Development of Taï Forest alphavirus trans-replicase assay systems in mammalian and insect cells

Abstract

Taï Forest alphavirus (TALV) is a poorly characterised insect-specific alphavirus that has remained difficult to study since its discovery due to its inability to grow in standard cell cultures. This study investigates the TALV by developing a mammalian and insect cell-based trans-replicase assay system. To develop the assay, plasmids separating viral replication into two functional components, the replication driver (replicase) and the replication template (minigenome), were constructed and tested by transfection into respective cell lines. The trans-replicase and split trans-replicase systems were used to investigate the compatibility of the TALV minigenome with replicases of other alphaviruses and vice versa. These results offer the first functional analysis of TALV replication, revealing that it is temperature-sensitive and dependent on unknown factors. This insight establishes a baseline for future studies of this understudied alphavirus.