Fallecker Catherine, Caporossi Alban, Rechoum Yassine, Garzoni Frederic, Larrat Sylvie, François Olivier, Fender Pascal, Morand Patrice, Berger Imre, Petit Marie-Anne, Drouet Emmanuel
Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000, Grenoble, France.
Institut de Biologie et de Pathologie (IBP), Centre Hospitalier Universitaire (CHU) Grenoble-Alpes, CS10217, 38043, Grenoble Cedex 9, France.
Virol J. 2017 Aug 22;14(1):161. doi: 10.1186/s12985-017-0828-z.
The existing literature about HCV association with, and replication in mosquitoes is extremely poor. To fill this gap, we performed cellular investigations aimed at exploring (i) the capacity of HCV E1E2 glycoproteins to bind on Aedes mosquito cells and (ii) the ability of HCV serum particles (HCVsp) to replicate in these cell lines.
First, we used purified E1E2 expressing baculovirus-derived HCV pseudo particles (bacHCVpp) so we could investigate their association with mosquito cell lines from Aedes aegypti (Aag-2) and Aedes albopictus (C6/36). We initiated a series of infections of both mosquito cells (Ae aegypti and Ae albopictus) with the HCVsp (Lat strain - genotype 3) and we observed the evolution dynamics of viral populations within cells over the course of infection via next-generation sequencing (NGS) experiments.
Our binding assays revealed bacHCVpp an association with the mosquito cells, at comparable levels obtained with human hepatocytes (HepaRG cells) used as a control. In our infection experiments, the HCV RNA (+) were detectable by RT-PCR in the cells between 21 and 28 days post-infection (p.i.). In human hepatocytes HepaRG and Ae aegypti insect cells, NGS experiments revealed an increase of global viral diversity with a selection for a quasi-species, suggesting a structuration of the population with elimination of deleterious mutations. The evolutionary pattern in Ae albopictus insect cells is different (stability of viral diversity and polymorphism).
These results demonstrate for the first time that natural HCV could really replicate within Aedes mosquitoes, a discovery which may have major consequences for public health as well as in vaccine development.
关于丙型肝炎病毒（HCV）与蚊子的关联以及在蚊子体内复制的现有文献极为匮乏。为填补这一空白，我们进行了细胞研究，旨在探索（i）HCV E1E2糖蛋白与埃及伊蚊细胞结合的能力，以及（ii）HCV血清颗粒（HCVsp）在这些细胞系中复制的能力。
首先，我们使用表达纯化E1E2的杆状病毒衍生的HCV假颗粒（bacHCVpp），以便研究它们与埃及伊蚊（Aag - 2）和白纹伊蚊（C6/36）的蚊子细胞系的关联。我们用HCVsp（Lat株 - 基因型3）对两种蚊子细胞（埃及伊蚊和白纹伊蚊）进行了一系列感染，并通过下一代测序（NGS）实验观察了感染过程中细胞内病毒群体的进化动态。
我们的结合试验表明bacHCVpp与蚊子细胞有关联，其水平与用作对照的人肝细胞（HepaRG细胞）相当。在我们的感染实验中，感染后21至28天（p.i.），通过RT - PCR可在细胞中检测到HCV RNA（+）。在人肝细胞HepaRG和埃及伊蚊昆虫细胞中，NGS实验显示总体病毒多样性增加，并选择了一种准种，这表明群体结构的形成伴随着有害突变的消除。白纹伊蚊昆虫细胞中的进化模式不同（病毒多样性和多态性的稳定性）。
这些结果首次证明天然HCV确实可以在伊蚊体内复制，这一发现可能对公共卫生以及疫苗开发产生重大影响。
