EFFECT OF NEONATAL BCG ADMINISTRATION ON INNATE AND ADAPTIVE IMMUNE RESPONSES TO INFECTION WITH ROTAVIRUS LIVE ATTENUATED VACCINE STRAIN IN HIV-EXPOSED AND UNEXPOSED INFANTS

项目摘要 卡介苗是一种有效的先天免疫刺激剂，并已用作癌症治疗的佐剂。BCG有 还显示出改善与TB无关的婴儿发病率和死亡率，并改善婴儿对 在新生儿常规接种卡介苗的国家，然而，流行病学研究表明， 由于它们的设计和/或BCG产品的不同，产生了相互矛盾的结果。在此，我们建议 研究卡介苗的非特异性保护作用，通过调查先天性和适应性免疫反应， 用轮状病毒减毒活疫苗病毒（RoV）感染作为感染的替代物。我们将测量 巴西婴儿的反应，他们在出生后第一周接受BCG治疗（BCG+）， 美国婴儿，谁不接受卡介苗（BCG-）。我们还将探讨BCG的非特异性作用机制， 防止异源感染。我们的研究结果可能为免疫调节提供一个框架， 婴儿的感染发病率和死亡率较高，对疫苗的反应较低， 与年龄较大的儿童和年轻人相比。此外，我们还将研究卡介苗在艾滋病毒- 暴露未感染（HEU）和未接触艾滋病毒（HUU）的婴儿。高浓缩铀的使用量不断增加， 易感染、住院和死亡，并伴有多种先天性和适应性免疫缺陷 与HUU相比，HUU使它们成为增强免疫干预的重要候选者。我们 假设BCG对婴儿异源感染的保护作用是由以下因素介导的： 激活经过训练的先天免疫，控制感染的初始阶段，并支持 强大的适应性免疫反应。这一假设将在以下具体目标中阐述： 目标1。为了评估对RoV的先天性和适应性免疫应答的程度及其对免疫应答的影响， 与BCG-HEU和HUU相比，BCG+ HEU和HUU与病毒清除率相关。 我们将测量先天免疫细胞表型、细胞因子表达、RoV特异性体液和细胞免疫应答。 在6周龄时施用RoV疫苗后，免疫力和RoV脱落。 目标二。目的探讨卡介苗对先天免疫的功能和表观遗传学影响， 使用BCG和模式识别受体（PRR）激动剂复制这种效应的体外系统。 我们将建立一个BCG刺激的体外系统，该系统可以复制NK细胞、γδ T细胞和抗原提呈细胞 在体内施用BCG后观察到的表型和DNA甲基化谱。然后我们将开发一个 PRR激动剂的混合物，其再现体外BCG刺激的效果，并且可以被翻译为 作为高浓缩铀和其他高危婴儿的免疫增强剂的临床用途。 冲击使用客观的实验室为基础的结果措施和足够的样本量，这项研究将提供 急需明确的证据证明BCG异源免疫刺激对婴儿的有益作用。

Project Summary BCG is a potent stimulator of innate immunity and has been used as an adjuvant in cancer therapy. BCG has also been shown to improve TB-unrelated infant morbidity and mortality and improve infant responses to vaccines in countries where BCG is routinely administered to neonates. However, epidemiologic studies have generated conflicting results due to their design and/or to the different BCG products. Here we propose to study the nonspecific protective effect of BCG by investigating innate and adaptive immune responses to infection with the rotavirus live attenuated vaccine virus (RoV) as a surrogate of infection. We will measure responses in Brazilian infants, who receive BCG in the first week of life per standard of care (BCG+), and in US infants, who do not receive BCG (BCG-). We will also investigate the mechanism of BCG's nonspecific protection against heterologous infections. Our results may create a framework for immune modulatory interventions in infants, who have higher infectious morbidity and mortality and lower responses to vaccines compared with older children and young adults. Moreover, we will investigate the effect of BCG both in HIV- exposed uninfected (HEU) and in HIV-unexposed (HUU) infants. HEU are a growing population with increased susceptibility to infections, hospitalization and death and with multiple innate and adaptive immune defects compared with HUU, which makes them important candidates for boosting immune interventions. We hypothesized that the protective effect of BCG against heterologous infections in infants is mediated by activation of trained innate immunity that controls the initial stages of infection and supports generation of robust adaptive immune responses.This hypothesis will be addressed in the following Specific Aims: Aim 1. To assess the magnitude of innate and adaptive immune responses to RoV and their association with viral clearance in BCG+ HEU and HUU in comparison with BCG- HEU and HUU. We will measure innate immune cell phenotypes, cytokine expression, RoV-specific humoral and cellular immunity, and RoV shedding, after administration of the RoV vaccine at 6 weeks of age. Aim 2. To investigate the functional and epigenetic effect of BCG on innate immunity and develop an in vitro system that reproduces this effect using BCG and pattern recognition receptor (PRR) agonists. We will develop an in vitro system of BCG stimulation that reproduces the NK, γδ T and antigen presenting cell phenotypic and DNA methylation profiles observed after in vivo BCG administration. Then we will develop a cocktail of PRR agonists that reproduces the effect of in vitro BCG stimulation and could be translated for clinical use as an immune boosting agent for HEU and other high risk infants. Impact. Using objective laboratory-based outcome measures and an ample sample size, this study will provide the highly needed definitive proof of the beneficial effect of BCG heterologous immune stimulation in infants.