Emerging CRISPR Approaches for Countering Immune Evasion: Insight from Recent Studies

Cancer immunotherapy has recently become an essential approach for treating cancer, showing considerable promise as a substitute for surgery, radiation therapy, and conventional chemotherapy. It primarily aims to boost the host’s natural defense system to com-bat cancer malignancies by utilizing components of immune checkpoint blockades (ICBs), mainly programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), and along with elements of adoptive cellular therapies (ACTs) like Chimeric Antigen Receptor (CAR) therapy, T Cell Receptor (TCR) therapy and Tu-mor-Infiltrating Lymphocyte (TIL) therapy. However, cancer cells tend to undermine the effectiveness of cancer immunotherapeutic strategies by employing one or more immune evasion mechanisms. The present review briefly discusses the key mechanisms of cancer immune evasion and highlights how the CRISPR/Cas9 systems, as gene editing tools, are set to enhance cancer immunotherapy for treating various challenging cancers. We emphasize that CRISPR/Cas9 systems can be used to explore and positively alter the genes of the immune system, boosting the effectiveness of cancer immunotherapy by editing immune checkpoints, TILs, and CAR-T cells, and disrupting genes facilitating tumors to evade the immune system.