CRISPR-Cas based targeting of host and viral genes as an antiviral strategy.

Viral infections in human are leading cause of mortality and morbidity across the globe. Several viruses (including HIV and Herpesvirus), have evolved ingenious strategies to evade host-immune system and persist life-long. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated (Cas) is an ancient antiviral system recently discovered in bacteria that has shown tremendous potential as a precise, invariant genome editing tool. Using CRISPR-Cas based system to activate host defenses or genetic modification of viral genome can provide novel, exciting and successful antiviral mechanisms and treatment modalities. In this review, we will provide progress on the CRISPR-Cas based antiviral approaches that facilitate clearance of virus-infected cells and/or prohibit virus infection or replication. We will discuss on the possibilities of CRIPSR-Cas as prophylaxis and therapy in viral infections and review the challenges of this potent gene editing technology.