Overcoming barriers to solid tumor immunotherapy using natural killer cell therapies designed to mimic intraepithelial group 1 innate lymphoid cells

Abstract

Abstract Our work aims to design cell-based immunotherapies for maximum solid tumor efficacy by leveraging insights from tissue-resident cells and single-cell RNA sequencing of innate immune cell subsets present within patient tumors. We discovered that by co-culturing peripheral blood natural killer cells (pbNKs) with irradiated epithelial tumor cells, we induced high expression of surface integrins, increased cytotoxicity and IFNg production, decreased sensitivity to TGFb, and significantly enhanced solid tumoroid infiltration. The cells were profiled using CyTOF and we determined that they closely resembled intraepithelial group 1 innate lymphoid cells, so we refer to them as ieILC1-like cells. We quantified the cytotoxicity of ieILC1-like cells against a variety of target cell lines and determined that they are broadly cytotoxic and capable of antibody-dependent cellular cytotoxicity, which was assessed using cetuximab. Tumor-infiltrating capacity was modeled using 3D tumoroids grown from single-cell suspensions of epithelial tumor cell lines in basement membrane extracts; ieILC1-like NK cells or pbNK cells were fluorescently labeled, added to tumoroids, and imaged using confocal microscopy. We stimulated the cells in the presence or absence of overnight TGFb exposure to determine the extent of TGFb-mediated immunosuppression. ieILC1-like cells were more resistant to TGFb and produced significantly more IFNg after stimulation than their pbNK counterparts. Preliminary in vivo work indicates that ieILC1-like cells perform comparably to K562-expanded NK cells. Thus, ieILC1-like NK cells represent a novel class of cell therapy that are more capable of infiltrating solid tumors and resisting their immunosuppressive cues. Supported by NIH R35DE030054.