Together, these findings show that hnCD16-iNK cells combined with mAbs are highly effective against hematologic malignancies and solid tumors that are typically resistant to NK cellmediated killing, demonstrating the feasibility of producing a standardized off-the-shelf engineered NK cell therapy with improved ADCC properties to treat malignancies that are otherwise refractory. == Visual Abstract == == Introduction == Cell-based anticancer immunotherapies have experienced great advances in the past few years.1Although chimeric CT96 antigen receptor (CAR)expressing T cells have garnered the most attention, clinical trials using natural killer (NK) cells have demonstrated that they are safe and effective.2-5In recent clinical trials, NK cells have been shown to possess potent antiacute myeloid leukemia effects without eliciting serious adverse effects, such as graft-versus-host disease, neurotoxicity, and cytokine release syndrome.4,6,7However, the adoptive transfer of NK cells to patients with B-cell lymphoma, ovarian carcinoma, or renal cell carcinoma has demonstrated low efficacy and has lacked specific tumor-targeting receptors8-10. NK cellbased clinical trials have used a variety of cell sources, including peripheral bloodderived NK (PB-NK) cells, umbilical cord bloodisolated NK (UCB-NK) cells, umbilical cord blood CD34+cellderived NK cells, and the NK cell line NK-92.7,11-14Although these trials have demonstrated clinical safety, each cell source is confined by limitations.11,12,15The NK cell yields and subsets from PB-NK cells and UCB-NK cells are extremely donor dependent and are not derived from a single renewable source, making product standardization and multiple-dosing strategies difficult.16,17Additionally, genetic modification of primary NK cells is challenging and highly variable, making it difficult to develop consistent and reproducible engineered NK cell therapies.18Lastly, although NK-92 cells are from a single source, they lack many standard NK cell markers and, like a transformed cell, must be mitotically inactivated before infusion to prevent uncontrolled proliferation.13This eliminates the ability of NK-92 cell treatment to expand upon infusion, a critical factor for NK cell antitumor activity.2,4,7,19In contrast, human being induced pluripotent stem cell (iPSC)derived NK (iNK) cells can be produced in a homogenous and clinically scalable manner, are capable of being genetically edited in the iPSC stage, and have proven in vivo proliferative capacity.20-23Therefore, iNK cells are an important source of standardized off-the-shelf NK cell therapy to treat refractory malignancies.24 NK cellmediated antitumor activity is usually regulated through a repertoire of activating and inhibitory cell surface receptors, including natural cytotoxicity receptors, killer immunoglobulin receptors, and immunoglobulin G (IgG) Fc receptor FcRIIIa (CD16a).4,5,25CD16a binds the Fc portion of IgG when attached to a target cell to Lomitapide mesylate mediate antibody-dependent cell-mediated cytotoxicity (ADCC), a key effector and tumor antigen-targeting mechanism of NK cells.26The binding affinity of CD16a to IgG varies between its allelic variants. a alternative source for human being induced pluripotent stem cellderived NK (hnCD16-iNK) cells. Compared with unmodified iNK cells and peripheral bloodderived NK (PB-NK) cells, hnCD16-iNK cells proved to be highly resistant to activation-induced cleavage of CD16a. We found that hnCD16-iNK cells were functionally adult and exhibited enhanced ADCC against multiple tumor focuses on. In vivo xenograft studies using a human being B-cell lymphoma shown that treatment with hnCD16-iNK cells and anti-CD20 mAb led to significantly improved regression of B-cell lymphoma compared with treatment utilizing anti-CD20 mAb with PB-NK cells or unmodified iNK cells. hnCD16-iNK cells, combined with anti-HER2 mAb, also mediated improved survival in an ovarian malignancy xenograft model. Together, these findings display that hnCD16-iNK cells combined with mAbs are highly effective against Lomitapide mesylate hematologic malignancies and solid tumors that are typically resistant to NK cellmediated killing, demonstrating the feasibility of producing a standardized off-the-shelf designed NK cell therapy with improved ADCC properties to treat malignancies that are normally refractory. == Visual Abstract == == Intro == Cell-based anticancer immunotherapies have experienced great advances in the past few years.1Although chimeric antigen receptor (CAR)expressing T cells have garnered probably the most attention, medical trials using natural killer (NK) cells have proven that they are safe and effective.2-5In recent medical trials, NK cells have been shown to possess potent antiacute myeloid leukemia effects without eliciting severe adverse effects, such as graft-versus-host disease, neurotoxicity, and cytokine release syndrome.4,6,7However, the adoptive transfer of NK cells to individuals with B-cell lymphoma, ovarian carcinoma, or renal cell carcinoma has demonstrated low effectiveness and has lacked specific tumor-targeting receptors8-10. NK cellbased medical trials have used a variety of cell sources, including peripheral bloodderived NK (PB-NK) cells, umbilical wire bloodisolated NK (UCB-NK) cells, umbilical wire blood CD34+cellderived NK cells, and the NK cell collection NK-92.7,11-14Although these trials have proven medical safety, each cell source is usually limited by limitations.11,12,15The NK cell yields and subsets from PB-NK cells and UCB-NK cells are extremely donor dependent and are not derived from a Lomitapide mesylate single renewable source, making product standardization and multiple-dosing strategies hard.16,17Additionally, genetic modification of primary NK cells is challenging and highly variable, making it difficult to develop consistent and reproducible engineered NK cell therapies.18Lastly, although NK-92 cells are from a single source, they lack many standard NK cell markers and, like a transformed cell, must be mitotically inactivated before infusion to prevent uncontrolled proliferation.13This eliminates the ability of NK-92 cell treatment to expand upon infusion, a critical factor for NK cell antitumor activity.2,4,7,19In contrast, human being induced pluripotent stem cell (iPSC)derived NK (iNK) cells can be produced in a homogenous and clinically scalable manner, are capable of being genetically edited in the iPSC stage, and have proven in vivo proliferative capacity.20-23Therefore, iNK cells are an important source of standardized off-the-shelf NK cell therapy to treat refractory malignancies.24 NK cellmediated antitumor activity is controlled through a repertoire of activating and inhibitory cell surface receptors, including organic cytotoxicity receptors, killer immunoglobulin receptors, and immunoglobulin G (IgG) Fc receptor FcRIIIa (CD16a).4,5,25CD16a binds the Fc portion of IgG when attached to a target cell to mediate antibody-dependent cell-mediated cytotoxicity (ADCC), a key effector and tumor antigen-targeting mechanism of NK cells.26The binding affinity of CD16a to IgG varies between its allelic variants. Specifically, CD16a with valine at position 158 (158V) has a higher affinity for IgG than does CD16a with phenylalanine at the same position.27,28In addition to the clinical observation that NK cells enhance the efficacy of therapeutic monoclonal antibodies (mAbs),29CD16a offers been shown to Lomitapide mesylate play an Lomitapide mesylate important part in the clinical establishing, because patients with high-affinity CD16a with 158V have had higher objective responses and progression-free survival when treated with cetuximab, trastuzumab, or rituximab.30-32Notably, the CD16a molecule is cleaved from the surface of activated NK cells by a disintegrin and metalloproteinase-17 (ADAM17), which is constitutively expressed about the surface of NK cells,33-36leading to NK cell dysfunction and reduced ADCC capacity.35Our group previously identified the ADAM17 cleavage site of CD16 and produced a high-affinity noncleavable version of CD16a (hnCD16) by mutating the cleavage site in the 158V variant.33 We hypothesized that executive iNK cells with hnCD16 would overcome the challenges faced with NK cell therapies. Specifically, we demonstrate that iNK cells uniformly expressing hnCD16 (hnCD16-iNK cells) exhibit potent ADCC against hematological malignancies and solid tumors. Notably, a multidose routine of hnCD16-iNK cells derived from an designed clonal human being iPSC collection given with anti-CD20 mAb treatment mediated potent activity and improved long-term survival inside a mouse xenograft lymphoma model. Consequently, standardized off-the-shelf hnCD16-iNK cells with enhanced ADCC effector function, in combination with readily available anti-tumor mAbs,.