FOXO1 is a master regulator of memory programming in CAR T cells

Therapeutic Reprogramming toward Regenerative Medicine

Therapeutic reprogramming represents a transformative paradigm in regenerative medicine, developing new approaches in cell therapy, small molecule drugs, biologics, and gene therapy to address unmet medical challenges. This paradigm encompasses the precise modulation of cellular fate and function to either generate safe and functional cells ex vivo for cell-based therapies or to directly reprogram endogenous cells in vivo or in situ for tissue repair and regeneration. Building on the discovery of induced pluripotent stem cells (iPSCs), advancements in chemical modulation and CRISPR-based gene editing have propelled a new iterative medicine paradigm, focusing on developing scalable, standardized cell therapy products from universal starting materials and enabling iterative improvements for more effective therapeutic profiles. Beyond cell-based therapies, non-cell-based therapeutic strategies targeting endogenous cells may offer a less invasive, more convenient, accessible, and cost-effective alternative for treating a broad range of diseases, potentially rejuvenating tissues and extending healthspan.

Purinergic signaling by TCRαβ+ double-negative T regulatory cells ameliorates liver ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is an important cause of liver injury following liver transplantation and major resections, and neutrophils are the key effector cells in HIRI. Double-negative T regulatory cells (DNT) are increasingly recognized as having critical regulatory functions in the immune system. Whether DNT expresses distinct immunoregulatory mechanisms to modulate neutrophils, as in HIRI, remains largely unknown. In this study, we found that murine and human DNT highly expressed CD39 that protected DNT from extracellular ATP-induced apoptosis and generated adenosine in tandem with CD73, to induce high levels of neutrophil apoptosis. Furthermore, extracellular adenosine enhanced DNT survival and suppressive function by upregulating survivin and NKG2D expression via the A2AR/pAKT/FOXO1 signaling pathway. Adoptive transfer of DNT ameliorated HIRI in mice through the inhibition of neutrophils in a CD39-dependent manner. Lastly, the adoptive transfer of A2ar-/- DNT validated the importance of adenosine/A2AR signaling, in promoting DNT survival and immunomodulatory function to protect against HIRI in vivo. In conclusion, purinergic signaling is crucial for DNT homeostasis in HIRI. Augmentation of CD39 or activation of A2AR signaling in DNT may provide novel therapeutic strategies to target innate immune disorders.

A metabolic pathway for improving adoptive cellular therapy

In this issue of Cancer Cell, Qiu et al. use single-cell metabolic analysis to identify reduced mannose metabolism as a previously unknown feature of exhausted T cells. This metabolic pathway can be targeted to enhance memory and persistence of adoptively transferred T cells, resulting in improved anti-tumor efficacy.

La dolce vita: fueling chimeric antigen receptor (CAR) T cells with Glut1 to improve therapeutic efficacy

The approval of chimeric antigen receptor (CAR) T cell therapies for the treatment of hematological cancers has marked a new era in cancer care, with seven products being FDA approved since 2017. However, challenges remain, and while profound effects are observed initially in myeloma, the majority of patients relapse, which is concomitant with poor CAR T cell persistence. Similarly, the efficacy of CAR T cell therapy is limited in solid tumors, largely due to tumor antigen heterogeneity, immune evasion mechanisms, and poor infiltration and persistence. In this recent study, Guerrero et al endeavor to improve the efficacy of human CAR T cells by overexpressing the glucose transporter GLUT1 and show that GLUT1 overexpressing CAR T cells have improved capacity to persist and control tumor burden in vivo.

Antigen experience history directs distinct functional states of CD8+ CAR T cells during the antileukemia response

Although chimeric antigen receptor (CAR) T cells are effective against B-lineage malignancies, post-CAR relapse is common, and efficacy in other tumors is limited. These challenges may be addressed through rational manipulations to control CAR T cell function. Here we examine the impact of cognate T cell antigen experience on subsequent CD8+ CAR T cell activity. Prior antigen encounter resulted in superior effector function against leukemia expressing low target antigen density at the expense of reduced proliferative capacity and susceptibility to dysfunction at limiting CAR doses. Distinctive temporal transcriptomic and epigenetic profiles in naive-derived and memory-derived CAR T cells identified RUNX family transcription factors as potential targets to augment the function of naive-derived CD8+ CAR T cells. RUNX2 overexpression enhanced antitumor efficacy of mouse CAR T cells, dependent on prior cell state, and heightened human CAR T cell functions. Our data demonstrate that prior antigen experience of CAR T cells determines functional attributes and amenability to transcription factor-mediated functional enhancement.

Universal CAR cell therapy: Challenges and expanding applications

Chimeric Antigen Receptor (CAR) T cell therapy has gained success in adoptive cell therapy for hematological malignancies. Although most CAR cell therapies in clinical trials or markets remain autologous, their acceptance has been limited due to issues like lengthy manufacturing, poor cell quality, and demanding cost. Consequently, "Off-the-shelf", universal CAR (UCAR) cell therapy has emerged. Current concerns with UCAR therapies revolve around side effects such as graft versus host disease (GVHD) and host versus graft response (HVGR). Preclinical research on UCAR cell therapies aims to enhance efficacy and minimize these side effects. Common approaches involve gene editing techniques to knock out T cell receptor (TCR), human leukocyte antigen (HLA), and CD52 expression to mitigate GVHD and HVGR risks. However, these methods carry drawbacks including potential genotoxicity of the edited cells. Most recently, novel editing techniques, such as epigenetic editing and RNA writer systems, have been developed to reduce the risk of GVHD and HVGR, allowing for multiplex editing at different sites. Additionally, incorporating more cell types into UCAR cell therapies, like T-cell subtypes (DNT, γδT, virus-specific T cells) and NK cells, can efficiently target tumors without triggering side effects. In addition, the limited efficacy of T cells and NK cells against solid tumors is being addressed through CAR-Macrophages. In summary, CAR cell therapy has evolved to accommodate multiple cell types while expanding applications to various diseases, including hematologic malignancies and solid tumors, which holds tremendous growth potential and is promised to improve the lives of more patients in the future.

Engineered Cellular Therapies for the Treatment of Thoracic Cancers

Thoracic malignancies (lung cancers and malignant pleural mesothelioma) are prevalent worldwide and are associated with high morbidity and mortality. Effective treatments are needed for patients with advanced disease. Cell therapies are a promising approach to the treatment of advanced cancers that make use of immune effector cells that have the ability to mediate antitumor immune responses. In this review, we discuss the prospect of chimeric antigen receptor-T (CAR-T) cells, natural killer (NK) cells, T cell receptor-engineered (TCR-T) cells, and tumor-infiltrating lymphocytes (TILs) as treatments for thoracic malignancies. CAR-T cells and TILs have proven successful in several hematologic cancers and advanced melanoma, respectively, but outside of melanoma, results have thus far been unsuccessful in most other solid tumors. NK cells and TCR-T cells are additional cell therapy platforms with their own unique advantages and challenges. Obstacles that must be overcome to develop effective cell therapy for these malignancies include selecting an appropriate target antigen, combating immunosuppressive cells and signaling molecules present in the tumor microenvironment, persistence, and delivering a sufficient quantity of antitumor immune cells to the tumor. Induced pluripotent stem cells (iPSCs) offer great promise as a source for both NK and T cell-based therapies due to their unlimited expansion potential. Here, we review clinical trial data, as well as recent basic scientific advances that offer insight into how we may overcome these obstacles, and provide an overview of ongoing trials testing novel strategies to overcome these obstacles.

Targeting metabolic pathway enhance CAR-T potency for solid tumor

Chimeric antigen receptor (CAR) T cells have great potential in cancer therapy, particularly in treating hematologic malignancies. However, their efficacy in solid tumors remains limited, with a significant proportion of patients failing to achieve long-term complete remission. One major challenge is the premature exhaustion of CAR-T cells, often due to insufficient metabolic energy. The survival, function and metabolic adaptation of CAR-T cells are key determinants of their therapeutic efficacy. We explore how targeting metabolic pathways in the tumor microenvironment can enhance CAR-T cell therapy by addressing metabolic competition and immunosuppression that impair CAR-T cell function. Tumors undergo metabolically reprogrammed to meet their rapid proliferation, thereby modulating metabolic pathways in immune cells to promote immunosuppression. The distinct metabolic requirements of tumors and T cells create a competitive environment, affecting the efficacy of CAR-T cell therapy. Recent research on glucose, lipid and amino acid metabolism, along with the interactions between tumor and immune cell metabolism, has revealed that targeting these metabolic processes can enhance antitumor immune responses. Combining metabolic interventions with existing antitumor therapies can fulfill the metabolic demands of immune cells, providing new ideas for tumor immunometabolic therapies. This review discusses the latest advances in the immunometabolic mechanisms underlying tumor immunosuppression, their implications for immunotherapy, and summarizes potential metabolic targets to improve the efficacy of CAR-T therapy.

Oxidative stress controls lncRNA-mediated sow granulosa cell functions in a FoxO1-dependent manner

BACKGROUND

Oxidative stress (OS) is involved in low female fertility by altering multi-omics such as the transcriptome, miRome, and lncRNome in follicular cells and follicular fluid. However, the mechanism by which OS affects multi-omics dynamics remains largely unknown. Here, we report that OS induces lncRNome dynamics in sow granulosa cells (sGCs), which is partially dependent on the transcription factor activity of its effector, FoxO1.

RESULTS

A total of 2,283 putative FoxO recognition elements (FREs) were identified in the promoters of 394 lncRNAs, accounting for 91.20% (394/432) of the lncRNAs regulated by OS. ChIP and reporter assays showed that the effector FoxO1 mediated OS regulation of lncRNA transcription in a transcription factor activity-dependent manner. In sGCs, OS induces the transcription and function (e.g., apoptosis) of NORSF (non-coding RNA involved in sow fertility), a nuclear lncRNA involved in sGC function via FoxO1. Furthermore, FoxO1 has been identified as a transcriptional activator of NORSF in sGCs that interacts with the FRE motif of its promoter. Meanwhile, OS downregulates the transcription of CYP19A1, which encodes an essential enzyme for estrogen synthesis and 17β-estradiol (E2) release by sGCs via the FoxO1 and NORSF axis. Phenotypically, dysregulation of NORSF transcription caused by 2 novel adjacent transitions in the promoter leads to decreased sow fertility.

CONCLUSION

These results suggest a model of OS-stimulated lncRNome dynamics in sGCs and a new signaling pathway of OS that influences sGC function and sow fertility.

Targeting metabolic dysfunction of CD8 T cells and natural killer cells in cancer

The importance of metabolic pathways in regulating immune responses is now well established, and a mapping of the bioenergetic metabolism of different immune cell types is under way. CD8 T cells and natural killer (NK) cells contribute to cancer immunosurveillance through their cytotoxic functions and secretion of cytokines and chemokines, complementing each other in target recognition mechanisms. Several immunotherapies leverage these cell types by either stimulating their activity or redirecting their specificity against tumour cells. However, the anticancer activity of CD8 T cells and NK cells is rapidly diminished in the tumour microenvironment, closely linked to a decline in their metabolic capacities. Various strategies have been developed to restore cancer immunosurveillance, including targeting bioenergetic metabolism or genetic engineering. This Review provides an overview of metabolic dysfunction in CD8 T cells and NK cells within the tumour microenvironment, highlighting current therapies aiming to overcome these issues.

Correlative studies reveal factors contributing to successful CAR-T cell therapies in cancer

Cellular and targeted immunotherapies have revolutionized cancer treatments in the last several decades. Successful cellular therapies require both effective and durable cytotoxic activity from the immune cells as well as an accessible and susceptible response from targeted cancer cells. Correlative studies from clinical trials as well as real-world data from FDA-approved therapies have revealed invaluable insights about immune cell factors and cancer cell factors that impact rates of response and relapse to cellular therapies. This review focuses on the flagship cellular therapy of engineered chimeric antigen receptor T-cells (CAR-T cells). Within the CAR-T cell compartment, we discuss discoveries about T-cell phenotype, transcriptome, epigenetics, cytokine signaling, and metabolism that inform the cell manufacturing process to produce the most effective and durable CAR-T cells. Within the cancer cell compartment, we discuss mechanisms of resistance and relapse caused by mutations, alternative splicing, post-transcriptional modifications, and cellular reprogramming. Continued correlative and mechanistic studies are required to help us further optimize cellular therapies in a variety of malignancies.

TIL Therapy in Lung Cancer: Current Progress and Perspectives

Lung cancer remains the most prevalent malignant tumor worldwide and is the leading cause of cancer-related mortality. Although immune checkpoint blockade has revolutionized the treatment of advanced lung cancer, many patients still do not respond well, often due to the lack of functional T cell infiltration. Adoptive cell therapy (ACT) using expanded immune cells has emerged as an important therapeutic modality. Tumor-infiltrating lymphocytes (TIL) therapy is one form of ACT involving the administration of expanded and activated autologous T cells derived from surgically resected cancer tissues and reinfusion into patients and holds great therapeutic potential for lung cancer. In this review, TIL therapy is introduced and its suitability for lung cancer is discussed. Then its historical and clinical developments are summarized, and the methods developed up-to-date to identify tumor-recognizing TILs and optimize TIL composition. Some perspectives toward future TIL therapy for lung cancer are also provided.

Epigenetics behind CD8+ T cell activation and exhaustion

CD8+ T cells play a critical role in specific immunity. In recent years, cell therapy has been emerging rapidly. The specific cytotoxic capabilities of these cells enable them to precisely identify and kill cells presenting specific antigens. This has demonstrated promise in the treatment of autoimmune diseases and cancers, with wide-ranging applications and value. However, in some diseases, such as tumors and chronic infections, T cells may adopt an exhausted phenotype, resulting in a loss of cytotoxicity and limiting their further application. Epigenetics plays a significant role in the differentiation and regulation of gene expression in cells. There is extensive evidence indicating that epigenetic remodeling plays an important role in T cell exhaustion. Therefore, further understanding its role in CD8+ T cell function can provide insights into the programmatic regulation of CD8+ T cells from a genetic perspective and overcome these diseases. We attempted to describe the relationship between the activation, function, and exhaustion mechanisms of CD8+ T cells, as well as epigenetics. This understanding makes it possible for us to address the aforementioned issues.

Stage-specific CAR-mediated signaling generates naïve-like, TCR-null CAR T cells from induced pluripotent stem cells

Genetically modified, induced pluripotent stem cells (iPSCs) offer a promising allogeneic source for the generation of functionally enhanced, chimeric antigen receptor (CAR) T cells. However, the signaling of CARs during early T cell development and the removal of the endogenous T cell receptor required to prevent alloreactivity pose significant challenges to the production of mature conventional CAR T cells from iPSCs. Here, we show that TCR-null, CD8αβ CAR T cells can be efficiently generated from iPSCs by engineering stage-specific onset of CAR expression and signaling to both permit conventional T cell development and to induce efficient positive selection. CAR T cells produced using this approach displayed a uniform, naïve T cell phenotype and demonstrated superior antigen-specific cytotoxicity compared to iPSC-derived effector memory CAR T cells. Multimodal sequencing revealed CAR-mediated positive selection induced the persistent upregulation of key transcription factors involved in naïve T cell development. Achieving precise control of CAR expression and signaling in developmentally sensitive T precursors will be critical to realizing the full potential for "off-the-shelf", iPSC-derived cellular therapies.

Affinity-tuned mesothelin CAR T cells demonstrate enhanced targeting specificity and reduced off-tumor toxicity

The application of chimeric antigen receptor (CAR) T cell therapy in solid tumors is hindered by life-threatening toxicities resulting from on-target, off-tumor killing of nonmalignant cells that express low levels of the target antigen. Mesothelin (MSLN) has been identified as a target antigen for CAR T cell treatment of mesothelioma, lung, ovarian, and other cancers because of its high expression on tumor cells and limited expression on mesothelial cells. However, fatal off-tumor toxicity of high-affinity MSLN-targeting CAR T cells has been reported in multiple clinical trials. In this study, we constructed CARs using mutant variants of a single-domain nanobody that bind both human and mouse MSLN with a wide range of affinities and examined tumor responses and their toxicities from on-target, off-tumor interactions in mouse models. CAR T cells with low nanomolar affinity (equilibrium dissociation constant, KD) exhibited profound systemic expansion with no apparent infiltration into the tumor. With a gradual reduction of CAR affinity toward the micromolar KD, the expansion of CAR T cells became more restricted to tumors. Our preclinical studies demonstrated that high-affinity MSLN CARs were associated with fatal on-target, off-tumor toxicity and that affinity-tuned CARs rendered T cells more selective for MSLN-high tumors.

H2S-Prdx4 axis mitigates Golgi stress to bolster tumor-reactive T cell immunotherapeutic response

The role of tumor microenvironment (TME)-associated inadequate protein modification and trafficking due to insufficiency in Golgi function, leading to Golgi stress, in the regulation of T cell function is largely unknown. Here, we show that disruption of Golgi architecture under TME stress, identified by the decreased expression of GM130, was reverted upon treatment with hydrogen sulfide (H2S) donor GYY4137 or overexpressing cystathionine β-synthase (CBS), an enzyme involved in the biosynthesis of endogenous H2S, which also promoted stemness, antioxidant capacity, and increased protein translation, mediated in part by endoplasmic reticulum-Golgi shuttling of Peroxiredoxin-4. In in vivo models of melanoma and lymphoma, antitumor T cells conditioned ex vivo with exogenous H2S or overexpressing CBS demonstrated superior tumor control upon adoptive transfer. Further, T cells with high Golgi content exhibited unique metabolic and glycation signatures with enhanced antitumor capacity. These data suggest that strategies to mitigate Golgi network stress or using Golgihi tumor-reactive T cells can improve tumor control upon adoptive transfer.

FoxO1 signaling in B cell malignancies and its therapeutic targeting

FoxO transcription factors (FoxO1, FoxO3a, FoxO4, FoxO6) are a highly evolutionary conserved subfamily of the 'forkhead' box proteins. They have traditionally been considered tumor suppressors, but FoxO1 also exhibits oncogenic properties. The complex nature of FoxO1 is illustrated by its various roles in B cell development and differentiation, immunoglobulin gene rearrangement and cell-surface B cell receptor (BCR) structure, DNA damage control, cell cycle regulation, and germinal center reaction. FoxO1 is tightly regulated at a transcriptional (STAT3, HEB, EBF, FoxOs) and post-transcriptional level (Akt, AMPK, CDK2, GSK3, IKKs, JNK, MAPK/Erk, SGK1, miRNA). In B cell malignancies, recurrent FoxO1 activating mutations (S22/T24) and aberrant nuclear export and activity have been described, underscoring the potential of its therapeutic inhibition. Here, we review FoxO1's roles across B cell and myeloid malignancies, namely acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), mantle cell lymphoma (MCL), Burkitt lymphoma (BL), Hodgkin lymphoma (HL), and multiple myeloma (MM). We also discuss preclinical evidence for FoxO1 targeting by currently available inhibitors (AS1708727, AS1842856, cpd10).

Optimizing CAR-T cell therapy for solid tumors: current challenges and potential strategies

Chimeric antigen receptor (CAR)-T cell therapy demonstrates substantial efficacy in various hematological malignancies. However, its application in solid tumors is still limited. Clinical studies report suboptimal outcomes such as reduced cytotoxicity of CAR-T cells and tumor evasion, underscoring the need to address the challenges of sliding cytotoxicity in CAR-T cells. Despite improvements from fourth and next-generation CAR-T cells, new challenges include systemic toxicity from continuously secreted proteins, low productivity, and elevated costs. Recent research targets genetic modifications to boost killing potential, metabolic interventions to hinder tumor progression, and diverse combination strategies to enhance CAR-T cell therapy. Efforts to reduce the duration and cost of CAR-T cell therapy include developing allogenic and in-vivo approaches, promising significant future advancements. Concurrently, innovative technologies and platforms enhance the potential of CAR-T cell therapy to overcome limitations in treating solid tumors. This review explores strategies to optimize CAR-T cell therapies for solid tumors, focusing on enhancing cytotoxicity and overcoming application restrictions. We summarize recent advances in T cell subset selection, CAR-T structural modifications, infiltration enhancement, genetic and metabolic interventions, production optimization, and the integration of novel technologies, presenting therapeutic approaches that could improve CAR-T cell therapy's efficacy and applicability in solid tumors.

Advancing CAR T-cell therapies: Preclinical insights and clinical translation for hematological malignancies

Chimeric antigen receptor (CAR) T-cell therapy has achieved significant success in achieving durable and potentially curative responses in patients with hematological malignancies. CARs are tailored fusion proteins that direct T cells to a specific antigen on tumor cells thereby eliciting a targeted immune response. The approval of several CD19-targeted CAR T-cell therapies has resulted in a notable surge in clinical trials involving CAR T cell therapies for hematological malignancies. Despite advancements in understanding response mechanisms, resistance patterns, and adverse events associated with CAR T-cell therapy, the translation of these insights into robust clinical efficacy has shown modest outcomes in both clinical trials and real-world scenarios. Therefore, the assessment of CAR T-cell functionality through rigorous preclinical studies plays a pivotal role in refining therapeutic strategies for clinical applications. This review provides an overview of the various in vitro and animal models used to assess the functionality of CAR T-cells. We discuss the findings from preclinical research involving approved CAR T-cell products, along with the implications derived from recent preclinical studies aiming to optimize the functionality of CAR T-cells. The review underscores the importance of robust preclinical evaluations and the need for models that accurately replicate human disease to bridge the gap between preclinical success and clinical efficacy.

Claudin 1, 4, 6 and 18 isoform 2 as targets for the treatment of cancer (Review)

The 24 claudin (CLDN) genes in the human genome encode 26 representative CLDN family proteins. CLDNs are tetraspan‑transmembrane proteins at tight junctions. Because several CLDN isoforms, such as CLDN6 and CLDN18.2, are specifically upregulated in human cancer, CLDN‑targeting monoclonal antibodies (mAbs), antibody‑drug conjugates (ADCs), bispecific antibodies (bsAbs) and chimeric antigen receptor (CAR) T cells have been developed. In the present review, CLDN1‑, 4‑, 6‑ and 18.2‑targeting investigational drugs in clinical trials are discussed. CLDN18.2‑directed therapy for patients with gastric and other types of cancer is the most advanced area in this field. The mouse/human chimeric anti‑CLDN18.2 mAb zolbetuximab has a single‑agent objective response rate (ORR) of 9%, and increases progression‑free and overall survival in combination with chemotherapy. The human/humanized anti‑CLDN18.2 mAb osemitamab, and ADCs AZD0901, IBI343 and LM‑302, with single‑agent ORRs of 28‑60%, have been tested in phase III clinical trials. In addition, bsAbs, CAR T cells and their derivatives targeting CLDN4, 6 or 18.2 are in phase I and/or II clinical trials. AZD0901, IBI343, zolbetuximab and the anti‑CLDN1 mAb ALE.C04 have been granted fast track designation or priority review designation by the US Food and Drug Administration.

Applying metabolic control strategies to engineered T cell cancer therapies

Chimeric antigen receptor (CAR) T cells are an engineered immunotherapy that express synthetic receptors to recognize and kill cancer cells. Despite their success in treating hematologic cancers, CAR T cells have limited efficacy against solid tumors, in part due to the altered immunometabolic profile within the tumor environment, which hinders T cell proliferation, infiltration, and anti-tumor activity. For instance, CAR T cells must compete for essential nutrients within tumors, while resisting the impacts of immunosuppressive metabolic byproducts. In this review, we will describe the altered metabolic features within solid tumors that contribute to immunosuppression of CAR T cells. We'll discuss how overexpression of key metabolic enzymes can enhance the ability of CAR T cells to resist corresponding tumoral metabolic changes or even revert the metabolic profile of a tumor to a less inhibitory state. In addition, metabolic remodeling is intrinsically linked to T cell activity, differentiation, and function, such that metabolic engineering strategies can also promote establishment of more or less efficacious CAR T cell phenotypes. Overall, we will show how applying metabolic engineering strategies holds significant promise in improving CAR T cells for the treatment of solid tumors.

Chimeric antigen receptor T-cell therapy in patients with malignant glioma-From neuroimmunology to clinical trial design considerations

Clinical trials evaluating chimeric antigen receptor (CAR) T-cell therapy in patients with malignant gliomas have shown some early promise in pediatric and adult patients. However, the long-term benefits and safety for patients remain to be established. The ultimate success of CAR T-cell therapy for malignant glioma will require the integration of an in-depth understanding of the immunology of the central nervous system (CNS) parenchyma with strategies to overcome the paucity and heterogeneous expression of glioma-specific antigens. We also need to address the cold (immunosuppressive) microenvironment, exhaustion of the CAR T-cells, as well as local and systemic immunosuppression. Here, we discuss the basics and scientific considerations for CAR T-cell therapies and highlight recent clinical trials. To help identify optimal CAR T-cell administration routes, we summarize our current understanding of CNS immunology and T-cell homing to the CNS. We also discuss challenges and opportunities related to clinical trial design and patient safety/monitoring. Finally, we provide our perspective on future prospects in CAR T-cell therapy for malignant gliomas by discussing combinations and novel engineering strategies to overcome immuno-regulatory mechanisms. We hope this review will serve as a basis for advancing the field in a multiple discipline-based and collaborative manner.

The multifaceted roles of TCF1 in innate and adaptive lymphocytes

The immune system requires a complex network of specialized cell types to defend against a range of threats. The specific roles and destinies of these cell types are enforced by a constellation of gene regulatory programs, which are orchestrated through lineage-specifying transcription factors. T Cell Factor 1 (TCF1) is a central transcription factor in many of these programs, guiding the development and functionality of both adaptive and innate lymphoid cells. This review highlights recent insights into the function of TCF1 in a variety of lymphoid cell subsets and its potential for translational applications in immune disorders and cancer.

Therapeutic advantage of combinatorial CAR T cell and chemo-therapies

Chimeric antigen receptor (CAR) T cell therapies have transformed outcomes for many patients with hematological malignancies. However, some patients do not respond to CAR T cell treatment, and adapting CAR T cells for solid and brain tumors has been met with many challenges including a hostile tumor microenvironment and poor CAR T cell persistence. Thus, it is unlikely that CAR T cell therapy alone will be sufficient for consistent, complete tumor clearance across cancer patients. Combinatorial therapies of CAR T cells and chemotherapeutics are a promising approach for overcoming this as chemotherapeutics could augment CAR T cells for improved anti-tumor activity or work in tandem with CAR T cells to clear tumors. Herein, we review efforts towards achieving successful CAR T cell and chemical drug combination therapies. We focus on combination therapies with approved chemotherapeutics as these will be more easily translated to the clinic, but also review non-approved chemotherapeutics and drug screens designed to reveal promising new CAR T cell and chemical drug combinations. Together, this review highlights the promise of CAR T cell and chemotherapy combinations with specific focus on how combinatorial therapy overcomes challenges faced by either monotherapy and supports the potential of this therapeutic strategy to improve outcomes for cancer patients. Significance Statement Improving currently available CAR T cell products via combinatorial therapy with chemotherapeutics has the potential to drastically expand the types of cancers and number of patients that could benefit from these therapies when neither alone has been sufficient to achieve tumor clearance. Herein, we provide a thorough review of the current efforts towards studying CAR T and chemotherapy combinatorial therapies and provide perspectives on optimal ways to identify new and effective combinations moving forward.

Single-cell CAR T atlas reveals type 2 function in 8-year leukaemia remission

Despite a high response rate in chimeric antigen receptor (CAR) T cell therapy for acute lymphocytic leukaemia (ALL)1-3, approximately 50% of patients relapse within the first year4-6, representing an urgent question to address in the next stage of cellular immunotherapy. Here, to investigate the molecular determinants of ultralong CAR T cell persistence, we obtained a single-cell multi-omics atlas from 695,819 pre-infusion CAR T cells at the basal level or after CAR-specific stimulation from 82 paediatric patients with ALL enrolled in the first two CAR T ALL clinical trials and 6 healthy donors. We identified that elevated type 2 functionality in CAR T infusion products is significantly associated with patients maintaining a median B cell aplasia duration of 8.4 years. Analysis of ligand-receptor interactions revealed that type 2 cells regulate a dysfunctional subset to maintain whole-population homeostasis, and the addition of IL-4 during antigen-specific activation alleviates CAR T cell dysfunction while enhancing fitness at both transcriptomic and epigenomic levels. Serial proteomic profiling of sera after treatment revealed a higher level of circulating type 2 cytokines in 5-year or 8-year relapse-free responders. In a leukaemic mouse model, type 2high CAR T cell products demonstrated superior expansion and antitumour activity, particularly after leukaemia rechallenge. Restoring antitumour efficacy in type 2low CAR T cells was attainable by enhancing their type 2 functionality, either through incorporating IL-4 into the manufacturing process or by priming manufactured CAR T products with IL-4 before infusion. Our findings provide insights into the mediators of durable CAR T therapy response and suggest potential therapeutic strategies to sustain long-term remission by boosting type 2 functionality in CAR T cells.

AMPK agonism optimizes the in vivo persistence and anti-leukemia efficacy of chimeric antigen receptor T cells

BACKGROUND

Chimeric antigen receptor T cell (CART) therapy has seen great clinical success. However, up to 50% of leukemia patients relapse and long-term survivor data indicate that CART cell persistence is key to enforcing relapse-free survival. Unfortunately, ex vivo expansion protocols often drive metabolic and functional exhaustion, reducing in vivo efficacy. Preclinical models have demonstrated that redirecting metabolism ex vivo can improve in vivo T cell function and we hypothesized that exposure to an agonist targeting the metabolic regulator AMP-activated protein kinase (AMPK), would create CARTs capable of both efficient leukemia clearance and increased in vivo persistence.

METHODS

CART cells were generated from healthy human via lentiviral transduction. Following activation, cells were exposed to either Compound 991 or DMSO for 96 hours, followed by a 48-hour washout. During and after agonist treatment, T cells were harvested for metabolic and functional assessments. To test in vivo efficacy, immunodeficient mice were injected with luciferase+ NALM6 leukemia cells, followed one week later by either 991- or DMSO-expanded CARTs. Leukemia burden and anti-leukemia efficacy was assessed via radiance imaging and overall survival.

RESULTS

Human T cells expanded in Compound 991 activated AMPK without limiting cellular expansion and gained both mitochondrial density and improved handling of reactive oxygen species (ROS). Importantly, receipt of 991-exposed CARTs significantly improved in vivo leukemia clearance, prolonged recipient survival, and increased CD4+ T cell yields at early times post-injection. Ex vivo, 991 agonist treatment mimicked nutrient starvation, increased autophagic flux, and promoted generation of mitochondrially-protective metabolites.

DISCUSSION

Ex vivo expansion processes are necessary to generate sufficient cell numbers, but often promote sustained activation and differentiation, negatively impacting in vivo persistence and function. Here, we demonstrate that promoting AMPK activity during CART expansion metabolically reprograms cells without limiting T cell yield, enhances in vivo anti-leukemia efficacy, and improves CD4+ in vivo persistence. Importantly, AMPK agonism achieves these results without further modifying the expansion media, changing the CART construct, or genetically altering the cells. Altogether, these data highlight AMPK agonism as a potent and readily translatable approach to improve the metabolic profile and overall efficacy of cancer-targeting T cells.

Histone marks identify novel transcription factors that parse CAR-T subset-of-origin, clinical potential and expansion

Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionised blood cancer treatment. Parsing the genetic underpinnings of T cell quality and CAR-T efficacy is challenging. Transcriptomics inform CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasises effector and metabolism genes. Here we explore whether analyses of transcriptionally repressive and permissive histone methylation marks describe CAR-T cell functional states and therapeutic potential beyond transcriptomic analyses. Histone mark analyses improve identification of differences between naïve, central memory, and effector memory CD8 + T cell subsets of human origin, and CAR-T derived from these subsets. We find important differences between CAR-T manufactured from central memory cells of healthy donors and of patients. By examining CAR-T products from a clinical trial in lymphoma (NCT01865617), we find a novel association between the activity of the transcription factor KLF7 with in vivo CAR-T accumulation in patients and demonstrate that over-expression of KLF7 increases in vitro CAR-T proliferation and IL-2 production.  In conclusion, histone marks provide a rich dataset for identification of functionally relevant genes not apparent by transcriptomics.

Transcriptional rewiring in CD8+ T cells: implications for CAR-T cell therapy against solid tumours

T cells engineered to express chimeric-antigen receptors (CAR-T cells) can effectively control relapsed and refractory haematological malignancies in the clinic. However, the successes of CAR-T cell therapy have not been recapitulated in solid tumours due to a range of barriers such as immunosuppression, poor infiltration, and tumour heterogeneity. Numerous strategies are being developed to overcome these barriers, which include improving culture conditions and manufacturing protocols, implementing novel CAR designs, and novel approaches to engineering the T cell phenotype. In this review, we describe the various emerging strategies to improve CAR T cell therapy for solid tumours. We specifically focus on new strategies to modulate cell function and fate that have precipitated from the growing knowledge of transcriptional circuits driving T cell differentiation, with the ultimate goal of driving more productive anti-tumour T cell immunity. Evidence shows that enrichment of particular phenotypic subsets of T cells in the initial cell product correlates to improved therapeutic responses and clinical outcomes. Furthermore, T cell exhaustion and poor persistence are major factors limiting therapeutic efficacy. The latest preclinical work shows that targeting specific master regulators and transcription factors can overcome these key barriers, resulting in superior T cell therapeutic products. This can be achieved by targeting key transcriptional circuits promoting memory-like phenotypes or sustaining key effector functions within the hostile tumour microenvironment. Additional discussion points include emerging considerations for the field such as (i) targeting permutations of transcription factors, (ii) transient expression systems, (iii) tissue specificity, and (iv) expanding this strategy beyond CAR-T cell therapy and cancer.

Revolutionizing CAR T-Cell Therapies: Innovations in Genetic Engineering and Manufacturing to Enhance Efficacy and Accessibility

Chimeric antigen receptor (CAR) T-cell therapy has achieved notable success in treating hematological cancers but faces significant challenges in solid-tumor treatment and overall efficacy. Key limitations include T-cell exhaustion, tumor relapse, immunosuppressive tumor microenvironments (TME), immunogenicity, and antigen heterogeneity. To address these issues, various genetic engineering strategies have been proposed. Approaches such as overexpression of transcription factors or metabolic armoring and dynamic CAR regulation are being explored to improve CAR T-cell function and safety. Other efforts to improve CAR T-cell efficacy in solid tumors include targeting novel antigens or developing alternative strategies to address antigen diversity. Despite the promising preclinical results of these solutions, challenges remain in translating CAR T-cell therapies to the clinic to enable economically viable access to these transformative medicines. The efficiency and scalability of autologous CAR T-cell therapy production are hindered by traditional, manual processes which are costly, time-consuming, and prone to variability and contamination. These high-cost, time-intensive processes have complex quality-control requirements. Recent advancements suggest that smaller, decentralized solutions such as microbioreactors and automated point-of-care systems could improve production efficiency, reduce costs, and shorten manufacturing timelines, especially when coupled with innovative manufacturing methods such as transposons and lipid nanoparticles. Future advancements may include harmonized consumables and AI-enabled technologies, which promise to streamline manufacturing, reduce costs, and enhance production quality.

Unlocking the potential of iPSC-derived immune cells: engineering iNK and iT cells for cutting-edge immunotherapy

Induced pluripotent stem cells (iPSCs) have emerged as a revolutionary tool in cell therapies due to their ability to differentiate into various cell types, unlimited supply, and potential as off-the-shelf cell products. New advances in iPSC-derived immune cells have generated potent iNK and iT cells which showed robust killing of cancer cells in animal models and clinical trials. With the advent of advanced genome editing technologies that enable the development of highly engineered cells, here we outline 12 strategies to engineer iPSCs to overcome limitations and challenges of current cell-based immunotherapies, including safety switches, stealth edits, avoiding graft-versus-host disease (GvHD), targeting, reduced lymphodepletion, efficient differentiation, increased in vivo persistence, stemness, metabolic fitness, homing/trafficking, and overcoming suppressive tumor microenvironment and stromal cell barrier. With the development of advanced genome editing techniques, it is now possible to insert large DNA sequences into precise genomic locations without the need for DNA double strand breaks, enabling the potential for multiplexed knock out and insertion. These technological breakthroughs have made it possible to engineer complex cell therapy products at unprecedented speed and efficiency. The combination of iPSC derived iNK, iT and advanced gene editing techniques provides new opportunities and could lead to a new era for next generation of cell immunotherapies.

FoxO1 Alleviates the Mitochondrial ROS Levels Induced by α-Synuclein Preformed Fibrils in BV-2 Microglial Cells

Parkinson's disease (PD) is a complex neurodegenerative disorder marked by the gradual deterioration of dopaminergic neurons, especially in the substantia nigra pars compacta (SNc). Dysregulation of the transcription factor FoxO1 is associated with various neurodegenerative conditions, including Alzheimer's disease and PD, though the specific mechanisms involved are not fully understood. This study explores the effects of α-Synuclein preformed fibrils (PFF) on BV-2 microglial cells, focusing on changes in molecular characteristics and their impact on neuronal degeneration. Our results demonstrate that PFF treatment significantly increases FoxO1 mRNA (p = 0.0443) and protein (p = 0.0216) levels, leading to its nuclear translocation (p = 0.0142) and enhanced expression of genes involved in the detoxification of reactive oxygen species (ROS), such as Catalase (Cat, p = 0.0249) and superoxide dismutase 2 (Sod2, p = 0.0313). Furthermore, we observed that PFF treatment elevates mitochondrial ROS levels. However, cells lacking FoxO1 or treated with FoxO1 inhibitors showed increased vulnerability to PFF-induced ROS, attributed to reduced expression of ROS detoxifying enzymes Cat and Sod2 (p < 0.0001). Besides enhancing ROS production, inhibiting FoxO1 also heightens neurotoxicity induced by PFF treatment in microglia-conditioned medium (p < 0.0001). Conversely, treatment with N-acetylcysteine or bacterial superoxide dismutase A mitigated the ROS increase induced by PFF (p < 0.0001). These findings suggest the essential role of FoxO1 in regulating ROS levels, which helps alleviate pathology in PFF-induced PD models. Our study provides insights into the genetic mechanisms of PD and suggests potential pathways for developing novel therapeutic strategies.

T cell dysfunction and therapeutic intervention in cancer

Recent advances in immunotherapy have affirmed the curative potential of T cell-based approaches for treating relapsed and refractory cancers. However, the therapeutic efficacy is limited in part owing to the ability of cancers to evade immunosurveillance and adapt to immunological pressure. In this Review, we provide a brief overview of cancer-mediated immunosuppressive mechanisms with a specific focus on the repression of the surveillance and effector function of T cells. We discuss CD8+ T cell exhaustion and functional heterogeneity and describe strategies for targeting the molecular checkpoints that restrict T cell differentiation and effector function to bolster immunotherapeutic effects. We also delineate the emerging contributions of the tumor microenvironment to T cell metabolism and conclude by highlighting discovery-based approaches for developing future cellular therapies. Continued exploration of T cell biology and engineering hold great promise for advancing therapeutic interventions for cancer.

Biomarkers of outcome in patients undergoing CD19 CAR-T therapy for large B cell lymphoma

CD19-directed autologous chimeric antigen receptor T cell (CAR-T) therapy has transformed the management of relapsed/refractory (R/R) large B cell lymphoma (LBCL). Initially approved in the third line and beyond setting, CAR-T is now standard of care (SOC) for second-line treatment in patients with refractory disease or early relapse (progression within 12 months) following primary chemoimmunotherapy. Despite becoming SOC, most patients do not achieve complete response, and long-term cure is only observed in approximately 40% of patients. Accordingly, there is an urgent need to better understand the mechanisms of treatment failure and to identify patients that are unlikely to benefit from SOC CAR-T. The field needs robust biomarkers to predict treatment outcome, as better understanding of prognostic factors and mechanisms of resistance can inform on the design of novel treatment approaches for patients predicted to respond poorly to SOC CAR-T. This review aims to provide a comprehensive overview of clinical, molecular, imaging, and cellular features that have been shown to influence outcomes of CAR-T therapy in patients with R/R LBCL.

Rab5 Overcomes CAR T Cell Dysfunction Induced by Tumor-Mediated CAR Capture

Continuous interaction between chimeric antigen receptor (CAR) T cell (CART) and tumors often result in CART dysfunction and tumor escape. We observed that tumors can take up CAR molecules, leaving CARTs without surface-expressed CARs and thus unable to kill tumors after prolonged exposure. Overexpression of Rab5 resulted in augmented clathrin-independent endocytosis, preventing loss of surface-expressed CARs, and enhanced CART activity. Interestingly, we observed membrane protrusions on the CART cell surface which disappeared after multiple tumor challenges. Rab5 maintained these protrusions after repeated tumor engagements and their presence correlated with effective tumor clearance, suggesting a link between endocytosis, membrane protrusions, and cytolytic activity. In vivo , Rab5-expressing CARTs demonstrated improved activity and were able to clear an otherwise refractory mesothelin-expressing solid cancer in humanized mice by maintaining CAR surface expression within the tumor. Thus, pairing Rab5 with CAR expression could improve the clinical efficacy of CART therapy. Highlights "CAR-jacking" occurs when surface CAR is internalized by target tumor cells.Rab5 overexpression prevents "CAR-jacking" and enhances CART function.Rab5 promotes CAR endocytic recycling and maintains membrane protrusions.Rab5-expressing CARTs exhibit enhanced therapeutic efficacy against solid tumors.

Fueling CARs: metabolic strategies to enhance CAR T-cell therapy

CAR T cells are widely applied for relapsed hematological cancer patients. With six approved cell therapies, for Multiple Myeloma and other B-cell malignancies, new insights emerge. Profound evidence shows that patients who fail CAR T-cell therapy have, aside from antigen escape, a more glycolytic and weakened metabolism in their CAR T cells, accompanied by a short lifespan. Recent advances show that CAR T cells can be metabolically engineered towards oxidative phosphorylation, which increases their longevity via epigenetic and phenotypical changes. In this review we elucidate various strategies to rewire their metabolism, including the design of the CAR construct, co-stimulus choice, genetic modifications of metabolic genes, and pharmacological interventions. We discuss their potential to enhance CAR T-cell functioning and persistence through memory imprinting, thereby improving outcomes. Furthermore, we link the pharmacological treatments with their anti-cancer properties in hematological malignancies to ultimately suggest novel combination strategies.

The Fate(s) of CAR T-Cell Therapy: Navigating the Risks of CAR+ T-Cell Malignancy

The introduction of chimeric antigen receptor (CAR) T-cell therapy represents a landmark advancement in treating resistant forms of cancer such as leukemia, lymphoma, and myeloma. However, concerns about long-term safety have emerged following an FDA investigation into reports of second primary malignancies (SPM) after CAR-T cell treatment. This review offers a thorough examination of how genetically modified T cells might transform into CAR+ SPM. It explores genetic and molecular pathways leading to T-cell lymphomagenesis, the balance between CAR T-cell persistence, stemness, and oncogenic risk, and the trade-off of T-cell exhaustion, which may limit therapy efficacy but potentially reduce lymphomagenesis risk. Significance: An FDA probe into 22 cases of second primary T-cell malignancies following CAR T-cell therapy stresses the need to investigate their origins. Few may arise from preexisting genetic and epigenetic alterations and those introduced during therapeutic engineering. Technological advances, regulatory oversight, and patient monitoring are essential to mitigate potential risks.