Vav proteins do not influence dengue virus replication but are associated with induction of phospho-ERK, IL-6, and viperin mRNA following DENV infection in vitro.

IMPORTANCE: Dengue disease is characterized by an inflammatory-mediated immunopathology, with elevated levels of circulating factors including TNF-α and IL-6. If the damaging inflammatory pathways could be blocked without loss of antiviral responses or exacerbating viral replication, then this would be of potential therapeutic benefit. The study here has investigated the Vav guanine exchange factors as a potential alternative signaling pathway that may drive dengue virus (DENV)-induced inflammatory responses, with a focus on Vav1 and 2. While Vav proteins were positively associated with mRNA for inflammatory cytokines, blocking Vav signaling didn't affect DENV replication but prevented DENV-induction of p-ERK and enhanced IL-6 (inflammatory) and viperin (antiviral) mRNA. These initial data suggest that Vav proteins could be a target that does not compromise control of viral replication and should be investigated further for broader impact on host inflammatory responses, in settings such as antibody-dependent enhancement of infection and in different cell types.