Aedes aegypti Beta-1,3-Glucan-Binding Protein Inhibits Dengue and ZIKA Virus Replication

GNBPB6, a beta-1,3-glucan-binding protein, was identified in the transcriptome of Aedes aegypti (A. aegypti) with dengue (DENV), Zika (ZIKV), and chikungunya viruses (CHIKV). In this study, we not only clarified that DENV2 and ZIKV regulate the changes in GNBPB6 expression but also identified the relationship of this gene with viral infections. The changes in GNBPB6 expression were quantified and showed a decrease in A. aegypti cells (Aag2 cells) at 2 dpi and 3 dpi and an increase at 4 dpi and 5 dpi (p < 0.05). A significant increase was observed only at 5 dpi after DENV2 infection. Subsequently, a GNBPB6 knockout (KO) cell line was constructed using the CRISPR/Cas9 system, and the DENV2 and ZIKV RNA copies, along with cell densities, were quantified and compared between the KO and wild type (WT) cells at different dpi. The result showed that DENV2 and ZIKV RNA copies were significantly increased in the KO cell line with no significant change in cell growth. Finally, DENV2 copies decreased after GNBPB6 was complemented in the KO. In conclusion, GNBPB6 knockout and complementation in Aag2 cells revealed that GNBPB6 can inhibit the replication of both DENV2 and ZIKV. These results contribute to subsequent research on mosquito-virus interactions.