DNA Damage Response Signaling Is Crucial for Effective Chikungunya Virus Replication

Abstract

Viruses utilize a plethora of strategies to manipulate the host pathways and hijack host machineries for efficient replication. Several DNA and few RNA viruses are reported to interact with proteins involved in DNA damage responses (DDRs). As the DDR pathways have never been explored in alphaviruses, this investigation intended to understand the importance of the DDR pathways in chikungunya virus (CHIKV) infection in vitro, in vivo, and ex vivo models. The study revealed that CHIKV infection activated the Chk2 and Chk1 proteins associated with the DDR signaling pathways in Vero, RAW264.7, and C2C12 cells. The comet assay revealed an increase in DNA damage by 95%. Inhibition of both ATM-ATR kinases by the ATM/ATR kinase inhibitor (AAKi) showed a drastic reduction in the viral particle formation in vitro. Next, the treatment of CHIKV-infected C57BL/6 mice with this drug reduced the disease score substantially with a 93% decrease in the viral load. The same was observed in human peripheral blood mononuclear cell (hPBMC)-derived monocyte-macrophage populations. Additionally, silencing of Chk2 and Chk1 reduced viral progeny formation by 91.2% and 85.5%, respectively. Moreover, CHIKV-nsP2 was found to interact with Chk2 and Chk1 during CHIKV infection. Furthermore, CHIKV infection induced cell cycle arrest in G1 and G2 phases. In conclusion, this work demonstrated for the first time the mechanistic insights regarding the induction of the DDR pathways by CHIKV that might contribute to the designing of effective therapeutics for the control of this virus infection in the future