Tick feeding regulation by orthologous tick saliva serine protease inhibitors

描述（由申请人提供）：在美国，人类媒介传播的疾病主要是蜱传播的。本研究的目的是鉴定、鉴定和验证美洲钝尾虫和肩背硬蜱唾液丝氨酸蛋白酶抑制剂（serpins）作为白尾鹿免疫蜱虫感染的疫苗靶抗原。为了完成摄食，蜱必须克服宿主防御反应、血液凝固、补体激活和炎症，这些都是丝氨酸蛋白酶介导的途径，由蛇蛋白严格控制。我们的实验室和其他人提出，蜱在摄食过程中表达并向宿主注射蛇蛋白，以调节宿主对蜱摄食活动的防御反应。在正在进行的NIHR03项目的最后一年，我们筛选了10个美洲蜱（Aam）蜱唾液腺（SG）蛇形蛋白，并验证了其中2个蛇形蛋白(S)， AamS6和AamS8分泌到蜱的唾液中，这代表了它们在蜱取食时注射到宿主体内。我们扩展了这些研究并鉴定了14种对血粉有反应的肩胛骨蜱SG蛇。在本提案中，我们将利用NIHR03项目中开发的方案来验证14种肩胛棘猴SG蛇形蛋白在蜱虫唾液中的分泌。我们观察到美洲蜱和蓖麻蜱两种唾液蛇形蛋白在蜱中高度保守。因此，我们假设蜱利用同源的蜱唾液蛇形蛋白调节蜱的摄食，免疫阻断蜱唾液蛇形蛋白功能将阻止多种蜱的摄食成功。白尾鹿（Odocoileus virginianus）在美国主要人类蜱传疾病（TBD），莱姆病，人类无形体病，巴贝斯虫病和埃利希体病以及南方蜱相关皮疹病（STARI）的出现中的重要性已经得到认识。因此，本提案中的数据将与开发预防人类TBD的新技术直接相关。在这个应用程序中有3个特定的目标。首先是验证16种血粉反应性肩胛骨蜱唾液腺蛇形蛋白在蜱唾液中的分泌。二是研究美洲蜱和镰形蜱土蜱唾液蛇形蛋白在蜱摄食调节中的作用。目的验证重组蜱虫唾液丝氨酸抗原免疫白尾鹿对蜱虫侵染的免疫和免疫抗体反应。

DESCRIPTION (provided by applicant): In the United States human vector borne diseases are primarily tick borne. The goals of this research are identification, characterization and validation of Amblyomma americanum and Ixodes scapularis tick saliva serine protease inhibitors (serpins) as vaccine target antigens for immunization of white tailed deer against tick infestation. To complete feeding, ticks must overcome host defense reactions, blood coagulation, complement activation and inflammation, all of which are serine protease mediated pathways that are tightly controlled by serpins. Our lab and others have proposed that during feeding, ticks express and inject serpins into the host to regulate evasion of host defense response to tick feeding activity. In an ongoing NIHR03 project in its final year we have screened 10 A. americanum (Aam) tick salivary gland (SG) serpin, and validated that 2 of the serpins (S), AamS6 and AamS8 are secreted into tick saliva, which is proxy for their injection into the host during tick feeding. We have extended these studies and identified 14 blood meal responsive I. scapularis tick SG serpins. In this proposal we will utilize protocols developed in the NIHR03 project to validate secretion of the 14 I. scapularis SG serpins into tick saliva. We have observed that the two A. americanum tick saliva serpins as well as the I. ricinus tick saliva serpin are highly conserved in ticks. Thus, we hypothesize that ticks utilize orthologous tick saliva serpins to regulate tick feeding and that immunologically blocking tick saliva serpin functions will prevent feeding success of multiple tick species. The importance of white tailed deer (Odocoileus virginianus) in the emergence of major human tick borne diseases (TBD) in the United States, Lyme disease, human anaplasmosis, babesiosis and ehrlichiosis and the southern tick-associated rash illness (STARI) has been recognized. Thus data in this proposal will be directly relevant towards efforts to develop novel technologies to prevent human TBD. There are 3 specific aims in this application. The first is to validate secretion of 16 blood meal responsive I. scapularis tick salivary gland serpins into tick saliva. The second is to characterize role(s) of A. americanum and I. scapularis native tick saliva serpins in tick feeding regulation. To validate tick immunity and anamnestic antibody response to tick infestation of white tailed deer immunized with recombinant tick saliva serpin antigens. PUBLIC HEALTH RELEVANCE: In the United States ticks transmit more vector borne disease agents than any other vector arthropod. Limitations associated with current acaricide based tick control strategies that threaten the future sustainability of containment programs for tick borne illnesses, have necessitated the need for development of alternative tick control strategies. Identification of important tick proteins that regulate tick physiology and facilitate tick feeding is important before alternative tick control methods can be developed.