Molecular Basis of Infectivity of Brugia malayi microfilariae

描述(申请人提供)：淋巴丝虫病是热带地区发病的主要原因，由蚊媒传播的丝虫病引起。这些线虫的生命周期是复杂的，依赖于幼虫阶段从蚊子传播到人类，反之亦然。我们的长期目标是确定对蚊子宿主的L1期寄生虫(微丝虫)的传染性至关重要的寄生虫分子，希望它们能够成为减少人与媒介传播的目标。在人类宿主的淋巴管内，成虫交配，雌性幼虫排出未成熟的微丝虫。幼虫被带到外周循环中，并在进食血液时被蚊子媒介摄取。然而，新生微丝虫对蚊子宿主并不立即有效，但在摄取之前必须在血流中经历成熟过程。成熟伴随着微丝虫蛋白表达的变化，我们的假设是，未成熟和成熟微丝虫之间的感染力差异可以用基因表达的差异来解释。我们将通过使用微阵列技术比较未成熟和成熟微丝虫的基因表达模式来检验这一假设。该项目的具体目的是：(1)利用蚊虫感染性分析来证明未成熟和成熟的马来丝虫微丝虫感染性状态的差异；(2)利用微阵列杂交技术来寻找成熟过程中差异表达的微丝虫基因；(3)通过将差异表达的基因产物按所提出的功能分组，并使用实时荧光定量PCR来验证转录模式，以寻找进一步研究的候选基因。这一方法将使我们能够识别促进新生马来芽胞杆菌幼虫成熟的分子，使其能够从人传播到传播蚊子的媒介。可以想象，在成熟过程中发挥不可或缺作用的寄生虫分子可以成为旨在抑制繁殖或减少向蚊子传播的药物或疫苗的靶点。这些战略有可能打破淋巴丝虫病的传播循环，减轻热带国家的疾病和残疾负担。

DESCRIPTION (provided by applicant): Lymphatic filariasis is a major cause of morbidity in the tropics, and is caused by mosquito-borne filarial nematodes in the general Wuchereria and Brugia. The life cycle of these nematodes is complex, and relies on transmission of larval stages from mosquito to human, and vice versa. Our long-term objectives are to characterize parasite molecules that are crucial for the infectivity of the L1 stage parasites (microfilariae) for the mosquito host, in the hopes that they can be targeted to curtail man-to-vector transmission. Within the lymphatics of the human host, adult worms copulate and the females shed live immature microfilariae. The larvae are carried into the peripheral circulation and are ingested by the mosquito vector during a blood meal. Newborn microfilariae, however, are not immediately effective for the mosquito host, but must undergo a maturation process in the bloodstream prior to uptake. Maturation is accompanied by changes in microfilarial protein expression, and our hypothesis is that the difference in infectivity between immature and mature microfilariae can be explained by differences in gene expression. We will test this hypothesis by comparing gene expression patterns of immature and mature microfilariae using microarray technology. The specific aims of this project are to: (1) demonstrate the difference in infectivity status of immature and mature Brugia malayi microfilariae using mosquito infectivity assays, (2) use microarray hybridization technology to identify microfilarial genes that are differentially expressed during maturation, and (3) develop candidates for further study by grouping differentially expressed gene products by proposed function and verifying transcriptional patterns using real time PCR. This approach will allow us to identify molecules that promote maturation of newborn B. malayi larvae that allow transmission from man to the disseminating mosquito vector. It's conceivable that parasite molecules that play integral roles in the maturation process can be targeted by drugs or vaccines designed to inhibit reproduction or curtail transmission to the mosquito. These strategies have the potential for breaking the transmission cycle of lymphatic filariasis and reducing the burden of illness and disability in tropical nations.