Generation and Functional Characterization of Anti-CD19 Chimeric Antigen Receptor-Natural Killer Cells from Human Induced Pluripotent Stem Cells

OGT and OGA gene-edited human induced pluripotent stem cells for dissecting the functional roles of O-GlcNAcylation in hematopoiesis

Hematopoiesis continues throughout life to produce all types of blood cells from hematopoietic stem cells (HSCs). Metabolic state is a known regulator of HSC self-renewal and differentiation, but whether and how metabolic sensor O-GlcNAcylation, which can be modulated via an inhibition of its cycling enzymes O-GlcNAcase (OGA) and O-GlcNAc transferase (OGT), contributes to hematopoiesis remains largely unknown. Herein, isogenic, single-cell clones of OGA-depleted (OGAi) and OGT-depleted (OGTi) human induced pluripotent stem cells (hiPSCs) were successfully generated from the master hiPSC line MUSIi012-A, which were reprogrammed from CD34+ hematopoietic stem/progenitor cells (HSPCs) containing epigenetic memory. The established OGAi and OGTi hiPSCs exhibiting an increase or decrease in cellular O-GlcNAcylation concomitant with their loss of OGA and OGT, respectively, appeared normal in phenotype and karyotype, and retained pluripotency, although they may favor differentiation toward certain germ lineages. Upon hematopoietic differentiation through mesoderm induction and endothelial-to-hematopoietic transition, we found that OGA inhibition accelerates hiPSC commitment toward HSPCs and that disruption of O-GlcNAc homeostasis affects their commitment toward erythroid lineage. The differentiated HSPCs from all groups were capable of giving rise to all hematopoietic progenitors, thus confirming their functional characteristics. Altogether, the established single-cell clones of OGTi and OGAi hiPSCs represent a valuable platform for further dissecting the roles of O-GlcNAcylation in blood cell development at various stages and lineages of blood cells. The incomplete knockout of OGA and OGT in these hiPSCs makes them susceptible to additional manipulation, i.e., by small molecules, allowing the molecular dynamics studies of O-GlcNAcylation.

Development of NK cell-based cancer immunotherapies through receptor engineering

Natural killer (NK) cell-based immunotherapies are attracting increasing interest in the field of cancer treatment. Early clinical trials have shown promising outcomes, alongside satisfactory product efficacy and safety. Recent developments have greatly increased the therapeutic potential of NK cells by endowing them with enhanced recognition and cytotoxic capacities. This review focuses on surface receptor engineering in NK cell therapy and discusses its impact, challenges, and future directions.Most approaches are based on engineering with chimeric antigen receptors to allow NK cells to target specific tumor antigens independent of human leukocyte antigen restriction. This approach has increased the precision and potency of NK-mediated recognition and elimination of cancer cells. In addition, engineering NK cells with T-cell receptors also mediates the recognition of intracellular epitopes, which broadens the range of target peptides. Indirect tumor peptide recognition by NK cells has also been improved by optimizing immunoglobulin constant fragment receptor expression and signaling. Indeed, engineered NK cells have an improved ability to recognize and destroy target cells coated with specific antibodies, thereby increasing their antibody-dependent cellular cytotoxicity. The ability of NK cell receptor engineering to promote the expansion, persistence, and infiltration of transferred cells in the tumor microenvironment has also been explored. Receptor-based strategies for sustained NK cell functionality within the tumor environment have also been discussed, and these strategies providing perspectives to counteract tumor-induced immunosuppression.Overall, receptor engineering has led to significant advances in NK cell-based cancer immunotherapies. As technical challenges are addressed, these innovative treatments will likely reshape cancer immunotherapy.

Application Prospect of Induced Pluripotent Stem Cells in Organoids and Cell Therapy

Since its inception, induced pluripotent stem cell (iPSC) technology has been hailed as a powerful tool for comprehending disease etiology and advancing drug screening across various domains. While earlier iPSC-based disease modeling and drug assessment primarily operated at the cellular level, recent years have witnessed a significant shift towards organoid-based investigations. Organoids derived from iPSCs offer distinct advantages, particularly in enabling the observation of disease progression and drug metabolism in an in vivo-like environment, surpassing the capabilities of iPSC-derived cells. Furthermore, iPSC-based cell therapy has emerged as a focal point of clinical interest. In this review, we provide an extensive overview of non-integrative reprogramming methods that have evolved since the inception of iPSC technology. We also deliver a comprehensive examination of iPSC-derived organoids, spanning the realms of the nervous system, cardiovascular system, and oncology, as well as systematically elucidate recent advancements in iPSC-related cell therapies.

Chimeric antigen receptor natural killer cells: a promising antitumor immunotherapy

Chimeric antigen receptor (CAR) T cells have been successfully used in adoptive cell therapy for malignancies. However, some obstacles, including side effects such as graft-versus-host disease and cytokine release syndrome, therapy resistance, limited sources, as well as high cost, limited the application of CAR T cells. Recently, CAR natural killer (NK) cells have been pursued as the effector cells for adoptive immunotherapy for their attractive merits of strong intrinsic antitumor activity and relatively mild side effects. Additionally, CAR NK cells can be available from various sources and do not require strict human leukocyte antigen matching, which suggests them as promising "off-the-shelf" products for clinical application. Although the use of CAR NK cells is restrained by the limited proliferation and impaired efficiency within the immunosuppressive tumor microenvironment, further investigation in optimizing CAR structure and combination therapies will overcome these challenges. This review will summarize the advancement of CAR NK cells, CAR NK cell manufacture, the clinical outcomes of CAR NK therapy, the challenges in the field, and prospective solutions. Besides, we will discuss the emerging application of other immune cells for CAR engineering. Collectively, this comprehensive review will provide a valuable and informative summary of current progress and evaluate challenges and future opportunities of CAR NK cells in tumor treatment.

Advances in CAR-Engineered Immune Cell Generation: Engineering Approaches and Sourcing Strategies

Chimeric antigen receptor T-cell (CAR-T) therapy has emerged as a highly efficacious treatment modality for refractory and relapsed hematopoietic malignancies in recent years. Furthermore, CAR technologies for cancer immunotherapy have expanded from CAR-T to CAR-natural killer cell (CAR-NK), CAR-cytokine-induced killer cell (CAR-CIK), and CAR-macrophage (CAR-MΦ) therapy. Nevertheless, the high cost and complex manufacturing processes of ex vivo generation of autologous CAR products have hampered broader application. There is an urgent need to develop an efficient and economical paradigm shift for exploring new sourcing strategies and engineering approaches toward generating CAR-engineered immune cells to benefit cancer patients. Currently, researchers are actively investigating various strategies to optimize the preparation and sourcing of these potent immunotherapeutic agents. In this work, the latest research progress is summarized. Perspectives on the future of CAR-engineered immune cell manufacturing are provided, and the engineering approaches, and diverse sources used for their development are focused upon.

Anti-TIM3 chimeric antigen receptor-natural killer cells from engineered induced pluripotent stem cells effectively target acute myeloid leukemia cells

BACKGROUND

Acute myeloid leukemia (AML) is a clonal malignant disorder which originates from a small number of leukemia-initiating cells or leukemic stem cells (LSCs)-the subpopulation that is also the root cause of relapsed/refractory AML. Chimeric antigen receptor (CAR)-T cell therapy has proved successful at combating certain hematologic malignancies, but has several hurdles that limit its widespread applications. CAR-natural killer (NK) cells do not carry the risk of inducing graft-versus-host disease (GvHD) frequently associated with allogeneic T cells, thereby overcoming time-consuming, autologous cell manufacturing, and have relatively safer clinical profiles than CAR-T cells. The present study aimed to generate anti-TIM3 CAR-NK cells targeting LSCs from a clonal master induced pluripotent stem cells engineered with the third-generation anti-TIM3 CAR.

METHODS

A clonal master umbilical cord blood NK-derived induced pluripotent stem cell (iPSC) line, MUSIi013-A, was used as a starting cells for engineering of an anti-TIM3 CAR harboring TIM3 scFv fragment (clone TSR-022), CD28, 4-1BB, and CD3ζ signaling (CAR-TIM3). The established CAR-TIM3 iPSCs were further differentiated under serum- and feeder-free conditions into functional CAR-TIM3 NK cells and tested for its anti-tumor activity against various TIM3-positive AML cells.

RESULTS

We successfully established a single-cell clone of CAR-TIM3 iPSCs, as validated by genomic DNA sequencing as well as antibody and antigen-specific detection. We performed thorough iPSC characterization to confirm its retained pluripotency and differentiation capacity. The established CAR-TIM3 iPSCs can be differentiated into CAR-TIM3 NK-like cells, which were further proven to have enhanced anti-tumor activity against TIM3-positive AML cells with minimal effect on TIM3-negative cells when compared with wild-type (WT) NK-like cells from parental iPSCs.

CONCLUSIONS

iPSCs engineered with CARs, including the established single-cell clone CAR-TIM3 iPSCs herein, are potential alternative cell source for generating off-the-shelf CAR-NK cells as well as other CAR-immune cells. The feasibility of differentiation of functional CAR-TIM3 NK cells under serum- and feeder-free conditions support that Good Manufacturing Practice (GMP)-compliant protocols can be further established for future clinical applications.