由蚊子傳播的病毒疾病如西尼羅河熱,、革登熱、基孔肯雅熱等在世界各地迅速傳播,，弗吉尼亞理工大學(xué)的科學(xué)家們正在研究蚊子的免疫系統(tǒng)及病原體是如何克服免疫系統(tǒng)并傳染給人類和其他動(dòng)物宿主,。
幾乎在世界的每一個(gè)地區(qū)，人類和動(dòng)物正經(jīng)歷著由病毒感染的蚊子叮咬所致的高水平的發(fā)病率和死亡率,。已有超過100種由吸血節(jié)肢動(dòng)物如蚊子傳播的病毒與人類或動(dòng)物的疾病有關(guān),。
2種尤其猖獗的是黃熱病蚊子（埃及伊蚊）和亞洲虎蚊（白紋伊蚊），這2者很容易辨別,，因?yàn)樗鼈冇袟l紋狀的圖案,。盡管原產(chǎn)于非洲和亞洲，這些蚊子可以通過搭乘舊輪胎等傳播到西方國家,。
弗吉尼亞理工大學(xué)的研究人員最近在庫蚊中發(fā)現(xiàn)了一種新型的抗病毒途徑,。Kevin Myles和Zach Adelman在本月的PLoS Pathogens期刊上發(fā)表了他們的研究結(jié)果。
"我們之前的研究表明,，在庫蚊中存在由siRNAs指導(dǎo)的抗病毒反應(yīng),。然而，我們這里展示的是另一類源自病毒的小RNA,，它呈現(xiàn)出很多與piRNAs相似的特性,，"他們解釋道。Myles和Adelman及其同事使用一種被稱為下一代測序的技術(shù)幫助了他們的發(fā)現(xiàn),。
新發(fā)現(xiàn)的抗病毒途徑似乎發(fā)揮著比先前描述的siRNA途徑更寬泛的作用,，顯示出其為強(qiáng)大的免疫系統(tǒng)。因此,，理解病毒如何繞開蚊子的雙重抗病毒反應(yīng)對于科學(xué)家來說是越來越有趣的挑戰(zhàn),。
"在由蚊子傳播病原體的情況下，我們的健康取決于蚊子的免疫反應(yīng),，因?yàn)樗_實(shí)能對我們自身的免疫反應(yīng)有用,，但對于蚊子的免疫系統(tǒng)我們了解的還出奇的少，"Males說,。（生物谷bioon.com）
doi:10.1371/journal.ppat.1002470
PMC:
PMID:
Production of Virus-Derived Ping-Pong-Dependent piRNA-like Small RNAs in the Mosquito Soma
Elaine M. Morazzani, Michael R. Wiley, Marta G. Murreddu, Zach N. Adelman, Kevin M. Myles.
Abstract： The natural maintenance cycles of many mosquito-borne pathogens require establishment of persistent non-lethal infections in the invertebrate host. The mechanism by which this occurs is not well understood, but we have previously shown that an antiviral response directed by small interfering RNAs (siRNAs) is important in modulating the pathogenesis of alphavirus infections in the mosquito. However, we report here that infection of mosquitoes with an alphavirus also triggers the production of another class of virus-derived small RNAs that exhibit many similarities to ping-pong-dependent piwi-interacting RNAs (piRNAs). However, unlike ping-pong-dependent piRNAs that have been described previously from repetitive elements or piRNA clusters, our work suggests production in the soma. We also present evidence that suggests virus-derived piRNA-like small RNAs are capable of modulating the pathogenesis of alphavirus infections in dicer-2 null mutant mosquito cell lines defective in viral siRNA production. Overall, our results suggest that a non-canonical piRNA pathway is present in the soma of vector mosquitoes and may be acting redundantly to the siRNA pathway to target alphavirus replication.
