Sessions October M, Wilm Andreas, Kamaraj Uma Sangumathi, Choy Milly M, Chow Angelia, Chong Yuwen, Ong Xin Mei, Nagarajan Niranjan, Cook Alex R, Ooi Eng Eong
Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore.
Computational and Systems Biology, Genome Institute of Singapore, Singapore.
PLoS Negl Trop Dis. 2015 Sep 1;9(9):e0004044. doi: 10.1371/journal.pntd.0004044. eCollection 2015.
Dengue viruses (DENV) cause debilitating and potentially life-threatening acute disease throughout the tropical world. While drug development efforts are underway, there are concerns that resistant strains will emerge rapidly. Indeed, antiviral drugs that target even conserved regions in other RNA viruses lose efficacy over time as the virus mutates. Here, we sought to determine if there are regions in the DENV genome that are not only evolutionarily conserved but genetically constrained in their ability to mutate and could hence serve as better antiviral targets. High-throughput sequencing of DENV-1 genome directly from twelve, paired dengue patients' sera and then passaging these sera into the two primary mosquito vectors showed consistent and distinct sequence changes during infection. In particular, two residues in the NS5 protein coding sequence appear to be specifically acquired during infection in Ae. aegypti but not Ae. albopictus. Importantly, we identified a region within the NS3 protein coding sequence that is refractory to mutation during human and mosquito infection. Collectively, these findings provide fresh insights into antiviral targets and could serve as an approach to defining evolutionarily constrained regions for therapeutic targeting in other RNA viruses.
登革病毒（DENV）在整个热带地区引发使人虚弱并可能危及生命的急性疾病。尽管正在进行药物研发工作，但人们担心耐药菌株会迅速出现。事实上，即使是针对其他RNA病毒保守区域的抗病毒药物，随着病毒变异，其效力也会随着时间的推移而丧失。在此，我们试图确定登革病毒基因组中是否存在不仅在进化上保守，而且在突变能力上受到遗传限制，因此可以作为更好的抗病毒靶点的区域。直接对来自12对登革热患者血清的登革病毒1型基因组进行高通量测序，然后将这些血清接种到两种主要蚊虫媒介中，结果显示在感染过程中出现了一致且独特的序列变化。特别是，NS5蛋白编码序列中的两个残基似乎是在埃及伊蚊而非白纹伊蚊感染期间特异性获得的。重要的是，我们在NS3蛋白编码序列中确定了一个在人和蚊虫感染期间不易发生突变的区域。总的来说，这些发现为抗病毒靶点提供了新的见解，并可作为一种方法来确定其他RNA病毒中用于治疗靶向的进化受限区域。
