Molecular Basis of Infectivity of Brugia malayi microfilariae

描述（由申请人提供）：淋巴丝虫病是热带地区发病率的主要原因，在一般的乌切里亚和布鲁贾由蚊子传播的丝虫病引起。这些线虫的生命周期是复杂的，并且依赖于幼虫阶段从蚊子到人类的传播，反之亦然。我们的长期目标是表征对L1期寄生虫（微丝虫）对蚊子宿主的传染性至关重要的寄生虫分子，希望它们可以被靶向以减少人到媒介的传播。在人类宿主的淋巴管内，成虫交配，雌虫排出未成熟的微丝。幼虫被带入外周循环，并在吸血期间被蚊子媒介摄入。然而，新生的微丝虫不会立即对蚊子宿主有效，而必须在吸收之前在血液中经历成熟过程。成熟伴随着微丝虫蛋白表达的变化，我们的假设是未成熟微丝虫和成熟微丝虫感染性的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验证这一假设。本项目的具体目的是：(1)利用蚊子传染性测试证明未成熟和成熟的马来布鲁氏微丝蚴的传染性状态的差异；(2)利用微阵列杂交技术鉴定成熟过程中差异表达的微丝蚴基因；(3)通过提出的功能对差异表达的基因产物进行分组，并利用实时PCR验证转录模式，开发候选基因以供进一步研究。这种方法将使我们能够确定促进新生马来芽孢杆菌幼虫成熟的分子，这些幼虫可以从人传播到传播媒介蚊子。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被药物或疫苗靶向，以抑制繁殖或减少传播给蚊子。这些战略有可能打破淋巴丝虫病的传播周期，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.