Mechanisms and Immune consequences of atypical efferocytosis of neutrophils during Porphyromonas gingivalis infection.

项目摘要/摘要 招募到细菌感染或炎症部位的中性粒细胞最终会发生凋亡，并 被吞噬细胞如巨噬细胞在原位清除。“效应细胞吞噬”或吞噬细胞对细胞凋亡的摄取 细胞(AC)是一个高度选择性的过程，依赖于对凋亡相关配体的识别，如 作为磷脂酰丝氨酸(PS)，通过吞噬细胞上的泡腾细胞受体。这些交互作用会引发 下游信号，关闭炎症途径，并协调水解性分解 吞噬小体/泡泡小体内的急性冠脉综合征，以便最终清除。几种病原体可以操纵 胞吐作用，以破坏免疫清除。我们发现牙周致病菌--卟啉单胞菌 牙周炎使用一种新的机制，通过导致活体中性粒细胞摄取来调节泡腾细胞吞噬作用 PS非依赖的方式，可能绕过PS结合的泡腾细胞受体的参与和/或激活。 我们的初步数据显示，活细胞的这种非典型的泡腾作用导致了PRO-2的持续产生 炎性细胞因子和巨噬细胞激活促分解途径的严重失败。我们 牙周病患者牙周炎中牙龈假单胞菌介导的非典型泡沫化作用的假设 以及免疫耐受性的崩溃。在本提案的目标1中，我们将描述特定的信号通路 这在机制上将摄取活的中性粒细胞与促炎细胞因子的产生联系起来。在AIM 2 在这项提案中，我们将确定摄入活的中性粒细胞是否会导致降解延迟，这是由于 泡沫体不完全成熟，导致水解力减弱。净空有瑕疵 泡沫体内的急性冠脉综合征与慢性炎症和自体炎症后遗症的关系日益密切。 大量的疾病。总体而言，由这笔拨款产生的数据不仅将摆脱机械性的洞察 由牙龈假单胞菌引起的非典型泡沫症，但也将有助于设计新的治疗方法 减轻与牙周炎相关的慢性炎症。此外，此应用程序还包括一个 全面的培训计划，将使我能够加强我定义科学问题和 使用强大的技术技能和概念理解能力回答问题。我会继续扩大我的 在宿主-病原体相互作用、先天免疫反应和细胞信号通路方面的专业知识 从拟议的培训中获得的知识和技能将在今后的工作中发挥重要作用 追求独立调查员的职业生涯。

PROJECT SUMMARY/ABSTRACT Neutrophils recruited to the sites of bacterial infection or inflammation eventually undergo apoptosis and are cleared in situ by phagocytic cells such as macrophages. ‘Efferocytosis’ or the phagocytic uptake of apoptotic cells (AC), is a highly selective process that relies upon the recognition of apoptosis associated ligands, such as phosphatidylserine (PS), by efferocytic receptors on the engulfing cells. These interactions initiate downstream signaling that shuts down inflammatory pathways and orchestrates the hydrolytic breakdown of ACs within phagosomes/efferosomes for their eventual clearance. Several pathogens can manipulate efferocytosis in order to subvert immune clearance. We found that the periodontal pathogen Porphyromonas gingivalis uses a novel mechanism to dysregulate efferocytosis by causing the uptake of live neutrophils in a PS independent manner, possibly bypassing engagement and/or activation of PS binding efferocytic receptors. Our preliminary data show that this atypical efferocytosis of live cells resulted in sustained production of pro- inflammatory cytokines and a profound failure of macrophages to activate pro-resolution pathways. We hypothesize that P. gingivalis mediated atypical efferocytosis perpetuates inflammation in periodontal disease and breakdown of immune tolerance. In Aim 1 of this proposal, we will delineate specific signaling pathways that mechanistically link ingestion of live neutrophils to the generation of proinflammatory cytokines. In Aim 2 of this proposal, we will determine whether ingestion of live neutrophils results in degradation delays due to incomplete maturation of the efferosomes, resulting in diminished hydrolytic capacity. Defects in clearance of ACs within efferosomes is increasingly linked to chronic inflammation and autoinflammatory sequalae in a large number of diseases. Overall, the data generated from this grant will not only shed mechanistic insights atypical efferocytosis caused by a P. gingivalis but will also be useful in designing new therapeutic approaches to abate chronic inflammation associated with periodontitis. Furthermore, this application includes a comprehensive training plan that will enable me to strengthen my ability to define scientific questions and answer them using the strong technical skillset and conceptual understanding. I will continue to expand my expertise in areas of host-pathogen interactions, innate immune responses, and cellular signaling pathways and the knowledge and skill sets gained from the proposed training will be invaluable moving forward as I pursue a career as an independent investigator.