Expression of chimeric receptor composed of immunoglobulin-derived V regions and T-cell receptor-derived C regions

Mechanisms of antigen-dependent resistance to chimeric antigen receptor (CAR)-T cell therapies

Cancer immunotherapy has reshaped the landscape of cancer treatment over the past decades. Genetic manipulation of T cells to express synthetic receptors, known as chimeric antigen receptors (CAR), has led to the creation of tremendous commercial and therapeutic success for the treatment of certain hematologic malignancies. However, since the engagement of CAR-T cells with their respective antigens is solely what triggers their cytotoxic reactions against target cells, the slightest changes to the availability and/or structure of the target antigen often result in the incapacitation of CAR-T cells to enforce tumoricidal responses. This results in the resistance of tumor cells to a particular CAR-T cell therapy that requires meticulous heeding to sustain remissions in cancer patients. In this review, we highlight the antigen-dependent resistance mechanisms by which tumor cells dodge being recognized and targeted by CAR-T cells. Moreover, since substituting the target antigen is the most potent strategy for overcoming antigen-dependent disease relapse, we tend to highlight the current status of some target antigens that might be considered suitable alternatives to the currently available antigens in various cancers. We also propose target antigens whose targeting might reduce the off-tumor adverse events of CAR-T cells in certain malignancies.

Reconfiguring the immune system to target cancer: Therapies based on T cells, cytokines, and vaccines

Over the years, extensive research has been dedicated to performing in-depth analysis of cancer to uncover the intricate details of its nature - including the types of cancer, causative agents, stimulators of disease progression, factors contributing to poor prognosis, and efficient therapies to restrict the metastatic aggressiveness. This chapter highlights the mechanisms through which different arms of the host immune system - namely cytokines, lymphocytes, antigen-presenting cells (APCs) -can be mobilized to eradicate cancer. Most malignant tumors are either poorly immunogenic, or are harbored in a highly immuno-suppressive microenvironment. This is why reinforcing the host's anti-tumor defenses, through infusion of pro-inflammatory cytokines, tumor antigen-loaded APCs, and anti-tumor cytotoxic cells has emerged as a viable treatment option against cancer. The chapter also highlights the ongoing preclinical and clinical studies in different malignancies and the outcome of various therapies. Although these methods are not foolproof, and antigen escape variants can still evade or develop resistance to customized therapies, they achieve disease stabilization in several cases when conventional treatments fail. In many instances, combination therapies involving cytokines, T cells, and vaccinations prove more effective than monotherapies. The limitations of the current therapies are also discussed, along with ongoing modifications aimed at improving efficacy.

CAR-T cell therapy in the treatment of relapsed or refractory primary central nervous system lymphoma: recent advances and challenges

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive lymphoma that is isolated in the central nervous system (CNS) or vitreoretinal space. High-dose methotrexate (HD-MTX)-based immunochemotherapy is the frontline for its treatment, with a high early response rate. However, relapsed or refractory (R/R) patients present numerous difficulties and challenges in clinical treatment. Chimeric antigen receptor (CAR)-T cells offer a promising option for the treatment of hematologic malignancies, especially in the R/R B-cell lymphoma and multiple myeloma. Despite the exclusion of most PCNSL cases from pivotal CAR-T cell trials due to their specific tumor microenvironment (TME), available preclinical and clinical studies with small cohorts suggest an overall acceptable safety profile and remarkable anti-tumor effects. In this review, we will provide the development process of CAR-T cells and summarize the research progress, limitations, and future perspectives of CAR-T cell therapy in patients with R/R PCNSL.

CAR-T cell therapy for breast cancer: Current status and future perspective

Within the expanding therapeutic landscape for breast cancer (BC), metastatic breast cancer (MBC) remains virtually incurable and tend to develop resistance to conventional treatments ultimately leading to metastatic progression and death. Cellular immunotherapy (CI), particularly chimeric antigen receptor-engineered T (CAR-T) cells, has emerged as a promising approach for addressing this challenge. In the wake of their striking efficacy against hematological cancers, CAR-T cells have also been used where the clinical need is greatest - in patients with aggressive BCs. Unfortunately, current outcomes fall considerably short of replicating that success, primarily owing to the scarcity of tumor-specific antigens and the immunosuppressive microenvironment within BC. Herein, we provide an up-to-date overview of both preclinical and clinical data concerning the application of CAR-T cell therapy in BC. By surveying the existing literature, we discuss the prevailing constrains of this therapeutic approach and overview possible strategies to advance it in the context of breast malignancies. Possible approaches include employing synthetic biology to refine antigen targeting and mitigate off-target toxicity, utilizing logic-gated CAR constructs to enhance specificity, and leveraging armored CARs to remodel the tumor micro-environment. Temporal and spatial regulation of CAR-T cells using inducible gene switches and external triggers further improves safety and functionality. In addition, promoting T cell homing through chemokine receptor engineering and enhancing manufacturing processes with universal CAR platforms expand therapeutic applicability. These innovations not only address antigen escape and T cell exhaustion but also optimize the efficacy and safety profile of CAR-T cell therapy. We, therefore, outline a trajectory wherein CAR-T cells may evolve from a promising experimental approach to a standard modality in BC therapy.

Recent advancements in improving the efficacy and safety of chimeric antigen receptor (CAR)-T cell therapy for hepatocellular carcinoma

The liver is one of the most frequent sites of primary malignancies in humans. Hepatocellular carcinoma (HCC) is one of the most prevalent solid tumors with poor prognosis. Current treatments showed limited efficacy in some patients, and, therefore, alternative strategies, such as immunotherapy, cancer vaccines, adoptive cell therapy (ACT), and recently chimeric antigen receptors (CAR)-T cells, are developed to offer better efficacy and safety profile in patients with HCC. Unlike other ACTs like tumor-infiltrating lymphocytes (TILs), CAR-T cells are equipped with engineered CAR receptors that effectively identify tumor antigens and eliminate cancer cells without major histocompatibility complex (MHC) restriction. This process induces intracellular signaling, leading to T lymphocyte recruitment and subsequent activation of other effector cells in the tumor microenvironment (TME). Until today, novel approaches have been used to develop more potent CAR-T cells with robust persistence, specificity, trafficking, and safety. However, the clinical application of CAR-T cells in solid tumors is still challenging. Therefore, this study aims to review the advancement, prospects, and possible avenues of CAR-T cell application in HCC following an outline of the CAR structure and function.

From ex vivo to in vivo chimeric antigen T cells manufacturing: new horizons for CAR T-cell based therapy

In the past decades, Chimeric Antigen Receptor (CAR)-T cell therapy has achieved remarkable success, leading to the approval of six therapeutic products for haematological malignancies. Recently, the therapeutic potential of this therapy has also been demonstrated in non-tumoral diseases. Currently, the manufacturing process to produce clinical-grade CAR-T cells is complex, time-consuming, and highly expensive. It involves multiple steps, including the collection of T cells from patients or healthy donors, in vitro engineering and expansion, and finally reinfusion into patients. Therefore, despite the impressive clinical outcomes, ex vivo manufacturing process makes CAR-T cells out of reach for many cancer patients. Direct in vivo engineering of T cells could be a more rapid solution able to circumvent both the complexity and the costs associated with ex vivo manufactured CAR-T cells. This novel approach allows to completely eliminate ex vivo cell manipulation and expansion while producing therapeutic cell populations directly in vivo. To date, several studies have demonstrated the feasibility of in vivo T cell reprogramming, by employing injectable viral- or nanocarrier-based delivery platforms in tumour animal models. Additionally, in vivo production of CAR-T cells might reduce the incidence, or at least the severity, of systemic toxicities frequently occurring with ex vivo produced CAR-T cells, such as cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. In this review, we highlight the challenges associated with the current ex vivo manufacturing protocols and review the latest progresses in the emerging field of in vivo CAR-T therapy, by comparing the various platforms so far investigated. Moreover, we offer an overview of the advantages deriving from in vivo reprogramming of other immune cell types, such as Natural Killer and macrophages, with CAR constructs.

Optimising CAR T therapy for the treatment of solid tumors

INTRODUCTION

Adoptive immunotherapy using chimeric antigen receptor (CAR)-engineered T cells has proven transformative in the management of B cell and plasma cel derived malignancies. However, solid tumors have largely proven to be resistant to this therapeutic modality. Challenges include the paucity of safe target antigens, heterogeneity of target expression within the tumor, difficulty in delivery of CAR T cells to the site of disease, poor penetration within solid tumor deposits and inability to circumvent the array of immunosuppressive and biophysical barriers imposed by the solid tumor microenvironment.

AREAS COVERED

Literature was reviewed on the PubMed database, excluding occasional papers which were not available as open access publications or through other means.

EXPERT OPINION

Here, we have surveyed the large body of technological advances that have been made in the quest to bridge the gap toward successful deployment of CAR T cells for the treatment of solid tumors. These encompass the development of more sophisticated targeting strategies to engage solid tumor cells safely and comprehensively, improved drug delivery solutions, design of novel CAR architectures that achieve improved functional persistence and which resist physical, chemical and biological hurdles present in tumor deposits. Prospects for combination therapies that incorporate CAR T cells are also considered.

Current Non-Viral-Based Strategies to Manufacture CAR-T Cells

The successful application of CAR-T cells in the treatment of hematologic malignancies has fundamentally changed cancer therapy. With increasing numbers of registered CAR-T cell clinical trials, efforts are being made to streamline and reduce the costs of CAR-T cell manufacturing while improving their safety. To date, all approved CAR-T cell products have relied on viral-based gene delivery and genomic integration methods. While viral vectors offer high transfection efficiencies, concerns regarding potential malignant transformation coupled with costly and time-consuming vector manufacturing are constant drivers in the search for cheaper, easier-to-use, safer, and more efficient alternatives. In this review, we examine different non-viral gene transfer methods as alternatives for CAR-T cell production, their advantages and disadvantages, and examples of their applications. Transposon-based gene transfer methods lead to stable but non-targeted gene integration, are easy to handle, and achieve high gene transfer rates. Programmable endonucleases allow targeted integration, reducing the potential risk of integration-mediated malignant transformation of CAR-T cells. Non-integrating CAR-encoding vectors avoid this risk completely and achieve only transient CAR expression. With these promising alternative techniques for gene transfer, all avenues are open to fully exploiting the potential of next-generation CAR-T cell therapy and applying it in a wide range of applications.

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.

Coley's Toxin to First Approved Therapeutic Vaccine-A Brief Historical Account in the Progression of Immunobiology-Based Cancer Treatment

Cancer immunobiology is one of the hot topics of discussion amongst researchers today, and immunotherapeutic modalities are among the selected few emerging approaches to cancer treatment that have exhibited a promising outlook. However, immunotherapy is not a new kid on the block; it has been around for centuries. The origin of cancer immunotherapy in modern medicine can be traced back to the initial reports of spontaneous regression of malignant tumors in some patients following an acute febrile infection, at the turn of the twentieth century. This review briefly revisits the historical accounts of immunotherapy, highlighting some of the significant developments in the field of cancer immunobiology, that have been instrumental in bringing back the immunotherapeutic approaches to the forefront of cancer research. Some of the topics covered are: Coley's toxin-the first immunotherapeutic; the genesis of the theory of immune surveillance; the discovery of T lymphocytes and dendritic cells and their roles; the role of tumor antigens; relevance of tumor microenvironment; the anti-tumor (therapeutic) ability of Bacillus Calmette- Guérin; Melacine-the first therapeutic vaccine engineered; theories of immunoediting and immunophenotyping of cancer; and Provenge-the first FDA-approved therapeutic vaccine. In this review, head and neck cancer has been taken as the reference tumor for narrating the progression of cancer immunobiology, particularly for highlighting the advent of immunotherapeutic agents.

TCR-mimicking STAR conveys superior sensitivity over CAR in targeting tumors with low-density neoantigens

Targeting tumor-specific neoantigens holds promise for cancer immunotherapy, but their ultra-low expression on tumor cells poses challenges for T cell therapies. Here, we found that chimeric antigen receptors (CARs) exhibit 10-100 times lower sensitivity than T cell receptors (TCRs) when targeting human leukocyte antigen (HLA) class I-presented p53R175H neoantigen. To enhance CAR functionality, we introduced T cell receptor fusion constructs (TRuCs) and synthetic TCRs and antigen receptors (STARs). Our data show that STARs optimally reproduce TCR antigen sensitivity, outperforming CARs and TRuCs in redirecting CD8+ and CD4+ T cells to recognize HLA class I neoantigens. STAR-T cells demonstrate superior killing of cancer cell lines with low neoantigen density in vitro and improved tumor control in mouse models compared to CAR-T and TRuC-T cells. These findings highlight CAR sensitivity limitations and present STARs as more effective synthetic receptors for T cell-based immunotherapy against tumors with low neoantigen density.

MAGE-A4 pMHC-targeted CAR-T cells exploiting TCR machinery exhibit significantly improved in vivo function while retaining antigen specificity

BACKGROUND

The development of chimeric antigen receptor (CAR)-T cell therapies for solid tumors has attracted considerable attention, yet their clinical efficacy remains limited. Therefore, various efforts have been made to improve the efficacy of CAR-T cell therapy. As one promising strategy, incorporating the T-cell receptor (TCR) machinery into CAR structures has been reported to improve the efficacy of CAR-T cells in studies using conventional CARs targeting such as EGFR. However, in the case of peptide/major histocompatibility complex (pMHC)-targeted CARs, the advantages of exploiting TCR machinery have not been fully elucidated. We recently developed MAGE-A4-derived pMHC (MAGE-A4 pMHC)-targeted CAR-T cells (MA-CAR-T cells) using a highly specific human scFv antibody against MAGE-A4p230-239/HLA-A*02:01. We aimed to determine whether MAGE-A4 pMHC-targeted CAR-T cells using the TCR machinery (Hybrid MA-TCR-T cells) exhibit superior functionality without compromising antigen specificity.

METHODS

We constructed a retroviral vector expressing Hybrid MA-TCR where MAGE-A4 pMHC-specific scFv are fused to human TCR constant chains.

RESULTS

Hybrid MA-TCR-T cells demonstrated superior in vitro functions compared with MA-CAR-T cells, while maintaining strict antigen specificity. In addition, functional superiority of Hybrid MA-TCR-T cells to MA-CAR-T cells became more pronounced on repetitive antigen stimulation. In particular, Hybrid MA-TCR-T cells significantly inhibited tumor growth in an immunodeficient mouse model more effectively than MA-CAR-T cells. Ex vivo analyses indicated that their enhanced therapeutic efficacy might result from higher infiltration of functionally active, less differentiated Hybrid MA-TCR-T cells in tumor tissues.

CONCLUSIONS

These findings suggest that leveraging the TCR machinery is a promising strategy for enhancing pMHC-targeted CAR-T cell therapy for solid tumors, potentially leading to more effective treatments.

The future of cellular therapy for the treatment of renal cell carcinoma

INTRODUCTION

Systemic treatment options for renal cell carcinoma (RCC) have expanded considerably in recent years, and both tyrosine kinase inhibitors and immune checkpoint inhibitors, alone or in combination, have entered the clinical arena. Adoptive cell immunotherapies have recently revolutionized the treatment of cancer and hold the promise to further advance the treatment of RCC.

AREAS COVERED

In this review, we summarize the latest preclinical and clinical development in the field of adoptive cell immunotherapy for the treatment of RCC, focusing on lymphokine-activated killer (LAK) cells, cytokine-induced killer (CIK) cells, tumor-infiltrating T cells (TILs), TCR-engineered T cells, chimeric antigen receptor (CAR) T cells, and dendritic cell vaccination strategies. Perspectives on emerging cellular products including CAR NK cells, CAR macrophages, as well as γδ T cells are also included.

EXPERT OPINION

So far, areas of greater therapeutic success of adoptive cell therapies include the adjuvant administration of CIK cells and the transfer of anti-CD70 CAR T cells in patients with metastatic RCC. Bench to bedside and back research will be needed to overcome current limitations of adoptive cell therapies in RCC, primarily aiming at improving the safety of immune cell products, optimizing their antitumor activity and generating off-the-shelf products ready for clinical use.

From TCR fundamental research to innovative chimeric antigen receptor design

Engineered T cells that express chimeric antigen receptors (CARs) have transformed the treatment of haematological cancers. CARs combine the tumour-antigen-binding function of antibodies with the signalling functions of the T cell receptor (TCR) ζ chain and co-stimulatory receptors. The resulting constructs aim to mimic the TCR-based and co-receptor-based activation of T cells. Although these have been successful for some types of cancer, new CAR formats are needed, to limit side effects and broaden their use to solid cancers. Insights into the mechanisms of TCR signalling, including the identification of signalling motifs that are not present in the TCR ζ chain and mechanistic insights in TCR activation, have enabled the development of CAR formats that outcompete the current CARs in preclinical mouse models and clinical trials. In this Perspective, we explore the mechanistic rationale behind new CAR designs.

Application of novel CAR technologies to improve treatment of autoimmune disease

Chimeric antigen receptor (CAR) T cell therapy has become an important treatment for hematological cancers, and its success has spurred research into CAR T cell therapies for other diseases, including solid tumor cancers and autoimmune diseases. Notably, the development of CAR-based treatments for autoimmune diseases has shown great progress recently. Clinical trials for anti-CD19 and anti-BCMA CAR T cells in treating severe B cell-mediated autoimmune diseases, like systemic lupus erythematosus (SLE), have shown lasting remission thus far. CAR T cells targeting autoreactive T cells are beginning clinical trials for treating T cell mediated autoimmune diseases. Chimeric autoantigen receptor (CAAR) T cells specifically target and eliminate only autoreactive B cells, and they have shown promise in treating mucosal pemphigus vulgaris and MuSK myasthenia gravis. Regulatory CAR T cells have also been developed, which show potential in altering autoimmune affected areas by creating a protective barrier as well as helping decrease inflammation. These new treatments are only the beginning of potential CAR T cell applications in treating autoimmune disease. Novel CAR technologies have been developed that increase the safety, potency, specificity, and efficacy of CAR T cell therapy. Applying these novel modifications to autoimmune CARs has the potential to enhance the efficacy and applicability of CAR therapies to autoimmune disease. This review will detail several recently developed CAR technologies and discuss how their application to autoimmune disease will improve this emerging field. These include logic-gated CARs, soluble protein-secreting CARs, and modular CARs that enable CAR T cell therapies to be more specific, reach a wider span of target cells, be safer for patients, and give a more potent cytotoxic response. Applying these novel CAR technologies to the treatment of autoimmune diseases has the potential to revolutionize this growing application of CAR T cell therapies.

High specificity of engineered T cells with third generation CAR (CD28-4-1BB-CD3-ζ) based on biotin-bound monomeric streptavidin for potential tumor immunotherapy

Introduction

Immunotherapy has revolutionized cancer treatment, and Chimeric Antigen Receptor T cell therapy (CAR-T) is a groundbreaking approach. Traditional second-generation CAR-T therapies have achieved remarkable success in hematological malignancies, but there is still room for improvement, particularly in developing new targeting strategies. To address this limitation, engineering T cells with multi-target universal CARs (UniCARs) based on monomeric streptavidin has emerged as a versatile approach in the field of anti-tumor immunotherapy. However, no studies have been conducted on the importance of the intracellular signaling domains of such CARs and their impact on efficiency and specificity.

Method

Here, we developed second-generation and third-generation UniCARs based on an extracellular domain comprising an affinity-enhanced monomeric streptavidin, in addition to CD28 and 4-1BB co-stimulatory intracellular domains. These UniCAR structures rely on a biotinylated intermediary, such as an antibody, for recognizing target antigens. In co-culture assays, we performed a functional comparison between the third-generation UniCAR construct and two second-generation UniCAR variants, each incorporating either the CD28 or 4-1BB as co-stimulatory domain.

Results

We observed that components in culture media could inhibit the binding of biotinylated antibodies to monomeric streptavidin-CARs, potentially compromising their efficacy. Furthermore, third-generation UniCAR-T cells showed robust cytolytic activity against cancer cell lines upon exposure to specific biotinylated antibodies like anti-CD19 and anti-CD20, underscoring their capability for multi-targeting. Importantly, when assessing engineered UniCAR-T cell activation upon encountering their target cells, third-generation UniCAR-T cells exhibited significantly enhanced specificity compared to second-generation CAR-T cells.

Discussion

First, optimizing culture conditions would be essential before deploying UniCAR-T cells clinically. Moreover, we propose that third-generation UniCAR-T cells are excellent candidates for preclinical research due to their high specificity and multi-target anti-tumor cytotoxicity.

MCMC Methods for Parameter Estimation in ODE Systems for CAR-T Cell Cancer Therapy

Chimeric antigen receptor (CAR)-T cell therapy represents a breakthrough in treating resistant hematologic cancers. It is based on genetically modifying T cells transferred from the patient or a donor. Although its implementation has increased over the last few years, CAR-T has many challenges to be addressed, for instance, the associated severe toxicities, such as cytokine release syndrome. To model CAR-T cell dynamics, focusing on their proliferation and cytotoxic activity, we developed a mathematical framework using ordinary differential equations (ODEs) with Bayesian parameter estimation. Bayesian statistics were used to estimate model parameters through Monte Carlo integration, Bayesian inference, and Markov chain Monte Carlo (MCMC) methods. This paper explores MCMC methods, including the Metropolis-Hastings algorithm and DEMetropolis and DEMetropolisZ algorithms, which integrate differential evolution to enhance convergence rates. The theoretical findings and algorithms were validated using Python and Jupyter Notebooks. A real medical dataset of CAR-T cell therapy was analyzed, employing optimization algorithms to fit the mathematical model to the data, with the PyMC library facilitating Bayesian analysis. The results demonstrated that our model accurately captured the key dynamics of CAR-T cell therapy. This conclusion underscores the potential of parameter estimation to improve the understanding and effectiveness of CAR-T cell therapy in clinical settings.

ReCARving the future: bridging CAR T-cell therapy gaps with synthetic biology, engineering, and economic insights

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematologic malignancies, offering remarkable remission rates in otherwise refractory conditions. However, its expansion into broader oncological applications faces significant hurdles, including limited efficacy in solid tumors, safety concerns related to toxicity, and logistical challenges in manufacturing and scalability. This review critically examines the latest advancements aimed at overcoming these obstacles, highlighting innovations in CAR T-cell engineering, novel antigen targeting strategies, and improvements in delivery and persistence within the tumor microenvironment. We also discuss the development of allogeneic CAR T cells as off-the-shelf therapies, strategies to mitigate adverse effects, and the integration of CAR T cells with other therapeutic modalities. This comprehensive analysis underscores the synergistic potential of these strategies to enhance the safety, efficacy, and accessibility of CAR T-cell therapies, providing a forward-looking perspective on their evolutionary trajectory in cancer treatment.

The Future of CAR T Therapeutics to Treat Autoimmune Disorders

The concept of chimeric antigen receptor (CAR) T cell therapy emerged from cancer immunotherapy and has been rapidly adapted and developed for the treatment of autoimmune, especially B-cell-driven, diseases since the first publication of an article featuring a patient with systemic lupus erythematosus in 2021. Phase II studies are about to start, but up to now, only case reports and small series have been published. In contrast to hemato-oncological diseases, where an aggressive response to malignant cells and long-lasting persistence of CAR T cells has been aimed at and observed in many patients, this is not the case with autoimmune diseases but might not be necessary to control disease. Future studies will focus on the optimal target but also on the optimal level of immunogenicity. The latter can be influenced by numerous modulations that affect not only cytokine release but also regulation. In addition, there are potential applications in regulatory cells such as CAR regulatory T cells (Treg). The question of toxicity reduction must also be addressed, as long-term complications such as the potential development of malignant diseases, infections, or cytopenia must be considered even more critically in the area of autoimmune diseases than is the case for patients with oncologic diseases. Alternative antibody-based therapies using the same target (e.g., CD3/CD19 bispecific targeting antibodies) have not been used in these patients and might also be considered in the future. In conclusion, CAR T cell therapy represents a promising therapeutic approach for autoimmune diseases, offering a targeted strategy to modulate immune responses and restore immune tolerance.

CAR-T Cell Therapy in Pancreatic and Biliary Tract Cancers: An Updated Review of Clinical Trials

BACKGROUND

Pancreatic and biliary tract cancers are digestive system tumors with dismal prognosis and limited treatment options. The effectiveness of conventional surgical interventions, radiation therapy, and systemic therapy is restricted in these cases. Furthermore, clinical trials have shown that immunotherapy using immune checkpoint inhibitors has only demonstrated modest clinical results when applied to patients with pancreatobiliary tumors. This highlights the importance of implementing combination immunotherapy approaches or exploring alternative therapeutic strategies to improve treatment outcomes.

MATERIALS AND METHODS

We reviewed the relevant literature on chimeric antigen receptor (CAR)-T cell therapy for pancreatobiliary cancers from PubMed/Medline and ClinicalTrials.gov and retrieved the relevant data accordingly. Attention was additionally given to the examination of grey literature with the aim of obtaining additional details regarding ongoing clinical trials. We mainly focused on abstracts and presentations and e-posters and slides of recent important annual meetings (namely ESMO Immuno-Oncology Congress, ESMO Congress, ASCO Virtual Scientific Program, ASCO Gastrointestinal Cancers Symposium).

RESULTS

CAR-T cell therapy has emerged as a promising and evolving treatment approach for pancreatic and biliary tract cancer. This form of adoptive cell therapy utilizes genetic engineering to modify the expression of specific antibodies on the surface of T cells enabling them to target specific cancer-associated antigens and to induce potent anti-tumor activity. The aim of this review is to provide an updated summary of the available evidence from clinical trials that have explored the application of CAR-T cell therapy in treating pancreatobiliary cancers.

CONCLUSIONS

While the utilization of CAR-T cell therapy in pancreatobiliary cancers is still in its initial phases with only a limited amount of clinical data available, the field is advancing rapidly, incorporating novel technologies to mitigate potential toxicities and enhance antigen-directed tumor eradication.

Strategies for Improving CAR T Cell Persistence in Solid Tumors

CAR T cells require optimization to be effective in patients with solid tumors. There are many barriers affecting their ability to succeed. One barrier is persistence, as to achieve an optimal antitumor response, infused CAR T cells must engraft and persist. This singular variable is impacted by a multitude of factors-the CAR T cell design, lymphodepletion regimen used, expansion method to generate the T cell product, and more. Additionally, external agents can be utilized to augment CAR T cells, such as the addition of novel cytokines, pharmaceutical drugs that bolster memory formation, or other agents during either the ex vivo expansion process or after CAR T cell infusion to support them in the oppressive tumor microenvironment. This review highlights many strategies being used to optimize T cell persistence as well as future directions for improving the persistence of infused cells.

Chimeric antigen receptor (CAR) T-cell therapy: Harnessing extracellular vesicles for enhanced efficacy

A cutting-edge approach in cell-based immunotherapy for combating resistant cancer involves genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes. In recent years, these therapies have demonstrated effectiveness, leading to their commercialization and clinical application against certain types of cancer. However, CAR-T therapy faces limitations, such as the immunosuppressive tumour microenvironment (TME) that can render CAR-T cells ineffective, and the adverse side effects of the therapy, including cytokine release syndrome (CRS). Extracellular vesicles (EVs) are a diverse group of membrane-bound particles released into the extracellular environment by virtually all cell types. They are essential for intercellular communication, transferring cargoes such as proteins, lipids, various types of RNAs, and DNA fragments to target cells, traversing biological barriers both locally and systemically. EVs play roles in numerous physiological processes, with those from both immune and non-immune cells capable of modulating the immune system through activation or suppression. Leveraging this capability of EVs to enhance CAR-T cell therapy could represent a significant advancement in overcoming its current limitations. This review examines the current landscape of CAR-T cell immunotherapy and explores the potential role of EVs in augmenting its therapeutic efficacy.

Novel strategies in Parkinson's disease treatment: a review

An unprecedented extension of life expectancy observed during the past century drastically increased the number of patients diagnosed with Parkinson's diseases (PD) worldwide. Estimated costs of PD alone reached $52 billion per year, making effective neuroprotective treatments an urgent and unmet need. Current treatments of both AD and PD focus on mitigating the symptoms associated with these pathologies and are not neuroprotective. In this review, we discuss the most advanced therapeutic strategies that can be used to treat PD. We also critically review the shift of the therapeutic paradigm from a small molecule-based inhibition of protein aggregation to the utilization of natural degradation pathways and immune cells that are capable of degrading toxic amyloid deposits in the brain of PD patients.

Beyond CAR-T: The rise of CAR-NK cell therapy in asthma immunotherapy

Asthma poses a major public health burden. While existing asthma drugs manage symptoms for many, some patients remain resistant. The lack of a cure, especially for severe asthma, compels exploration of novel therapies. Cancer immunotherapy successes with CAR-T cells suggest its potential for asthma treatment. Researchers are exploring various approaches for allergic diseases including membrane-bound IgE, IL-5, PD-L2, and CTLA-4 for asthma, and Dectin-1 for fungal asthma. NK cells offer several advantages over T cells for CAR-based immunotherapy. They offer key benefits: (1) HLA compatibility, meaning they can be used in a wider range of patients without the need for matching tissue types. (2) Minimal side effects (CRS and GVHD) due to their limited persistence and cytokine profile. (3) Scalability for "off-the-shelf" production from various sources. Several strategies have been introduced that highlight the superiority and challenges of CAR-NK cell therapy for asthma treatment including IL-10, IFN-γ, ADCC, perforin-granzyme, FASL, KIR, NCRs (NKP46), DAP, DNAM-1, TGF-β, TNF-α, CCL, NKG2A, TF, and EGFR. Furthermore, we advocate for incorporating AI for CAR design optimization and CRISPR-Cas9 gene editing technology for precise gene manipulation to generate highly effective CAR constructs. This review will delve into the evolution and production of CAR designs, explore pre-clinical and clinical studies of CAR-based therapies in asthma, analyze strategies to optimize CAR-NK cell function, conduct a comparative analysis of CAR-T and CAR-NK cell therapy with their respective challenges, and finally present established novel CAR designs with promising potential for asthma treatment.

CAR-T cell technologies that interact with the tumour microenvironment in solid tumours

INTRODUCTION

Chimeric antigen receptor (CAR) T-cells have emerged as a ground-breaking therapy for the treatment of hematological malignancies due to their capacity for rapid tumor-specific killing and long-lasting tumor immunity. However, the same success has not been observed in patients with solid tumors. Largely, this is due to the additional challenges imposed by safe and uniform target selection, inefficient CAR T-cell access to sites of disease and the presence of a hostile immunosuppressive tumor microenvironment.

AREAS COVERED

Literature was reviewed on the PubMed database from the first description of a CAR by Kuwana, Kurosawa and colleagues in December 1987 through to the present day. This literature indicates that in order to tackle solid tumors, CAR T-cells can be further engineered with additional armoring strategies that facilitate trafficking to and infiltration of malignant lesions together with reversal of suppressive immune checkpoints that operate within solid tumor lesions.

EXPERT OPINION

In this review, we describe a number of recent advances in CAR T-cell technology that set out to combat the problems imposed by solid tumors including tumor recruitment, infiltration, immunosuppression, metabolic compromise, and hypoxia.

Exploring the Complexity and Promise of Tumor Immunotherapy in Drug Development

Cancer represents a significant threat to human health, and traditional chemotherapy or cytotoxic therapy is no longer the sole or preferred approach for managing malignant tumors. With advanced research into the immunogenicity of tumor cells and the growing elderly population, tumor immunotherapy has emerged as a prominent therapeutic option. Its significance in treating elderly cancer patients is increasingly recognized. In this study, we review the conceptual classifications and benefits of immunotherapy, and discuss recent developments in new drugs and clinical progress in cancer treatment through various immunotherapeutic modalities with different mechanisms. Additionally, we explore the impact of immunosenescence on the effectiveness of cancer immunotherapy and propose innovative and effective strategies to rejuvenate senescent T cells.

CAR-T cell therapy: a game-changer in cancer treatment and beyond

In recent years, cancer has become one of the primary causes of mortality, approximately 10 million deaths worldwide each year. The most advanced, chimeric antigen receptor (CAR) T cell immunotherapy has turned out as a promising treatment for cancer. CAR-T cell therapy involves the genetic modification of T cells obtained from the patient's blood, and infusion back to the patients. CAR-T cell immunotherapy has led to a significant improvement in the remission rates of hematological cancers. CAR-T cell therapy presently limited to hematological cancers, there are ongoing efforts to develop additional CAR constructs such as bispecific CAR, tandem CAR, inhibitory CAR, combined antigens, CRISPR gene-editing, and nanoparticle delivery. With these advancements, CAR-T cell therapy holds promise concerning potential to improve upon traditional cancer treatments such as chemotherapy and radiation while reducing associated toxicities. This review covers recent advances and advantages of CAR-T cell immunotherapy.

CAR-T Cells in Acute Myeloid Leukemia: Where Do We Stand?

Despite recent advances, the prognosis of acute myeloid leukemia (AML) remains unsatisfactory due to disease recurrence and the development of resistance to both conventional and novel therapies. Engineered T cells expressing chimeric antigen receptors (CARs) on their cellular surface represent one of the most promising anticancer agents. CAR-T cells are increasingly used in patients with B cell malignancies, with remarkable clinical results despite some immune-related toxicities. However, at present, the role of CAR-T cells in myeloid neoplasms, including AML, is extremely limited, as specific molecular targets for immune cells are generally lacking on AML blasts. Besides the paucity of dispensable targets, as myeloid antigens are often co-expressed on normal hematopoietic stem and progenitor cells with potentially intolerable myeloablation, the AML microenvironment is hostile to T cell proliferation due to inhibitory soluble factors. In addition, the rapidly progressive nature of the disease further complicates the use of CAR-T in AML. This review discusses the current state of CAR-T cell therapy in AML, including the still scanty clinical evidence and the potential approaches to overcome its limitations, including genetic modifications and combinatorial strategies, to make CAR-T cell therapy an effective option for AML patients.

The synergistic immunotherapeutic impact of engineered CAR-T cells with PD-1 blockade in lymphomas and solid tumors: a systematic review

Currently, therapies such as chimeric antigen receptor-T Cell (CAR-T) and immune checkpoint inhibitors like programmed cell death protein-1 (PD-1) blockers are showing promising results for numerous cancer patients. However, significant advancements are required before CAR-T therapies become readily available as off-the-shelf treatments, particularly for solid tumors and lymphomas. In this review, we have systematically analyzed the combination therapy involving engineered CAR-T cells and anti PD-1 agents. This approach aims at overcoming the limitations of current treatments and offers potential advantages such as enhanced tumor inhibition, alleviated T-cell exhaustion, heightened T-cell activation, and minimized toxicity. The integration of CAR-T therapy, which targets tumor-associated antigens, with PD-1 blockade augments T-cell function and mitigates immune suppression within the tumor microenvironment. To assess the impact of combination therapy on various tumors and lymphomas, we categorized them based on six major tumor-associated antigens: mesothelin, disialoganglioside GD-2, CD-19, CD-22, CD-133, and CD-30, which are present in different tumor types. We evaluated the efficacy, complete and partial responses, and progression-free survival in both pre-clinical and clinical models. Additionally, we discussed potential implications, including the feasibility of combination immunotherapies, emphasizing the importance of ongoing research to optimize treatment strategies and improve outcomes for cancer patients. Overall, we believe combining CAR-T therapy with PD-1 blockade holds promise for the next generation of cancer immunotherapy.

CAR Cells beyond Classical CAR T Cells: Functional Properties and Prospects of Application

Chimeric antigen receptors (CARs) are genetically engineered receptors that recognize antigens and activate signaling cascades in a cell. Signal recognition and transmission are mediated by the CAR domains derived from different proteins. T cells carrying CARs against tumor-associated antigens have been used in the development of the CAR T cell therapy, a new approach to fighting malignant neoplasms. Despite its high efficacy in the treatment of oncohematological diseases, CAR T cell therapy has a number of disadvantages that could be avoided by using other types of leukocytes as effector cells. CARs can be expressed in a wide range of cells of adaptive and innate immunity with the emergence or improvement of cytotoxic properties. This review discusses the features of CAR function in different types of immune cells, with a particular focus on the results of preclinical and clinical efficacy studies and the safety of potential CAR cell products.

Non-viral delivery of RNA for therapeutic T cell engineering

Adoptive T cell transfer has shown great success in treating blood cancers, resulting in a growing number of FDA-approved therapies using chimeric antigen receptor (CAR)-engineered T cells. However, the effectiveness of this treatment for solid tumors is still not satisfactory, emphasizing the need for improved T cell engineering strategies and combination approaches. Currently, CAR T cells are mainly manufactured using gammaretroviral and lentiviral vectors due to their high transduction efficiency. However, there are concerns about their safety, the high cost of producing them in compliance with current Good Manufacturing Practices (cGMP), regulatory obstacles, and limited cargo capacity, which limit the broader use of engineered T cell therapies. To overcome these limitations, researchers have explored non-viral approaches, such as membrane permeabilization and carrier-mediated methods, as more versatile and sustainable alternatives for next-generation T cell engineering. Non-viral delivery methods can be designed to transport a wide range of molecules, including RNA, which allows for more controlled and safe modulation of T cell phenotype and function. In this review, we provide an overview of non-viral RNA delivery in adoptive T cell therapy. We first define the different types of RNA therapeutics, highlighting recent advancements in manufacturing for their therapeutic use. We then discuss the challenges associated with achieving effective RNA delivery in T cells. Next, we provide an overview of current and emerging technologies for delivering RNA into T cells. Finally, we discuss ongoing preclinical and clinical studies involving RNA-modified T cells.

A new vision of the efficacy of both CAR-NK and CAR-T cells in treating cancers and autoimmune diseases

Chimeric Antigen Receptor (CAR) based therapies are becoming increasingly important in treating patients. CAR-T cells have been shown to be highly effective in the treatment of hematological malignancies. However, harmful therapeutic barriers have been identified, such as the potential for graft-versus-host disease (GVHD), neurotoxicity, and cytokine release syndrome (CRS). As a result, CAR NK-cell therapy is expected to be a new therapeutic option. NK cells act as cytotoxic lymphocytes, supporting the innate immune response against autoimmune diseases and cancer cells by precisely detecting and eliminating malignant cells. Genetic modification of these cells provides a dual approach to the treatment of AD and cancer. It can be used through both CAR-independent and CAR-dependent mechanisms. The use of CAR-based cell therapies has been successful in treating cancer patients, leading to further investigation of this innovative treatment for alternative diseases, including AD. The complementary roles of CAR T and CAR NK cells have stimulated exploration in this area. Our study examines the latest research on the therapeutic effectiveness of these cells in treating both cancer and ADs.

Chimeric Antigen Receptor (CAR) T-Cell Therapy in Hematologic Malignancies: Clinical Implications and Limitations

Chimeric antigen receptor (CAR) T-cell therapy has become a powerful treatment option in B-cell and plasma cell malignancies, and many patients have benefited from its use. To date, six CAR T-cell products have been approved by the FDA and EMA, and many more are being developed and investigated in clinical trials. The whole field of adoptive cell transfer has experienced an unbelievable development process, and we are now at the edge of a new era of immune therapies that will have its impact beyond hematologic malignancies. Areas of interest are, e.g., solid oncology, autoimmune diseases, infectious diseases, and others. Although much has been achieved so far, there is still a huge effort needed to overcome significant challenges and difficulties. We are witnessing a rapid expansion of knowledge, induced by new biomedical technologies and CAR designs. The era of CAR T-cell therapy has just begun, and new products will widen the therapeutic landscape in the future. This review provides a comprehensive overview of the clinical applications of CAR T-cells, focusing on the approved products and emphasizing their benefits but also indicating limitations and challenges.

Chimeric antigen receptor (CAR) modified T Cells in acute myeloid leukemia: limitations and expectations

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy with a poor prognosis despite the advent of novel therapies. Consequently, a major need exists for new therapeutic options, particularly for patients with relapsed/refractory (R/R) AML. In recent years, it has been possible to individualize the treatment of a subgroup of patients, particularly with the emergence of multiple targeted therapies. Nonetheless, a considerable number of patients remain without therapeutic options, and overall prognosis remains poor because of a high rate of disease relapse. In this sense, cellular therapies, especially chimeric antigen receptor (CAR)-T cell therapy, have dramatically shifted the therapeutic options for other hematologic malignancies, such as diffuse large B cell lymphoma and acute lymphoblastic leukemia. In contrast, effectively treating AML with CAR-based immunotherapy poses major biological and clinical challenges, most of them derived from the unmet need to identify target antigens with expression restricted to the AML blast without compromising the viability of the normal hematopoietic stem cell counterpart. Although those limitations have hampered CAR-T cell therapy translation to the clinic, there are several clinical trials where target antigens, such as CD123, CLL-1 or CD33 are being used to treat AML patients showing promising results. Moreover, there are continuing efforts to enhance the specificity and efficacy of CAR-T cell therapy in AML. These endeavors encompass the exploration of novel avenues, including the development of dual CAR-T cells and next-generation CAR-T cells, as well as the utilization of gene editing tools to mitigate off-tumor toxicities. In this review, we will summarize the ongoing clinical studies and the early clinical results reported with CAR-T cells in AML, as well as highlight CAR-T cell limitations and the most recent approaches to overcome these barriers. We will also discuss how and when CAR-T cells should be used in the context of AML.

The preclinical discovery and clinical development of ciltacabtagene autoleucel (Cilta-cel) for the treatment of multiple myeloma

INTRODUCTION

Despite remarkable therapeutic advances over the last two decades, which have resulted in dramatic improvements in patient survival, multiple myeloma (MM) is still considered an incurable disease. Therefore, there is a high need for new treatment strategies. Genetically engineered/redirected chimeric antigen receptor (CAR) T cells may represent the most compelling modality of immunotherapy for cancer treatment in general, and MM in particular. Indeed, unprecedented response rates have led to the recent approvals of the first two BCMA-targeted CAR T cell products idecabtagene-vicleucel ('Ide-cel') and ciltacabtagene-autoleucel ('Cilta-Cel') for the treatment of heavily pretreated MM patients. In addition, both are emerging as a new standard-of-care also in earlier lines of therapy.

AREAS COVERED

This article briefly reviews the history of the preclinical development of CAR T cells, with a particular focus on Cilta-cel. Moreover, it summarizes the newest clinical data on Cilta-cel and discusses strategies to further improve its activity and reduce its toxicity.

EXPERT OPINION

Modern next-generation immunotherapy is continuously transforming the MM treatment landscape. Despite several caveats of CAR T cell therapy, including its toxicity, costs, and limited access, prolonged disease-free survival and potential cure of MM are finally within reach.

Recent advances on CAR-T signaling pave the way for prolonged persistence and new modalities in clinic

Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment of hematological malignancies. The importance of the receptor costimulatory domain for long-term CAR-T cell engraftment and therapeutic efficacy was demonstrated with second-generation CAR-T cells. Fifth generation CAR-T cells are currently in preclinical trials. At the same time, the processes that orchestrate the activation and differentiation of CAR-T cells into a specific phenotype that predisposes them to long-term persistence are not fully understood. This review highlights ongoing research aimed at elucidating the role of CAR domains and T-cell signaling molecules involved in these processes.

Adoptive Immune Effector Cell Therapies in Cancer and Solid Organ Transplantation: A Review

Cancer is one of the most devastating complications of kidney transplantation and constitutes one of the leading causes of morbidity and mortality among solid organ transplantation (SOT) recipients. Immunosuppression, although effective in preventing allograft rejection, inherently inhibits immune surveillance against oncogenic viral infections and malignancy. Adoptive cell therapy, particularly immune effector cell therapy, has long been a modality of interest in both cancer and transplantation, though has only recently stepped into the spotlight with the development of virus-specific T-cell therapy and chimeric antigen receptor T-cell therapy. Although these modalities are best described in hematopoietic cell transplantation and hematologic malignancies, their potential application in the SOT setting may hold tremendous promise for those with limited therapeutic options. In this review, we provide a brief overview of the development of adoptive cell therapies with a focus on virus-specific T-cell therapy and chimeric antigen receptor T-cell therapy. We also describe the current experience of these therapies in the SOT setting as well as the challenges in their application and future directions in their development.

Immunotherapy for Pediatric Gliomas: CAR-T Cells Against B7H3: A Review of the Literature

BACKGROUND

B7H3 is a co-stimulatory molecule for immune reactions found on the surface of tumor cells in a wide variety of tumors. Preclinical and clinical studies have reported it as a tumor target towards which various immunotherapy modalities could be directed. So far, good results have been obtained in hematological neoplasms; however, a contrasting situation is evident in solid tumors, including those of the CNS, which show high refractoriness to current treatments. The appearance of cellular immunotherapies has transformed oncology due to the reinforcement of the immune response that is compromised in people with cancer.

OBJECTIVE

This article aims to review the literature to describe the advancement in knowledge on B7H3 as a target of CAR-T cells in pediatric gliomas to consider them as an alternative in the treatment of these patients.

RESULTS

Although B7H3 is considered a suitable candidate as a target agent for various immunotherapy techniques, there are still limitations in using CAR-T cells to achieve the desired success.

CONCLUSION

Results obtained with CAR-T cells can be further improved by the suggested proposals; therefore, more clinical trials are needed to study this new therapy in children with gliomas.

Implications of Senescent T Cells for Cancer Immunotherapy

T-cell senescence is thought to result from the age-related loss of the ability to mount effective responses to pathogens and tumor cells. In addition to aging, T-cell senescence is caused by repeated antigenic stimulation and chronic inflammation. Moreover, we demonstrated that T-cell senescence was induced by treatment with DNA-damaging chemotherapeutic agents. The characteristics of therapy-induced senescent T (TIS-T) cells and general senescent T cells are largely similar. Senescent T cells demonstrate an increase in the senescence-associated beta-galactosidase-positive population, cell cycle arrest, secretion of senescence-associated secretory phenotypic factors, and metabolic reprogramming. Furthermore, senescent T cells downregulate the expression of the co-stimulatory molecules CD27 and CD28 and upregulate natural killer cell-related molecules. Moreover, TIS-T cells showed increased PD-1 expression. However, the loss of proliferative capacity and decreased expression of co-stimulatory molecules associated with T-cell senescence cause a decrease in T-cell immunocompetence. In this review, we discuss the characteristics of senescent T-cells, including therapy-induced senescent T cells.

Recruiting In Vitro Transcribed mRNA against Cancer Immunotherapy: A Contemporary Appraisal of the Current Landscape

Over 100 innovative in vitro transcribed (IVT)-mRNAs are presently undergoing clinical trials, with a projected substantial impact on the pharmaceutical market in the near future. Τhe idea behind this is that after the successful cellular internalization of IVT-mRNAs, they are subsequently translated into proteins with therapeutic or prophylactic relevance. Simultaneously, cancer immunotherapy employs diverse strategies to mobilize the immune system in the battle against cancer. Therefore, in this review, the fundamental principles of IVT-mRNA to its recruitment in cancer immunotherapy, are discussed and analyzed. More specifically, this review paper focuses on the development of mRNA vaccines, the exploitation of neoantigens, as well as Chimeric Antigen Receptor (CAR) T-Cells, showcasing their clinical applications and the ongoing trials for the development of next-generation immunotherapeutics. Furthermore, this study investigates the synergistic potential of combining the CAR immunotherapy and the IVT-mRNAs by introducing our research group novel, patented delivery method that utilizes the Protein Transduction Domain (PTD) technology to transduce the IVT-mRNAs encoding the CAR of interest into the Natural Killer (NK)-92 cells, highlighting the potential for enhancing the CAR NK cell potency, efficiency, and bioenergetics. While IVT-mRNA technology brings exciting progress to cancer immunotherapy, several challenges and limitations must be acknowledged, such as safety, toxicity, and delivery issues. This comprehensive exploration of IVT-mRNA technology, in line with its applications in cancer therapeutics, offers valuable insights into the opportunities and challenges in the evolving landscape of cancer immunotherapy, setting the stage for future advancements in the field.

CAR-T cell therapy for hematological malignancies: History, status and promise

For many years, the methods of cancer treatment are usually surgery, chemotherapy and radiation therapy. Although these methods help to improve the condition, most tumors still have a poor prognosis. In recent years, immunotherapy has great potential in tumor treatment. Chimeric antigen receptor T-cell immunotherapy (CAR-T) uses the patient's own T cells to express chimeric antigen receptors. Chimeric antigen receptor (CAR) recognizes tumor-associated antigens and kills tumor cells. CAR-T has achieved good results in the treatment of hematological tumors. In 2017, the FDA approved the first CAR-T for the treatment of B-cell acute lymphoblastic leukemia (ALL). In October of the same year, the FDA approved CAR-T to treat B-cell lymphoma. In order to improve and enhance the therapeutic effect, CAR-T has become a research focus in recent years. The structure of CAR, the targets of CAR-T treatment, adverse reactions and improvement measures during the treatment process are summarized. This review is an attempt to highlight recent and possibly forgotten findings of advances in chimeric antigen receptor T cell for treatment of hematological tumors.

Sophisticated genetically engineered macrophages, CAR-Macs, in hitting the bull's eye for solid cancer immunotherapy approaches

Studies have begun to employ macrophages engineered with chimeric antigen receptor (CAR-Macs) against solid tumors since they can enter solid tumor tissue and interact with approximately all cellular components in the tumor microenvironment. The chimeric antigen receptor (CAR) has emerged as an appealing strategy for improving immune cells' ability to detect cancer. Tumor-associated macrophages (TAMs) generated with CAR designs exhibit appropriate potency based on their capacity to enter solid tumors and communicate through the inhibitory tumor microenvironment. CAR-Macs technology is a new therapeutic method for attacking cancer cells by switching pro-tumoral M2 macrophages to anti-tumoral M1 macrophages, enhancing macrophage phagocytosis, or increasing antigen presentation activity. CAR-Macs may have a prevailing impact on surrounding immune cells, indicating that they retain anti-tumor activity in the presence of human M2 macrophages, demonstrating their use in CAR technology. Understanding the biology of TAM and targeting novel domains for the advanced CAR-Macrophage platform, it will be feasible to add a new dimension to immunotherapy techniques used exclusively in solid malignancies. This review describes how CAR-Macs technologies modulate CAR-Macrophage production, potential target biomarkers on these platforms, their role in immunotherapeutic approaches, and tumor microenvironment.

Immune Effector Cell-Associated HLH-like Syndrome: A Review of the Literature of an Increasingly Recognized Entity

Since CAR-T cell therapy was initially approved in 2017, its use has become more prevalent and so have its side effects. CAR-T-related HLH, also named immune effector cell-associated HLH-like syndrome (IEC-HS), is a rare but fatal toxicity if not recognized promptly. We conducted a review of the literature in order to understand the prevalence of IEC-HS as well as clarify the evolution of the diagnostic criteria and treatment recommendations. IEC-HS occurrence varies between CAR-T cell products and the type of malignancy treated. Diagnosis can be challenging as there are no standardized diagnostic criteria, and its clinical features can overlap with cytokine release syndrome and active hematological disease. Suggested treatment strategies have been extrapolated from prior experience in HLH and include anakinra, corticosteroids and ruxolitinib. IEC-HS is a potentially fatal toxicity associated with CAR-T cell therapy. Early recognition with reliable diagnostic criteria and prompt implementation of treatment specific to IEC-HS is imperative for improving patient outcomes.

Induced Pluripotent Stem Cell-Derived Chimeric Antigen Receptor T Cells: The Intersection of Stem Cells and Immunotherapy

Chimeric antigen receptor (CAR) T cell therapy is a promising cell-based immunotherapy applicable to various cancers. High cost of production, immune rejection, heterogeneity of cell product, limited cell source, limited expandability, and relatively long production time have created the need to achieve a universal allogeneic CAR-T cell product for "off-the-shelf" application. Since the innovation of induced pluripotent stem cells (iPSCs) by Yamanaka et al., extensive efforts have been made to prepare an unlimited cell source for regenerative medicine, that is, immunotherapy. In the autologous grafting approach, iPSCs prepare the desired cell source for generating autologous CAR-T cells through more accessible and available sources. In addition, generating iPSC-derived CAR-T cells is a promising approach to achieving a suitable source for producing an allogeneic CAR-T cell product. In brief, the first step is reprogramming somatic cells (accessible from peripheral blood, skin, etc.) to iPSCs. In the next step, CAR expression and T cell lineage differentiation should be applied in different arrangements. In addition, in an allogeneic manner, human leukocyte antigen/T cell receptor (TCR) deficiency should be applied in iPSC colonies. The allogeneic iPSC-derived CAR-T cell experiments showed that simultaneous performance of HLA/TCR deficiency, CAR expression, and T cell lineage differentiation could bring the production to the highest efficacy in generating allogeneic iPSC-derived CAR-T cells.

Learning from the microbes: exploiting the microbiome to enforce T cell immunotherapy

The opportunities genetic engineering has created in the field of adoptive cellular therapy for cancer are accelerating the development of novel treatment strategies using chimeric antigen receptor (CAR) and T cell receptor (TCR) T cells. The great success in the context of hematologic malignancies has made especially CAR T cell therapy a promising approach capable of achieving long-lasting remission. However, the causalities involved in mediating resistance to treatment or relapse are still barely investigated. Research on T cell exhaustion and dysfunction has drawn attention to host-derived factors that define both the immune and tumor microenvironment (TME) crucially influencing efficacy and toxicity of cellular immunotherapy. The microbiome, as one of the most complex host factors, has become a central topic of investigations due to its ability to impact on health and disease. Recent findings support the hypothesis that commensal bacteria and particularly microbiota-derived metabolites educate and modulate host immunity and TME, thereby contributing to the response to cancer immunotherapy. Hence, the composition of microbial strains as well as their soluble messengers are considered to have predictive value regarding CAR T cell efficacy and toxicity. The diversity of mechanisms underlying both beneficial and detrimental effects of microbiota comprise various epigenetic, metabolic and signaling-related pathways that have the potential to be exploited for the improvement of CAR T cell function. In this review, we will discuss the recent findings in the field of microbiome-cancer interaction, especially with respect to new trajectories that commensal factors can offer to advance cellular immunotherapy.

Unravelling the Glioblastoma Tumour Microenvironment: Can Aptamer Targeted Delivery Become Successful in Treating Brain Cancers?

The key challenges to treating glioblastoma multiforme (GBM) are the heterogeneous and complex nature of the GBM tumour microenvironment (TME) and difficulty of drug delivery across the blood-brain barrier (BBB). The TME is composed of various neuronal and immune cells, as well as non-cellular components, including metabolic products, cellular interactions, and chemical compositions, all of which play a critical role in GBM development and therapeutic resistance. In this review, we aim to unravel the complexity of the GBM TME, evaluate current therapeutics targeting this microenvironment, and lastly identify potential targets and therapeutic delivery vehicles for the treatment of GBM. Specifically, we explore the potential of aptamer-targeted delivery as a successful approach to treating brain cancers. Aptamers have emerged as promising therapeutic drug delivery vehicles with the potential to cross the BBB and deliver payloads to GBM and brain metastases. By targeting specific ligands within the TME, aptamers could potentially improve treatment outcomes and overcome the challenges associated with larger therapies such as antibodies.

Bridging the Gap between Innate and Adaptive Immunity in the Lung: Summary of the Aspen Lung Conference 2022

Although significant strides have been made in the understanding of pulmonary immunology, much work remains to be done to comprehensively explain coordinated immune responses in the lung. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic only served to highlight the inadequacy of current models of host-pathogen interactions and reinforced the need for current and future generations of immunologists to unravel complex biological questions. As part of that effort, the 64th Annual Thomas L. Petty Aspen Lung Conference was themed "Bridging the Gap between Innate and Adaptive Immunity in the Lung" and featured exciting work from renowned immunologists. This report summarizes the proceedings of the 2022 Aspen Lung Conference, which was convened to discuss the roles played by innate and adaptive immunity in disease pathogenesis, evaluate the interface between the innate and adaptive immune responses, assess the role of adaptive immunity in the development of autoimmunity and autoimmune lung disease, discuss lessons learned from immunologic cancer treatments and approaches, and define new paradigms to harness the immune system to prevent and treat lung diseases.

A systems and computational biology perspective on advancing CAR therapy

In the recent decades, chimeric antigen receptor (CAR) therapy signaled a new revolutionary approach to cancer treatment. This method seeks to engineer immune cells expressing an artificially designed receptor, which would endue those cells with the ability to recognize and eliminate tumor cells. While some CAR therapies received FDA approval and others are subject to clinical trials, many aspects of their workings remain elusive. Techniques of systems and computational biology have been frequently employed to explain the operating principles of CAR therapy and suggest further design improvements. In this review, we sought to provide a comprehensive account of those efforts. Specifically, we discuss various computational models of CAR therapy ranging in scale from organismal to molecular. Then, we describe the molecular and functional properties of costimulatory domains frequently incorporated in CAR structure. Finally, we describe the signaling cascades by which those costimulatory domains elicit cellular response against the target. We hope that this comprehensive summary of computational and experimental studies will further motivate the use of systems approaches in advancing CAR therapy.