Identification of novel anti-virulence compounds against Pathogenic Burkholderia

鉴定针对致病性伯克霍尔德氏菌的新型抗毒力化合物

基本信息

批准号：
10193104
负责人：
Matthew M Schaefers
金额：
$ 26.55万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-17 至 2023-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10193104
关键词：
Abscess Antibiotic Resistance Antibiotics Australia Bacteria Bacterial Genes Biological Assay Bioterrorism Boston Burkholderia Burkholderia Infections Burkholderia cepacia complex Burkholderia pseudomallei Caulobacter Cell Culture Techniques Chronic Clinical Cystic Fibrosis Development Disease Disease Outbreaks Effectiveness Fever Gene Expression Regulation Genes Genetic Variation Genome Genomics Goals Gram-Negative Bacteria In Vitro Infection Lead Life Lung infections Melioidosis Membrane Microbe Modeling Mutation Oxygen Pathogenesis Pathogenicity Pathway interactions Patients Pediatric Hospitals Permeability Persons Pneumonia Pseudomonas aeruginosa Pseudomonas aeruginosa infection Publishing Reporter Research Resistance Rhizobium Sensory Sepsis Soil Southeastern Asia Structure System Systemic infection Therapeutic Therapeutic Agents Toxic effect Tropical Climate Variant Virulence Virulent Water Work antimicrobial drug bacterial genome sequencing beta-Lactamase chronic infection cystic fibrosis patients efflux pump healthcare-associated infections high throughput screening macrophage member mortality novel novel therapeutic intervention novel therapeutics pathogen programs protein-histidine kinase pulmonary function decline small molecule libraries targeted agent transcription factor

项目摘要

Project Abstract The long-term goal of this project is to develop novel therapeutics for the treatment of the Gram-negative pathogens in the Burkholderia genus which includes the Burkholderia cepacia complex (BCC) and Burkholderia pseudomallei. These pathogens cause serious, chronic lung infections and are also major causes of healthcare-associated infections. Treatment of infections caused by these pathogens is often difficult due to the broad-spectrum antibiotic resistance that is commonly seen. The development of novel therapeutics to treat these pathogens is critically needed. Our published work analyzing the genomic diversity of isolates of the BCC species B. dolosa and B. multivorans collected from people with CF has led to the discovery that the fixL gene appears to be under strong positive selection. FixL has been described in Rhizobium and Caulobacter as a sensory histidine kinase of a two-component system that detects oxygen tension and phosphorylates the transcription factor FixJ under low oxygen conditions. Our previous work has found that the BCC FixLJ system is required for pathogenesis and modulation of this pathway has profound effects of virulence. Interestingly, constructs carrying evolved FixL variants associated with periods of clinical decline in patients were more virulent in multiple infection models compared to isogenic constructs carrying ancestral FixL variants. These more virulent FixL sequences had lower FixLJ activity than less virulent constructs carrying ancestral FixL variants demonstrating that increased FixLJ activity is determinantal to virulence. We hypothesize that we can reduce Burkholderia virulence by activating the FixLJ pathway. By targeting virulence, we predict that the bacteria would no longer be able to infect or persist within the host. In the first aim of this project we will identify compounds that activate FixLJ using a high-throughput screen with a Burkholderia fix pathway reporter strain. In Aim 2 we will evaluate promising lead compounds identified in Aim 1 for their in vitro effectiveness at reducing virulence of multiple Burkholderia species using an in vitro macrophage assay. We also will evaluate the toxicity of lead compounds using cell culture. We plan to identify 3-4 lead compounds with an EC50 in the low micromolar (1-10) range and a toxicity at least 5-fold higher than the EC50. These lead compounds will be further developed into therapies for use to treat Burkholderia infections.

项目摘要该项目的长期目标是开发新的治疗剂来治疗革兰氏阴性伯克霍尔德属中的病原体，包括伯克霍尔德·西帕西亚综合体（BCC）和 Burkholderia pseudomallei。这些病原体引起严重的慢性肺部感染，也是主要原因与医疗保健相关的感染。由于这些病原体引起的感染的治疗通常很难通常看到的广谱抗生素抗性。新颖的治疗方法的发展严重需要治疗这些病原体。我们发表的工作分析了分离株的基因组多样性 BCC物种B. Dolosa和B.从患有CF的人那里收集的Multivorans已发现Fixl 基因似乎处于强烈的阳性选择之下。固定在根瘤菌和花椰菜中被描述为两个组分系统的感觉组氨酸激酶，可检测氧张力并磷酸化在低氧气条件下的转录因子fixj。我们以前的工作发现BCC FixlJ系统这是该途径的发病机理所必需的，具有毒力的深刻作用。有趣的是，携带与患者临床下降期有关的携带进化固定变体的结构更多与携带祖先固定变体的同源构建体相比，多种感染模型中有力。这些比携带祖先固定的毒气构造的更毒的固定序列具有较低的FixLJ活性证明增加的fixlj活性是毒力的决定性的变体。我们假设我们可以通过激活FixLJ途径来减少Burkholderia毒力。通过靶向毒力，我们预测细菌将不再能够在宿主中感染或持续存在。在该项目的第一个目标中，我们将确定使用Burkholderia fix pathway Reporter菌株使用高通量屏幕激活FIXLJ的化合物。在AIM 2中，我们将评估AIM 1中确定的有希望的铅化合物的体外有效性使用体外巨噬细胞测定法降低多种伯克霍尔德物种的毒力。我们还将评估使用细胞培养物的铅化合物的毒性。我们计划在EC50中识别3-4种铅化合物低微摩尔（1-10）范围和毒性至少比EC50高5倍。这些铅化合物将是进一步发展为用于治疗Burkholderia感染的疗法。