Gene-Based Natural Killer Cell Therapies for the Treatment of Pediatric Hematologic Malignancies

Abstract

Pediatric blood cancers are among the most common malignancies that afflict children. Intensive chemotherapy is not curative in many cases, and novel therapies are urgently needed. NK cells hold promise for use as immunotherapeutic effectors due to their favorable safety profile, intrinsic cytotoxic properties, and potential for genetic modification that can enhance specificity and killing potential. NK cells can be engineered to express CARs targeting tumor-specific antigens, to downregulate inhibitory and regulatory signals, to secrete cytokine, and to optimize interaction with small molecule engagers. Understanding NK cell biology is key to designing immunotherapy for clinical translation.

Keywords: Blood cancer; Genetic engineering; Immunotherapy; NK cell.

Fig. 1.

Methods of Genetic Engineering in NK Cells. (A) Viral-mediated, including γ-retroviral and lentiviral vectors. (B) Nonviral mediated, including electroporation, Charge-altering releasable transporters, and transposon systems. (C) Targeted knockdown and knock-in, including zinc-finger nucleases (ZFN), transcription activator-like nucleases (TALENs), and CRISPR/Cas9 systems as NK cell engineering methods.

Fig. 2.

NK Cell Engineering for Therapeutic Application. Schematic depicting (A) Expression of CARs targeting TAA to enhance cytotoxicity and NK cell activation. (B) Constitutive secretion or (C) membrane-tethered cytokine can sustain NK cell activation and persistence. (D) Enhanced surface expression of chemokine receptors can mediate NK cell localization to tumor along chemokine gradients. (E) Engager molecules (BiKEs or TriKEs) can be combined with engineered CD16 to direct powerful ADCC of tumor cells. Incorporation of IL15 in the small molecule can further support persistence.