An Ftr1 vaccine to abrogate mucormycosis

描述（由申请方提供）：毛霉菌病是一种危及生命的感染，发生在因糖尿病酮症酸中毒、中性粒细胞减少、皮质类固醇使用和/或血清铁升高而免疫功能低下的患者中。由于这些危险因素的流行率上升，毛霉菌病的发病率也有所上升。尽管进行了毁容手术和积极的抗真菌治疗，毛霉菌病的死亡率仍然> 50%，在播散性疾病患者中接近100%。显然，迫切需要新的策略来预防和治疗毛霉菌病。 血清铁水平升高的患者对毛霉菌病特别敏感。这些患者包括酮症酸中毒（DKA）的糖尿病患者和去铁胺治疗的患者。去铁胺作为一种异种铁载体，为毛霉菌病的病原体提供以前不可用的铁。我们已经表明，铁螯合剂以外的去铁胺螯合保护小鼠免受感染根霉，最常见的分离生物体从毛霉病患者。我们还证明，高亲和力铁通透酶（rFTR 1）基因编码的蛋白质（rFtr 1 p），这是铁运输到真菌细胞所需的，在体内表达，是R. - 是的此外，我们发现，被动免疫与抗rFtr 1 p抗体开始之前和感染后继续显着提高小鼠的存活率，否则致命的R。肺部感染。我们建议进一步确定抗rFtr 1 p抗体对R. - 是的此外，我们将确定抗rFtr 1 p抗体在感染其他毛霉目、烟曲霉或白色念珠菌的小鼠中的保护范围和机制，因为rFtr 1 p与来自这些真菌的高亲和力铁渗透酶具有相当大的同一性。 证明抗rFtr 1 p抗体的连续治疗潜力的原理将为RO 1应用提供基础，其中基于抗体的治疗策略将进一步优化以对抗毛霉菌病，并将开发保护性单克隆抗体。最终，rFtr 1 p作为抗体治疗靶点的作用的定义有可能为这些破坏性感染提供全新的治疗干预。 公共卫生相关性：铁对根霉的生长至关重要，根霉是一种真菌，会导致糖尿病、癌症或其他免疫系统薄弱的患者发生危及生命的感染。目前毛霉菌病的治疗选择是不充分的，50%或更多的毛霉菌病患者尽管治疗仍死于感染。我们建议开发一种基于抗体的疗法，阻断真菌吸收铁的能力，从而阻止其生长并提高感染患者的生存率。

DESCRIPTION (provided by applicant): Mucormycosis is a life-threatening infection that occurs in patients immunocompromised by diabetic ketoacidosis, neutropenia, corticosteroid use, and/or increased serum iron. Because of the rising prevalence of these risk factors, the incidence of mucormycosis has risen. Despite disfiguring surgery and aggressive antifungal therapy, the mortality of mucormycosis remains >50%, and approaches 100% in patients with disseminated disease. Clearly new strategies to prevent and treat mucormycosis are urgently needed. Patients with elevated levels of available serum iron are uniquely susceptible to mucormycosis. These patients include diabetics in ketoacidosis (DKA) and deferoxamine- treated patients. Deferoxamine acts as a xeno-siderophore which supplies the agents of mucormycosis with previously unavailable iron. We have shown that iron chelation with chelators other than deferoxamine protects mice from infection with Rhizopus oryzae, the most commonly isolated organism from patients with mucormycosis. We also demonstrated that the high affinity iron permease (rFTR1) gene encodes a protein (rFtr1p) which is required for iron transport into the fungal cell, is expressed in vivo, and is required for virulence of R. oryzae. Further, we found that passive immunization with anti-rFtr1p antibodies initiated prior to and continued after infection markedly improves survival of mice with otherwise lethal R. oryzae infection. We propose to further define the therapeutic efficacy and mechanism of protection of anti-rFtr1p antibodies against R. oryzae. Additionally, we will determine the breadth and mechanism of protection of anti-rFtr1p antibodies in mice infected with other Mucorales, Aspergillus fumigatus or Candida albicans since rFtr1p has considerable identity to high affinity iron permeases from these fungi. Demonstration of proof of principle of the adjunctive therapeutic potential of anti-rFtr1p antibodies will provide a foundation for an RO1 application in which antibody-based therapeutic strategies will be further optimized against mucormycosis, and protective monoclonal antibodies will be developed. Ultimately, definition of the role of rFtr1p as a target for antibody treatment has the potential to enable a completely novel therapeutic intervention for these devastating infections. PUBLIC HEALTH RELEVANCE: Iron is essential for the growth of Rhizopus oryzae, a fungus that causes life-threatening infections in patients with diabetes, cancer, or other causes of weak immune systems. Current treatment options for mucormycosis are inadequate, and 50% or more of patients with mucormycosis die of the infection despite treatment. We propose to develop an antibody-based therapy that blocks the ability of the fungus to take up iron, thereby preventing its growth and improving the survival of infected patients.