Pneumocystis jirovecii Targeted Antiopportunistic Agents

耶氏肺孢子虫靶向抗机会药物

• 批准号: 8416314
• 负责人: ALEEM GANGJEE
• 金额: $ 35.79万
• 依托单位: DUQUESNE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8416314
• 关键词: 2-cyclopentyl-5-(5-isoquinolylsulfonyl)-6-nitro-1H-benzo(D)imidazole; 3-Dimensional; Acquired Immunodeficiency Syndrome; Adverse reactions; Animal Model; Binding; Biological; Centers for Disease Control and Prevention (U.S.); Cessation of life; Clinical; Data; Databases; 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; Inhibitory Concentration 50; 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; pathogen; patient population; pharmacophore; preclinical study; research clinical testing; sulfa drug

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）：正如美国疾病控制与预防中心在2009年4月10日《MMWR》中所述，尽管有高效抗逆转录病毒疗法（HAART或ART），但机会性感染（oi）仍然是导致艾滋病毒感染者大量发病和死亡的主要原因。这对于由乙氏肺囊虫引起的主要成骨不全，肺炎（PCP）尤其重要。甲氧苄啶/磺胺甲恶唑（TMP/SMX），双氢叶酸还原酶（DHFR）抑制剂（TMP）和双氢叶酸合成酶（DHPS）抑制剂（SMX）的组合，是治疗PCP的一线药物。由于对磺胺类药物和TMP的不良反应和耐药性以及二线药物的失败率和不良反应，这一选择的失败使得迫切需要替代药物。我们的研究小组已经从人类病原体吉氏肺囊虫（pjDHFR）中分离并鉴定了难以捉摸的DHFR，并表明它在治疗药物的抑制活性方面与其替代物卡氏肺囊虫（pcDHFR）（发生在啮齿动物中）不同。此外，我们已经鉴定了两个系列的化合物（1、3、5和6），它们对pjDHFR的选择性比hDHFR高19-99倍，对pjDHFR的Ki值和IC50值分别为皮摩尔和纳摩尔。据我们所知，我们是唯一能够获得pjDHFR和对pjDHFR具有高选择性（19-99倍）和效力（皮摩尔和纳摩尔）的化合物的团队（与hDHFR相比）。最近，我们还克隆并表达了临床相关的、对TMP耐药的pjDHFR双突变体，发现我们的化合物在面对TMP的500倍耐药时，对双突变体pjDHFR仍保持纳米摩尔的抑制作用，并将在我们的评估中使用这些。这是迄今为止利用卡氏弓形虫替代DHFR以及体内模型来评估吉罗氏弓形虫感染药物的一个范式改变事件。具体目标是：1)合成I-XII系列化合物；2)评价化合物作为hDHFR和野生型及耐药突变体pjDHFR的抑制剂；3)评价Aim 2在人胚胎肺成纤维细胞中的毒性；4)评估目标2和目标3中选择的类似物(5)的血清结合、代谢稳定性和药代动力学，并在小鼠感染P. jrovecii模型中开发和评估。Cody博士将对1,3和5以及从系列I-XII中选择的具有pjDHFR和hDHFR的化合物进行x射线晶体结构测定，以提供对类似物的选择性和效力的分子理解。这项研究将确定有效和选择性抑制pjDHFR的结构要求，并将有助于未来的药物设计和药效团的产生。此外，它将首次提供基于人类病原体（P. jirovecii）而不是替代病原体（P. carinii）的DHFR的动物模型中化合物的评价。该研究应确定用于临床评价的潜在化合物，以及单独或联合使用的耐药PCP。