Lysozymes and immunity in Anopheles gambiae

描述（申请人提供）：疟疾是一种由疟原虫属寄生原生动物引起的疾病，通过蚊子传播给人类。每年有数亿人感染这种生物体，造成数百万人死亡，其中大多数是幼儿。问题是如何恶化，因为越来越多的寄生虫抗药性。由于杀虫剂抗药性、成本增加和训练有素人员的流失，蚊虫控制也受到威胁。因此，需要新的疟疾控制方法。研究的一个重要目标是蚊子和寄生虫之间的相互作用。我们研究的长期目标是了解载体能力的分子决定因素。我们研究蚊子杀死寄生虫的方式，寄生虫如何避免这些反应，以及疟原虫成功发育所需的蚊子因素。有了这些知识，我们可以尝试通过对媒介蚊子的遗传或化学操作来增强导致蚊子/寄生虫不相容性的机制，或者通过靶向寄生虫发育所必需的蚊子分子来阻断寄生虫的传播。拟议的研究将集中在c型溶菌酶如何影响冈比亚按蚊中的疟原虫发育。溶菌酶c-1基因的沉默导致感染疟原虫的蚊子数量急剧减少。出乎意料的是，赖氨酸c-1与卵囊结合，因此这种蛋白质直接与寄生虫相互作用。具体目标1将侧重于1）使用免疫组织化学技术描述Lys c-1如何与疟疾寄生虫的中肠和唾液阶段相互作用; 2）确定抗Lys c-1抗体是否可用于阻断寄生虫发育; 3）表征Lys c-1通过基因沉默和随后的细菌感染对抗菌免疫的贡献。当寄生虫感染发生时，另外两种溶菌酶，Lys c-2和Lys c-7在蚊子中肠中上调。具体目标2将检查1）基因敲除Lys c-2或c-7对寄生虫发育的影响;以及2）通过蛋白质印迹、免疫组织化学和定量PCR描述寄生虫感染期间发生的蛋白质和转录物的变化。

DESCRIPTION (provided by applicant): Malaria, a disease caused by parasitic protozoans in the genus Plasmodium, is transmitted by mosquitoes to humans. Each year, hundreds of millions of people are infected with this organism and millions of fatalities result, mostly in young children. The problem is how worsening because of the increasing resistance of parasites to drugs. Mosquito control is also threatened because of insecticide resistance, increasing costs, and loss of trained personnel. Thus, new methods for malaria control are needed. An important target for research is the interaction between the mosquito and the parasite. The long-term goal of our research is to understand the molecular determinants of vector competence. We study the ways mosquitoes can kill parasites and how parasites avoid these responses as well as the mosquito factors that malaria parasites require for successful development. With this knowledge, we can attempt to enhance mechanisms that cause mosquito/parasite incompatibilitity through genetic or chemical manipulation of vector mosquitoes or to block the transmission of parasites by targeting mosquito molecules essential for parasite development. The proposed research will focus on how c-type lysozymes affect Plasmodium development in Anopheles gambiae. Silencing of the lysozyme c-1 gene results in a dramatic reduction in the number of mosquitoes that become infected with Plasmodium. Unexpectedly, Lys c-1 binds to oocysts, so this protein directly interacts with parasites. Specific Aim 1 will focus on 1) describing how Lys c-1 interacts with midgut and salivary stages of malaria parasites, using immunohistqchemical techniques; 2) determining whether anti Lys c-1 antibodies can be used to block parasite development; and 3) characterizing the contribution of Lys c-1 to antibacterial immunity, through gene silencing and subsequent infection with bacteria. Two other lysozymes, Lys c-2 and Lys c-7, are upregulated in the mosquito midgut when parasite infection occurs. Specific Aim 2 will examine 1) the effect of gene knockdown of Lys c-2 or c-7 on parasite development; and, 2) describing the changes in proteins and transcripts that occur during parasite infections, through western blotting, immunohistochemistry, and quantitative PCR.