Project description:Cell-based immunotherapy can control bulky tumors, but effector cell persistence, tumor resistance, inconsistencies of the manufactured product, and treatment cost continue to pose challenges. To address these limitations, we developed a triple gene-edited induced pluripotent stem cell (iPSC) platform for broad patient-based adoptive cell therapy. iPSCs were engineered to express a high affinity, non-cleavable version of the Fc receptor CD16a to augment antibody-mediated activity and a membrane-bound IL-15/IL-15R fusion (IL-15RF) protein to promote survival and maturation. The third edit was knockout of the ecto-enzyme CD38 that hydrolyzes NAD+ and is the target of the therapeutic antibody daratumumab. Natural killer (NK) cells derived from these iPSCs displayed metabolic features and gene expression profiles similar to those of adaptive NK cells that arise in response to cytomegalovirus (CMV) infection. These engineered iPSC-derived NK cells, termed iADAPT, persisted in vivo in the absence of exogenous cytokine and could be combined with daratumumab for efficient killing of multiple myeloma and acute myeloid leukemia cells both in vitro and in vivo. This strategy has broad off-the-shelf potential for the treatment of patients with advanced cancer.
Project description:Select subsets of immune effector cells have the greatest propensity to mediate antitumor responses. However, procuring these subsets is challenging, and cell-based immunotherapy is hampered by limited effector-cell persistence and lack of on-demand availability. To address these limitations, we generated a triple-gene-edited induced pluripotent stem cell (iPSC). The clonal iPSC line was engineered to express a high affinity, non-cleavable version of the Fc receptor CD16a and a membrane-bound interleukin (IL)-15/IL-15R fusion protein. The third edit was a knockout of the ecto-enzyme CD38, which hydrolyzes NAD+. Natural killer (NK) cells derived from these uniformly engineered iPSCs, termed iADAPT, displayed metabolic features and gene expression profiles mirroring those of cytomegalovirus-induced adaptive NK cells. iADAPT NK cells persisted in vivo in the absence of exogenous cytokine and elicited superior antitumor activity. Our findings suggest that unique subsets of the immune system can be modeled through iPSC technology for effective treatment of patients with advanced cancer.
Project description:Natural killer (NK) cells are innate lymphocytes with a refined ability to recognize transformed cells through a broad array of activating receptors in combination with stochastically expressed inhibitory receptors that recognize MHC-class I. Recent advances in NK cell biology have revealed a high degree of functional plasticity that can be attributed to dynamic cell-to-cell interactions in concert with transcriptional and epigenetic reprogramming. Here, we discuss how new insights into the adaptive behavior of NK cells pave the way for next generation cell therapy based on guided differentiation and selective expansion of particularly cytotoxic NK cell subsets.
Project description:Cancer immunotherapy is gaining increasing attention. However, immune checkpoints are exploited by cancer cells to evade anti-tumor immunotherapy. Here, we knocked out NKG2A, an immune checkpoint expressed on natural killer (NK) cells, in human pluripotent stem cells (hPSCs) and differentiated these hPSCs into NK (PSC-NK) cells. We show that NKG2A knockout (KO) enhances the anti-tumor and anti-viral capabilities of PSC-NK cells. NKG2A KO endows PSC-NK cells with higher cytotoxicity against HLA-E-expressing glioblastoma (GBM) cells, leukemia cells, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected cells in vitro. The NKG2A KO PSC-NK cells also exerted potent anti-tumor activity in vivo, leading to substantially suppressed tumor progression and prolonged survival of tumor-bearing mice in a xenograft GBM mouse model. These findings underscore the potential of PSC-NK cells with immune checkpoint KO as a promising cell-based immunotherapy. The unlimited supply and ease of genetic engineering of hPSCs makes genetically engineered PSC-NK an attractive option for easily accessible "off-the-shelf" cancer immunotherapy.
Project description:Natural killer (NK) cells are a type of innate lymphocytes that play key roles in immune surveillance against tumors and viral infection. NK cells distinguish abnormal cells from healthy cells by cell-cell interaction with cell surface proteins and then attack target cells via multiple mechanisms involving TRAIL, Fas Ligand, cytokine secretion, perforin, and granzymes. In addition, extracellular vesicles (EVs), including exosomes derived from NK cells (NK-EVs), possess cytotoxic capacity against tumor cells, but their characteristics and regulation by cytokines remain unknown. Here, we report that EVs derived from human NK-92 cells stimulated with IL-15 + IL-21 show enhanced cytotoxic capacity against tumor cells in a granzyme B independent manner. In addition, small RNA-seq and mass spectrometry analyses indicate that miRNA and protein profiles in EVs are altered by cytokine stimulation. We also show NK-EVs are taken up by target cells via macropinocytosis. Collectively, our findings reveal novel characteristics of NK-EVs and the mechanism of their incorporation into target cells.
Project description:The mechanisms underlying human NK cell phenotypic and functional heterogeneity are unknown. Here, we describe the emergence of diverse subsets of human NK cells selectively lacking expression of signaling proteins following cytomegalovirus (CMV) infection. The absence of B and myeloid cell-related signaling protein expression in these NK cell subsets correlated with promoter DNA hypermethylation. Intriguingly, geneome-wide analyses revealed patterns of DNA methylation that were strikingly similar between CMV-associated adaptive NK cells and cytotoxic effector CD8+ T cells, but differed from those of canonical NK cells. A total of 23 samples were analyzed (4 sorted NK cell subsets and 2 sorted T cell subsets each from 4 individual donors). In one donor only 5 subsets were analyzed. Bisulfite-converted genomic DNA was hybridized to the Illumina Human Methylation450 BeadChip
Project description:Traditional sources of NK cells, such as peripheral blood, are limited by availability and donor variability. Additionally, in vitro expansion can lead to functional exhaustion and gene editing challenges. This study aims to harness iPSC technology to provide a consistent and scalable source of NK cells, overcoming the limitations of traditional sources and enhancing the potential for cancer immunotherapy applications.
Project description:Natural killer (NK) cells, key antitumor effectors of the innate immune system, are endowed with the unique ability to spontaneously eliminate cells undergoing a neoplastic transformation. Given their broad reactivity against diverse types of cancer and close association with cancer prognosis, NK cells have gained considerable attention as a promising therapeutic target for cancer immunotherapy. NK cell-based therapies have demonstrated favorable clinical efficacies in several hematological malignancies but limited success in solid tumors, thus highlighting the need to develop new therapeutic strategies to restore and optimize anti-tumor activity while preventing tumor immune escape. The current therapeutic modalities yielding encouraging results in clinical trials include the blockade of immune checkpoint receptors to overcome the immune-evasion mechanism used by tumors and the incorporation of tumor-directed chimeric antigen receptors to enhance NK cell anti-tumor specificity and activity. These observations, together with recent advances in the understanding of NK cell activation within the tumor microenvironment, will facilitate the optimal design of NK cell-based therapy against a broad range of cancers and, more desirably, refractory cancers. [BMB Reports 2021; 54(1): 44-58].
Project description:The mechanisms underlying human NK cell phenotypic and functional heterogeneity are unknown. Here, we describe the emergence of diverse subsets of human NK cells selectively lacking expression of signaling proteins following cytomegalovirus (CMV) infection. The absence of B and myeloid cell-related signaling protein expression in these NK cell subsets correlated with promoter DNA hypermethylation. Intriguingly, geneome-wide analyses revealed patterns of DNA methylation that were strikingly similar between CMV-associated adaptive NK cells and cytotoxic effector CD8+ T cells, but differed from those of canonical NK cells.