Experimental adaptation of dengue virus 1 to Aedes albopictus mosquitoes by in vivo selection

Dengue virus (DENV) is mainly transmitted by the mosquito Aedes aegypti while in Europe, Aedes albopictus causes human DENV cases since 2010. Identifying mutations that make DENV more competent for transmission by Ae. albopictus will help to predict emergence of epidemic strains. Using a protocol of in vivo selection of DENV-1 by 10 serial passages in Ae. albopictus mosquitoes, we have obtained strains presenting several adaptive mutations across the DENV genome. Importantly, the mosquito-adapted strains displayed enhanced transmission in Ae. albopictus adults and increased replicative fitness in mosquito cells. Thus, our in vivo selection may help to forecast the emergence of DENV variants with high epidemic potential in temperate regions, which is an important tool for prevention of DENV disease in Europe.