Hematopoietic stem cell- and induced pluripotent stem cell-derived CAR-NK cells as reliable cell-based therapy solutions

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.

CAR products from novel sources: a new avenue for the breakthrough in cancer immunotherapy

Chimeric antigen receptor (CAR) T cell therapy has transformed cancer immunotherapy. However, significant challenges limit its application beyond B cell-driven malignancies, including limited clinical efficacy, high toxicity, and complex autologous cell product manufacturing. Despite efforts to improve CAR T cell therapy outcomes, there is a growing interest in utilizing alternative immune cells to develop CAR cells. These immune cells offer several advantages, such as major histocompatibility complex (MHC)-independent function, tumor microenvironment (TME) modulation, and increased tissue infiltration capabilities. Currently, CAR products from various T cell subtypes, innate immune cells, hematopoietic progenitor cells, and even exosomes are being explored. These CAR products often show enhanced antitumor efficacy, diminished toxicity, and superior tumor penetration. With these benefits in mind, numerous clinical trials are underway to access the potential of these innovative CAR cells. This review aims to thoroughly examine the advantages, challenges, and existing insights on these new CAR products in cancer treatment.

Mini-TCRs: Truncated T cell receptors to generate T cells from induced pluripotent stem cells

Allogeneic T cell platforms utilizing induced pluripotent stem cell (iPSC) technology exhibit significant promise for the facilitation of adoptive immunotherapies. While mature T cell receptor (TCR) signaling plays a crucial role in generating T cells from iPSCs, the introduction of exogenous mature TCR genes carries a potential risk of causing graft-versus-host disease (GvHD). In this study, we present the development of truncated TCRα and TCRβ chains, termed mini-TCRs, which lack variable domains responsible for recognizing human leukocyte antigen (HLA)-peptide complexes. We successfully induced cytotoxic T lymphocytes (CTLs) from iPSCs by employing mini-TCRs. Combinations of TCRα and TCRβ fragments were screened from mini-TCR libraries based on the surface localization of CD3 proteins and their ability to transduce T cell signaling. Consequently, mini-TCR-expressing iPSCs underwent physiological T cell development, progressing from the CD4 and CD8 double-positive stage to the CD8 single-positive stage. The resulting iPSC-derived CTLs exhibited comparable cytokine production and cytotoxicity in comparison to that of full-length TCR-expressing T lymphocytes when chimeric antigen receptors (CARs) were expressed. These findings demonstrate the potential of mini-TCR-carrying iPSCs as a versatile platform for CAR T cell therapy, offering a promising avenue for advancing adoptive immunotherapies.

The future of affordable cancer immunotherapy

The treatment of cancer was revolutionized within the last two decades by utilizing the mechanism of the immune system against malignant tissue in so-called cancer immunotherapy. Two main developments boosted cancer immunotherapy: 1) the use of checkpoint inhibitors, which are characterized by a relatively high response rate mainly in solid tumors; however, at the cost of serious side effects, and 2) the use of chimeric antigen receptor (CAR)-T cells, which were shown to be very efficient in the treatment of hematologic malignancies, but failed to show high clinical effectiveness in solid tumors until now. In addition, active immunization against individual tumors is emerging, and the first products have reached clinical approval. These new treatment options are very cost-intensive and are not financially compensated by health insurance in many countries. Hence, strategies must be developed to make cancer immunotherapy affordable and to improve the cost-benefit ratio. In this review, we discuss the following strategies: 1) to leverage the antigenicity of "cold tumors" with affordable reagents, 2) to use microbiome-based products as markers or therapeutics, 3) to apply measures that make adoptive cell therapy (ACT) cheaper, e.g., the use of off-the-shelf products, 4) to use immunotherapies that offer cheaper platforms, such as RNA- or peptide-based vaccines and vaccines that use shared or common antigens instead of highly personal antigens, 5) to use a small set of predictive biomarkers instead of the "sequence everything" approach, and 6) to explore affordable immunohistochemistry markers that may direct individual therapies.

Reprogramming iPSCs to study age-related diseases: Models, therapeutics, and clinical trials

The unprecedented rise in life expectancy observed in the last decades is leading to a global increase in the ageing population, and age-associated diseases became an increasing societal, economic, and medical burden. This has boosted major efforts in the scientific and medical research communities to develop and improve therapies to delay ageing and age-associated functional decline and diseases, and to expand health span. The establishment of induced pluripotent stem cells (iPSCs) by reprogramming human somatic cells has revolutionised the modelling and understanding of human diseases. iPSCs have a major advantage relative to other human pluripotent stem cells as their obtention does not require the destruction of embryos like embryonic stem cells do, and do not have a limited proliferation or differentiation potential as adult stem cells. Besides, iPSCs can be generated from somatic cells from healthy individuals or patients, which makes iPSC technology a promising approach to model and decipher the mechanisms underlying the ageing process and age-associated diseases, study drug effects, and develop new therapeutic approaches. This review discusses the advances made in the last decade using iPSC technology to study the most common age-associated diseases, including age-related macular degeneration (AMD), neurodegenerative and cardiovascular diseases, brain stroke, cancer, diabetes, and osteoarthritis.

Characterization of the biological and transcriptomic signatures of natural killer cells derived from cord blood and peripheral blood

Longitudinal studies have indicated the pivotal role of natural killer cells (NKs) in the elimination of certain infections and malignancies. Currently, perinatal blood (PB) and cord blood (CB) have been considered with promising prospective for autogenous and allogeneic NKs transplantation, yet the similarities and differences at the biological and molecular levels are largely obscure. We isolated mononuclear cells (MNCs) from PB and CB, and compared the biological phenotypes of resident NKs by flow cytometry and cell counting. Then, we turned to our well-established "3ILs" strategy and co-culture for NK cell activation and cytotoxicity analyses, respectively. Finally, with the aid of transcriptomic analyses, we further dissected the signatures of PB-NKs and CB-NKs. CB-NKs revealed superiority in cellular vitality over PB-NKs, together with variations in subpopulations. CB-NKs showed higher cytotoxicity over PB-NKs against K562 cells. Furthermore, we found both NKs revealed multifaceted conservations and differences in gene expression profiling and genetic variations, together with gene subsets and signaling pathway. Collectively, both NKs revealed multifaceted similarities and diverse variations at the cellular and transcriptomic levels. Our findings would benefit the further exploration of the biological and transcriptomic properties of CB-NKs and PB-NKs, together with the development of NK cell-based cytotherapy.

Cell Reprogramming Techniques: Contributions to Cancer Therapy

The reprogramming of terminally differentiated cells over the past few years has become important for induced pluripotent stem cells (iPSCs) in the field of regenerative medicine and disease drug modeling. At the same time, iPSCs have also played an important role in human cancer research. iPSCs derived from cancer patients can be used to simulate the early progression of cancer, for drug testing, and to study the molecular mechanism of cancer occurrence. In recent years, with the application of cellular immunotherapy in cancer therapy, patient-derived iPSC-induced immune cells (T, natural killer, and macrophage cells) solve the problem of immune rejection and have higher immunogenicity, which greatly improves the therapeutic efficiency of immune cell therapy. With the continuous progress of cancer differentiation therapy, iPSC technology can reprogram cancer cells to a more primitive pluripotent undifferentiated state, and successfully reverse cancer cells to a benign phenotype by changing the epigenetic inheritance of cancer cells. This article reviews the recent progress of cell reprogramming technology in human cancer research, focuses on the application of reprogramming technology in cancer immunotherapy and the problems solved, and summarizes the malignant phenotype changes of cancer cells in the process of reprogramming and subsequent differentiation.

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

Natural killer (NK) cells are a part of innate immunity that can be activated rapidly in response to malignant transformed cells without prior sensitization. Engineering NK cells to express chimeric antigen receptors (CARs) allows them to be directed against corresponding target tumor antigens. CAR-NK cells are regarded as a promising candidate for cellular immunotherapy alternatives to conventional CAR-T cells, due to the relatively low risk of graft-versus-host disease and safer clinical profile. Human induced pluripotent stem cells (iPSCs) are a promising renewable cell source of clinical NK cells. In the present study, we successfully introduced a third-generation CAR targeting CD19, which was validated to have effective signaling domains suitable for NK cells, into umbilical cord blood NK-derived iPSCs, followed by a single-cell clone selection and thorough iPSC characterization. The established single-cell clone of CAR19-NK/iPSCs, which is highly desirable for clinical application, can be differentiated using serum- and feeder-free protocols into functional CAR19-iNK-like cells with improved anti-tumor activity against CD19-positive hematologic cancer cells when compared with wild-type (WT)-iNK-like cells. With the feasibility of being an alternative source for off-the-shelf CAR-NK cells, a library of single-cell clones of CAR-engineered NK/iPSCs targeting different tumor antigens may be created for future clinical application.

CD19/CD22 bispecific chimeric antigen receptor‑NK‑92 cells are developed and evaluated

Anti-CD19 chimeric antigen receptor (CAR)-T cells have improved the outcomes of patients with B cell leukemia and lymphoma. However, their applications and positive outcomes remain limited. CAR-T cells are currently restricted to autologous blood as their source and their use can lead to downregulation of CD19 expression along with complications such as graft-versus-host disease and cytokine release syndrome. The present study aimed to develop anti-CD19/CD22 bispecific CAR structures using an anti-CD22 monoclonal antibody clone from chickens and analyze them in natural killer (NK)-92 cells, a human NK cell line, in vitro and in vivo. Anti-CD19/CD22 CAR-NK-92 cell cytotoxicity was assessed by the survival of target cells and counted using flow cytometry. Anti-CD22/CD19 and loop-structured anti-CD19/CD22 bi-specific CAR-NK-92 cells showed improved efficacy against OCI-Ly7 cells, a human B cell lymphoma cell line, compared with other CAR structures. These results demonstrate the potential of anti-CD19/CD22 bispecific CAR-NK cells and suggested that optimizing CAR structures in NK cells can improve the efficacy of CAR therapy.

Apoptosis inhibition enhances induced pluripotent stem cell generation during T cell reprogramming

The widespread adoption of chimeric antigen receptor (CAR)-T cell therapy has been hindered by its complex and costly manufacturing process. Induced pluripotent stem cells (iPSCs) have shown promise as a cellular immunotherapy alternative, due to their unlimited self-renewal potential in culture and capacity to differentiate into functional immune cell types. However, it is imperative to carefully select the original cell for iPSC seed preparation, as iPSCs have been found to retain the epigenetic imprint of the original somatic cells. Additionally, the efficiency of reprogramming terminal differentiated cells for immunotherapy must be addressed. Our research highlights the superiority of lymphocyte-origin cells over embryonic stem cells in functional immune cell differentiation. Furthermore, blocking Fas-FasL induced apoptosis in T cells significantly improves iPSC generation. Interestingly, transient Fas suppression in T cells does not alter the expression of Fas in the resulting iPSCs or affect their differentiation potential. This finding brings up new avenues in the field of cellular immunotherapy and provides a solution for creating high-quality and suitable iPSCs for lymphocyte differentiation for immunotherapy purposes.

Advances in NK cell therapy for brain tumors

Despite advances in treatment regimens that comprise surgery, chemotherapy, and radiation, outcome of many brain tumors remains dismal, more so when they recur. The proximity of brain tumors to delicate neural structures often precludes complete surgical resection. Toxicity and long-term side effects of systemic therapy remain a concern. Novel therapies are warranted. The field of NK cell-based cancer therapy has grown exponentially and currently constitutes a major area of immunotherapy innovation. This provides a new avenue for the treatment of cancerous lesions in the brain. In this review, we explore the mechanisms by which the brain tumor microenvironment suppresses NK cell mediated tumor control, and the methods being used to create NK cell products that subvert immune suppression. We discuss the pre-clinical studies evaluating NK cell-based immunotherapies that target several neuro-malignancies and highlight advances in molecular imaging of NK cells that allow monitoring of NK cell-based therapeutics. We review current and ongoing NK cell based clinical trials in neuro-oncology.

Generating universal chimeric antigen receptor expressing cell products from induced pluripotent stem cells: beyond the autologous CAR-T cells

ABSTRACT

Adoptive therapeutic immune cells, such as chimeric antigen receptor (CAR)-T cells and natural killer cells, have established a new generation of precision medicine based on which dramatic breakthroughs have been achieved in intractable lymphoma treatments. Currently, well-explored approaches focus on autologous cells due to their low immunogenicity, but they are highly restricted by the high costs, time consumption of processing, and the insufficiency of primary cells in some patients. Induced pluripotent stem cells (iPSCs) are cell sources that can theoretically produce indefinite well-differentiated immune cells. Based on the above facts, it may be reasonable to combine the iPSC technology and the CAR design to produce a series of highly controllable and economical "live" drugs. Manufacturing hypoimmunogenic iPSCs by inactivation or over-expression at the genetic level and then arming the derived cells with CAR have emerged as a form of "off-the-shelf" strategy to eliminate tumor cells efficiently and safely in a broader range of patients. This review describes the reasonability, feasibility, superiority, and drawbacks of such approaches, summarizes the current practices and relevant research progress, and provides insights into the possible new paths for personalized cell-based therapies.

Chimeric antigen receptor-engineered NK cells: new weapons of cancer immunotherapy with great potential

Chimeric antigen receptor (CAR)-engineered T (CAR-T) cells have obtained prominent achievement in the clinical immunotherapy of hematological malignant tumors, leading to a rapid development of cellular immunotherapy in cancer treatment. Scientists are also aware of the prospective advantages of CAR engineering in cellular immunotherapy. Due to various limitations such as the serious side effects of CAR-T therapy, researchers began to investigate other immune cells for CAR modification. Natural killer (NK) cells are critical innate immune cells with the characteristic of non-specifically recognizing target cells and with the potential to become "off-the-shelf" products. In recent years, many preclinical studies on CAR-engineered NK (CAR-NK) cells have shown their remarkable efficacy in cancer therapy and their superiority over autologous CAR-T cells. In this review, we summarize the generation, mechanisms of anti-tumor activity and unique advantages of CAR-NK cells, and then analyze some challenges and recent clinical trials about CAR-NK cells therapy. We believe that CAR-NK therapy is a promising prospect for cancer immunotherapy in the future.

A bibliometric and scientific knowledge-map study of the chimeric antigen receptor (CAR) natural killer (NK) cell-related research from 2010 to 2022

Objectives

As emerging adoptive immunotherapy after CAR-T cell therapy, CAR-NK cell therapy has been developing rapidly in recent years. Presently, the research on CAR-NK cells has become a hotspot in the field of tumor immunotherapy.

Methods

In this descriptive study, CtieSpace and VOSviewer were used to perform the bibliometric and scientific knowledge-map analysis of articles and reviews related to CAR-NK cells.

Results

5371 authors from 715 institutions in 65 countries published 1028 papers about CAR-NK cells in 346 journals. The number of publications related to CAR-NK cells was increasing overall, especially from 2018 to 2021. The United States was in a leading position. The most active institution was Univ Texas, MD Anderson Cancer Center (USA). The journal with the most publications was Frontiers in immunology, and the most co-cited journal was Blood. The researcher with the most published papers was Winfried S. Wels, while the most co-cited researcher was Shannon L Maude. The research of CAR-NK cells in hematological malignancies and solid tumors (especially the selection of targets and the evaluation of efficacy and safety) was a research hotspot in this field. The emerging topics mainly included three aspects. First, further improve the proliferation and persistence of NK cells in vivo. Secondly, optimizing and improving the CAR structure for NK cells to improve the anti-tumor ability of CAR-NK cells. Thirdly, the related research of CRISPR/Cas9 gene-editing technology in constructing engineered immune cells.

Conclusion

In this study, a bibliometric and scientific knowledge-map study provided a unique and objective perspective for the CAR-NK cell field. This information would provide a helpful reference for researchers interested in this field.

Alternative CAR Therapies: Recent Approaches in Engineering Chimeric Antigen Receptor Immune Cells to Combat Cancer

For nearly three decades, chimeric antigen receptors (CARs) have captivated the interest of researchers seeking to find novel immunotherapies to treat cancer. CARs were first designed to work with T cells, and the first CAR T cell therapy was approved to treat B cell lymphoma in 2017. Recent advancements in CAR technology have led to the development of modified CARs, including multi-specific CARs and logic gated CARs. Other immune cell types, including natural killer (NK) cells and macrophages, have also been engineered to express CARs to treat cancer. Additionally, CAR technology has been adapted in novel approaches to treating autoimmune disease and other conditions and diseases. In this article, we review these recent advancements in alternative CAR therapies and design, as well as their mechanisms of action, challenges in application, and potential future directions.

Off-the-Shelf Chimeric Antigen Receptor Immune Cells from Human Pluripotent Stem Cells

Autologous chimeric antigen receptor (CAR) T cells have expanded the scope and therapeutic potential of anti-cancer therapy. Nevertheless, autologous CAR-T therapy has been challenging due to labor some manufacturing processes for every patient, and the cost due to the complexity of the process. Moreover, T cell dysfunction results from the immunosuppressive tumor microenvironment in certain patients. Considering technical challenges in autologous donors, the development of safe and efficient allogeneic CAR-T therapy will address these issues. Since the advent of the generation of immune cells from pluripotent stem cells (PSCs), numerous studies focus on the off-the-shelf generation of CAR-immune cells derived from the universal donor PSCs, which simplifies the manufacturing process and standardizes CAR-T products. In this review, we will discuss advances in the generation of immune cells from PSCs, together with the potential and perspectives of CAR-T, CAR-macrophages, and CAR-natural killer (NK) cells in cancer treatment. The combination of PSC-derived immune cells and CAR engineering will pave the way for developing next-generation cancer immunotherapy.

Prospects for Development of Induced Pluripotent Stem Cell-Derived CAR-Targeted Immunotherapies

Technologies required to generate induced pluripotent stem cells (iPSC) were first described 15 years ago, providing a strong impetus to the field of regenerative medicine. In parallel, immunotherapy has finally emerged as a clinically meaningful modality of cancer therapy. In particular, impressive efficacy has been achieved in patients with selected haematological malignancies using ex vivo expanded autologous T cells engineered to express chimeric antigen receptors (CARs). While solid tumours account for over 90% of human cancer, they currently are largely refractory to this therapeutic approach. Nonetheless, given the considerable innovation taking place worldwide in the CAR field, it is likely that effective solutions for common solid tumours will emerge in the near future. Such a development will create significant new challenges in the scalable delivery of these complex, costly and individualised therapies. CAR-engineered immune cell products that originate from iPSCs offer the potential to generate unlimited numbers of homogeneous, standardised cell products in which multiple defined gene modification events have been introduced to ensure safety, potency and reproducibility. Here, we review some of the emerging strategies in use to engineer CAR-expressing iPSC-derived drug products.

Targeted integration of EpCAM-specific CAR in human induced pluripotent stem cells and their differentiation into NK cells

Background

Redirection of natural killer (NK) cells with chimeric antigen receptors (CAR) is attractive in developing off-the-shelf CAR therapeutics for cancer treatment. However, the site-specific integration of a CAR gene into NK cells remains challenging.

Methods

In the present study, we genetically modified human induced pluripotent stem cells (iPSCs) with a zinc finger nuclease (ZFN) technology to introduce a cDNA encoding an anti-EpCAM CAR into the adeno-associated virus integration site 1, a “safe harbour” for transgene insertion into human genome, and next differentiated the modified iPSCs into CAR-expressing iNK cells.

Results

We detected the targeted integration in 4 out of 5 selected iPSC clones, 3 of which were biallelically modified. Southern blotting analysis revealed no random integration events. iNK cells were successfully derived from the modified iPSCs with a 47-day protocol, which were morphologically similar to peripheral blood NK cells, displayed NK phenotype (CD56+CD3-), and expressed NK receptors. The CAR expression of the iPSC-derived NK cells was confirmed with RT-PCR and flow cytometry analysis. In vitro cytotoxicity assay further confirmed their lytic activity against NK cell-resistant, EpCAM-positive cancer cells, but not to EpCAM-positive normal cells, demonstrating the retained tolerability of the CAR-iNK cells towards normal cells.

Conclusion

Looking ahead, the modified iPSCs generated in the current study hold a great potential as a practically unlimited source to generate anti-EpCAM CAR iNK cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02648-4.

Induced Pluripotent Stem Cells as a Tool for Modeling Hematologic Disorders and as a Potential Source for Cell-Based Therapies

The breakthrough in human induced pluripotent stem cells (hiPSCs) has revolutionized the field of biomedical and pharmaceutical research and opened up vast opportunities for drug discovery and regenerative medicine, especially when combined with gene-editing technology. Numerous healthy and patient-derived hiPSCs for human disease modeling have been established, enabling mechanistic studies of pathogenesis, platforms for preclinical drug screening, and the development of novel therapeutic targets/approaches. Additionally, hiPSCs hold great promise for cell-based therapy, serving as an attractive cell source for generating stem/progenitor cells or functional differentiated cells for degenerative diseases, due to their unlimited proliferative capacity, pluripotency, and ethical acceptability. In this review, we provide an overview of hiPSCs and their utility in the study of hematologic disorders through hematopoietic differentiation. We highlight recent hereditary and acquired genetic hematologic disease modeling with patient-specific iPSCs, and discuss their applications as instrumental drug screening tools. The clinical applications of hiPSCs in cell-based therapy, including the next-generation cancer immunotherapy, are provided. Lastly, we discuss the current challenges that need to be addressed to fulfill the validity of hiPSC-based disease modeling and future perspectives of hiPSCs in the field of hematology.

Chimeric Antigen Receptor-Engineered Natural Killer (CAR NK) Cells in Cancer Treatment; Recent Advances and Future Prospects

Natural Killer (NK) cells are critical members of the innate immunity lymphocytes and have a critical role in host defense against malignant cells. Adoptive cell therapy (ACT) using chimeric antigen receptor (CAR) redirects the specificity of the immune cell against a target-specific antigen. ACT has recently created an outstanding opportunity for cancer treatment. Unlike CAR-armored T cells which hadnsome shortcomings as the CAR-receiving construct, Major histocompatibility complex (MHC)-independency, shorter lifespan, the potential to produce an off-the-shelf immune product, and potent anti-tumor properties of the NK cells has introduced NK cells as a potent alternative target for expression of CAR. Here, we aim to provide an updated overview on the current improvements in CAR NK design and immunobiology and describe the potential of CAR-modified NK cells as an alternative “off-the-shelf” carrier of CAR. We also provide lists for the sources of NK cells in the process of CAR NK cell production, different methods for transduction of the CAR genetic sequence to NK cells, the differences between CAR T and CAR NK, and CAR NK-targeted tumor antigens in current studies. Additionally, we provide data on recently published preclinical and clinical studies of CAR NK therapy and a list of finished and ongoing clinical trials. For achieving CAR NK products with higher efficacy and safety, we discuss current challenges in transduction and expansion of CAR NK cells, CAR NK therapy side effects, and challenges that limit the optimal efficacy of CAR NK cells and recommend possible solutions to enhance the persistence, function, safety, and efficacy of CAR NK cells with a special focus on solid tumors.

Hematopoietic stem cell- and induced pluripotent stem cell-derived CAR-NK cells as reliable cell-based therapy solutions

Hematopoietic stem cell‐ (HSC) and induced pluripotent stem (iPS) cell‐derived natural killer (NK) cells containing engineered functions, such as chimeric antigen receptors (CAR), offer great promise for the treatment of seemingly incurable oncological malignancies. Today, some of the main challenges of CAR cell‐based therapeutics are the long manufacturing time and safety of the cell sources used. Additional challenges include avoiding graft vs host disease (GVHD) and cytokine release syndrome (CRS). Here, we show compelling evidence for the use of NK cell therapeutics as a reliable off‐the‐shelf option, as they address key issues. Furthermore, we highlight how iPS cells and directed differentiation toward HSC and NK cells address industrial scalability and safety.