS) from Brucella abortus (Vanderbilt) In summary, the paBCG vaccine technology was developed in SERCEB-member institutions and is poised to be part of a ¿deliverable¿ that replaces the current BCG vaccine. This project will explore cell signaling mechanisms associated with antigen presentation to better understand the immune responses unmasked during vaccination with paBCG compared to BCG. This will help in designing vaccines against other intracellular bacterial pathogens and in designing adjuvant strategies to target the early host response.