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天然免疫刺激剂，已被用作癌症治疗的佐剂。卡介苗已经 也被证明可以改善与结核病无关的婴儿发病率和死亡率，并改善婴儿对 在那些新生儿常规接种卡介苗的国家接种疫苗。然而，流行病学研究已经 由于它们的设计和/或不同的卡介苗产品，产生了相互矛盾的结果。在此，我们建议 通过研究卡介苗的先天和获得性免疫反应来研究卡介苗的非特异性保护作用 感染轮状病毒减毒活疫苗病毒(ROV)作为感染的替代品。我们将衡量 根据护理标准(BCG+)在生命第一周接受卡介苗治疗的巴西婴儿的反应 美国婴儿，不接受卡介苗(BCG-)。我们还将探讨卡介苗的非特异性机制 针对异源感染的保护。我们的结果可能会为免疫调节创造一个框架 对感染发病率和死亡率较高、对疫苗反应率较低的婴儿进行干预 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对HIV- 暴露在未感染(HEU)和未暴露于艾滋病毒(HUU)的婴儿中。HEU是一个不断增长的人口 易受感染、住院和死亡，并具有多种先天和获得性免疫缺陷 与HUU相比，这使它们成为加强免疫干预的重要候选者。我们 假设卡介苗对婴儿异源感染的保护作用是通过以下途径实现的 激活训练有素的先天免疫，控制感染的初始阶段，并支持产生 强健的适应性免疫反应。这一假设将在以下具体目标中得到解决： 目的1.评估ROV及其受体的先天和获得性免疫反应的大小。 卡介苗+HEU和HUU与BCG-HEU和HUU的病毒清除的相关性。 我们将测量先天性免疫细胞表型、细胞因子表达、ROV特异性体液和细胞 在6周龄接种ROV疫苗后，免疫和ROV脱落。 目的2.探讨卡介苗对天然免疫功能和表观遗传学的影响，为进一步研究卡介苗的免疫机制奠定基础。 使用卡介苗和模式识别受体(PRR)激动剂重现这种效应的体外系统。 我们将开发一种体外卡介苗刺激系统，复制NK、γδT和抗原提呈细胞 观察卡介苗体内给药后的表型和DNA甲基化情况。然后我们将开发一种 PRR激动剂的鸡尾酒，复制体外卡介苗刺激的效果，并可翻译为 临床用作HEU和其他高危婴儿的免疫增强剂。 冲击力。使用客观的基于实验室的结果测量和充足的样本量，这项研究将提供 卡介苗异种免疫刺激对婴儿的有益效果亟需确凿证据。

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.