Pneumocystis jirovecii Targeted Antiopportunistic Agents

耶氏肺孢子虫靶向抗机会药物

基本信息

批准号：
8996110
负责人：
ALEEM GANGJEE
金额：
$ 38.07万
依托单位：
DUQUESNE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-02-01 至 2018-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8996110
关键词：
3-Dimensional Acquired Immunodeficiency Syndrome Adverse reactions Animal Model Binding Biological Centers for Disease Control and Prevention (U.S.)Cessation of life Clinical Data Decision Trees Digit structure Dihydrofolate Reductase Dihydrofolate Reductase Inhibitor Dihydropteroate Synthase Drug Design Drug Evaluation Drug Kinetics Drug resistance Embryo Evaluation Event Failure Fibroblasts Future Generations Goals HIV Highly Active Antiretroviral Therapy Human Infection Kinetics Lung Metabolic Modeling Molecular Molecular Models Morbidity - disease rate Normal Cell Opportunistic Infections Organism Patients Persons Pharmaceutical Preparations Pneumocystis Pneumocystis carinii Pneumonia Quality of life Quantitative Structure-Activity Relationship Reporting Resistance Rodent Roentgen Rays Series Serum Structure Sulfamethoxazole System Testing Therapeutic Agents Time Toxic effect Trimethoprim-Sulfamethoxazole X-Ray Crystallography absorption analog base clinically relevant computational chemistry cytotoxicity in vitro activity in vivo in vivo Model inhibitor/antagonist killings molecular modeling mortality mouse model mutant nanomolar pathogen patient population pharmacophore preclinical study research clinical testing sulfa drug

项目摘要

DESCRIPTION (provided by applicant): Despite the availability of highly active antiretroviral therapy (HAART or ART), opportunistic infections (OIs) remain the leading cause of considerable morbidity and mortality in HIV infected persons as stated by the CDC in MMWR, April 10, 2009. This is particularly important with the leading OI, pneumonia (PCP), caused by Pneumocystis jirovecii. Trimethoprim/sulfamethoxazole (TMP/SMX), the combination of a dihydrofolate reductase (DHFR) inhibitor (TMP) and a dihydropteroate synthase (DHPS) inhibitor (SMX) for PCP is the first- line agent. The failure of this option due to adverse reactios and resistance to the sulfa drug as well as TMP along with the failure rate and adverse reactions of second-line agents necessitates the urgent need for alternate agents. Our group has isolated and characterized the elusive DHFR from the human pathogen Pneumocystis jirovecii (pjDHFR) and shown it to be distinct and different from its surrogate Pneumocystis carinii (pcDHFR) (occurs in rodents), with respect to inhibitory activities of therapeutic agents. n addition, we have identified two series of compounds (1, 3, 5 and 6) with selectivity for pjDHFR over hDHFR of 19-99-fold with picomolar and nanomolar Ki and IC50 values for pjDHFR. To our knowledge, we are the only group with access to pjDHFR and compounds that have both high selectivity (19-99-fold) and potency (picomolar and nanomolar) against pjDHFR (compared to hDHFR). Recently we have also cloned and expressed clinically relevant, TMP-resistant double mutants of pjDHFR and found that our compounds retain nanomolar inhibition against the double mutant pjDHFR in the face of TMP's 500-fold resistance, and will also use these in our evaluations. This is a paradigm changing event in the evaluation of drugs for P. jirovecii infection that up until now has utilized the surrogate P. carinii for DHFR as well as in vivo models. The Specific Aims are to: 1) synthesize proposed compounds in Series I-XII; 2) evaluate the compounds as inhibitors of hDHFR and wild type and resistant mutant pjDHFR; 3) evaluate selected analogs from Aim 2 in human embryonic lung fibroblasts for toxicity; 4) evaluate selected analogs (5) from Aims 2 and 3 for serum binding, metabolic stability and pharmacokinetics and develop and evaluate in a mouse model of P. jirovecii infection. X-ray crystal structure determination of 1, 3 and 5 and selected compounds from Series I-XII with pjDHFR and hDHFR will be done by Dr. Cody to afford a molecular understanding of the selectivity and potency of the analogs. This study will determine the structural requirements for potent and selective inhibition of pjDHFR and will assist in future drug design and pharmacophore generation. In addition it will provide, for the first time, the evaluation of compounds in a P. jirovecii animal model based on DHFR from the human pathogen (P. jirovecii) rather than a surrogate (P. carinii). The study should identify potential compounds for clinical evaluation against PCP and resistant PCP to be used alone or in combination.

描述（由申请人提供）：尽管有高度活跃的抗逆转录病毒疗法（HAART或ART），但在2009年4月10日，CDC在MMWR中所述的HIV感染者中，机会主义感染（OIS）仍然是艾滋病毒感染者的大量发病率和死亡率的主要原因。三甲氧苄啶/磺胺甲恶唑（TMP/SMX），二氢叶酸还原酶（DHFR）抑制剂（TMP）和二氢蛋白酶抑制剂（DHPS）抑制剂（SMX）的组合是PCP的第一线剂。由于不良反应和对Sulfa药物的耐药性以及TMP的抗性以及二线剂的失败率和不良反应，因此这种选择的失败需要迫切需要替代药物。我们的小组已将难以捉摸的DHFR与人类病原体肺炎藻（Jirovecii）（PJDHFR）（PJDHFR）隔离并表征，并表明其与其替代性肺炎藻（PCDHFR）（发生在啮齿动物）中，与啮齿动物的替代性肺炎症（PCDHFR）不同。 n补充，我们已经确定了两种系列化合物（1、3、5和6），对PJDHFR的选择性超过了19-99倍的pJDHFR，PICOMOLOL和NAMOLOR KI和PJDHFR的IC50值。据我们所知，我们是唯一可以访问PJDHFR的群体，并且对PJDHFR（与HDHFR相比）具有高选择性（19-99倍）和效力（picomolol和纳摩尔）的化合物。最近，我们还克隆并表达了PJDHFR的临床相关的，耐TMP的双突变体，发现我们的化合物在面对TMP的500倍耐药的情况下保留了对双突变体PJDHFR的纳摩尔抑制作用，并且还将在我们的评估中使用这些抑制作用。这是对P. jirovecii感染的药物评估的范式变化事件，到目前为止，它一直利用DHFR和体内模型的代理P. carinii。具体目的是：1）在I-XII系列中合成所提出的化合物； 2）评估化合物作为HDHFR和野生型和抗性突变体PJDHFR的抑制剂； 3）评估人类胚胎肺成纤维细胞中的AIM 2中所选的类似物的毒性； 4）从AIM 2和3中评估选定的类似物（5），以进行血清结合，代谢稳定性和药代动力学，并在P. jirovecii感染的小鼠模型中开发和评估。 1、3和5的X射线晶体结构的测定以及来自PJDHFR和HDHFR系列的I-XII选择的化合物将由Cody博士进行，以提供对模拟的选择性和效力的分子理解。这项研究将确定对PJDHFR有效和选择性抑制的结构要求，并将有助于未来的药物设计和药物团产生。此外，它将首次提供基于人类病原体（P. jirovecii）的DHFR的P. jirovecii动物模型中的化合物的评估，而不是替代物（P. carinii）。该研究应确定针对PCP的临床评估和抗性PCP的潜在化合物，以单独或组合使用。