Macrophage Regulation of Immune Pathogenesis of Biliary Atresia

项目概要： 候选人和职业发展：泰勒博士是儿科肝病学家和儿科助理教授 在西北大学。她对基础科学和转化研究保持着浓厚的兴趣 在她早期的职业生涯中。她的长期职业目标是成为一名独立资助的医生科学家 重点关注儿童胆汁淤积性肝病的免疫学。K08提案将有助于实现这一目标 通过以下具体目标的目标：1）发展泰勒博士的科学和专业技能， 先进的免疫学和生物信息学，和2）定义胆道中的致病性巨噬细胞（M β）亚群 闭锁（BA），以最终开发细胞亚群特异性治疗策略。泰勒博士和她的同事，博士。 Perlman和绿色博士制定了一个详细的战略，通过仔细 计划的课程工作，教学法，实验室技术，并在西北合作。现时的建议 将奠定基础，为未来的R01水平的建议M β驱动的调节适应性免疫的BA。 研究计划：BA是一种婴儿期胆汁淤积性肝病，是儿科肝脏疾病的主要原因。 移植BA被认为是由对环境触发的异常免疫反应引起的，然而， 疾病进展的确切机制仍然未知。有证据表明，MBA在BA中发挥着核心作用 然而，在发病机制中，M细胞是异质的和可塑的细胞群，并且先前的研究没有 区分不同的子集。我们是第一个证明在儿童胆汁淤积症中M β异质性的研究。 通过单细胞RNA测序，确定了3种不同的胆汁淤积性肝脏M β亚群：脂质 相关M β、单核细胞样M β和适应性M β。其中，适应性M β表现出增加 参与淋巴细胞活化的基因的表达以及BA和BA之间更大的疾病特异性差异， 胆汁淤积的非免疫病因学。这些发现表明，适应性M β可能是致病亚群 在BA中通过刺激已知在BA中起作用的T细胞免疫应答。在目前的提案中，我们 将建立在这一初步数据和调查的假设，适应性M β驱动的致病性 BA通过募集炎性M细胞和T细胞。为了评估这一假设，我们制定了 以下两个相互关联的具体目的：1）确定新的脂质相关的单核细胞样的， 人BA中的适应性M受体与无移植存活率相关，2）确定适应性M受体是否与移植存活率相关。 人BA对于鼠BA的疾病机制是必需的。通过在人类和小鼠中的平行研究， BA，以及与新生儿胆管结扎的创新非免疫小鼠模型的比较，我们将 鉴定驱动免疫损伤的BA特异性M β亚群。完成这些目标后取得的成果 可以确定新的治疗靶点，用于BA中的M β免疫调节以延长无移植存活。

PROJECT SUMMARY: Candidate and Career Development: Dr. Taylor is a pediatric hepatologist and Assistant Professor of Pediatrics at Northwestern University. She has maintained a strong interest in basic science and translational research throughout her early career. Her long-term career goal is to become an independently funded physician-scientist with a focus on the immunology of pediatric cholestatic liver disease. This K08 proposal will help achieve this goal through the following specific objectives: 1) develop Dr. Taylor’s scientific and professional skills in advanced immunology and bioinformatics, and 2) define the pathogenic macrophage (M) subsets in biliary atresia (BA) to ultimately develop cell subset-specific treatment strategies. Dr. Taylor and her co-mentors, Dr. Perlman and Dr. Green, have developed a detailed strategy to achieve these objectives through carefully planned course work, didactics, laboratory techniques, and collaborations at Northwestern. The current proposal will lay the foundation for future R01-level proposals on M-driven regulation of adaptive immunity in BA. Research Plan: BA is a cholestatic liver disease of infancy that is the leading cause of pediatric liver transplantation. BA is thought to arise from an aberrant immune response to an environmental trigger, however, the exact mechanism of disease progression remains unknown. Evidence points to a central role for M in BA pathogenesis, however, M are a heterogeneous and plastic cell population, and prior studies have not distinguished between subsets. We are the first to demonstrate the M heterogeneity in pediatric cholestatic liver disease through single-cell RNA sequencing and identified 3 distinct cholestatic liver M subsets: lipid associated M, monocyte-like M, and adaptive M. Among these, adaptive M demonstrated increased expression of genes involved in lymphocyte activation and greater disease-specific differences between BA and a non-immune etiology of cholestasis. These findings suggest that adaptive M may be the pathogenic subset in BA through stimulation of the T cell immune response known to play a role in BA. In the current proposal we will build upon this Preliminary Data and investigate the hypothesis that adaptive M drive the pathogenicity of BA through recruitment of inflammatory M and T cells. To evaluate this hypothesis we have formulated the following two interrelated Specific Aims: 1) determine whether the novel lipid-associated, monocyte-like, and adaptive M in human BA correlate with transplant-free survival, and 2) determine whether the adaptive M in human BA are essential for the disease mechanism of murine BA. Through parallel studies in human and murine BA, as well as comparison to an innovative non-immune murine model of neonatal bile duct ligation, we will identify the BA-specific M subsets that drive immune injury. Results obtained upon completion of these aims may identify new therapeutic targets for M immune modulation in BA to prolong transplant-free survival.