Orchestrated efforts on host network hijacking: Processes governing virus replication

Dai, Xiaofeng; Hakizimana, Olivier; Zhang, Xuanhao; Kaushik, Aman Chandra; Zhang, Jianying

The innate immune response is the first-line host defense against viral invasion, which is rapid and functions toward either infection clearance or process halt until an adaptive response is initiated [69, 70] . The innate immune response is interconnected with and fed into the scheme of adaptive response via interferons (IFNs), which belong to cytokines and are required for pathogen elimination [69] . Upon viral infection, the molecular patterns of viruses are detected by various cellular sensors including Toll-like receptors (TLRs) and intracellular helicases such as RIG-I and MDA5, which activate IFN-regulatory factors (IRFs) such as IRF3 to induce the expression of a spectrum of IFN-responsive genes. Typical IFNresponsive gene products include, e.g., protein kinase R (PKR), endoribonuclease L (RNase L), promyelocytic leukemia (PML) nuclear bodies, and cellular restriction factors [71, 72] . Viruses have evolved various mechanisms to subvert the host immune response including, e.g. blocking the induction process of IFN response and suppressing IFN response genes.