RNA interference acts as a natural antiviral response to O'nyong-nyong virus (Alphavirus; Togaviridae) infection of Anopheles gambiae
RNA interference acts as a natural antiviral response to O'nyong-nyong virus (Alphavirus; Togaviridae) infection of Anopheles gambiae
复制标题
DOI：
10.1073/pnas.0406983101
复制
发表时间：
2004-12-07
影响因子：
11.1
通讯作者：
Olson, KE
中科院分区：
文献类型：
--
作者：
Keene, KM;Foy, BD;Olson, KE
RNA干扰（RNAi）是由双链RNA（dsRNA）在真核生物中触发的，它会破坏任何与dsRNA触发物具有序列同一性的mRNA。冈比亚按蚊的RNAi途径可以通过用来自A.冈比亚Argonaute 2（AgAgo 2）基因。我们假设RNAi也可以作为甲病毒在A.因为RNA病毒在复制过程中形成dsRNA。沉默AgAgo 2表达可使A.冈比亚蚊子对病毒感染较宽容。为了确定RNAi是否影响A.为了检测O 'nyong-nyong病毒（ONNV）在冈比亚的感染情况，我们工程化了表达增强型GFP（eGFP）作为标记物的遗传修饰的ONNV。胸腔内注射ONNV-eGFP后，ONNV-eGFP缓慢扩散至其他A.冈比亚组织在9天的孵育期内。然后用病毒和对照β-半乳糖苷酶dsRNA（dsbetagal;注意“ds”用作前缀以指示源自整个给定基因的dsRNA）或ONNV dsnsP 3共注射蚊子。用dsnsP 3处理显著抑制病毒传播，如通过eGFP表达模式所确定的。在注射后第3天和第6天，来自与dsnsP 3共注射的蚊子的ONNV-eGFP滴度显著低于与dsbetagal共注射的蚊子。然后用ONNV-eGFP和dsAgAgo 2共注射蚊子。用病毒和AgAgo 2 dsRNA共注射的蚊子在注射后3或6天显示出广泛的eGFP表达和比dsbetagal对照高16倍的病毒滴度。这些观察结果为RNAi是A.冈比亚，他们认为，先天免疫反应条件载体的能力。
RNA interference (RNAi) is triggered in eukaryotic organisms by double-stranded RNA (dsRNA), and it destroys any mRNA that has sequence identity with the dsRNA trigger. The RNAi pathway in Anopheles gambiae can be silenced by transfecting cells with dsRNA derived from exon sequence of the A. gambiae Argonaute2 (AgAgo2) gene. We hypothesized that RNAi may also act as an antagonist to alphavirus replication in A. gambiae because RNA viruses form dsRNA during replication. Silencing AgAgo2 expression would make A. gambiae mosquitoes more permissive to virus infection. To determine whether RNAi conditions the vector competence of A. gambiae for O'nyong-nyong virus (ONNV), we engineered a genetically modified ONNV that expresses enhanced GFP (eGFP) as a marker. After intrathoracic injection, ONNV-eGFP slowly spread to other A. gambiae tissues over a 9-day incubation period. Mosquitoes were then coinjected with virus and either control beta-galactosidase dsRNA (dsbetagal; note that "ds" is used as a prefix to indicate the dsRNA derived from a given gene throughout) or ONNV dsnsP3. Treatment with dsnsP3 inhibited virus spread significantly, as determined by eGFP expression patterns. ONNV-eGFP titers from mosquitoes coinjected with dsnsP3 were significantly lower at 3 and 6 days after injection than in mosquitoes coinjected with dsbetagal. Mosquitoes were then coinjected with ONNV-eGFP and dsAgAgo2. Mosquitoes coinjected with virus and AgAgo2 dsRNA displayed widespread eGFP expression and virus titers 16-fold higher than dsbetagal controls after 3 or 6 days after injection. These observations provide direct evidence that RNAi is an antagonist of ONNV replication in A. gambiae, and they suggest that the innate immune response conditions vector competence.