Confirmation that host reverse transcriptase is required to maintain persistent dengue virus infections in mosquito cells

Abstract

In 2008 it was revealed that C6/36 cells challenged with Dengue virus serotype 2 (DENV-2 strain NGC) show cytopathic effects (CPE) but can recover via 2-day serial passaging leading to morphologically normal cell cultures despite persistent infection with DENV-2. In 2009 it was hypothesized that ability to accommodate DENV-2 was dependent on host reverse-transcriptase (HRT) activity. This was proven in 2016 using the RT inhibitor azidothymidine (AZT, a nucleoside analogue and antiretroviral drug) to treat C6/36 cells challenged with DENV-1. Here these results are confirmed using a different RT inhibitor tenofovir disoproxil fumarate (TDF) with different C6/36 cell line and DENV-2. In addition, we confirm earlier work from 2021 that persistent HRT activity is also required to maintain persistent tolerance to DENV-2 infections. Specifically, TDF treatment (0.1 mM) blocked viral accommodation and returned cells to the lethal infection pathway characterized by CPE. This phenomenon has practical applications for screening grossly healthy, living commercial crustaceans and insects for viral pathogens and for research on the development of viral tolerant breeding stocks for commercial crustaceans and insects.