Limiting effects of a tick kunitz protease inhibitor on rickettsial infection

蜱库尼兹蛋白酶抑制剂对立克次体感染的限制作用

• 批准号: 7741122
• 负责人: SHANE M CERAUL
• 金额: $ 16.2万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7741122
• 关键词: Address; Adherence; Affect; Affinity; Animals; Antibodies; Arthropods; Binding; Biological Assay; Biology; Blood; Blood group antibody D; Bovine Anaplasmosis; Cell Surface Proteins; Cell surface; Cells; Co-Immunoprecipitations; Data; Dermacentor; Development; Disease; Disseminated Malignant Neoplasm; Endosomes; Equilibrium; Escherichia coli; Fabaceae; Fever; Future; Goals; Growth; Host Defense; Human; In Vitro; Infection; Instruction; Ixodidae; Knowledge; Laboratories; Learning; Ligands; Lyme Disease; Mediating; Membrane Proteins; Methods; Microbe; Micrococcus luteus; Midgut; Molecular; National Institute of Allergy and Infectious Disease; Organism; PAWR protein; Peptide Hydrolases; Physiological; Plant Roots; Principal Investigator; Property; Protease Inhibitor; Proteins; Public Health; Publications; RNA Interference; Radar; Recombinants; Research; Research Infrastructure; Rhizobium; Rickettsia; Rocky Mountain Spotted Fever; Role; Serum; Side; Specificity; Spottings; Surface; Symbiosis; Testing; Tick Control; Ticks; Vaccines; Vector-transmitted infectious disease; base; cancer cell; defense response; design; disease transmission; fighting; in vivo; interest; medical specialties; meetings; method development; microbial; microorganism; pathogen; prevent; protein protein interaction; public education; research study; response; success; therapy design; transmission process; trend; vector; vector transmission

DESCRIPTION (provided by applicant): Successful tick-rickettsiae symbioses become stable as each organism's struggle for survival levels to a state of tolerance. Research demonstrates that Rickettsia montanensis elicits a defense response from the hard tick, Dermacentor variabilis. To establish a niche within a tick, rickettsiae must evade that response. Defining the biology that drives the transmission of vector-borne diseases has implications for public health. For instance, deciphering the underpinnings of the balance between tick defense and rickettsial invasion forms the basis of research that aims to interrupt transmission of vector-borne diseases. NIAID identified disruption of disease transmission by arthropods as a major research focus in its publication "Planning for the 21st Century." My long-term goal is to understand how vector-borne pathogens colonize arthropods in the presence of an active host defense response. Our preliminary studies support our central hypothesis that D. variabilis-Kunitz-type protease inhibitor (Dv-KPI) limits rickettsial infection of the tick midgut by inactivating a rickettsial colonization factor. First, antibody-mediated neutralization of Dv-KPI results in increased rickettsial colonization in vitro. Second, RNAi-mediated knockdown of Dv-KPI in ticks results in an increase in R. montanensis burden in the midgut. Third, a bacterial affinity pulldown assay shows that Dv-KPI associates with R. montanensis. Fourth, a preliminary pulldown study suggests that Dv-KPI precipitates a rickettsial ligand. To address my long-term goal, NIAID's research focus and the central hypothesis, two aims are proposed. Specific Aim I - To determine if Dv-KPI limits R. montanensis entry and transmigration of the D. variabilis midgut. By suppressing Dv-KPI function in the tick, we will test further the effect that Dv-KPI has on rickettsial colonization and transmigration though the tick midgut. We will also investigate if entry is limited at the host cell perimeter or through endosomal escape. Specific Aim II - To identify the rickettsial ligand(s) for Dv-KPI. Using pulldown and Co-IP methods, we will identify and confirm the identity of the interacting rickettsial ligand(s). Completion of these aims will help to define the molecular attributes of the tick-rickettsiae interaction, which is central to the natural transmission cycle that leads to human infection. RELEVANCE (See instructions): Dv-KPI's observed affect on rickettsial growth forms the basis of our studies to investigate the factors that contribute to a state of tolerance between the tick and rickettsiae. Exploiting this knowledge to develop methods to interrupt tick transmission of pathogenic rickettsiae to humans addresses NIAID's research focus to disrupt disease transmission by arthropods.

描述（由申请人提供）：随着每个生物体为生存水平达到宽容状态而成功的Tick-Rickettsiae Symbioses变得稳定。研究表明，立克蒙塔尼斯（Rickettsia Montanensis）引起了硬滴答性变性的防御反应。为了在壁虱中建立一个利基市场，立克西亚必须逃避这种反应。定义驱动向量传播疾病传播的生物学对公共卫生有影响。例如，解读tick防御和立克入侵之间平衡的基础是旨在中断媒介传播疾病传播的研究的基础。 NIAID确定了节肢动物对疾病传播的破坏是其出版“ 21世纪计划”中的主要研究。我的长期目标是了解在积极的宿主防御反应的情况下如何在节肢动物上定居节肢动物。我们的初步研究支持了我们的中心假设：D。variabilis-kunitz型蛋白酶抑制剂（DV-KPI）通过失活体力中的肠内肠病限制了tick中肠感染的立克感染。首先，DV-KPI的抗体介导的中和导致体外身分式定植增加。其次，RNAi介导的DV-KPI在ticks中的敲低导致Midgut的R. Montanensis负担增加。第三，细菌亲和力下拉分析表明，DV-KPI与蒙塔尼斯菌相关。第四，一项初步的下拉研究表明，DV-KPI会沉淀出人力体配体。为了解决我的长期目标，NIAID的研究重点和中心假设，提出了两个目标。具体目的I-确定DV -KPI是否限制了D. variabilis Midgut的Montanensis进入和移民。通过抑制tick中的DV-KPI功能，我们将进一步测试DV-KPI对Rickettsial殖民化和tick虫中肠的迁移的影响。我们还将调查在宿主细胞周长或通过内体逃生的限制进入。特定的目标II-确定DV -KPI的立克配体。使用下拉和co-IP方法，我们将识别并确认相互作用的立体配体的身份。这些目的的完成将有助于定义tick-Rickettsiae相互作用的分子属性，这对于导致人类感染的自然传输周期至关重要。 相关性（请参阅说明）：DV-KPI对立克人士增长的影响构成了我们研究的基础，以调查有助于tick虫和立克西亚之间宽容状态的因素。利用这种知识来开发方法，以中断致病性立克的滴答传播到人类的滴答传播，这探讨了Niaid的研究重点，以破坏节肢动物传播的疾病传播。