PGA antigenemia for early diagnosis of anthrax

PGA 抗原血症用于炭疽的早期诊断

• 批准号: 7163709
• 负责人: Thomas R Kozel
• 金额: $ 54.37万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-15 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7163709
• 关键词: Acute; Adjuvant; Affinity; Agonist; Anthrax disease; Antibodies; Antibody Formation; Antigens; Appearance; Bacillus anthracis; Bacillus anthracis spore; Bacteremia; Biological Assay; Bioterrorism; Blood; Body Fluids; Breathing; Class; Clinical; Collaborations; Detection; Development; Diagnosis; Diagnostic; Differential Diagnosis; Drug Kinetics; Drug or chemical Tissue Distribution; Early Diagnosis; Encapsulated; Enzyme-Linked Immunosorbent Assay; Event; Exhibits; Facility Construction Funding Category; Glutamic Acid; Goals; Hand; Health Sciences; Human Resources; Hybridomas; Immunization; Immunoassay; Immunoglobulin Class Switching; Immunoglobulin G; Infection; Laboratories; Laboratory culture; Lead; Libraries; Modeling; Monoclonal Antibodies; Mus; Nature; Nevada; New Mexico; Outcome; Patients; Performance; Polysaccharides; Private Sector; Production; Research Institute; Serum; Signal Transduction; Solid; Specificity; TNFRSF5 gene; Technology; Training; Universities; Virulence; base; capsule; communicable disease diagnosis; concept; day; emergency service responder; immunogenicity; in vivo; indexing; medical schools; member; microorganism antigen; nonhuman primate; outcome forecast; programs; prototype; rapid diagnosis; research study; respiratory; response; success; tool; translational study

DESCRIPTION (provided by applicant): Success in treatment of anthrax is critically dependent on rapid diagnosis. As a consequence, there is an acute need for diagnostic tools that can be used in a first responder clinical setting where anthrax will be initially encountered. Detection of microbial antigens in body fluids is a proven technology in diagnosis of infectious disease. Bacillus anthracis is surrounded by an anti-phagocytic capsule that is composed of poly-y-D-glutamic acid (PGA), raising the possibility than immunoassay for PGA could be a means for early, specific, rapid and inexpensive diagnosis of anthrax. To date, development of an immunoassay for PGA has been hampered by the poor immunogenicity of PGA and the complete absence of information regarding production of PGA in vivo. In preliminary experiments, high affinity monoclonal antibodies (mAbs) reactive with PGA were produced and used to construct an immunoassay for PGA. The assay has an extraordinarily high sensitivity, with a lower limit near 100 pg/ml. The immunoassay was used to assess PGA antigenemia in a murine model of inhalation anthrax. The results showed that the initial presence of detectable PGA in blood coincided with the occurrence of detectable bacteremia. Full bacteremia was accompanied by a massive antigenemia with antigen titers as high as 1/5,000,000 48 h after infection. Six specific aims are proposed: i) to identify the immunochemical variables that influence the performance of immunoassay for PGA, ii) to evaluate the efficacy of an immunoassay for diagnosis and assessment of prognosis and treatment in a murine model of inhalation anthrax, iii) to assess tissue distribution and pharmacokinetics for clearance of PGA in vivo, iv) to develop, in cooperation with a private sector partner, a prototype "potential ultimate product" for antigen detection in anthrax, v) to determine the specificity of a PGA-based immunoassay for anthrax, and iv) to evaluate the efficacy of PGA immunoassay a non-human primate model of anthrax. This is a translational study that has the potential to dramatically impact diagnosis and treatment of anthrax. The study takes advantage of a library of PGA mAbs that is already in hand and optimizes a proven technology for use with PGA, a heretofore understudied class of microbial antigens. The overall goal is production of a prototype immunoassay for PGA that can be used in a first responder clinical setting where anthrax will be initially encountered.

描述（由申请人提供）：炭疽治疗的成功关键取决于快速诊断。因此，迫切需要可以在最初遇到炭疽的第一反应者临床环境中使用的诊断工具。检测体液中的微生物抗原是诊断传染病的成熟技术。炭疽芽孢杆菌被一种由聚γ-D-谷氨酸（PGA）组成的抗吞噬囊所包围，这使得PGA的免疫检测成为一种早期、特异、快速和廉价的炭疽诊断方法。迄今为止，PGA的免疫原性差和完全缺乏关于体内PGA产生的信息阻碍了PGA免疫测定的发展。在初步实验中，制备了与PGA反应的高亲和力单克隆抗体（mAb），并用于构建PGA的免疫测定法。该测定具有非常高的灵敏度，下限接近100 pg/ml。免疫测定法用于评估吸入性炭疽小鼠模型中的PGA抗原血症。结果表明，血液中可检测到的PGA的初始存在与可检测到的菌血症的发生相一致。完全菌血症伴随大量抗原血症，感染后48 h抗原滴度高达1/5，000，000。提出了六个具体目标：i）鉴定影响PGA免疫测定性能的免疫化学变量，ii）评价免疫测定在吸入性炭疽的鼠模型中用于诊断和预后评估以及治疗的功效，iii）评估体内PGA清除的组织分布和药代动力学，iv）与私营部门合作伙伴合作开发，用于炭疽抗原检测的原型“潜在最终产品”，v）确定基于PGA的炭疽免疫测定的特异性，和iv）评价PGA免疫测定对炭疽的非人灵长类动物模型的功效。这是一项转化研究，有可能极大地影响炭疽的诊断和治疗。该研究利用了已经掌握的PGA mAb库，并优化了与PGA一起使用的成熟技术，PGA是迄今为止研究不足的一类微生物抗原。总体目标是生产PGA的原型免疫测定，可用于最初遇到炭疽的第一反应者临床环境。