Prospects to improve chimeric antigen receptor T-cell therapy for solid tumors

Induction of tumor cell autosis by myxoma virus-infected CAR-T and TCR-T cells to overcome primary and acquired resistance

Cytotoxicity of tumor-specific T cells requires tumor cell-to-T cell contact-dependent induction of classic tumor cell apoptosis and pyroptosis. However, this may not trigger sufficient primary responses of solid tumors to adoptive cell therapy or prevent tumor antigen escape-mediated acquired resistance. Here we test myxoma virus (MYXV)-infected tumor-specific T (TMYXV) cells expressing chimeric antigen receptor (CAR) or T cell receptor (TCR), which systemically deliver MYXV into solid tumors to overcome primary resistance. In addition to T cell-induced apoptosis and pyroptosis, tumor eradication by CAR/TCR-TMYXV cells is also attributed to tumor cell autosis induction, a special type of cell death. Mechanistically, T cell-derived interferon γ (IFNγ)-protein kinase B (AKT) signaling synergizes with MYXV-induced M-T5-SKP-1-VPS34 signaling to trigger robust tumor cell autosis. CAR/TCR-TMYXV-elicited autosis functions as a type of potent bystander killing to restrain antigen escape. We uncover an unexpected synergy between T cells and MYXV to bolster solid tumor cell autosis that reinforces tumor clearance.

Are chimeric antigen receptor T cells (CAR-T cells) the future in immunotherapy for autoimmune diseases?

OBJECTIVE

CAR-T cell therapy has revolutionized the treatment of oncological diseases, and potential uses in autoimmune diseases have recently been described. The review aims to integrate the available data on treatment with CAR-T cells, emphasizing autoimmune diseases, to determine therapeutic advances and their possible future clinical applicability in autoimmunity.

MATERIALS AND METHODS

A search was performed in PubMed with the keywords "Chimeric Antigen Receptor" and "CART cell". The documents of interest were selected, and a critical review of the information was carried out.

RESULTS

In the treatment of autoimmune diseases, in preclinical models, three different cellular strategies have been used, which include Chimeric antigen receptor T cells, Chimeric autoantibody receptor T cells, and Chimeric antigen receptor in regulatory T lymphocytes. All three types of therapy have been effective. The potential adverse effects within them, cytokine release syndrome, cellular toxicity and neurotoxicity must always be kept in mind.

CONCLUSIONS

Although information in humans is not yet available, preclinical models of CAR-T cells in the treatment of autoimmune diseases show promising results, so that in the future, they may become a useful and effective therapy in the treatment of these pathologies.

Cell therapies in the clinic

Cell therapies have emerged as a promising therapeutic modality with the potential to treat and even cure a diverse array of diseases. Cell therapies offer unique clinical and therapeutic advantages over conventional small molecules and the growing number of biologics. Particularly, living cells can simultaneously and dynamically perform complex biological functions in ways that conventional drugs cannot; cell therapies have expanded the spectrum of available therapeutic options to include key cellular functions and processes. As such, cell therapies are currently one of the most investigated therapeutic modalities in both preclinical and clinical settings, with many products having been approved and many more under active clinical investigation. Here, we highlight the diversity and key advantages of cell therapies and discuss their current clinical advances. In particular, we review 28 globally approved cell therapy products and their clinical use. We also analyze >1700 current active clinical trials of cell therapies, with an emphasis on discussing their therapeutic applications. Finally, we critically discuss the major biological, manufacturing, and regulatory challenges associated with the clinical translation of cell therapies.

Single-Cell Transcriptomic Analysis Reveals BCMA CAR-T Cell Dynamics in a Patient with Refractory Primary Plasma Cell Leukemia

Chimeric antigen receptor T cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in clinical patients remains unexplored. Here, we longitudinally profiled the transcriptomes of 55,488 T cells including CAR-T products, CAR-T cells, and endogenous T cells at the peak and remission phases in a plasma cell leukemia (PCL) patient treated with BCMA CAR-T cells by single-cell transcriptomic analysis. Our results showed distinct CAR-T and endogenous T cell subsets indicating stage-specific expression in proliferation, cytotoxicity, and intercellular signaling pathways. Furthermore, we found that CAR-T cells at peak phase gradually convert to a highly cytotoxic state from a highly proliferative state along a development trajectory. Moreover, re-analysis of a single cell study from CD8+ CD19 CAR-T confirmed our findings. These commonalities suggest conserved mechanisms for CAR-T treatment across hematological malignancies. Taken together, our current study provides insight into CAR-T cell dynamics during CAR-T therapy and proves that both BCMA CAR-T and CD19 CAR-T have similar transcriptional characteristics, especially at the CAR-T peak phase.

Non-invasive monitoring of the kinetic infiltration and therapeutic efficacy of nanoparticle-labeled chimeric antigen receptor T cells in glioblastoma via 7.0-Tesla magnetic resonance imaging

BACKGROUND AIMS

Chimeric antigen receptor (CAR) T-cell therapy is a promising treatment strategy in solid tumors. In vivo cell tracking techniques can help us better understand the infiltration, persistence and therapeutic efficacy of CAR T cells. In this field, magnetic resonance imaging (MRI) can achieve high-resolution images of cells by using cellular imaging probes. MRI can also provide various biological information on solid tumors.

METHODS

The authors adopted the amino alcohol derivatives of glucose-coated nanoparticles, ultra-small superparamagnetic particles of iron oxide (USPIOs), to label CAR T cells for non-invasive monitoring of kinetic infiltration and persistence in glioblastoma (GBM). The specific targeting CARs included anti-human epidermal growth factor receptor variant III and IL13 receptor subunit alpha 2 CARs.

RESULTS

When using an appropriate concentration, USPIO labeling exerted no negative effects on the biological characteristics and killing efficiency of CAR T cells. Increasing hypointensity signals could be detected in GBM models by susceptibility-weighted imaging MRI ranging from 3 days to 14 days following the injection of USPIO-labeled CAR T cells. In addition, nanoparticles and CAR T cells were found on consecutive histopathological sections. Moreover, diffusion and perfusion MRI revealed significantly increased water diffusion and decreased vascular permeability on day 3 after treatment, which was simultaneously accompanied by a significant decrease in tumor cell proliferation and increase in intercellular tight junction on immunostaining sections.

CONCLUSION

These results establish an effective imaging technique that can track CAR T cells in GBM models and validate their early therapeutic effects, which may guide the evaluation of CAR T-cell therapies in solid tumors.

Challenges and strategies of clinical application of CAR-T therapy in the treatment of tumors-a narrative review

Chimeric antigen receptor T-cell (CAR-T) therapy has achieved good therapeutic efficacy in the treatment of hematological malignancies. In August 2017, Novartis Kymriah (CAR-T cells targeting CD19) was approved by the FDA, indicating the real entry of CAR-T cell therapy into clinical applications and making CAR-T cell therapy the most attractive technology in the field of tumor treatment. In October 2017, the FDA approved the world’s second CAR-T cell therapy—Yescarta. The launch of these products has attracted wide attention to CAR-T cell therapy. CAR-T cell therapy has achieved significant effect in the treatment of tumors, however, CAR-T therapy also faces clinical problems, such as cytokine release syndrome (CRS), poor therapeutic efficacy in solid tumors, and high rates of tumor recurrence. At present, the side effects of CAR-T therapy have attracted a large amount of attention, which has resulted in investigations into strategy establishment. With a deepening understanding of CAR-T therapy and the continuous optimization of therapeutic regimens, its toxicity and side effects have been partially controlled. This study set out to analyze the problems in the clinical application of CAR-T therapy encountered in recent years and to introduce corresponding strategies, with the aim of providing a basis of reference for clinicians and scientists in the management of CAR-T therapy in clinical practice and in the CAR-T therapy research.

Production of CAR T-cells by GMP-grade lentiviral vectors: latest advances and future prospects

Chimeric antigen receptor (CAR) T-cells represent a paradigm shift in cancer immunotherapy and a new milestone in the history of oncology. In 2017, the Food and Drug Administration approved two CD19-targeted CAR T-cell therapies (Kymriah™, Novartis, and Yescarta™, Kite Pharma/Gilead Sciences) that have remarkable efficacy in some B-cell malignancies. The CAR approach is currently being evaluated in multiple pivotal trials designed for the immunotherapy of hematological malignancies as well as solid tumors. To generate CAR T-cells ex vivo, lentiviral vectors (LVs) are particularly appealing due to their ability to stably integrate relatively large DNA inserts, and to efficiently transduce both dividing and nondividing cells. This review discusses the latest advances and challenges in the design and production of CAR T-cells, and the good manufacturing practices (GMP)-grade production process of LVs used as a gene transfer vehicle. New developments in the application of CAR T-cell therapy are also outlined with particular emphasis on next-generation allogeneic CAR T-cells.

Research Techniques Made Simple: CAR T-Cell Therapy

Chimeric antigen receptor (CAR) and chimeric autoantibody receptor T-cell therapy hold great promise in the treatment of cancer and autoimmune disease, respectively. This powerful technique involves genetically engineering T lymphocytes to enable selective destruction of disease-causing cells. In the current approach, a patient's T cells are genetically engineered to express an antigen-specific antibody fragment fused to activating cytoplasmic T-cell signaling domains. After ex vivo activation and genetic modification of a patient's own T cells, the individually tailored CAR T cells are then infused into the patient for the selective destruction of cells bearing the targeted antigen. CAR T cells directed against the CD19 antigen expressed on B lymphoma cells have shown remarkable clinical efficacy in the treatment of refractory lymphoma, with two anti-CD19 CAR-T products recently gaining approval from the US Food and Drug Administration. For dermatological disease, preliminary studies have shown efficacy of CAR T cells in targeting melanoma cells and the pathogenic B cells in pemphigus vulgaris. Despite its great promise, current clinical CAR T-cell (or CAR-T) therapy carries a high risk of cytokine release syndrome, a potentially fatal systemic inflammatory response that can be manifest in cutaneous findings. For the dermatologist, the rapid clinical emergence of CAR-T therapy promises to treat and cure a variety of dermatological conditions, but it also requires an astute awareness of potential cutaneous complications in the increasing number of patients undergoing CAR-T therapy.

Genetically enhanced T lymphocytes and the intensive care unit

Chimeric antigen receptor-modified T cells (CAR-T cells) and donor lymphocyte infusion (DLI) are important protocols in lymphocyte engineering. CAR-T cells have emerged as a new modality for cancer immunotherapy due to their potential efficacy against hematological malignancies. These genetically modified receptors contain an antigen-binding moiety, a hinge region, a transmembrane domain, and an intracellular costimulatory domain resulting in lymphocyte T cell activation subsequent to antigen binding. In present-day medicine, four generations of CAR-T cells are described depending on the intracellular signaling domain number of T cell receptors. DLI represents a form of adoptive therapy used after hematopoietic stem cell transplant for its anti-tumor and anti-infectious properties. This article covers the current status of CAR-T cells and DLI research in the intensive care unit (ICU) patient, including the efficacy, toxicity, side effects and treatment.

Prospects for chimeric antigen receptor-modified T cell therapy for solid tumors

The potential for adoptive cell immunotherapy as a treatment against cancers has been demonstrated by the remarkable response in some patients with hematological malignancies using autologous T cells endowed with chimeric antigen receptors (CARs) specific for CD19. Clinical efficacy of CAR-T cell therapy for the treatment of solid tumors, however, is rare due to physical and biochemical factors. This review focuses on different aspects of multiple mechanisms of immunosuppression in solid tumors. We characterize the current state of CAR-modified T cell therapy and summarize the various strategies to combat the immunosuppressive microenvironment of solid tumors, with the aim of promoting T cell cytotoxicity and enhancing tumor cell eradication.

Chimeric antigen receptor T-cell therapy for glioblastoma

Chimeric antigen receptor (CAR) T-cell therapy has shown great promise in the treatment of hematological disease, and its utility for treatment of solid tumors is beginning to unfold. Glioblastoma continues to portend a grim prognosis and immunotherapeutic approaches are being explored as a potential treatment strategy. Identification of appropriate glioma-associated antigens, barriers to cell delivery, and presence of an immunosuppressive microenvironment are factors that make CAR T-cell therapy for glioblastoma particularly challenging. However, insights gained from preclinical studies and ongoing clinical trials indicate that CAR T-cell therapy will continue to evolve and likely become integrated with current therapeutic strategies for malignant glioma.

Cancer Immunotherapy and Personalized Medicine: Emerging Technologies and Biomarker-Based Approaches

Purpose of review

The vision and strategy for the 21st century treatment of cancer calls for a personalized approach in which therapy selection is designed for each individual patient. While genomics has led the field of personalized cancer medicine over the past several decades by connecting patient-specific DNA mutations with kinase-targeted drugs, the recent discovery that tumors evade immune surveillance has created unique challenges to personalize cancer immunotherapy. In this mini-review we will discuss how personalized medicine has evolved recently to accommodate the emerging era of cancer immunotherapy. Moreover, we will discuss novel platform technologies that have been engineered to address some of the persisting limitations.

Recent finding

Beginning with early evidence in personalized medicine, we discuss how biomarker-driven approaches to predict clinical success have evolved to account for the heterogeneous tumor ecosystem. In the emerging field of cancer immunotherapy, this challenge requires the use of a novel set of tools, distinct from the classic approach of next-generation genomic sequencing-based strategies. We will introduce new techniques that seek to tailor immunotherapy by re-programming patient-autologous T-cells, and new technologies that are emerging to predict clinical efficacy by mapping infiltration of lymphocytes, and harnessing fully humanized platforms that reconstruct and interrogate immune checkpoint blockade, ex-vivo.

Summary

While cancer immunotherapy is now leading to durable outcomes in difficult-to-treat cancers, success is highly variable. Developing novel approaches to study cancer immunotherapy, personalize treatment to each patient, and achieve greater outcomes is penultimate to developing sustainable cures in the future. Numerous techniques are now emerging to help guide treatment decisions, which go beyond simple biomarker-driven strategies, and are now we are seeking to interrogate the entirety of the dynamic tumor ecosystem.

Viroimmunotherapy for Colorectal Cancer: Clinical Studies

Colorectal cancer is a leading cause of cancer incidence and death. Therapies for those with unresectable or recurrent disease are not considered curative at present. More effective and less toxic therapies are desperately needed. Historically, the immune system was thought to be an enemy to oncolytic viral therapy. Thinking that oncolysis would be the only mechanism for cell death, oncolytic virologists theorized that immune clearance was a detriment to oncolysis. Recent advances in our understanding of the tumor microenvironment, and the interplay of tumor survival and a patient's immune system have called into question our understanding of both arenas. It remains unclear what combination of restrictions or enhancements of innate and/or cell-mediated immunity can yield the highest likelihood of viral efficacy. This article reviews the variety of mechanisms explored for viruses such as immunotherapy for colorectal cancer.