按蚊体内的氨基酸是虫媒阶段疟原虫蛋白质合成的主要来源，其水平是决定按蚊对疟原虫易感性的重要因素。按蚊氨基酸运输蛋白是维持体内各组织间氨基酸水平的关键分子，这类蛋白是否影响按蚊传播疟原虫的能力还不清楚。本申请前期在对此类蛋白的筛选过程中发现PATH特异性表达于中肠上皮细胞，且受疟原虫诱导表达，说明此蛋白可以感应中肠内由于疟原虫感染而引起的氨基酸水平的变化；敲低PATH后，发现按蚊体内疟原虫数量显著下降，说明PATH有利于疟原虫感染按蚊。为进一步了解PATH促进按蚊传播疟原虫的机制，本申请拟研究PATH在氨基酸转运过程中的作用，以及这种作用对疟原虫蛋白质合成影响；对按蚊的合成代谢通路（Target of rapamycin，TOR）和免疫信号通路的调控作用，以及这种调控作用对疟原虫的影响，从而增加对两者在营养代谢相互作用中的认识，为发展新型虫媒防控手段提供理论依据。

Malaria parasites must complete their lifecycle in mosquitoes by scavenging nutritions from host, but the metabolic interactions between vector and Plasmodium is unknown. Our previous studies showed that amino acid transporter, path was induced 24 hr post parasite infection. It was mainly expressed in the epithelia of mosquito midgut. In the absence of path, mosquito become significantly susceptible to Plasmodium invasion, which indicates that PATH my promote the infection of parasites in mosquito. To further understand the mechanism of PATH in vector competence, we will investigate 1) influence of PATH on parasites protein anabolism, 2) influence of PATH of TOR, and 3) influence of PATH on innate immunity. My final goal is set up knowledge base for developing transmission blocking vaccine.