Transferrin Combination Therapy to Address Antimicrobial Resistance

 描述(申请人提供)：由于耐药率上升，政策和舆论领袖呼吁开发全新的抗菌治疗范例，以补充传统抗生素。在这里，我们提出了一种创新的辅助抗菌方法，既可以防止致命病原体出现耐药性，又可以潜在地治疗XDR/PDR病原体。我们发现重组人转铁蛋白(RhTransferrin)能有效地隔离鲍曼不动杆菌、耐甲氧西林金黄色葡萄球菌(MRSA)和白色念珠菌中的铁，抑制它们的生长。重组人转铁蛋白治疗提高了感染了所有三种病原体的致死疫苗的小鼠的存活率。此外，在治疗MRSA菌血症的过程中，辅助性rhTransferrin治疗显著减少了利福平耐药的出现。最后，最近，我们发现重组人转铁蛋白和环丙沙星(环丙沙星)在体外对环丙沙星耐药肺炎克雷伯菌有协同作用。我们将测试这些发现对肺炎克雷伯菌和鲍曼不动杆菌的普适性。我们的新策略是通过使宿主环境不利于微生物生长来治疗感染和抑制耐药性的出现。我们将优化这一策略作为感染的辅助治疗，主要有三个目标：目标1：确定辅助性重组人转铁蛋白的体外效应 关于治疗高耐药革兰氏阴性病原菌的关键抗菌药的敏感性和耐药性的出现。对于一组基因特征良好的肺炎克雷伯菌和鲍曼不动杆菌，将确定重组人转铁蛋白对环丙沙星或美罗培南的体外敏感性和耐药性产生的影响。微量金属和血红素将被重新加入，以确定它们是否逆转了转铁蛋白介导的作用。体外时间杀伤试验将被用来确定rhTransferrin如何改变抗菌杀灭微生物的动力学目的2：确定添加与不添加rhTransferrin的抗菌剂的最佳药代动力学和药效学。一个复杂的恒化器系统将定义剂量，以优化药代动力学-药效学(PK-PD)重组人转铁蛋白和抗生素-转铁蛋白联合治疗对肺炎克雷伯菌和鲍曼不动杆菌的杀伤力和抗生素耐药性的影响。PD将通过测量rhTransferrin介导的金属隔离及其对微生物的影响来评估。目的3：明确辅助性重组人转铁蛋白治疗的体内疗效及耐药性的预防。AIMS 1和2将提供给药策略，以确定在静脉感染或经肺感染肺炎克雷伯菌或鲍曼不动杆菌的小鼠中，辅助性rhTransferrin加抗生素与单独使用抗生素的疗效。一些组将接受痕量金属或血红素治疗，以确定疗效是否逆转。影响：重组人转铁蛋白已经在铁超载患者的临床试验中进行了研究。拟议研究的完成将使rh Transferrin能够在临床上快速翻译，作为辅助治疗，以防止高耐药倾向的病原体出现抗药性。

 DESCRIPTION (provided by applicant): Due to rising rates of resistance, policy and opinion leaders have called for the development of entirely new paradigms of antimicrobial therapy to complement traditional antibiotics. Here we propose an innovative adjunctive antimicrobial approach to both prevent emergence of resistance in lethal pathogens and potentially treat XDR/PDR pathogens. We have found that recombinant human transferrin (rhTransferrin) effectively sequestered iron from Acinetobacter baumannii, methicillin resistant Staphylococcus aureus (MRSA), and Candida albicans, inhibiting their growth. Treatment with rhTransferrin improved survival of mice infected with lethal inocula of all three pathogens. Furthermore, adjunctive rhTransferrin therapy markedly reduced emergence of rifampin-resistance during treatment of mice with MRSA bacteremia. Finally, most recently, we found in vitro synergy between rhTransferrin and ciprofloxacin (cipro) against cipro-resistant K. pneumoniae. We will test the generalizability of these findings against Klebsiella pneumoniae and A. baumannii. Our novel strategy is to treat infection and inhibit emergence of resistance by rendering the host environment inhospitable to microbial growth. We will optimize this strategy as adjunctive therapy for infections in 3 AIMS: AIM 1: Determine the in vitro effects of adjunctive rhTransferrin on susceptibility and emergence of resistance to key antibacterial agents used to treat highly resistant Gram negative pathogens. The impact of rhTransferrin on in vitro susceptibility and resistance emergence to ciprofloxacin or meropenem will be defined for a panel of genetically well-characterized K. pneumoniae and A. baumannii strains. Trace metals and heme will be added back to determine if they reverse transferrin-mediated effects. In vitro time kill assays wil be used to determine how rhTransferrin alters the kinetics of antibacterial killing of the microbes AIM 2: Define optimal pharmacokinetics and pharmacodynamics of antibacterial agents with versus without adjunctive rhTransferrin. A sophisticated chemostat system will define dosing to optimize pharmacokinetic-pharmacodynamic (PK-PD) impact of rhTransferrin and antibiotic-transferrin combination therapy on cidality and emergence of antibiotic resistance of K. pneumoniae and A. baumannii. PD will be evaluated by measuring rhTransferrin-mediated metal sequestration and its impact on microbes. AIM 3: Define the in vivo efficacy and prevention of resistance of adjunctive rhTransferrin therapy. Aims 1 and 2 will inform dosing strategies to define efficacy of adjunctive rhTransferrin plus antibiotics vs. antibiotic alone in mice infected iv or via the lung with K. pneumoniae or A. baumannii. Some groups will be treated with trace metals or heme to determine if efficacy is reversed. IMPACT: rhTransferrin already has been studied in clinical trials of patients with iron overload. Completion of the proposed studies will enable rapid clinical translation of rhTransferrin as adjunctive therapy to prevent the emergence of antibacterial resistance among pathogens with a high propensity to develop resistance.