Engineering chimeric antigen receptor neutrophils from human pluripotent stem cells for targeted cancer immunotherapy

Induced Pluripotent Stem Cells-Based Regenerative Therapies in Treating Human Aging-Related Functional Decline and Diseases

A significant increase in life expectancy worldwide has resulted in a growing aging population, accompanied by a rise in aging-related diseases that pose substantial societal, economic, and medical challenges. This trend has prompted extensive efforts within many scientific and medical communities to develop and enhance therapies aimed at delaying aging processes, mitigating aging-related functional decline, and addressing aging-associated diseases to extend health span. Research in aging biology has focused on unraveling various biochemical and genetic pathways contributing to aging-related changes, including genomic instability, telomere shortening, and cellular senescence. The advent of induced pluripotent stem cells (iPSCs), derived through reprogramming human somatic cells, has revolutionized disease modeling and understanding in humans by addressing the limitations of conventional animal models and primary human cells. iPSCs offer significant advantages over other pluripotent stem cells, such as embryonic stem cells, as they can be obtained without the need for embryo destruction and are not restricted by the availability of healthy donors or patients. These attributes position iPSC technology as a promising avenue for modeling and deciphering mechanisms that underlie aging and associated diseases, as well as for studying drug effects. Moreover, iPSCs exhibit remarkable versatility in differentiating into diverse cell types, making them a promising tool for personalized regenerative therapies aimed at replacing aged or damaged cells with healthy, functional equivalents. This review explores the breadth of research in iPSC-based regenerative therapies and their potential applications in addressing a spectrum of aging-related conditions.

Chimeric antigen receptor therapies: Development, design, and implementation

Chimeric antigen receptor (CAR) T and natural killer (NK) cell therapies represent a promising strategy for the treatment of cancers and other chronic diseases. Engineered CAR constructs endow immune cells with the ability to target desired antigens with high specificity, allowing for directed responses to antigen-expressing cells. CAR T and NK cells have shown marked success in the treatment of hematologic malignancies, although there remains a large population of patients with disease that fails to respond to CAR therapies, and their efficacy in solid tumors is still limited. In this review, we provide a broad overview of the development, design, and implementation of CAR therapies from bench to bedside. We discuss the building blocks of CAR constructs and how these can be manipulated to optimize CAR functionality, review the possible sources of T and NK cells for CAR therapies, and examine the limitations of both CAR T and CAR NK cells. Finally, we discuss recent breakthroughs in the CAR field and consider how these advances may affect the success of CAR therapies in the years to come.

The road ahead for chimeric antigen receptor T cells

Chimeric antigen receptor T (CART) cell therapy is an innovative form of immunotherapy that has shown remarkable and long-term responses in patients with B-cell malignancies. Over the years, the field has made significant progress in our understanding of the successes and challenges associated with CART cell therapy. In this review, we provide an overview of the current state of CART cell therapy in the clinic. We detail current challenges including patient access, CART-associated toxicity, tumor heterogeneity, CART cell trafficking, the tumor microenvironment, and different CART cell fates. With each challenge, we review lessons learned, potential solutions and outline areas for future development. Finally, we discuss how the field of engineered cell therapy is moving into the treatment of solid tumors and other diseases beyond cancer.

Engineering innate immune cells for cancer immunotherapy

Innate immune cells, including natural killer cells, macrophages and γδ T cells, are gaining prominence as promising candidates for cancer immunotherapy. Unlike conventional T cells, these cells possess attributes such as inherent antitumor activity, rapid immune responses, favorable safety profiles and the ability to target diverse malignancies without requiring prior antigen sensitization. In this Review, we examine the engineering strategies used to enhance their anticancer potential. We discuss challenges associated with each cell type and summarize insights from preclinical and clinical work. We propose strategies to address existing barriers, providing a perspective on the advancement of innate immune engineering as a powerful modality in anticancer treatment.

Human induced pluripotent stem cells derived neutrophils display strong anti-microbial potencies

Neutrophils are essential innate immune cells with unusual anti-microbial properties while dysfunctions of neutrophils lead to severe health problems such as lethal infections. Generation of neutrophils from human induced pluripotent stem cells (hiPSCs) is highly promising to produce off-the-shelf neutrophils for transfusion therapies. However, the anti-microbial potencies of hiPSCs derived neutrophils (iNEUs) remain less documented. Here, we develop a scalable approach to generate iNEUs in a chemical defined condition. iNEUs display typical neutrophil characters in terms of phagocytosis, migration, formation of neutrophil extracellular traps (NETs), etc. Importantly, iNEUs display a strong killing potency against various bacteria such as K.pneumoniae, P.aeruginosa, E.coli and S.aureus. Moreover, transfusions of iNEUs in mice with neutrophil dysfunction largely enhance their survival in lethal infection of different bacteria. Together, our data show that hiPSCs derived neutrophils hold strong anti-microbial potencies to protect severe infections under neutrophil dysfunction conditions.

Are monocytes a preferable option to develop myeloid cell-based therapies for solid tumors?

In the last two decades, novel and promising cell-based therapies have populated the treatment landscape for haematological tumors. However, commonly exploited T and NK cell-based therapies show limited applicability to solid tumors. This is mainly given by the impaired tumor trafficking capability and limited effector activity of these cells within a highly immunosuppressive tumor microenvironment. Myeloid cells spontaneously home to tumors and can thus be reprogrammed and/or engineered to directly attack tumor cells or locally and selectively deliver therapeutically relevant payloads that may improve the efficacy of immunotherapy against difficult-to-access solid tumors. In the context of myeloid cell-based therapies, adoptive transfer of monocytes has often been overshadowed by infusion of differentiated macrophages or hematopoietic stem cell transplantation despite their promising therapeutic potential. Here, we summarize the recent improvements and benefits of using monocytes for the treatment of solid tumors, their current clinical applications and the challenges of their use as well as some possible strategies to overcome them.

Harnessing myeloid cells in cancer

Cancer-associated myeloid cells due to their plasticity play dual roles in both promoting and inhibiting tumor progression. Myeloid cells with immunosuppressive properties play a critical role in anti-cancer immune regulation. Cells of different origin, such as tumor associated macrophages (TAMs), tumor associated neutrophils (TANs), myeloid derived suppressor cells (also called MDSCs) and eosinophils are often expanded in cancer patients and significantly influence their survival, but also the outcome of anti-cancer therapies. For this reason, the variety of preclinical and clinical studies to modulate the activity of these cells have been conducted, however without successful outcome to date. In this review, pro-tumor activity of myeloid cells, myeloid cell-specific therapeutic targets, in vivo studies on myeloid cell re-polarization and the impact of myeloid cells on immunotherapies/genetic engineering are addressed. This paper also summarizes ongoing clinical trials and the concept of chimeric antigen receptor macrophage (CAR-M) therapies, and suggests future research perspectives, offering new opportunities in the development of novel clinical treatment strategies.

Microbiome dysbiosis, neutrophil recruitment and mesenchymal transition of mesothelial cells promotes peritoneal metastasis of colorectal cancer

Peritoneal metastasis (PM) is common in colorectal cancer (CRC), yet its underlying mechanisms are poorly understood. Here, we explored the transcriptional profile of CRC, PM and adjacent tissues revealing key players that facilitate PM. Single-cell analysis of 48 matched samples from 12 patients revealed that remodeling of malignant cells and the tumor microenvironment promotes CRC progression and metastasis. Multiplexed imaging confirmed depletion in PM by enrichment in CRC tissues of neutrophils associated with mucosal immunity disruption, intestinal microbiota dysbiosis and mesenchymal transition of both cancerous and mesothelial cells. Functional analyses in cell lines, organoids and in vivo models demonstrated that dysbiosis promoted inflammation and protumor neutrophil recruitment, while coupled mesenchymal transition of malignant and mesothelial cells disrupted the stromal structure and increased cancer cell invasiveness. Our findings suggest that targeting mesothelial cells and tumor microenvironment remodeling may offer therapeutic strategies for CRC-PM.

CAR-T cells in the treatment of multiple myeloma: an encouraging cell therapy

Multiple myeloma (MM) is a malignant disease of plasma cells that accounts for approximately 10% of all hematological malignancies and is characterized by a clonal proliferation of malignant plasma cells in the bone marrow. Numerous therapeutic strategies, including proteasome inhibitors, immunomodulators, monoclonal antibodies against CD38 and autologous stem cell transplantation, have prolonged the median survival of MM patients. Nevertheless, almost all MM patients suffer disease relapses due to drug resistance and eventually die from MM or MM-related complications. Chimeric antigen receptor (CAR) T-cell therapy is a novel immunotherapy strategy for MM and has shown encouraging results in several clinical trials. However, the use of CAR T-cell therapy for the treatment of MM is still associated with several difficulties, including antigen escape, poor persistence, an immunosuppressive microenvironment, cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, CAR T-cell-associated encephalopathy syndrome, cytopenia, and infections. In this review, we describe in detail the target antigens of CAR T cells in MM. We also comprehensively discuss recent innovations in the development of CAR T cells to improve clinical efficacy and strategies to overcome the limitations of CAR T-cell therapy in MM.

Forward programming of hPSCs to neutrophils using chemically defined media

Polymorphonuclear neutrophils (PMNs), the most abundant leukocytes circulating in human blood, are pivotal players in the innate immune system. In recent years, PMNs have gained increasing recognition for their significant involvement in the pathogenesis of a wide array of human diseases, including sepsis, pulmonary conditions, autoimmune disorders, and various cancers. Due to their terminally differentiated state, PMNs possess a short lifespan and exhibit limited proliferative potential, which makes continuous replenishment from the bone marrow essential for maintaining immune homeostasis. This demand underscores the need for efficient, reliable, and robust methods of PMN production. In this study, we evaluated three forward programming protocols and one directed differentiation protocol aimed at generating PMNs from human pluripotent stem cells (hPSCs). We analyzed not only their differentiation efficiency but also the transcriptomic profiles and functional capabilities of the resulting PMNs. Our findings revealed that both the forward programming method and the directed differentiation approach can successfully generate functional PMNs. Furthermore, by fine-tuning the culture media at various stages during forward programming, we identified an optimal protocol that significantly enhances hematopoietic differentiation potential and promotes the functional maturity of the neutrophils.

Pluripotent stem cell-based immunotherapy: advances in translational research, cell differentiation, and gene modifications

Cell-based immunotherapy, recognized as living drugs, is revolutionizing clinical treatment to advanced cancer and shaping the landscape of biomedical research for complex diseases. The differentiation of human pluripotent stem cells (PSCs) emerges as a novel platform with the potential to generate an unlimited supply of therapeutic immune cells, especially when coupled with gene modification techniques. PSC-based immunotherapy is expected to meet the vast clinical demand for living drugs. Here, we examine recent preclinical and clinical advances in PSC-based immunotherapy, focusing on PSC gene modification strategies and differentiation methods for producing therapeutic immune cells. We also discuss opportunities in this field and challenges in cell quality and safety and stresses the need for further research and transparency to unlock the full potential of PSC immunotherapies.

Adoptive Cell Therapy from the Dish: Potentiating Induced Pluripotent Stem Cells

Background

The clinical success of autologous adoptive cell therapy (ACT) is substantial but wide application is challenged by the quality and quantity of the patient's immune cells and the need for personalized manufacturing processes. Induced pluripotent stem cells (iPSCs) can be differentiated into immune effectors and thus provide an alternative, allogeneic cell source for ACT. Here, we compare iPSC-derived immune effectors to their PBMC-derived counterparts and review iPSC-derived ACT products currently under preclinical and clinical development.

Summary

iPSC-derived T cells, NK cells, macrophages, and neutrophils largely mimic their PBMC-derived counterparts in terms of cell-surface marker expression and cytotoxic effector functions. iPSC-derived immune effectors can be engineered with chimeric antigen receptors and other activating receptors to redirect their cytotoxic potential specifically to tumor-associated antigens (TAAs). However, several differences between iPSC- and PBMC-derived immune effectors remain and have inspired additional engineering strategies to enhance the antitumor capacity of iPSC-derived immune effectors.

Key Messages

iPSCs can be engineered to facilitate the generation of immune effectors with homogenous specificity for TAAs and enhanced effector functions. TAA-specific and functionally enhanced iPSC-derived T and NK cells are currently undergoing clinical evaluation in phase 1 trials. Engineered iPSC-derived macrophages and neutrophils are in preclinical development.

Neutrophil Engulfment in Cancer: Friend or Foe?

Neutrophils, the most abundant circulating white blood cells, are essential for the initial immune response to infection and injury. Emerging research reveals a dualistic function of neutrophils in cancer, where they can promote or inhibit tumor progression. This dichotomy is influenced by the tumor microenvironment, with neutrophils capable of remodeling the extracellular matrix, promoting angiogenesis, or alternatively inducing cancer cell death and enhancing immune responses. An intriguing yet poorly understood aspect of neutrophil-cancer interactions is the phenomenon of neutrophil engulfment by cancer cells, which has been observed across various cancers. This process, potentially mediated by LC3-associated phagocytosis (LAP), raises questions about whether it serves as a mechanism for immune evasion or contributes to tumor cell death through pathways like ferroptosis. This review examines current knowledge on neutrophil development, their roles in cancer, and the mechanisms of LAP in neutrophil engulfment by tumor cells. We discuss how manipulating LAP impacts cancer progression and may represent a therapeutic strategy. We also explore neutrophils' potential as delivery vehicles for cancer therapeutic agents. Understanding the complex functions of tumor-associated neutrophils (TANs) and the molecular mechanisms underlying LAP in cancer may open new avenues for effective therapeutic interventions and mitigate potential risks.

Advances in Engineering Myeloid Cells for Cell Therapy Applications

Myeloid cells, including macrophages, neutrophils, dendritic cells, and myeloid-derived suppressor cells, play crucial roles in the innate immune system, contributing to immune defense, tissue homeostasis, and organ development. They have tremendous potential as therapeutic tools for diseases such as cancer and autoimmune disorders, but harnessing cell engineering strategies to enhance potency and expand applications is challenging. Recent advancements in stem cell research have made it possible to differentiate human embryonic stem cells and induce pluripotent stem cells into various cell types, including myeloid cells, offering a promising new approach to generate myeloid cells for cell therapy. In this review, we explore the latest techniques for the genetic engineering of myeloid cells, discussing both established and emerging methodologies. We examine the challenges faced in this field and the therapeutic potential of engineered myeloid cells. We also describe examples of engineered macrophages, neutrophils, and dendritic cells in various disease contexts. By providing a detailed overview of the current state and future directions, we aim to highlight progress and ongoing efforts toward harnessing the full therapeutic potential of genetically engineered myeloid cells.

Underappreciated layers of antibody-mediated immune synapse architecture and dynamics

The biologic activities of antibody drugs are dictated by structure-function relationships-emerging from the kind, composition, and degree of interactions with a target antigen and with soluble and cellular antibody receptors of the innate immune system. These activities are canonically understood to be both modular: antigen recognition is driven by the heterodimeric antigen-binding fragment, and innate immune recruitment by the homodimeric constant/crystallizable fragment. The model that treats these domains with a high degree of independence has served the field well but is not without limitations. Here, we consider how new insights, particularly from structural studies, complicate the model of neat biophysical separation between these domains and shape our understanding of antibody effector functions. The emerging model endeavors to explain the phenotypic impact of both antibody intrinsic characteristics and extrinsic features-fitting them within a spatiotemporal paradigm that better accounts for observed antibody activities. In this review, we will use insights from recent models of classical complement complexes and T cell immune synapse formation to explore how structural differences in antibody-mediated immune synapses may relate to their functional diversity.

Exploring CAR-macrophages in non-tumor diseases: Therapeutic potential beyond cancer

BACKGROUND

After significant advancements in tumor treatment, personalized cell therapy based on chimeric antigen receptors (CAR) holds promise for transforming the management of various diseases. CAR-T therapy, the first approved CAR cell therapy product, has demonstrated therapeutic potential in treating infectious diseases, autoimmune disorders, and fibrosis. CAR-macrophages (CAR-Ms) are emerging as a promising approach in CAR immune cell therapy, particularly for solid tumor treatment, highlighting the feasibility of using macrophages to eliminate pathogens and abnormal cells.

AIM OF REVIEW

This review summarizes the progress of CAR-M therapy in non-tumor diseases and discusses various CAR intracellular activation domain designs and their potential to optimize therapeutic effects by modulating interactions between cellular components in the tissue microenvironment and CAR-M. Additionally, we discuss the characteristics and advantages of CAR-M therapy compared to traditional medicine and CAR-T/NK therapy, as well as the challenges and prospects for the clinical translation of CAR-M.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review provides a comprehensive understanding of CAR-M for the treatment of non-tumor diseases, analyzes the advantages and characteristics of CAR-M therapy, and highlights the important impact of CAR intracellular domain design on therapeutic efficacy. In addition, the challenges and clinical translation prospects of developing CAR-M as a new cell therapy are discussed.

Activated neutrophils: A next generation cellular immunotherapy

Cell therapies are at the forefront of novel therapeutics. Neutrophils, despite being the most populous immune cells in human blood circulation, are not considered a viable option for cellular therapies because of their short lifespan and poor understanding of their role in the pathophysiology of various diseases. In inflammatory conditions, neutrophils exhibit an activated phenotype. Activation brings about significant changes to neutrophil biology such as increased lifespan, inflammatory cytokine secretion, and enhanced effector functions. Activated neutrophils also possess the potential to stimulate the downstream immune response and are described as essential effectors in the immune response to tumors. This makes activated neutrophils an interesting candidate for cell therapies. Here, we review the biology of activated neutrophils in detail. We discuss the different ways neutrophils can be activated and the effect they have on other immune cells for stimulation of downstream immune response. We review the conditions where activated neutrophil therapy can be therapeutically beneficial and discuss the challenges associated with their eventual translation. Overall, this review summarizes the current state of understanding of neutrophil-based immunotherapies and their clinical potential.

Neutrophils in cancer drug resistance: Roles and therapeutic opportunities

The tumor microenvironment (TME) is closely associated with the therapeutic response and clinical outcome of cancer drug therapies, which mainly include immunotherapy, chemotherapy and targeted therapy. Neutrophils that infiltrate tumors, also known as tumor-associated neutrophils (TANs), constitute a primary part of the TME. However, the functional importance of TANs in cancer drug therapy has long been overlooked because of their relatively short life span. Recent studies have shown that TANs play crucial protumoral or antitumoral roles in cancer drug treatment, largely because of their diversity and plasticity. This review describes the development, heterogeneity and recruitment of neutrophils in the context of cancer and emphasizes the role and mechanisms of TANs in cancer drug resistance. Additionally, several potential neutrophil-targeted strategies are discussed.

The development and application of chimeric antigen receptor natural killer (CAR-NK) cells for cancer therapy: current state, challenges and emerging therapeutic advances

Immunotherapy has transformed the landscape of cancer treatment, with chimeric antigen receptor (CAR)-engineered T (CAR-T) cell therapy emerging as a front runner in addressing some hematological malignancies. Despite its considerable efficacy, the occurrence of severe adverse effects associated with CAR-T cell therapy has limited their scope and prompted the exploration of alternative therapeutic strategies. Natural killer (NK) cells, characterized by both their innate cytotoxicity and ability to lyse target cells without the constraint of peptide specificity conferred by a major histocompatibility complex (MHC), have similarly garnered attention as a viable immunotherapy. As such, another therapeutic approach has recently emerged that seeks to combine the continued success of CAR-T cell therapy with the flexibility of NK cells. Clinical trials involving CAR-engineered NK (CAR-NK) cell therapy have exhibited promising efficacy with fewer deleterious side effects. This review aims to provide a concise overview of the cellular and molecular basis of NK cell biology, facilitating a better understanding of advancements in CAR design and manufacturing. The focus is on current approaches and strategies employed in CAR-NK cell development, exploring at both preclinical and clinical settings. We will reflect upon the achievements, advantages, and challenges intrinsic to CAR-NK cell therapy. Anticipating the maturation of CAR-NK cell therapy technology, we foresee its encouraging prospects for a broader range of cancer patients and other conditions. It is our belief that this CAR-NK progress will bring us closer to making significant strides in the treatment of refractory and recurrent cancers, as well as other immune-mediated disorders.

Advancements in adoptive CAR immune cell immunotherapy synergistically combined with multimodal approaches for tumor treatment

Adoptive immunotherapy, notably involving chimeric antigen receptor (CAR)-T cells, has obtained Food and Drug Administration (FDA) approval as a treatment for various hematological malignancies, demonstrating promising preclinical efficacy against cancers. However, the intricate and resource-intensive autologous cell processing, encompassing collection, expansion, engineering, isolation, and administration, hamper the efficacy of this therapeutic modality. Furthermore, conventional CAR T therapy is presently confined to addressing solid tumors due to impediments posed by physical barriers, the potential for cytokine release syndrome, and cellular exhaustion induced by the immunosuppressive and heterogeneous tumor microenvironment. Consequently, a strategic integration of adoptive immunotherapy with synergistic multimodal treatments, such as chemotherapy, radiotherapy, and vaccine therapy etc., emerges as a pivotal approach to surmount these inherent challenges. This collaborative strategy holds the key to addressing the limitations delineated above, thereby facilitating the realization of more precise personalized therapies characterized by heightened therapeutic efficacy. Such synergistic strategy not only serves to mitigate the constraints associated with adoptive immunotherapy but also fosters enhanced clinical applicability, thereby advancing the frontiers of therapeutic precision and effectiveness.

Novel immunotherapeutic approaches in gastric cancer

Gastric cancer is a malignant tumor that ranks third in cancer-related deaths worldwide. Early-stage gastric cancer can often be effectively managed through surgical resection. However, the majority of cases are diagnosed in advanced stages, where outcomes with conventional radiotherapy and chemotherapy remain unsatisfactory. Immunotherapy offers a novel approach to treating molecularly heterogeneous gastric cancer by modifying the immunosuppressive tumor microenvironment. Immune checkpoint inhibitors and adoptive cell therapy are regarded as promising modalities in cancer immunotherapy. Food and Drug Administration-approved programmed death-receptor inhibitors, such as pembrolizumab, in combination with chemotherapy, have significantly extended overall survival in gastric cancer patients and is recommended as a first-line treatment. Despite challenges in solid tumor applications, adoptive cell therapy has demonstrated efficacy against various targets in gastric cancer treatment. Among these approaches, chimeric antigen receptor-T cell therapy research is the most widely explored and chimeric antigen receptor-T cell therapy targeting claudin18.2 has shown acceptable safety and robust anti-tumor capabilities. However, these advancements primarily remain in preclinical stages and further investigation should be made to promote their clinical application. This review summarizes the latest research on immune checkpoint inhibitors and adoptive cell therapy and their limitations, as well as the role of nanoparticles in enhancing immunotherapy.

Single cell autofluorescence imaging reveals immediate metabolic shifts of neutrophils with activation across biological systems

Neutrophils, the most abundant leukocytes in human peripheral circulation, are crucial for the innate immune response. They are typically quiescent but rapidly activate in response to infection and inflammation, performing diverse functions such as oxidative burst, phagocytosis, and NETosis, which require significant metabolic adaptation. Deeper insights into such metabolic changes will help identify regulation of neutrophil functions in health and diseases. Due to their short lifespan and associated technical challenges, the metabolic processes of neutrophils are not completely understood. This study uses optical metabolic imaging (OMI), which entails optical redox ratio and fluorescence lifetime imaging microscopy of intrinsic metabolic coenzymes NAD(P)H and FAD to assess the metabolic state of single neutrophils. Primary human neutrophils were imaged in vitro under a variety of activation conditions and metabolic pathway inhibitors, while metabolic and functional changes were confirmed with mass spectrometry, oxidative burst, and NETosis measurements. Our findings show that neutrophils undergo rapid metabolic remodeling to a reduced redox state indicated by changes in NAD(P)H lifetime and optical redox ratio, with a shift to an oxidized redox state during activation. Additionally, single cell OMI analysis reveals a heterogeneous metabolic response across neutrophils and human donors to live pathogen infection ( Pseudomonas aeruginosa and Toxoplasma gondii ). Finally, consistent OMI changes with activation were confirmed between in vitro human and in vivo zebrafish larvae neutrophils. This study demonstrates the potential of OMI as a versatile tool for studying neutrophil metabolism and underscores its use across different biological systems, offering insights into neutrophil metabolic activity and function at a single cell level.

The Pluripotent Path to Immunotherapy

Adoptive cell therapy (ACT) enhances the patient's own immune cells' ability to identify and eliminate cancer cells. Several immune cell types are currently being applied in autologous ACT, including T cells, natural killer (NK) cells, and macrophages. The cells' inherent antitumor capacity can be used, or they can be targeted toward tumor-associated antigen through expression of a chimeric antigen receptor (CAR). Although CAR-based ACT has achieved great results in hematologic malignancies, the accessibility of ACT is limited by the autologous nature of the therapy. Induced pluripotent stem cells (iPSCs) hold the potential to address this challenge, because they can provide an unlimited source for the in vitro generation of immune cells. Various immune subsets have been generated from iPSC for application in ACT, including several T-cell subsets (αβT cells, mucosal-associated invariant T cells, invariant NKT [iNKT] cells, and γδT cells), as well as NK cells, macrophages, and neutrophils. iPSC-derived αβT, NK, and iNKT cells are currently being tested in phase I clinical trials. The ability to perform (multiplexed) gene editing at the iPSC level and subsequent differentiation into effector populations not only expands the arsenal of ACT but allows for development of ACT utilizing cell types which cannot be efficiently obtained from peripheral blood or engineered and expanded in vitro.

Neutrophil chemotaxis score and chemotaxis-related genes have the potential for clinical application to prognosticate the survival of patients with tumours

As frontline cells, the precise recruitment of neutrophils is crucial for resolving inflammation and maintaining the homeostasis of the organism. Increasing evidence suggests the pivotal role of neutrophil chemotaxis in cancer progression and metastasis. Here, we collected clinical data and peripheral blood samples from patients with tumours to examine the alterations in the neutrophil quantity and chemotactic function using the Cell Chemotaxis Analysis Platform (CCAP). Transcriptome sequencing data of pan-cancer were obtained from The Cancer Genome Atlas (TCGA). Using the least absolute shrinkage and selection operator (LASSO) Cox regression model, we selected a total of 29 genes from 155 neutrophil- and chemotaxis-related genes to construct the ChemoScore model. Meanwhile, nomogram-based comprehensive model was established for clinical application. Furthermore, immunofluorescence (IF) staining was employed to assess the relationship between the neutrophils infiltrating and the survival outcomes of tumours. In this observational study, the chemotactic function of neutrophils was notably diminished in patients. The establishment and validation of ChemoScore suggested neutrophil chemotaxis to be a risk factor in most tumours, whereby higher scores were associated with poorer survival outcomes and were correlated with various immune cells and malignant biological processes. Moreover, IF staining of tumour tissue substantiated the adverse correlation between neutrophil infiltration and the survival of patients with lung adenocarcinoma (P = 0.0002) and colon adenocarcinoma (P = 0.0472). Taken together, patients with tumours demonstrated a decrease in chemotactic function. ChemoScore potentially prognosticates the survival of patients with tumours. Neutrophil chemotaxis provides novel directions and theoretical foundations for anti-tumour treatment.

Potential alternatives to αβ-T cells to prevent graft-versus-host disease (GvHD) in allogeneic chimeric antigen receptor (CAR)-based cancer immunotherapy: A comprehensive review

Currently, CAR-T cell therapy relies on an individualized manufacturing process in which patient's own T cells are infused back into patients after being engineered and expanded ex vivo. Despite the astonishing outcomes of autologous CAR-T cell therapy, this approach is endowed with several limitations and drawbacks, such as high cost and time-consuming manufacturing process. Switching the armature of CAR-T cell therapy from autologous settings to allogeneic can overcome several bottlenecks of the current approach. Nevertheless, the use of allogeneic CAR-T cells is limited by the risk of life-threatening GvHD. Thus, in recent years, developing a method to move CAR-T cell therapy to allogeneic settings without the risk of GvHD has become a hot research topic in this field. Since the alloreactivity of αβ T-cell receptor (TCR) accounts for developing GvHD, several efforts have been made to disrupt endogenous TCR of allogeneic CAR-T cells using gene editing tools to prevent GvHD. Nonetheless, the off-target activity of gene editing tools and their associated genotoxicities, as well as the negative consequences of endogenous TCR disruption, are the main concerns of using this approach. As an alternative, CAR αβ-T cells can be replaced with other types of CAR-engineered cells that are capable of recognizing and killing malignant cells through CAR while avoiding the induction of GvHD. These alternatives include T cell subsets with restricted TCR repertoire (γδ-T, iNKT, virus-specific T, double negative T cells, and MAIT cells), killer cells (NK and CIK cells), non-lymphocytic cells (neutrophils and macrophages), stem/progenitor cells, and cell-free extracellular vesicles. In this review, we discuss how these alternatives can move CAR-based immunotherapy to allogeneic settings to overcome the bottlenecks of autologous manner without the risk of GvHD. We comprehensively discuss the pros and cons of these alternatives over the traditional CAR αβ-T cells in light of their preclinical studies and clinical trials.

Neutrophil generation from hematopoietic progenitor cells and induced pluripotent stem cells (iPSCs): potential applications

Neutrophils are the most frequent immune cell type in peripheral blood, performing an essential role against pathogens. People with neutrophil deficiencies are susceptible to deadly infections, highlighting the importance of generating these cells in host immunity. Neutrophils can be generated from hematopoietic progenitor cells (HPCs) and embryonic stem cells (ESCs) using a cocktail of cytokines. In addition, induced pluripotent stem cells (iPSCs) can be differentiated into various functional cell types, including neutrophils. iPSCs can be derived from differentiated cells, such as skin and blood cells, by reprogramming them to a pluripotent state. Neutrophil generation from iPSCs involves a multistep process that can be performed through feeder cell-dependent and feeder cell-independent manners. Various cytokines and growth factors, in particular, stem cell facto, IL-3, thrombopoietin and granulocyte colony-stimulating factor (G-CSF), are used in both methods, especially, G-CSF which induces the final differentiation of neutrophils in the granulocyte lineage. iPSC-derived neutrophils have been used as a valuable tool for studying rare genetic disorders affecting neutrophils. The iPSC-derived neutrophils can also be used for disease modeling, infection research and drug discovery. However, several challenges must be overcome before iPSC-derived neutrophils can be used therapeutically in transplantation medicine. This review provides an overview of the commonly employed protocols for generating neutrophils from HPCs, ESCs and iPSCs and discusses the potential applications of the generated cells in research and medicine.

Beyond CAR T cells: exploring alternative cell sources for CAR-like cellular therapies

Chimeric antigen receptor (CAR)-T cell therapy has led to remarkable clinical outcomes in the treatment of hematological malignancies. However, challenges remain, such as limited infiltration into solid tumors, inadequate persistence, systemic toxicities, and manufacturing insufficiencies. The use of alternative cell sources for CAR-based therapies, such as natural killer cells (NK), macrophages (MΦ), invariant Natural Killer T (iNKT) cells, γδT cells, neutrophils, and induced pluripotent stem cells (iPSC), has emerged as a promising avenue. By harnessing these cells' inherent cytotoxic mechanisms and incorporating CAR technology, common CAR-T cell-related limitations can be effectively mitigated. We herein present an overview of the tumoricidal mechanisms, CAR designs, and manufacturing processes of CAR-NK cells, CAR-MΦ, CAR-iNKT cells, CAR-γδT cells, CAR-neutrophils, and iPSC-derived CAR-cells, outlining the advantages, limitations, and potential solutions of these therapeutic strategies.

Tumour-associated neutrophils: Potential therapeutic targets in pancreatic cancer immunotherapy

Pancreatic cancer (PC) is a highly malignant tumour of the digestive system with poor therapeutic response and low survival rates. Immunotherapy has rapidly developed in recent years and has achieved significant outcomes in numerous malignant neoplasms. However, responses to immunotherapy in PC are rare, and the immunosuppressive and desmoplastic tumour microenvironment (TME) significantly hinders their efficacy in PC. Tumour-associated neutrophils (TANs) play a crucial role in the PC microenvironment and exert a profound influence on PC immunotherapy by establishing a robust stromal shelter and restraining immune cells to assist PC cells in immune escape, which may subvert the current status of PC immunotherapy. The present review aims to offer a comprehensive summary of the latest progress in understanding the involvement of TANs in PC desmoplastic and immunosuppressive functions and to emphasise the potential therapeutic implications of focusing on TANs in the immunotherapy of this deleterious disease. Finally, we provide an outlook for the future use of TANs in PC immunotherapy.

PTP1B phosphatase dampens iPSC-derived neutrophil motility and antimicrobial function

Neutrophils are rapidly recruited to sites of infection and are critical for pathogen clearance. Therapeutic use of primary neutrophils has been limited, as they have a short lifespan and are not amenable to genetic manipulation. Human induced pluripotent stem cells (iPSCs) can provide a robust source of neutrophils for infusion and are genetically tractable. However, current work has indicated that dampened intracellular signaling limits iPSC-derived neutrophil (iNeutrophil) cellular activation and antimicrobial response. Here, we show that protein tyrosine phosphatase 1B (PTP1B) inhibits intracellular signaling and dampens iNeutrophil effector function. Deletion of the PTP1B phosphatase increased PI3K and ERK signaling and was associated with increased F-actin polymerization, cell migration, and phagocytosis. In contrast, other effector functions like NETosis and reactive oxygen species production were reduced. PTP1B-deficient neutrophils were more responsive to Aspergillus fumigatus and displayed rapid recruitment and control of hyphal growth. Accordingly, depletion of PTP1B increased production of inflammatory factors including the neutrophil chemokine interleukin-8. Taken together, these findings suggest that PTP1B limits iNeutrophil motility and antimicrobial function.

Designing Chimeric Antigen Receptors for Myeloid Immune Cells

Chimeric antigen receptor (CAR) myeloid cells are a promising potential alternative to CAR T-cells for solid tumor therapies. Myeloid CAR therapies have been tested in preclinical studies by either transferring established CD3-based T-cell CARs into myeloid cells, or by designing myeloid-specific signaling domains. While ITAM-based myeloid receptors (e.g., Fc-receptors) were often outperformed by classic CD3ζ-designs, toll-interleukin-1 receptor (TIR) and Mer receptor tyrosine kinase (MerTK) have shown promise for improving myeloid-specific cell activation. Addition of CD147 to stimulate matrix-metalloproteinase production and of cytokine genes (e.g. interferon γ) may further improve the efficacy of CAR-myeloid cells in the tumor immune microenvironment. While most work focused on CAR monocytes and macrophages, CAR-DC cells are also being studied as tumor vaccines in preclinical and early clinical phases. Lastly, even though CAR neutrophils are disadvantaged by a short lifespan, they could become viable by transfusing them as undifferentiated myeloid progenitors instead of effector cells. Here, we summarize the status of preclinical and clinical research on different CAR myeloid strategies, compare receptor designs, outline gaps in knowledge, conflicting results, and approaches for future preclinical studies that will allow translation of these technologies to the clinic.

Progress and pitfalls of gene editing technology in CAR-T cell therapy: a state-of-the-art review

CAR-T cell therapy has shown remarkable promise in treating B-cell malignancies, which has sparked optimism about its potential to treat other types of cancer as well. Nevertheless, the Expectations of CAR-T cell therapy in solid tumors and non-B cell hematologic malignancies have not been met. Furthermore, safety concerns regarding the use of viral vectors and the current personalized production process are other bottlenecks that limit its widespread use. In recent years the use of gene editing technology in CAR-T cell therapy has opened a new way to unleash the latent potentials of CAR-T cell therapy and lessen its associated challenges. Moreover, gene editing tools have paved the way to manufacturing CAR-T cells in a fully non-viral approach as well as providing a universal, off-the-shelf product. Despite all the advantages of gene editing strategies, the off-target activity of classical gene editing tools (ZFNs, TALENs, and CRISPR/Cas9) remains a major concern. Accordingly, several efforts have been made in recent years to reduce their off-target activity and genotoxicity, leading to the introduction of advanced gene editing tools with an improved safety profile. In this review, we begin by examining advanced gene editing tools, providing an overview of how these technologies are currently being applied in clinical trials of CAR-T cell therapies. Following this, we explore various gene editing strategies aimed at enhancing the safety and efficacy of CAR-T cell therapy.

Neutrophils, an emerging new therapeutic platform

Neutrophils possess unique characteristics that render them indispensable to health, and patients with irregular neutrophil counts or functions suffer from increased morbidity and mortality. As neutrophils are short-lived postmitotic cells, genetic aberrations cannot be corrected directly in neutrophils and must be targeted in their progenitors. Neutrophils are increasingly being contemplated for a range of therapeutic applications, including restoration or modulation of immune function and targeting of solid tumors. This review addresses the state-of-the-art in neutrophil transfusions and their possible applications for infectious disease prevention and treatment. It offers a landscape of the most recent gene therapy approaches to address neutrophil-related genetic diseases. We also discuss how ongoing research could broaden the applicability of neutrophil-based therapies to solid cancer treatments and beyond.

Neutrophils in Cancer immunotherapy: friends or foes?

Neutrophils play a Janus-faced role in the complex landscape of cancer pathogenesis and immunotherapy. As immune defense cells, neutrophils release toxic substances, including reactive oxygen species and matrix metalloproteinase 9, within the tumor microenvironment. They also modulate the expression of tumor necrosis factor-related apoptosis-inducing ligand and Fas ligand, augmenting their capacity to induce tumor cell apoptosis. Their involvement in antitumor immune regulation synergistically activates a network of immune cells, bolstering anticancer effects. Paradoxically, neutrophils can succumb to the influence of tumors, triggering signaling cascades such as JAK/STAT, which deactivate the immune system network, thereby promoting immune evasion by malignant cells. Additionally, neutrophil granular constituents, such as neutrophil elastase and vascular endothelial growth factor, intricately fuel tumor cell proliferation, metastasis, and angiogenesis. Understanding the mechanisms that guide neutrophils to collaborate with other immune cells for comprehensive tumor eradication is crucial to enhancing the efficacy of cancer therapeutics. In this review, we illuminate the underlying mechanisms governing neutrophil-mediated support or inhibition of tumor progression, with a particular focus on elucidating the internal and external factors that influence neutrophil polarization. We provide an overview of recent advances in clinical research regarding the involvement of neutrophils in cancer therapy. Moreover, the future prospects and limitations of neutrophil research are discussed, aiming to provide fresh insights for the development of innovative cancer treatment strategies targeting neutrophils.

Convergence of nanomedicine and neutrophils for drug delivery

Neutrophils have recently emerged as promising carriers for drug delivery due to their unique properties including rapid response toward inflammation, chemotaxis, and transmigration. When integrated with nanotechnology that has enormous advantages in improving treatment efficacy and reducing side effects, neutrophil-based nano-drug delivery systems have expanded the repertoire of nanoparticles employed in precise therapeutic interventions by either coating nanoparticles with their membranes, loading nanoparticles inside living cells, or engineering chimeric antigen receptor (CAR)-neutrophils. These neutrophil-inspired therapies have shown superior biocompatibility, targeting ability, and therapeutic robustness. In this review, we summarized the benefits of combining neutrophils and nanotechnologies, the design principles and underlying mechanisms, and various applications in disease treatments. The challenges and prospects for neutrophil-based drug delivery systems were also discussed.

Engineering and Targeting Neutrophils for Cancer Therapy

Neutrophils are the most abundant white blood cells in the circulation and act as the first line of defense against infections. Increasing evidence suggests that neutrophils possess heterogeneous phenotypes and functional plasticity in human health and diseases, including cancer. Neutrophils play multifaceted roles in cancer development and progression, and an N1/N2 paradigm of neutrophils in cancer is proposed, where N1 neutrophils exert anti-tumor properties while N2 neutrophils display tumor-supportive and immune-suppressive functions. Selective activation of beneficial neutrophil population and targeted inhibition or re-polarization of tumor-promoting neutrophils has shown an important potential in tumor therapy. In addition, due to the natural inflammation-responsive and physical barrier-crossing abilities, neutrophils and their derivatives (membranes and extracellular vesicles (EVs)) are regarded as advanced drug delivery carriers for enhanced tumor targeting and improved therapeutic efficacy. In this review, the recent advances in engineering neutrophils for drug delivery and targeting neutrophils for remodeling tumor microenvironment (TME) are comprehensively presented. This review will provide a broad understanding of the potential of neutrophils in cancer therapy.

Beyond binary: bridging neutrophil diversity to new therapeutic approaches in NSCLC

Neutrophils represent the most abundant myeloid cell subtype in the non-small-cell lung cancer (NSCLC) tumor microenvironment (TME). By anti- or protumor polarization, they impact multiple aspects of tumor biology and affect sensitivity to conventional therapies and immunotherapies. Single-cell RNA sequencing (scRNA-seq) analyses have unraveled an extensive neutrophil heterogeneity, helping our understanding of their pleiotropic role. In this review we summarize recent data and models on tumor-associated neutrophil (TAN) biology, focusing on the diversity that evolves in response to tumor-intrinsic cues. We categorize available transcriptomic profiles from different cancer entities into a defined set of neutrophil subclusters with distinct phenotypic properties, to step beyond the traditional binary N1/2 classification. Finally, we discuss potential ways to exploit these neutrophil states in the setting of anticancer therapy.

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.

Protocol for differentiation of functional macrophages from human induced pluripotent stem cells

Human induced pluripotent stem cell (hiPSC)-derived macrophages provide a valuable tool for disease modeling and drug discovery. Here, we present a protocol to generate functional macrophages from hiPSCs using a feeder-free hematopoietic differentiation technique. We describe steps for preparing hiPSCs, mesodermal differentiation, hematopoietic commitment, and macrophage differentiation and expansion. We then detail assays to characterize their phenotype, polarization, and phagocytic functions. The functional macrophages generated here could be used to generate organoids for disease modeling and drug discovery studies. For complete details on the use and execution of this protocol, please refer to Jeong et al.1 and Heo et al.2.

Harnessing bioengineered myeloid progenitors for precision immunotherapies

Granulocytes and macrophages are the frontline defenders of the innate immune system. These myeloid cells play a crucial role in not only eliminating pathogens and tumor cells, but also regulating adaptive immune responses. In neonatal sepsis and post-chemotherapy agranulocytosis, the absence of these cells leaves the host highly vulnerable to infections. Beyond replacement to prevent or control neutropenic sepsis, engineered myeloid cells may offer distinct opportunities for cell therapies. For example, the mobility and specific homing capacities of neutrophils to sites of inflammation could be exploited to deliver biocidal agents, or anti-inflammatory healing signals during sepsis, autoimmunity, and organ transplantation. Additionally, myeloid cells can be engineered to express chimeric antigen receptors (CAR), carry chemotherapeutics, or enhance lymphoid tumor killing. However, traditional methods of cell isolation are incapable of providing sufficient cell numbers of these short-lived cells; their propensity for premature activation further complicates their cell engineering. Here, we review current and future biotherapeutic innovations that employ engineered multipotent myeloid progenitors derived from either self-renewing human induced pluripotent stem cells (hiPSC) or primary CD34+ hematopoietic stem-progenitors. We provide a roadmap for solving the challenges of sourcing, cost, and production of engineered myeloid cell therapies.

ROS regulation in gliomas: implications for treatment strategies

Gliomas are one of the most common primary malignant tumours of the central nervous system (CNS), of which glioblastomas (GBMs) are the most common and destructive type. The glioma tumour microenvironment (TME) has unique characteristics, such as hypoxia, the blood-brain barrier (BBB), reactive oxygen species (ROS) and tumour neovascularization. Therefore, the traditional treatment effect is limited. As cellular oxidative metabolites, ROS not only promote the occurrence and development of gliomas but also affect immune cells in the immune microenvironment. In contrast, either too high or too low ROS levels are detrimental to the survival of glioma cells, which indicates the threshold of ROS. Therefore, an in-depth understanding of the mechanisms of ROS production and scavenging, the threshold of ROS, and the role of ROS in the glioma TME can provide new methods and strategies for glioma treatment. Current methods to increase ROS include photodynamic therapy (PDT), sonodynamic therapy (SDT), and chemodynamic therapy (CDT), etc., and methods to eliminate ROS include the ingestion of antioxidants. Increasing/scavenging ROS is potentially applicable treatment, and further studies will help to provide more effective strategies for glioma treatment.

Generation of chimeric antigen receptor macrophages from human pluripotent stem cells to target glioblastoma

Background

Glioblastoma (GBM) is an aggressive brain tumor giving a poor prognosis with the current treatment options. The advent of chimeric antigen receptor (CAR) T-cell therapy revolutionized the field of immunotherapy and has provided a new set of therapeutic options for refractory blood cancers. In an effort to apply this therapeutic approach to solid tumors, various immune cell types and CAR constructs are being studied. Notably, macrophages have recently emerged as potential candidates for targeting solid tumors, attributed to their inherent tumor-infiltrating capacity and abundant presence in the tumor microenvironment.

Materials and methods

In this study, we developed a chemically defined differentiation protocol to generate macrophages from human pluripotent stem cells (hPSCs). A GBM-specific CAR was genetically incorporated into hPSCs to generate CAR hPSC-derived macrophages.

Results

The CAR hPSC-derived macrophages exhibited potent anticancer activity against GBM cells in vitro.

Conclusion

Our findings demonstrate the feasibility of generating functional CAR-macrophages from hPSCs for adoptive immunotherapy, thereby opening new avenues for the treatment of solid tumors, particularly GBM.

Beyond the horizon: Neutrophils leading the way in the evolution of immunotherapy

Cancer is a complex and dynamic disease, initiated by a multitude of intrinsic mutations and progressed with the assistance of the tissue microenvironment, encompassed by stromal cells including immune cell infiltration. The novel finding that tumors can evade anti-cancer immune functions shaped the field of immunotherapy, which has been a revolutionary approach for the treatment of cancers. However, the development of predominantly T cell-targeted immunotherapy approaches, such as immune checkpoint inhibition, also brought about an accumulation of evidence demonstrating other immune cell drivers of tumor progression, such as innate immune cells and notably, neutrophils. In the past decade, neutrophils have emerged to be primary mediators of multiple cancer types and even in recent years, are gaining attention for their potential use in the next generation of immunotherapies. Here, we review current immunotherapy strategies and thoroughly discuss the roles of neutrophils in cancer and novel neutrophil-targeted methods for treating cancer.

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.

Application of adoptive cell therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a global health challenge. Novel treatment modalities are urgently needed to extend the overall survival of patients. The liver plays an immunomodulatory function due to its unique physiological structural characteristics. Therefore, following surgical resection and radiotherapy, immunotherapy regimens have shown great potential in the treatment of hepatocellular carcinoma. Adoptive cell immunotherapy is rapidly developing in the treatment of hepatocellular carcinoma. In this review, we summarize the latest research on adoptive immunotherapy for hepatocellular carcinoma. The focus is on chimeric antigen receptor (CAR)-T cells and T cell receptor (TCR) engineered T cells. Then tumour-infiltrating lymphocytes (TILs), natural killer (NK) cells, cytokine-induced killer (CIK) cells, and macrophages are briefly discussed. The main overview of the application and challenges of adoptive immunotherapy in hepatocellular carcinoma. It aims to provide the reader with a comprehensive understanding of the current status of HCC adoptive immunotherapy and offers some strategies. We hope to provide new ideas for the clinical treatment of hepatocellular carcinoma.

Neutrophils as potential therapeutic targets for breast cancer

Breast cancer (BC) remains the foremost cause of cancer mortality globally, with neutrophils playing a critical role in its pathogenesis. As an essential tumor microenvironment (TME) component, neutrophils are emerging as pivotal factors in BC progression. Growing evidence has proved that neutrophils play a Janus- role in BC by polarizing into the anti-tumor (N1) or pro-tumor (N2) phenotype. Clinical trials are evaluating neutrophil-targeted therapies, including Reparixin (NCT02370238) and Tigatuzumab (NCT01307891); however, their clinical efficacy remains suboptimal. This review summarizes the evidence regarding the close relationship between neutrophils and BC, emphasizing the critical roles of neutrophils in regulating metabolic and immune pathways. Additionally, we summarize the existing therapeutic approaches that target neutrophils, highlighting the challenges, and affirming the rationale for continuing to explore neutrophils as a viable therapeutic target in BC management.

Advancing CAR-based immunotherapies in solid tumors: CAR- macrophages and neutrophils

Macrophages and neutrophils are the main components of the innate immune system and play important roles in promoting angiogenesis, extracellular matrix remodeling, cancer cell proliferation, and metastasis in the tumor microenvironment (TME). They can also be harnessed to mediate cytotoxic tumor killing effects and orchestrate effective anti-tumor immune responses with proper stimulation and modification. Therefore, macrophages and neutrophils have strong potential in cancer immunotherapy. In this review, we briefly outlined the applications of macrophages or neutrophils in adoptive cell therapies, and focused on chimeric antigen receptor (CAR)-engineered macrophages (CAR-Ms) and neutrophils (CAR-Ns). We summarized the construction strategies, the preclinical and clinical studies of CAR-Ms and CAR-Ns. In the end, we briefly discussed the limitations and challenges of CAR-Ms and CAR-Ns, as well as future research directions to extend their applications in treating solid tumors.

A potential therapeutic target: The role of neutrophils in the central nervous system

Neutrophils play a critical role in immune defense as the first recruited and most abundant leukocytes in the innate immune system. As such, regulation of neutrophil effector functions have strong implications on immunity. These cells display a wide heterogeneity of function, including both inflammatory and immunomodulatory roles. Neutrophils commonly infiltrate the central nervous system (CNS) in response to varied pathological conditions. There is still little understanding of the role these cells play in the CNS in such conditions. In the present review, we will summarize what is known of neutrophil's role in cancer and Alzheimer's disease (AD), with a focus on highlighting the gaps in our understanding.

Successes and challenges in clinical gene therapy

Despite the ups and downs in the field over three decades, the science of gene therapy has continued to advance and provide enduring treatments for increasing number of diseases. There are active clinical trials approaching a variety of inherited and acquired disorders of different organ systems. Approaches include ex vivo modification of hematologic stem cells (HSC), T lymphocytes and other immune cells, as well as in vivo delivery of genes or gene editing reagents to the relevant target cells by either local or systemic administration. In this article, we highlight success and ongoing challenges in three areas of high activity in gene therapy: inherited blood cell diseases by targeting hematopoietic stem cells, malignant disorders using immune effector cells genetically modified with chimeric antigen receptors, and ophthalmologic, neurologic, and coagulation disorders using in vivo administration of adeno-associated virus (AAV) vectors. In recent years, there have been true cures for many of these diseases, with sustained clinical benefit that exceed those from other medical approaches. Each of these treatments faces ongoing challenges, namely their high one-time costs and the complexity of manufacturing the therapeutic agents, which are biological viruses and cell products, at pharmacologic standards of quality and consistency. New models of reimbursement are needed to make these innovative treatments widely available to patients in need.

Engineered hematopoietic and immune cells derived from human pluripotent stem cells

For the past decade, significant advances have been achieved in human hematopoietic stem cell (HSC) transplantation for treating various blood diseases and cancers. However, challenges remain with the quality control, amount, and cost of HSCs and HSC-derived immune cells. The advent of human pluripotent stem cells (hPSCs) may transform HSC transplantation and cancer immunotherapy by providing a cost-effective and scalable cell source for fundamental studies and translational applications. In this review, we discuss the current developments in the field of stem cell engineering for hematopoietic stem and progenitor cell (HSPC) differentiation and further differentiation of HSPCs into functional immune cells. The key advances in stem cell engineering include the generation of HSPCs from hPSCs, genetic modification of hPSCs, and hPSC-derived HSPCs for improved function, further differentiation of HPSCs into functional immune cells, and applications of cell culture platforms for hematopoietic cell manufacturing. Current challenges impeding the translation of hPSC-HSPCs and immune cells as well as further directions to address these challenges are also discussed.

GATA1 deletion in human pluripotent stem cells increases differentiation yield and maturity of neutrophils

Human pluripotent stem cell (hPSC)-derived tissues can be used to model diseases in cell types that are challenging to harvest and study at-scale, such as neutrophils. Neutrophil dysregulation, specifically neutrophil extracellular trap (NET) formation, plays a critical role in the prognosis and progression of multiple diseases, including COVID-19. While hPSCs can generate limitless neutrophils (iNeutrophils) to study these processes, current differentiation protocols generate heterogeneous cultures of granulocytes and precursors. Here, we describe a method to improve iNeutrophil differentiations through the deletion of GATA1. GATA1 knockout (KO) iNeutrophils are nearly identical to primary neutrophils in form and function. Unlike wild-type iNeutrophils, GATA1 KO iNeutrophils generate NETs in response to the physiologic stimulant lipopolysaccharide, suggesting they are a more accurate model when performing NET inhibitor screens. Furthermore, through deletion of CYBB, we demonstrate that GATA1 KO iNeutrophils are a powerful tool in determining involvement of a given protein in NET formation.