HMGB1-mediated host response to chronic bacterial infection

HMGB1介导的宿主对慢性细菌感染的反应

基本信息

批准号：
10671706
负责人：
STEVEN D GOODMAN
金额：
$ 72.07万
依托单位：
RESEARCH INST NATIONWIDE CHILDREN'S HOSP
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-22 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10671706
关键词：
3-Dimensional Affinity Amino Acid Sequence Amino Acids Animal Model Antibodies Architecture Bacteria Bacterial DNA Bacterial Infections Bacterial Proteins Binding Binding Proteins Biochemical Biological Assay Burkholderia cepacia Cell physiology Cells Chinchilla (genus)Chromatin Chronic Clinical Communities Cruciform DNA DNA DNA Binding DNA Structure DNA metabolism DNA-Binding Proteins Dangerousness Deoxyribonucleases Digestion Disease Dissection Effectiveness Elements Equilibrium Experimental Animal Model Extracellular Matrix Extracellular Structure Family Genetic Recombination Goals HMGB1 gene Human Immune response Immune system In Vitro Infection Inflammatory Inflammatory Response Lung infections Maintenance Mediating Microbial Biofilms Modeling Molecular Nontypable Haemophilus influenza Otitis Media Outcome Pathogenicity Pattern Permeability Physiology Play Polymers Process Property Proteins Reaction Resistance Resolution Role Sampling Sepsis Specificity Structure Testing Therapeutic Therapeutic Agents Treatment Efficacy Work acute infection antimicrobial bacterial community chronic infection effective therapy extracellular human disease human model human pathogen immune clearance in vitro activity in vivo inhibitor intercellular communication large scale production mindfulness mouse model novel pathogen pathogenic bacteria preference recurrent infection repaired scaffold virtual

项目摘要

PROJECT SUMMARY/ABSTRACT High Mobility Group Box 1 (HMGB1) is a 215-amino acid protein that plays multiple roles in humans. Intracellularly, HMGB1 is chromatin-associated and involved in virtually all types of DNA metabolism (e.g. replication, repair, recombination), primarily through its ability to bind with high affinity and specificity to various DNA structures. Extracellularly, HMGB1 is the prototypical damage-associated molecular pattern molecule (DAMP) with strong pro-inflammatory functions. Here, we have discovered, and will show, that endogenous HMGB1 has a heretofore unknown function in its ability to control bacteria that cause chronic and recurrent infections, which thereby contributes to the delicate balance of host-pathogen interactions. For bacteria to enter a chronic infection state, they must assume a community architecture called a biofilm, replete with a self-made extracellular matrix commonly composed of scaffolded extracellular DNA (eDNA) that is highly resistant to clearance by both the host immune system and antimicrobials. We have previously shown that this eDNA-dependent structure is stabilized by the DNABII family of bacterial proteins, that when added exogenously can drive free-living (planktonic) bacteria into a biofilm. Unlike these proteins, we show that HMGB1 destabilizes the eDNA structure and drives biofilm-resident bacteria into the planktonic, vulnerable state. The DNABII family and HMGB1 have similar DNA structure binding preferences in vitro despite a lack of primary amino acid sequence identity and secondary structure. We therefore hypothesize that despite their similar DNA structure binding preferences, these proteins facilitate converse reactions. Further, the fact that endogenous native HMGB1 steady state levels restrict, but fail to clear, chronic infections suggests a balance with HMGB1’s needed pro-inflammatory functions, i.e. release of bacteria from biofilms under strong inflammatory conditions could lead to sepsis. Herein, we will work under the scientific premise that eDNA-binding is essential for HMGB1 to disrupt bacterial biofilms and further, that it will be possible to separate its anti-biofilm activity from pro-inflammatory functions. Indeed, we have truncated HMGB1 to 97 amino acids, a form which still retains full anti-biofilm activity but without pro- inflammatory functions, thereby likely able to tip the host-pathogen interaction in favor of the host. Through the completion of 3 highly integrated specific aims, we will determine the capacity of this HMGB1 derived 97-mer to act as an anti-biofilm agent on biofilms formed by diverse human pathogens in vitro as well as biofilms within polymicrobial clinical samples, assayed ex-vivo (to determine the breadth of activity and support our overarching hypothesis; AIM 1), the anti-biofilm mechanism of action, through a process of DNA binding (AIM 2), and the therapeutic efficacy in two distinct animal models of biofilm infections (AIM 3).

项目概要/摘要高迁移率组盒 1 (HMGB1) 是一种 215 个氨基酸的蛋白质，在人类中发挥多种作用。在细胞内，HMGB1 与染色质相关并参与几乎所有类型的 DNA 代谢（例如 DNA 代谢）。复制、修复、重组），主要是通过其以高亲和力和特异性结合的能力在细胞外，HMGB1 是典型的损伤相关分子模式。在这里，我们已经发现并将证明，具有强促炎功能的分子（DAMP）。内源性 HMGB1 具有迄今为止未知的功能，能够控制导致慢性疾病的细菌。和反复感染，从而有助于宿主与病原体相互作用的微妙平衡。细菌要进入慢性感染状态，它们必须呈现出一种称为生物膜的群落结构，充满了自制的细胞外基质，通常由支架式细胞外 DNA (eDNA) 组成我们之前已经发现，它对宿主免疫系统和抗菌药物的清除具有高度抵抗力。表明这种依赖于 eDNA 的结构被细菌蛋白 DNABII 家族稳定，当我们发现，与这些蛋白质不同，外源添加可以将自由生活（浮游）细菌驱动到生物膜中。 HMGB1 破坏 eDNA 结构的稳定性并驱使生物膜驻留细菌进入浮游生物， DNABII家族和HMGB1在体外具有相似的DNA结构结合偏好。尽管缺乏一级氨基酸序列同一性和二级结构。尽管它们具有相似的 DNA 结构结合偏好，但这些蛋白质促进相反的反应。此外，内源性天然 HMGB1 稳态水平限制但未能清除慢性感染表明与 HMGB1 所需的促炎功能（即细菌释放）的平衡强烈炎症条件下的生物膜可能导致败血症。科学前提是，eDNA 结合对于 HMGB1 破坏细菌生物膜至关重要，而且，它将有可能将其抗生物膜活性与促炎功能分开。事实上，我们已经做到了。将 HMGB1 截短为 97 个氨基酸，这种形式仍保留完整的抗生物膜活性，但不具有亲炎症功能，从而可能使宿主与病原体的相互作用有利于宿主。完成3个高度集成的具体目标后，我们将确定这个HMGB1的衍生能力 97-mer 在体外和多种人类病原体形成的生物膜上充当抗生物膜剂多种微生物临床样本中的生物膜，进行离体分析（以确定活性的广度和支持我们的总体假设 AIM 1)，即通过 DNA 过程实现的抗生物膜作用机制结合（AIM 2），以及两种不同的生物膜感染动物模型的治疗效果（AIM 3）。