CRISPR Gene Editing of Human Primary NK and T Cells for Cancer Immunotherapy

Abstract

Antitumor activity of immune cells such as T cells and NK cells has made them auspicious therapeutic regimens for adaptive cancer immunotherapy. Enhancing their cytotoxic effects against malignancies and overcoming their suppression in tumor microenvironment (TME) may improve their efficacy to treat cancers. Clustered, regularly interspaced short palindromic repeats (CRISPR) genome editing has become one of the most popular tools to enhance immune cell antitumor activity. In this review we highlight applications and practicability of CRISPR/Cas9 gene editing and engineering strategies for cancer immunotherapy. In addition, we have reviewed several approaches to study CRISPR off-target effects.

Keywords: CAR-NK cell; CAR-T cells; CRISPR; CRISPR screening; NK cells; T cell; immunotherapy; off-target analysis.

Figure 1

CRISPR gene editing in T-cells. Several gene KO and KI have been tested in T-cells, here we summarized the targeted genes. T cell checkpoint inhibitory receptor KO such as TIM3, CTLA-4 and PD-1 KO resulted in higher antitumor activity of T-cells. CAR-T cell signaling modulation via inhibition of immunosuppressive TGF-β signaling showed significant improvement of CAR-T cells. Integration of CAR-T in TRAC locus may solve the mentioned problems with allogeneic CAR-T therapies.

Figure 2

CRISPR gene editing in NK cells. Several gene KO in NK cells have been done to improve NK cell function; here, we show some of the NK cell gene modifications. CD38 and SOCS/CISH KO can improve metabolism in NK cells. Inhibitory checkpoint receptor KO such as NKG2A and PD-1 KO. ADAM17 KO enhance CD16 mediated ADCC. Anti-CD19 CAR NK cells increase IL-15 production and enhance NK cell anti-tumor activity.