Gene silencing therapeutics for chronic infections in cystic fibrosis

囊性纤维化慢性感染的基因沉默疗法

• 批准号: 8511030
• 负责人: David Elihu Greenberg
• 金额: $ 24.83万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8511030
• 关键词: Acyl Carrier Protein; Anabolism; Animals; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Antisense Technology; Biological Assay; Burkholderia; Burkholderia cepacia complex; Cell Wall; Chemistry; Chronic; Clinical; Cystic Fibrosis; Databases; Deterioration; Development; Disease; Drug resistance; Escherichia coli; Essential Genes; Future; Gene Silencing; Gene Targeting; Genes; Goals; Growth; Human; In Vitro; Infection; Lactamase; Lead; Lipopolysaccharides; Lung; Messenger RNA; Methods; Microbial Biofilms; Minimum Inhibitory Concentration measurement; Modeling; Morbidity - disease rate; Multi-Drug Resistance; Mus; Pathway interactions; Patients; Peptides; Peptidoglycan; Pharmaceutical Preparations; Phase; Physiological; Predisposition; Proteins; Pseudomonas; Pseudomonas aeruginosa; Public Health; Research Design; Resistance; Respiratory physiology; Role; Salmonella; Structure; Syndrome; Testing; Therapeutic; Therapeutic Agents; Work; antimicrobial; bacterial resistance; cystic fibrosis patients; efflux pump; fatty acid biosynthesis; fighting; improved; in vivo; interest; mortality; mouse model; novel; pathogen; phosphorodiamidate morpholino oligomer; public health relevance; resistance mechanism; response; therapeutic development; therapeutic target

DESCRIPTION (provided by applicant): Gram-negative pathogens are becoming increasingly resistant to currently used antimicrobials. Furthermore, the pipeline for new antibiotics is slim and new therapies are urgently needed. This can be especially problematic in patients who suffer from chronic infections. Examples of inherently drug resistant Gram-negative pathogens are Pseudomonas aeruginosa and the Burkholderia cepacia complex (Bcc). These pathogens cause disease in a variety of settings, but are particularly devastating in patients with cystic fibrosis (CF). Chronic P. aeruginosa or Bcc infection can lead to both progressive pulmonary decline, as well as in Bcc infection, rapid deterioration in lung function referred to as "cepacia syndrome." We have been interested in using antisense molecules called PPMOs as potential therapeutics in these infections. These molecules block messenger RNA and block the formation of protein. We have demonstrated that PPMOs can be used to target genes that are essential for these pathogens to grow, specifically the gene acpP (that encodes the protein acyl carrier protein). We showed that blocking this protein is essential for Burkholderia and Pseudomonas to grow in vitro. We also showed that this PPMO improves survival in mice that were infected with Burkholderia. For this project, we propose to find other essential gene targets in these pathogens that can be blocked with PPMOs, and perform studies to evaluate the most promising compounds ability to improve survival in mouse models of infection. In the first phase of the project, we will target pathways that have been shown in other Gram-negative pathogens to be essential for growth. These will include genes important in the development of the cell wall and associated structures (lipopolysaccharide and peptidoglycan biosynthesis) as well as fatty acid biosynthesis (i.e. acyl carrier protein). In addition, we will try to block the genes that pla a role in antibiotic resistance to see if we can restore activity of currently existing antibiotics. he second phase of the project will be to evaluate lead PPMO candidates in mouse models of infection. We will use the PPMOs as treatments in pulmonary models of infection, assessing both systemic and pulmonary delivery of the compound. By the conclusion of this study, we hope to have promising novel treatments for two of the most devastating pathogens in CF that could advance to further clinical development. This work has implications not only for these infections in CF, but for other medically important Gram-negative pathogens.

描述（由申请人提供）：革兰氏阴性病原体对目前使用的抗菌素越来越具有耐药性。此外，新抗生素的研发渠道很少，迫切需要新的治疗方法。这在患有慢性感染的患者中尤其成问题。固有耐药革兰氏阴性病原体的例子是铜绿假单胞菌和洋葱伯克霍尔德菌复合物（Bcc）。这些病原体在各种情况下引起疾病，但在囊性纤维化（CF）患者中尤其具有破坏性。慢性铜绿假单胞菌或Bcc感染可导致进行性肺功能衰退，以及在Bcc感染时，肺功能迅速恶化，称为“cepacia综合征”。我们一直对使用反义分子PPMOs作为这些感染的潜在治疗方法很感兴趣。这些分子阻断信使RNA并阻断蛋白质的形成。我们已经证明，PPMOs可以用来靶向对这些病原体生长至关重要的基因，特别是acpP基因（编码酰基载体蛋白）。我们发现阻断这种蛋白是伯克氏菌和假单胞菌在体外生长所必需的。我们还发现，这种PPMO提高了感染伯克霍尔德菌的小鼠的存活率。在这个项目中，我们建议在这些病原体中寻找其他可以被PPMOs阻断的重要基因靶点，并进行研究来评估最有希望的化合物在小鼠感染模型中提高生存率的能力。在该项目的第一阶段，我们将以其他革兰氏阴性病原体中显示的对生长至关重要的途径为目标。这些将包括在细胞壁发育和相关结构（脂多糖和肽聚糖生物合成）以及脂肪酸生物合成（即酰基载体蛋白）中重要的基因。此外，我们将尝试阻断在抗生素耐药性中发挥作用的基因，看看我们是否能恢复现有抗生素的活性。该项目的第二阶段将是在小鼠感染模型中评估主要PPMO候选物。我们将使用PPMOs作为肺部感染模型的治疗方法，评估化合物的全身和肺部递送。通过这项研究的结论，我们希望对CF中两种最具破坏性的病原体有希望的新治疗方法，可以推进进一步的临床开发。这项工作不仅对CF中的这些感染有意义，而且对其他医学上重要的革兰氏阴性病原体也有意义。