伊蚊C型凝集素mosGCTL-2是登革病毒感染相关的重要蛋白质（英文）

C-type Lectin Protein mosGCTL-2 From Aedes aegypti is a Novel Factor for Dengue Virus Infection

C型凝集素是一类含有糖结合结构域的蛋白质,从节肢动物到哺乳动物的C型凝集素都具有共同的基序,它在进化上相当保守,在免疫反应中发挥重要作用.埃及伊蚊表达30多种C型凝集素蛋白,它是登革病毒的关键传播媒介,这些蛋白质对病毒和细菌感染均有至关重要的作用.最近研究表明,C型凝集素mosGCTL-3与二型登革热病毒包膜蛋白具有相互作用,能够增强登革病毒对埃及伊蚊的感染.在本文中,我们发现了C型凝集素蛋白mosGCTL-2具有与mosGCTL-3类似的功能.两种C型凝集素mosGCTL-2和mosGCTL-3的氨基酸残基序列一致性高达43.56%.为研究mosGCTL-2在登革病毒蚊媒传播中的作用,我们通过果蝇S2细胞表达系统表达纯化了mosGCTL-2蛋白.结果表明,mosGCTL-2与二型登革热病毒包膜蛋白的结合具有钙离子依赖性.进一步的研究表明,埃及伊蚊感染登革病毒能够诱导mosGCTL2表达上调,是二型登革热病毒感染埃及伊蚊所必需的蛋白质.以上研究说明,mosGCTL-2蛋白可能是在登革热病毒感染埃及伊蚊中起重要作用的一种模式识别受体.

C-type lectins(CTLs) are a family of carbohydrate-binding proteins that share a common structural motif;they are quite conserved evolutionarily from arthropods to mammals and play an essential role in immune responses. Aedes aegypti is a pivotal vector for the dengue virus and expresses more than 30 types of C-type lectins, which are critical for both viral and bacterial infections. A recent study indicates that mosGCTL-3 interacts with a dengue virus-2 envelope protein(DENV-2 E protein) in vivo and in vitro thereby enhancing the infection of A. aegypti. Here, in this report we found another C-type lectin protein, mosGCTL-2 with important functions similar to mosGCTL-3. Results from the phylogenetic tree analysis suggested that there is sequence similarity between mosGCTL-2 and mosGCTL-3, with 43.56% of their amino acid sequences being identical. We constructed Drosophila S2 cell expression system to purify mosGCTL-2. In vitro experiments showed that mosGCTL-2 binds to the DENV-2 E protein through a calcium-dependent manner. The upregulation of mosGCTL-2 was noted in A. aegypti and was important for dengue virus 2(DENV-2) infection in vivo. These findings suggest that mosGCTL-2 may be a pattern recognition receptor that performs an important function in the infection of A. aegypti by the dengue virus.