Design and development of therapies using chimeric antigen receptor-expressing T cells

Transcriptomic observations of intra and extracellular immunotherapy targets for pediatric brain tumors

OBJECTIVES

Despite surgical resection, chemoradiation, and targeted therapy, brain tumors remain a leading cause of cancer-related death in children. Immunotherapy has shown some promise and is actively being investigated for treating childhood brain tumors. However, a critical step in advancing immunotherapy for these patients is to uncover targets that can be effectively translated into therapeutic interventions.

METHODS

In this study, our team performed a transcriptomic analysis across pediatric brain tumor types to identify potential targets for immunotherapy. Additionally, we assessed components that may impact patient response to immunotherapy, including the expression of genes essential for antigen processing and presentation, inhibitory ligands and receptors, interferon signature, and overall predicted T cell infiltration.

RESULTS

We observed distinct expression patterns across tumor types. These included elevated expression of antigen genes and antigen processing machinery in some tumor types while other tumors had elevated inhibitory checkpoint receptors, known to be associated with response to checkpoint inhibitor immunotherapy.

CONCLUSION

These findings suggest that pediatric brain tumors exhibit distinct potential for specific immunotherapies. We believe our findings can guide investigators in their assessment of appropriate immunotherapy classes and targets in pediatric brain tumors.

Targeting cardiac fibrosis with Chimeric Antigen Receptor-Engineered Cells

Cardiac fibrosis poses a significant challenge in cardiovascular diseases due to its intricate pathogenesis, and there is currently no standardized and effective treatment approach. The fibrotic process entails the involvement of various cell types and molecular mechanisms, such as fibroblast activation and proliferation, increased collagen synthesis, and extracellular matrix rearrangement. Traditional therapies often fall short in efficacy or carry substantial side effects. However, recent studies have shown that Chimeric Antigen Receptor T (CAR-T) cells can selectively target and eliminate activated cardiac fibroblasts (CFs) in mice, leading to reduced cardiac fibrosis and improved myocardial tissue compliance. This breakthrough presents a new and promising avenue for treating cardiac fibrosis. Currently, CAR-T cell-based therapy for cardiac fibrosis is undergoing animal experimentation, indicating ample scope for enhancement. Future investigations could explore the application of CAR cell therapy in cardiac fibrosis treatment, including the potential of CAR-natural killer (CAR-NK) cells and CAR macrophages (CAR-M), offering novel insights and strategies for combating cardiac fibrosis.

Emerging advances in nano-biomaterial assisted amyloid beta chimeric antigen receptor macrophages (CAR-M) therapy: reducing plaque burden in Alzheimer's disease

Alzheimer's disease is the most common form, accounting for 60-70% of 55 million dementia cases. Even though the precise pathophysiology of AD is not completely understood, clinical trials focused on antibodies targeting aggregated forms of β amyloid (Aβ) have demonstrated that reducing amyloid plaques can arrest cognitive decline in patients in the early stages of AD. In this study, we provide an overview of current research and innovations for controlled release from nano-biomaterial-assisted chimeric antigen receptor macrophage (CAR-M) therapeutic strategies targeted at AD. Nano-bio materials, such as iron-oxide nanoparticles (IONPs), can be made selectively (Hp-Hb/mannose) to bind and take up Aβ plaques like CAR-M cells. By using nano-bio materials, both the delivery and stability of CAR-M cells in brain tissue can be improved to overcome the barriers of the BBB and enhance therapeutic effects. By enhancing the targeting capabilities and stability of CAR-M cells, mRNA-loaded nano-biomaterials can significantly improve the efficacy of immunotherapy for plaque reduction in AD. This novel strategy holds promise for translating preclinical successes into clinical applications, potentially revolutionising the management of AD.

Chimeric antigen receptor T-cell therapy for autoimmune diseases of the central nervous system: a systematic literature review

IMPORTANCE

B-cell-targeting monoclonal antibodies have demonstrated safety and efficacy in multiple sclerosis or anti-aquaporin-4 IgG positive neuromyelitis optica spectrum disorder. However, these therapies do not facilitate drug-free remission, which may become possible with cell-based therapies, including chimeric antigen receptor (CAR) T cells. CAR T-cell therapy holds promise for addressing other antibody-mediated CNS disorders, e.g., MOG-associated disease or autoimmune encephalitis.

OBJECTIVE

To provide an overview of the current clinical knowledge on CAR T-cell therapy in central nervous system autoimmunity.

EVIDENCE REVIEW

We searched PubMed, Embase, Google Scholar, PsycINFO, and clinicaltrials.gov using the terms 'CAR T cell' and 'multiple sclerosis/MS' or 'neuromyelitis optica/spectrum diseases/NMOSD' or 'MOG-associated disease/MOGAD 'or' autoimmune encephalitis' or 'neuroimmunology'.

FINDINGS

An ongoing phase I clinical trial has indicated the safety and benefits of anti-BCMA CAR T cells in 12 patients with AQP4-IgG seropositive neuromyelitis optica spectrum disorder. Case reports involving two individuals with progressive multiple sclerosis and one patient with stiff-person syndrome demonstrated a manageable safety profile following treatment with anti-CD19 CAR T cells. Recruitment has commenced for two larger studies in MS, and a phase I open-label basket study is underway to evaluate BCMA-directed CAR T cells in various antibody-associated inflammatory diseases, including MOG-associated disease. Preclinical research on NMDA receptor antibody autoimmune encephalitis treated with chimeric autoantibody receptor T cells generated promising data.

CONCLUSIONS AND RELEVANCE

There is minimal evidence of the benefits of CAR T-cell therapy in individuals with central nervous system-directed autoimmunity. Nevertheless, multicenter controlled clinical trials with a manageable safety profile appear feasible and are warranted due to very promising case experiences.

The peptide-based bispecific CAR T cells target EGFR and tumor stroma for effective cancer therapy

BACKGROUND AND PURPOSE

The efficacy of chimeric antigen receptor (CAR)-T cell for solid tumors is limited partially because of the lack of tumor-specific antigens and off-target effects. Low molecular weight peptides allowed CAR T cell to display several antigen receptors to reduce off-target effects. Here, we develop a peptide-based bispecific CAR for EGFR and tumor stroma, which are expressed in a variety of tumor types.

EXPERIMENTAL APPROACH AND KEY RESULTS

The peptide-based CAR T cells show excellent proliferation, cytotoxicity activity and are only activated by tumor cells overexpressing EGFR instead of normal cells with low EGFR expressing. In mouse xenograft models, the peptide bispecific CAR T cells can be delivered into the inner of tumor masses and thus are effective in inhibiting tumor growth. Meanwhile, they show strong expansion capacity and the property of maintaining long-term function in vivo. During treatment, no off-tumor toxicity is observed on healthy organs expressing lower levels of EGFR.

CONCLUSIONS & IMPLICATIONS

Our findings demonstrate that peptide-based bispecific CAR T holds great potential in solid tumor therapy due to an excellent targeting ability towards tumors and tumor microenvironment.

Generating advanced CAR-based therapy for hematological malignancies in clinical practice: targets to cell sources to combinational strategies

Chimeric antigen receptor T (CAR-T) cell therapy has been a milestone breakthrough in the treatment of hematological malignancies, offering an effective therapeutic option for multi-line therapy-refractory patients. So far, abundant CAR-T products have been approved by the United States Food and Drug Administration or China National Medical Products Administration to treat relapsed or refractory hematological malignancies and exhibited unprecedented clinical efficiency. However, there were still several significant unmet needs to be progressed, such as the life-threatening toxicities, the high cost, the labor-intensive manufacturing process and the poor long-term therapeutic efficacy. According to the demands, many researches, relating to notable technical progress and the replenishment of alternative targets or cells, have been performed with promising results. In this review, we will summarize the current research progress in CAR-T eras from the "targets" to "alternative cells", to "combinational drugs" in preclinical studies and clinical trials.

Targeting the EphA2 pathway: could it be the way for bone sarcomas?

Bone sarcomas are malignant tumors of mesenchymal origin. Complete surgical resection is the cornerstone of multidisciplinary treatment. However, advanced, unresectable forms remain incurable. A crucial step towards addressing this challenge involves comprehending the molecular mechanisms underpinning tumor progression and metastasis, laying the groundwork for innovative precision medicine-based interventions. We previously showed that tyrosine kinase receptor Ephrin Type-A Receptor 2 (EphA2) is overexpressed in bone sarcomas. EphA2 is a key oncofetal protein implicated in metastasis, self-renewal, and chemoresistance. Molecular, genetic, biochemical, and pharmacological approaches have been developed to target EphA2 and its signaling pathway aiming to interfere with its tumor-promoting effects or as a carrier for drug delivery. This review synthesizes the main functions of EphA2 and their relevance in bone sarcomas, providing strategies devised to leverage this receptor for diagnostic and therapeutic purposes, with a focus on its applicability in the three most common bone sarcoma histotypes: osteosarcoma, chondrosarcoma, and Ewing sarcoma.

Fate induction in CD8 CAR T cells through asymmetric cell division

Early expansion and long-term persistence predict efficacy of chimeric antigen receptor T cells (CARTs)1-7, but mechanisms governing effector versus memory CART differentiation and whether asymmetric cell division induces differential fates in human CARTs remain unclear. Here we show that target-induced proximity labelling enables isolation of first-division proximal-daughter and distal-daughter CD8 CARTs that asymmetrically distribute their surface proteome and transcriptome, resulting in divergent fates. Target-engaged CARs remain on proximal daughters, which inherit a surface proteome resembling activated-undivided CARTs, whereas the endogenous T cell receptor and CD8 enrich on distal daughters, whose surface proteome resembles resting CARTs, correlating with glycolytic and oxidative metabolism, respectively. Despite memory-precursor phenotype and in vivo longevity, distal daughters demonstrate transient potent cytolytic activity similar to proximal daughters, uncovering an effector-like state in distal daughters destined to become memory CARTs. Both partitioning of pre-existing transcripts and changes in RNA velocity contribute to asymmetry of fate-determining factors, resulting in diametrically opposed transcriptional trajectories. Independent of naive, memory or effector surface immunophenotype, proximal-daughter CARTs use core sets of transcription factors known to support proliferation and effector function. Conversely, transcription factors enriched in distal daughters restrain differentiation and promote longevity, evidenced by diminished long-term in vivo persistence and function of distal-daughter CARTs after IKZF1 disruption. These studies establish asymmetric cell division as a framework for understanding mechanisms of CART differentiation and improving therapeutic outcomes.

Bayesian network analysis of risk classification strategies in the regulation of cellular products

Cell therapy, a burgeoning therapeutic strategy, necessitates a scientific regulatory framework but faces challenges in risk-based regulation due to the lack of a global consensus on risk classification. This study applies Bayesian network analysis to compare and evaluate the risk classification strategies for cellular products proposed by the Food and Drug Administration (FDA), Ministry of Health, Labour and Welfare (MHLW), and World Health Organization (WHO), using real-world data to validate the models. The appropriateness of key risk factors is assessed within the three regulatory frameworks, along with their implications for clinical safety. The results indicate several directions for refining risk classification approaches. Additionally, a substudy focuses on a specific type of cell and gene therapy (CGT), chimeric antigen receptor (CAR) T cell therapy. It underscores the importance of considering CAR targets, tumor types, and costimulatory domains when assessing the safety risks of CAR T cell products. Overall, there is currently a lack of a regulatory framework based on real-world data for cellular products and a lack of risk-based classification review methods. This study aims to improve the regulatory system for cellular products, emphasizing risk-based classification. Furthermore, the study advocates for leveraging machine learning in regulatory science to enhance the assessment of cellular product safety, illustrating the role of Bayesian networks in aiding regulatory decision-making for the risk classification of cellular products.

The role of B7-H4 in ovarian cancer immunotherapy: current status, challenges, and perspectives

Immunotherapy stands as a critical and auspicious therapeutic approach in the fight against cancer nowadays. Immune checkpoint inhibitors, in particular, have garnered widespread employment and delivered groundbreaking therapeutic outcomes across various malignancies. However, the efficacy is unsatisfactory in the ovarian cancer. The pressing concerns of the substantial non-response rate require immediate attention. The pursuit of novel targets and the formulation of synergistic combination therapy approaches are imperative for addressing this challenge. B7-H4, a member of the B7 family of co-inhibitory molecules, exhibits high expression levels in ovarian cancer, correlating closely with tumor progression, drug resistance, and unfavorable prognosis. B7-H4 has the potential to serve as a valuable biomarker for evaluating the immune response of patients. Recent investigations and preclinical trials focusing on B7-H4 in the context of ovarian cancer immunotherapy highlight its emergence as a promising immunotherapeutic target. This review aims to discuss these findings and anticipate the future prospects of leveraging B7-H4 in ovarian cancer immunotherapy and targeted therapy.

Emerging role of immunogenic cell death in cancer immunotherapy: Advancing next-generation CAR-T cell immunotherapy by combination

Immunogenic cell death (ICD) is a stress-driven form of regulated cell death (RCD) in which dying tumor cells' specific signaling pathways are activated to release damage-associated molecular patterns (DAMPs), leading to the robust anti-tumor immune response as well as a reversal of the tumor immune microenvironment from "cold" to "hot". Chimeric antigen receptor (CAR)-T cell therapy, as a landmark in anti-tumor immunotherapy, plays a formidable role in hematologic malignancies but falls short in solid tumors. The Gordian knot of CAR-T cells for solid tumors includes but is not limited to, tumor antigen heterogeneity or absence, physical and immune barriers of tumors. The combination of ICD induction therapy and CAR-T cell immunotherapy is expected to promote the intensive use of CAR-T cell in solid tumors. In this review, we summarize the characteristics of ICD, stress-responsive mechanism, and the synergistic effect of various ICD-based therapies with CAR-T cells to effectively improve anti-tumor capacity.

Next-generation BCMA-targeted chimeric antigen receptor CARTemis-1: the impact of manufacturing procedure on CAR T-cell features

PURPOSE

CAR therapy targeting BCMA is under investigation as treatment for multiple myeloma. However, given the lack of plateau in most studies, pursuing more effective alternatives is imperative. We present the preclinical and clinical validation of a new optimized anti-BCMA CAR (CARTemis-1). In addition, we explored how the manufacturing process could impact CAR-T cell product quality and fitness.

METHODS

CARTemis-1 optimizations were evaluated at the preclinical level both, in vitro and in vivo. CARTemis-1 generation was validated under GMP conditions, studying the dynamics of the immunophenotype from leukapheresis to final product. Here, we studied the impact of the manufacturing process on CAR-T cells to define optimal cell culture protocol and expansion time to increase product fitness.

RESULTS

Two different versions of CARTemis-1 with different spacers were compared. The longer version showed increased cytotoxicity. The incorporation of the safety-gene EGFRt into the CARTemis-1 structure can be used as a monitoring marker. CARTemis-1 showed no inhibition by soluble BCMA and presents potent antitumor effects both in vitro and in vivo. Expansion with IL-2 or IL-7/IL-15 was compared, revealing greater proliferation, less differentiation, and less exhaustion with IL-7/IL-15. Three consecutive batches of CARTemis-1 were produced under GMP guidelines meeting all the required specifications. CARTemis-1 cells manufactured under GMP conditions showed increased memory subpopulations, reduced exhaustion markers and selective antitumor efficacy against MM cell lines and primary myeloma cells. The optimal release time points for obtaining the best fit product were > 6 and < 10 days (days 8-10).

CONCLUSIONS

CARTemis-1 has been rationally designed to increase antitumor efficacy, overcome sBCMA inhibition, and incorporate the expression of a safety-gene. The generation of CARTemis-1 was successfully validated under GMP standards. A phase I/II clinical trial for patients with multiple myeloma will be conducted (EuCT number 2022-503063-15-00).

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.

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.

Chimeric Antigen Receptor T Cell Bearing Herpes Virus Entry Mediator Co-Stimulatory Signal Domain Exhibits Exhaustion-Resistant Properties

Improving chimeric antigen receptor (CAR)-T cell therapeutic outcomes and expanding its applicability to solid tumors requires further refinement of CAR-T cells. We previously reported that CAR-T cells bearing a herpes virus entry mediator (HVEM)-derived co-stimulatory signal domain (CSSD) (HVEM-CAR-T cells) exhibit superior functions and characteristics. Here, we conducted comparative analyses to evaluate the impact of different CSSDs on CAR-T cell exhaustion. The results indicated that HVEM-CAR-T cells had significantly lower frequencies of exhausted cells and exhibited the highest proliferation rates upon antigenic stimulation. Furthermore, proliferation inhibition by programmed cell death ligand 1 was stronger in CAR-T cells bearing CD28-derived CSSD (CD28-CAR-T cells) whereas it was weaker in HVEM-CAR-T. Additionally, HVEM-CAR-T cells maintained a low exhaustion level even after antigen-dependent proliferation and exhibited potent killing activities, suggesting that HVEM-CAR-T cells might be less prone to early exhaustion. Analysis of CAR localization on the cell surface revealed that CAR formed clusters in CD28-CAR-T cells whereas uniformly distributed in HVEM-CAR-T cells. Analysis of CD3ζ phosphorylation indicated that CAR-dependent tonic signals were strongly sustained in CD28-CAR-T cells whereas they were significantly weaker in HVEM-CAR-T cells. Collectively, these results suggest that the HVEM-derived CSSD is useful for generating CAR-T cells with exhaustion-resistant properties, which could be effective against solid tumors.

The Current Landscape of Hypotheses Describing the Contribution of CD4+ Heterogeneous Populations to ALS

Amyotrophic Lateral Sclerosis (ALS) is a poorly understood and fatal disease. It has a low prevalence and a 2-4 year survival period. Various theories and hypotheses relating to its development process have been proposed, albeit with no breakthrough in its treatment. Recently, the role of the adaptive immune system in ALS, particularly CD4+ T cells, has begun to be investigated. CD4+ T cells are a heterogeneous group of immune cells. They include highly pro-inflammatory types such as Th1 and Th17, as well as highly anti-inflammatory cells such as Tregs. However, the landscape of the role of CD4+ T cells in ALS is still not clearly understood. This review covers current hypotheses that elucidate how various CD4+ T cells can contribute to ALS development. These hypotheses include the SWITCH model, which suggests that, in the early stages of the disease, Tregs are highly capable of regulating the immune response. However, in the later stages of the disease, it seems that pro-inflammatory cells such as Th1 and Th17 are capable of overwhelming Treg function. The reason why this occurs is not known. Several research groups have proposed that CD4+ T cells as a whole might experience aging. Others have proposed that gamma delta T cells might directly target Tregs. Additionally, other research groups have argued that less well-known CD4+ T cells, such as Emoes+ CD4+ T cells, may be directly responsible for neuron death by producing granzyme B. We propose that the ALS landscape is highly complicated and that there is more than one feasible hypothesis. However, it is critical to take into consideration the differences in the ability of different populations of CD4+ T cells to infiltrate the blood-brain barrier, taking into account the brain region and the time of infiltration. Shedding more light on these still obscure factors can help to create a personalized therapy capable of regaining the balance of power in the battle between the anti-inflammatory and pro-inflammatory cells in the central nervous system of ALS patients.

CAR-T lymphocyte-based cell therapies; mechanistic substantiation, applications and biosafety enhancement with suicide genes: new opportunities to melt side effects

Immunotherapy has made significant strides in cancer treatment with strategies like checkpoint blockade antibodies and adoptive T cell transfer. Chimeric antigen receptor T cells (CAR-T) have emerged as a promising approach to combine these strategies and overcome their limitations. This review explores CAR-T cells as a living drug for cancer treatment. CAR-T cells are genetically engineered immune cells designed to target and eliminate tumor cells by recognizing specific antigens. The study involves a comprehensive literature review on CAR-T cell technology, covering structure optimization, generations, manufacturing processes, and gene therapy strategies. It examines CAR-T therapy in haematologic cancers and solid tumors, highlighting challenges and proposing a suicide gene-based mechanism to enhance safety. The results show significant advancements in CAR-T technology, particularly in structure optimization and generation. The manufacturing process has improved for broader clinical application. However, a series of inherent challenges and side effects still need to be addressed. In conclusion, CAR-T cells hold great promise for cancer treatment, but ongoing research is crucial to improve efficacy and safety for oncology patients. The proposed suicide gene-based mechanism offers a potential solution to mitigate side effects including cytokine release syndrome (the most common toxic side effect of CAR-T therapy) and the associated neurotoxicity.

The crosstalk between immune cells and tumor pyroptosis: advancing cancer immunotherapy strategies

Pyroptosis is a cell death process characterized by cell swelling until membrane rupture and release of intracellular contents. As an effective tumor treatment strategy, inducing tumor cell pyroptosis has received widespread attention. In this process, the immune components within the tumor microenvironment play a key regulatory role. By regulating and altering the functions of immune cells such as cytotoxic T lymphocytes, natural killer cells, tumor-associated macrophages, and neutrophils, tumor cell pyroptosis can be induced. This article provides a comprehensive review of the molecular mechanisms of cell pyroptosis, the impact of the tumor immune microenvironment on tumor cell pyroptosis, and its mechanisms. It aims to gain an in-depth understanding of the communication between the tumor immune microenvironment and tumor cells, and to provide theoretical support for the development of new tumor immunotherapies.

The potential therapeutic targets of glutamine metabolism in head and neck squamous cell carcinoma

Targeting metabolic reprogramming may be an effective strategy to enhance cancer treatment efficacy. Glutamine serves as a vital nutrient for cancer cells. Inhibiting glutamine metabolism has shown promise in preventing tumor growth both in vivo and in vitro through various mechanisms. Therefore, this review collates recent scientific literature concerning the correlation between glutamine metabolism and cancer treatment. Novel treatment modalities based on amino acid transporters, metabolites, and glutaminase are discussed. Moreover, we demonstrate the relationship between glutamine metabolism and tumor proliferation, drug resistance, and the tumor immune microenvironment, offering new perspectives for the clinical treatment of head and neck squamous cell carcinoma, particularly for combined therapies. Identifying innovative approaches for enhancing the efficacy of glutamine-based metabolic therapy is crucial to improving HNSCC treatment.

Anti-BCMA CAR-T therapy for multiple myeloma with extramedullary disease: A case report and review of the literature

INTRODUCTION

Multiple myeloma (MM) with extramedullary disease (EMD) is rare in clinical practice, and B cell maturation antigen (BCMA) CAR-T cell therapy is a novel therapy for hematologic malignancies. Very few reports have been published on the effect of CAR-T-cell therapy in MM with EMD. Here, we report a case of MM with extramedullary lesions treated with BCMA CAR-T therapy.

CASE PRESENTATION

A 66-year-old female patient presented to our hospital with an enlarged left maxillary gingiva.

DIAGNOSIS

Diagnosis of indolent MM stage III (DS staging) and stage III (ISS and R ISS) with extramedullary lesions.

INTERVENTION

The patient underwent a clinical trial of humanized anti-BCMA CAR T cell therapy.

RESULTS

Symptoms improved; left gingival hyperplasia and swelling resolved; left buccal mass resolved; and neck and submandibular masses resolved. Pathological examination of the exfoliated masses showed necrotic tissue.

CONCLUSION

MM with extramedullary lesions often has limited treatment options, and traditional chemotherapy methods are ineffective; however, BCMA CAR-T cell therapy can significantly improve the symptoms of extramedullary lesions in MM.

The tumour microenvironment, treatment resistance and recurrence in glioblastoma

The adaptability of glioblastoma (GBM) cells, encouraged by complex interactions with the tumour microenvironment (TME), currently renders GBM an incurable cancer. Despite intensive research, with many clinical trials, GBM patients rely on standard treatments including surgery followed by radiation and chemotherapy, which have been observed to induce a more aggressive phenotype in recurrent tumours. This failure to improve treatments is undoubtedly a result of insufficient models which fail to incorporate components of the human brain TME. Research has increasingly uncovered mechanisms of tumour-TME interactions that correlate to worsened patient prognoses, including tumour-associated astrocyte mitochondrial transfer, neuronal circuit remodelling and immunosuppression. This tumour hijacked TME is highly implicated in driving therapy resistance, with further alterations within the TME and tumour resulting from therapy exposure inducing increased tumour growth and invasion. Recent developments improving organoid models, including aspects of the TME, are paving an exciting future for the research and drug development for GBM, with the hopes of improving patient survival growing closer. This review focuses on GBMs interactions with the TME and their effect on tumour pathology and treatment efficiency, with a look at challenges GBM models face in sufficiently recapitulating this complex and highly adaptive cancer.

NK-92 cells labeled with Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobes for the targeted treatment and noninvasive therapeutic evaluation of breast cancer

Adoptive cellular immunotherapy as a promising and alternative cancer therapy platform is critical for future clinical applications. Natural killer (NK) cells have attracted attention as an important type of innate immune regulatory cells that can rapidly kill multiple adjacent cancer cells. However, these cells are significantly less effective in treating solid tumors than in treating hematological tumors. Herein, we report the synthesis of a Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobe labeled with NK-92 cells that can be used for adoptive cellular immunotherapy, photodynamic therapy and dual-modality imaging-based in vivo fate tracking. The labeled NK-92 cells specifically target the tumor cells, which increases the amount of cancer cell apoptosis in vitro. Furthermore, the in vivo results indicate that the labeled NK-92 cells can be used for tumor magnetic resonance imaging and fluorescence imaging, adoptive cellular immunotherapy, and photodynamic therapy after tail vein injection. These data show that the developed multifunctional nanostructure is a promising platform for efficient innate immunotherapy, photodynamic treatment and noninvasive therapeutic evaluation of breast cancer.

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.

High-throughput system for the thermostability analysis of proteins

Thermal stability of proteins is a primary metric for evaluating their physical properties. Although researchers attempted to predict it using machine learning frameworks, their performance has been dependent on the quality and quantity of published data. This is due to the technical limitation that thermodynamic characterization of protein denaturation by fluorescence or calorimetry in a high-throughput manner has been challenging. Obtaining a melting curve that derives solely from the target protein requires laborious purification, making it far from practical to prepare a hundred or more samples in a single workflow. Here, we aimed to overcome this throughput limitation by leveraging the high protein secretion efficacy of Brevibacillus and consecutive treatment with plate-scale purification methodologies. By handling the entire process of expression, purification, and analysis on a per-plate basis, we enabled the direct observation of protein denaturation in 384 samples within 4 days. To demonstrate a practical application of the system, we conducted a comprehensive analysis of 186 single mutants of a single-chain variable fragment of nivolumab, harvesting the melting temperature (Tm) ranging from -9.3 up to +10.8°C compared to the wild-type sequence. Our findings will allow for data-driven stabilization in protein design and streamlining the rational approaches.

CAR-T-Cell-Based Cancer Immunotherapies: Potentials, Limitations, and Future Prospects

Cancer encompasses various elements occurring at the cellular and genetic levels, necessitating an immunotherapy capable of efficiently addressing both aspects. T cells can combat cancer cells by specifically recognizing antigens on them. This innate capability of T cells has been used to develop cellular immunotherapies, but most of them can only target antigens through major histocompatibility complexes (MHCs). New gene-editing techniques such as clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (CRISPR-cas9) can precisely edit the DNA sequences. CRISPR-cas9 has made it possible to generate genetically engineered chimeric antigen receptors (CARs) that can overcome the problems associated with old immunotherapies. In chimeric antigen receptor T (CAR-T) cell therapy, the patient's T cells are isolated and genetically modified to exhibit synthetic CAR(s). CAR-T cell treatment has shown remarkably positive clinical outcomes in cancers of various types. Nevertheless, there are various challenges that reduce CAR-T effectiveness in solid tumors. It is required to address these challenges in order to make CAR-T cell therapy a better and safer option. Combining CAR-T treatment with other immunotherapies that target multiple antigens has shown positive outcomes. Moreover, recently generated Boolean logic-gated advanced CARs along with artificial intelligence has expanded its potential to treat solid tumors in addition to blood cancers. This review aims to describe the structure, types, and various methods used to develop CAR-T cells. The clinical applications of CAR-T cells in hematological malignancies and solid tumours have been described in detail. In addition, this discussion has addressed the limitations associated with CAR-T cells, explored potential strategies to mitigate CAR-T-related toxicities, and delved into future perspectives.

Antitumor activity of genetically engineered NK-cells in non-hematological solid tumor: a comprehensive review

Recent advancements in genetic engineering have made it possible to modify Natural Killer (NK) cells to enhance their ability to fight against various cancers, including solid tumors. This comprehensive overview discusses the current status of genetically engineered chimeric antigen receptor NK-cell therapies and their potential for treating solid tumors. We explore the inherent characteristics of NK cells and their role in immune regulation and tumor surveillance. Moreover, we examine the strategies used to genetically engineer NK cells in terms of efficacy, safety profile, and potential clinical applications. Our investigation suggests CAR-NK cells can effectively target and regress non-hematological malignancies, demonstrating enhanced antitumor efficacy. This implies excellent promise for treating tumors using genetically modified NK cells. Notably, NK cells exhibit low graft versus host disease (GvHD) potential and rarely induce significant toxicities, making them an ideal platform for CAR engineering. The adoptive transfer of allogeneic NK cells into patients further emphasizes the versatility of NK cells for various applications. We also address challenges and limitations associated with the clinical translation of genetically engineered NK-cell therapies, such as off-target effects, immune escape mechanisms, and manufacturing scalability. We provide strategies to overcome these obstacles through combination therapies and delivery optimization. Overall, we believe this review contributes to advancing NK-cell-based immunotherapy as a promising approach for cancer treatment by elucidating the underlying mechanisms, evaluating preclinical and clinical evidence, and addressing remaining challenges.

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.

Rationally designed approaches to augment CAR-T therapy for solid tumor treatment

Chimeric antigen receptor T cell denoted as CAR-T therapy has realized incredible therapeutic advancements for B cell malignancy treatment. However, its therapeutic validity has yet to be successfully achieved in solid tumors. Different from hematological cancers, solid tumors are characterized by dysregulated blood vessels, dense extracellular matrix, and filled with immunosuppressive signals, which together result in CAR-T cells' insufficient infiltration and rapid dysfunction. The insufficient recognition of tumor cells and tumor heterogeneity eventually causes cancer reoccurrences. In addition, CAR-T therapy also raises safety concerns, including potential cytokine release storm, on-target/off-tumor toxicities, and neuro-system side effects. Here we comprehensively review various targeting aspects, including CAR-T cell design, tumor modulation, and delivery strategy. We believe it is essential to rationally design a combinatory CAR-T therapy via constructing optimized CAR-T cells, directly manipulating tumor tissue microenvironments, and selecting the most suitable delivery strategy to achieve the optimal outcome in both safety and efficacy.

Chimeric antigen receptor T-cell therapy in hematologic malignancies: Successes, challenges, and opportunities

The success of chimeric antigen receptor T-cell (CAR-T) therapy in hematologic malignancies has realized a longstanding effort toward harnessing the immune system to fight cancer in a truly personalized fashion. Second generation chimeric antigen receptors (CAR) incorporating co-stimulatory molecules like 4-1BB or CD28 were able to overcome some of the hindrances with initial CAR constructs resulting in efficacious products. Many second-generation CAR-T products have been approved in the treatment of relapsed/refractory hematologic malignancies including multiple myeloma (MM), non-Hodgkin lymphoma (NHL), and acute lymphoblastic leukemia. However, challenges remain in optimizing the manufacturing, timely access, limiting the toxicity from CAR-T infusions and improving sustainability of responses derived with CAR-T therapy. Here, we summarize the clinical trial data leading to approval CAR-T therapies in MM and NHL, discuss the limitations with current CAR-T therapy strategies and review emerging strategies for overcoming these limitations.

Current perspectives on resistance to chimeric antigen receptor T-cell therapy and strategies to improve efficacy in B-cell lymphoma

Although chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable efficacy in patients with chemo-refractory B-cell lymphoma, a significant portion is refractory or relapse. Resistance is a major barrier to improving treatment efficacy and long-term survival in CAR T-cell therapy, and clinicians have very limited tools to discriminate a priori patients who will or will not respond to treatment. While CD19-negative relapses due to loss of target antigen is well described, it accounts for only about 30% of cases with treatment failure. Recent efforts have shed light on mechanisms of CD19-positive relapse due to tumor intrinsic resistance, T-cell quality/manufacturing, or CAR T-cell exhaustion mediated by hostile tumor microenvironment. Here, we review the latest updates of preclinical and clinical trials to investigate the mechanisms of resistance and relapse post CAR T-cell therapy in B cell lymphoma and discuss novel treatment strategies to overcome resistance as well as advances that are useful for a CAR T therapist to optimize and personalize CAR T-cell therapy.

Beyond FOXP3: a 20-year journey unravelling human regulatory T-cell heterogeneity

The initial idea of a distinct group of T-cells responsible for suppressing immune responses was first postulated half a century ago. However, it is only in the last three decades that we have identified what we now term regulatory T-cells (Tregs), and subsequently elucidated and crystallized our understanding of them. Human Tregs have emerged as essential to immune tolerance and the prevention of autoimmune diseases and are typically contemporaneously characterized by their CD3+CD4+CD25high CD127lowFOXP3+ phenotype. It is important to note that FOXP3+ Tregs exhibit substantial diversity in their origin, phenotypic characteristics, and function. Identifying reliable markers is crucial to the accurate identification, quantification, and assessment of Tregs in health and disease, as well as the enrichment and expansion of viable cells for adoptive cell therapy. In our comprehensive review, we address the contributions of various markers identified in the last two decades since the master transcriptional factor FOXP3 was identified in establishing and enriching purity, lineage stability, tissue homing and suppressive proficiency in CD4+ Tregs. Additionally, our review delves into recent breakthroughs in innovative Treg-based therapies, underscoring the significance of distinct markers in their therapeutic utilization. Understanding Treg subsets holds the key to effectively harnessing human Tregs for immunotherapeutic approaches.

The persistence and antitumor efficacy of CAR-T cells are modulated by tonic signaling within the CDR

Chimeric antigen receptor (CAR) T cell therapy has demonstrated remarkable clinical efficacy, but challenges related to relapse and CAR-T cell exhaustion persist. One contributing factor to this exhaustion is CAR tonic signaling, where CAR-T cells self-activate without antigen stimulation, leading to reduced persistence and impaired antitumor activity. To address this issue, we conducted a preclinical study evaluating tonic signaling using nanobody-derived CAR-T cells. Our investigation revealed that specific characteristics of the complementary determining regions (CDRs), including low solubility, polarity, positive charge, energy, and area of ionic and positive CDR patches of amino acids, were associated with low antigen-independent tonic signaling. Significantly, we observed that stronger tonic signaling directly impacted CAR-T cell proliferation in vitro, consequently leading to CAR-T cell exhaustion and diminished persistence and effectiveness in vivo. Our findings provide compelling preclinical evidence and lay the foundation for the clinical assessment of CAR-T cells with distinct tonic signaling patterns. Understanding the role of CDRs in modulating tonic signaling holds promise for advancing the development of more efficient and durable CAR-T cell therapies, thereby enhancing the treatment of cancer and addressing the challenges of relapse in CAR-T cell therapy.

Acellular scaffold-based approach for in situ genetic engineering of host T-cells in solid tumor immunotherapy

BACKGROUND

Targeted T-cell therapy has emerged as a promising strategy for the treatment of hematological malignancies. However, its application to solid tumors presents significant challenges due to the limited accessibility and heterogeneity. Localized delivery of tumor-specific T-cells using biomaterials has shown promise, however, procedures required for genetic modification and generation of a sufficient number of tumor-specific T-cells ex vivo remain major obstacles due to cost and time constraints.

METHODS

Polyethylene glycol (PEG)-based three-dimensional (3D) scaffolds were developed and conjugated with positively charged poly-L-lysine (PLL) using carbamide chemistry for efficient loading of lentiviruses (LVs) carrying tumor antigen-specific T-cell receptors (TCRs). The physical and biological properties of the scaffold were extensively characterized. Further, the scaffold loaded with OVA-TCR LVs was implanted in B16F10 cells expressing ovalbumin (B16-OVA) tumor model to evaluate the anti-tumor response and the presence of transduced T-cells.

RESULTS

Our findings demonstrate that the scaffolds do not induce any systemic inflammation upon subcutaneous implantation and effectively recruit T-cells to the site. In B16-OVA melanoma tumor-bearing mice, the scaffolds efficiently transduce host T-cells with OVA-specific TCRs. These genetically modified T-cells exhibit homing capability towards the tumor and secondary lymphoid organs, resulting in a significant reduction of tumor size and systemic increase in anti-tumor cytokines. Immune cell profiling revealed a significantly high percentage of transduced T-cells and a notable reduction in suppressor immune cells within the tumors of mice implanted with these scaffolds.

CONCLUSION

Our scaffold-based T-cell therapy presents an innovative in situ localized approach for programming T-cells to target solid tumors. This approach offers a viable alternative to in vitro manipulation of T-cells, circumventing the need for large-scale in vitro generation and culture of tumor-specific T-cells. It offers an off-the-shelf alternative that facilitates the use of host cells instead of allogeneic cells, thereby, overcoming a major hurdle.

Tuning spacer length improves the functionality of the nanobody-based VEGFR2 CAR T cell

BACKGROUND

The chimeric antigen receptor-expressing T (CAR-T) cells for cancer immunotherapy have obtained considerable clinical importance. CAR T cells need an optimized intracellular signaling domain to get appropriately activated and also for the proper antigen recognition, the length and composition of the extracellular spacer are critical factors.

RESULTS

We constructed two third-generation nanobody-based VEGFR2-CARs containing either IgG1 hinge-CH2-CH3 region or hinge-only as long or short extracellular spacers, respectively. Both CARs also contained intracellular activating domains of CD28, OX40, and CD3ζ. The T cells from healthy individuals were transduced efficiently with the two CARs, and showed increased secretion of IL-2 and IFN-γ cytokines, and also CD69 and CD25 activation markers along with cytolytic activity after encountering VEGFR2+ cells. The VEGFR2-CAR T cells harboring the long spacer showed higher cytokine release and CD69 and CD25 expression in addition to a more efficient cytolytic effect on VEGFR2+ target cells.

CONCLUSIONS

The results demonstrated that the third-generation anti-VEGFR2 nanobody-based CAR T cell with a long spacer had a superior function and potentially could be a better candidate for solid tumor treatment.

Engineered CAR-T cells: An immunotherapeutic approach for cancer treatment and beyond

Chimeric Antigen Receptor (CAR) T cell therapy is a type of adoptive immunotherapy that offers a promising avenue for enhancing cancer treatment since traditional cancer treatments like chemotherapy, surgery, and radiation therapy have proven insufficient in completely eradicating tumors, despite the relatively positive outcomes. It has been observed that CAR-T cell therapy has shown promising results in treating the majority of hematological malignancies but also have a wide scope for other cancer types. CAR is an extra receptor on the T-cell that helps to increase and accelerate tumor destruction by efficiently activating the immune system. It is made up of three domains, the ectodomain, transmembrane, and the endodomain. The ectodomain is essential for antigen recognition and binding, whereas the co-stimulatory signal is transduced by the endodomain. To date, the Food and Drug Administration (FDA) has granted approval for six CAR-T cell therapies. However, despite its remarkable success, CAR-T therapy is associated with numerous adverse events and has certain limitations. This chapter focuses on the structure and function of the CAR domain, various generations of CAR, and the process of CAR-T cell development, adverse effects, and challenges in CAR-T therapy. CAR-T cell therapy also has scopes in other disease conditions which include systemic lupus erythematosus, multiple sclerosis, and myocardial fibrosis, etc.

Essentials of CAR-T Therapy and Associated Microbial Challenges in Long Run Immunotherapy

Chimeric antigen receptor (CAR)-T cell therapy has shown potential in improving outcomes for individuals with hematological malignancies. However, achieving long-term full remission for blood cancer remains challenging due to severe life-threatening toxicities such as limited anti-tumor efficacy, antigen escape, trafficking restrictions, and limited tumor invasion. Furthermore, the interactions between CAR-T cells and their host tumor microenvironments have a significant impact on CAR-T function. To overcome these considerable hurdles, fresh methodologies and approaches are needed to produce more powerful CAR-T cells with greater anti-tumor activity and less toxicity. Despite advances in CAR-T research, microbial resistance remains a significant obstacle. In this review, we discuss and describe the basics of CAR-T structures, generations, challenges, and potential risks of infections in CAR-T cell therapy.

The research status and prospects of MUC1 in immunology

In immune processes, molecular - molecular interactions are complex. As MUC1 often appears to be an important molecule in inflammation and tumor immunity, it is necessary to summarize the leading countries, authors, journals, and the cooperation among these entities and, most importantly, to determine the main research directions related to MUC1 in this field and the associated research frontiers. A total of 3,397 related studies published from 2012-2021 were retrieved from the Web of Science core database. The search strategy is TS= (MUC1 OR Mucin-1) refined by WEB OF SCIENCE CATEGORY (IMMUNOLOGY) AND [excluding] PUBLICATION YEARS: (2022) AND DOCUMENT TYPES: (ARTICLE OR REVIEW) AND LANGUAGES: (ENGLISH) AND WEB OF SCIENCE INDEX: (Web of Science Core Collection. SCI), with a timespan of 2012 to 2021. Documented bibliometric visual analysis was performed by CiteSpace and VOSviewer. The number of studies has increased every year. There are 1,982 articles and 1,415 reviews from 89 countries and regions, 3,722 organizations, 1,042 journals, and 17,948 authors. The United States, China, and Germany are the major countries producing publications on this issue. The most published author is Finn OJ and the most influential author is June CH. The key words "chimeric antigen receptor" and "T-cell" highlight the current hot spots and future trends in this field. Research on MUC1 in the field of immunology is still evolving. Through the bibliometric analysis of the existing publications, the current research hotspots and future development trends in this field can be obtained.

Chimeric Antigen Receptor T-Cell Therapy in Acute Myeloid Leukemia: State of the Art and Recent Advances

Chimeric antigen receptors (CAR)-T-cell therapy represents the most important innovation in onco-hematology in recent years. The progress achieved in the management of complications and the latest generations of CAR-T-cells have made it possible to anticipate in second-line the indication of this type of treatment in large B-cell lymphoma. While some types of B-cell lymphomas and B-cell acute lymphoid leukemia have shown extremely promising results, the same cannot be said for myeloid leukemias-in particular, acute myeloid leukemia (AML), which would require innovative therapies more than any other blood disease. The heterogeneities of AML cells and the immunological complexity of the interactions between the bone marrow microenvironment and leukemia cells have been found to be major obstacles to the clinical development of CAR-T in AML. In this review, we report on the main results obtained in AML clinical trials, the preclinical studies testing potential CAR-T constructs, and future perspectives.

Cas9-induced targeted integration of large DNA payloads in primary human T cells via homology-mediated end-joining DNA repair

The reliance on viral vectors for the production of genetically engineered immune cells for adoptive cellular therapies remains a translational bottleneck. Here we report a method leveraging the DNA repair pathway homology-mediated end joining, as well as optimized reagent composition and delivery, for the Cas9-induced targeted integration of large DNA payloads into primary human T cells with low toxicity and at efficiencies nearing those of viral vectors (targeted knock-in of 1-6.7 kb payloads at rates of up to 70% at multiple targeted genomic loci and with cell viabilities of over 80%). We used the method to produce T cells with an engineered T-cell receptor or a chimaeric antigen receptor and show that the cells maintained low levels of exhaustion markers and excellent capacities for proliferation and cytokine production and that they elicited potent antitumour cytotoxicity in vitro and in mice. The method is readily adaptable to current good manufacturing practices and scale-up processes, and hence may be used as an alternative to viral vectors for the production of genetically engineered T cells for cancer immunotherapies.

CAR T-cell Design-dependent Remodeling of the Brain Tumor Immune Microenvironment Modulates Tumor-associated Macrophages and Anti-glioma Activity

Understanding the intricate dynamics between adoptively transferred immune cells and the brain tumor immune microenvironment (TIME) is crucial for the development of effective T cell-based immunotherapies. In this study, we investigated the influence of the TIME and chimeric antigen receptor (CAR) design on the anti-glioma activity of B7-H3-specific CAR T-cells. Using an immunocompetent glioma model, we evaluated a panel of seven fully murine B7-H3 CARs with variations in transmembrane, costimulatory, and activation domains. We then investigated changes in the TIME following CAR T-cell therapy using high-dimensional flow cytometry and single-cell RNA sequencing. Our results show that five out of six B7-H3 CARs with single costimulatory domains demonstrated robust functionality in vitro. However, these CARs had significantly varied levels of antitumor activity in vivo. To enhance therapeutic effectiveness and persistence, we incorporated 41BB and CD28 costimulation through transgenic expression of 41BBL on CD28-based CAR T-cells. This CAR design was associated with significantly improved anti-glioma efficacy in vitro but did not result in similar improvements in vivo. Analysis of the TIME revealed that CAR T-cell therapy influenced the composition of the TIME, with the recruitment and activation of distinct macrophage and endogenous T-cell subsets crucial for successful antitumor responses. Indeed, complete brain macrophage depletion using a CSF1R inhibitor abrogated CAR T-cell antitumor activity. In sum, our study highlights the critical role of CAR design and its modulation of the TIME in mediating the efficacy of adoptive immunotherapy for high-grade glioma.

SIGNIFICANCE

CAR T-cell immunotherapies hold great potential for treating brain cancers; however, they are hindered by a challenging immune environment that dampens their effectiveness. In this study, we show that the CAR design influences the makeup of the immune environment in brain tumors, underscoring the need to target specific immune components to improve CAR T-cell performance, and highlighting the significance of using models with functional immune systems to optimize this therapy.

Advancing CART therapy for acute myeloid leukemia: recent breakthroughs and strategies for future development

Chimeric antigen receptor (CAR) T therapies are being developed for acute myeloid leukemia (AML) on the basis of the results obtained for other haematological malignancies and the need of new treatments for relapsed and refractory AML. The biggest challenge of CART therapy for AML is to identify a specific target antigen, since antigens expressed in AML cells are usually shared with healthy haematopoietic stem cells (HSC). The concomitant expression of the target antigen on both tumour and HSC may lead to on-target/off-tumour toxicity. In this review, we guide researchers to design, develop, and translate to the clinic CART therapies for the treatment of AML. Specifically, we describe what issues have to be considered to design these therapies; what in vitro and in vivo assays can be used to prove their efficacy and safety; and what expertise and facilities are needed to treat and manage patients at the hospital.

DIALing-up the preclinical characterization of gene-modified adoptive cellular immunotherapies

The preclinical characterization of gene modified adoptive cellular immunotherapy candidates for clinical development often requires the use of mouse models. Gene-modified lymphocytes (GML) incorporating chimeric antigen receptors (CAR) and T-cell receptors (TCR) into immune effector cells require in vivo characterization of biological activity, mechanism of action, and preclinical safety. Typically, this characterization involves the assessment of dose-dependent, on-target, on-tumor activity in severely immunocompromised mice. While suitable for the purpose of evaluating T cell-expressed transgene function in a living host, this approach falls short in translating cellular therapy efficacy, safety, and persistence from preclinical models to humans. To comprehensively characterize cell therapy products in mice, we have developed a framework called "DIAL". This framework aims to enable an end-to-end understanding of genetically engineered cellular immunotherapies in vivo, from infusion to tumor clearance and long-term immunosurveillance. The acronym DIAL stands for Distribution, Infiltration, Accumulation, and Longevity, compartmentalizing the systemic attributes of gene-modified cellular therapy and providing a platform for optimization with the ultimate goal of improving therapeutic efficacy. This review will discuss both existent and emerging examples of DIAL characterization in mouse models, as well as opportunities for future development and optimization.

Humanized single-domain antibody targeting HER2 enhances function of chimeric antigen receptor T cells

Introduction

Chimeric antigen receptors (CARs) can redirect T cells against antigen-expressing tumors, and each component plays an important role in the function and anti-tumor efficacy. It has been reported that using human sequences or a low affinity of CAR single-chain variable fragments (scFvs) in the CAR binding domains is a potential way to enhance the function of CAR-T cells. However, it remains largely unknown how a lower affinity of CARs using humanized scFvs affects the function of CAR-T cells until recently.

Methods

We used different humanized anti-HER2 antibodies as the extracellular domain of CARs and further constructed a series of the CAR-T cells with different affinity.

Results

We have observed that moderately reducing the affinity of CARs (light chain variable domain (VL)-based CAR-T) could maintain the anti-tumor efficacy, and improved the safety of CAR therapy both in vitro and in vivo compared with high-affinity CAR-T cells. Moreover, T cells expressing the VL domain only antibody exhibited long-lasting tumor elimination capability after multiple challenges in vitro, longer persistence and lower cytokine levels in vivo.

Discussion

Our findings provide an alternative option for CAR-T optimization with the potential to widen the use of CAR T cells.

CD276-CAR T cells and Dual-CAR T cells targeting CD276/FGFR4 promote rhabdomyosarcoma clearance in orthotopic mouse models

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood, whose prognosis is still poor especially for metastatic, high-grade, and relapsed RMS. New treatments are urgently needed, especially systemic therapies. Chimeric Antigen Receptor T cells (CAR Ts) are very effective against hematological malignancies, but their efficacy against solid tumors needs to be improved. CD276 (B7-H3) is a target upregulated in RMS and detected at low levels in normal tissues. FGFR4 is a very specific target for RMS. Here, we optimized CAR Ts for these two targets, alone or in combination, and tested their anti-tumor activity in vitro and in vivo.

METHODS

Four different single-domain antibodies were used to select the most specific FGFR4-CAR construct. RMS cell killing and cytokine production by CD276- and FGFR4-CAR Ts expressing CD8α or CD28 HD/TM domains in combination with 4-1BB and/or CD28 co-stimulatory domains were tested in vitro. The most effective CD276- and FGFR4-CAR Ts were used to generate Dual-CAR Ts. Tumor killing was evaluated in vivo in three orthotopic RMS mouse models.

RESULTS

CD276.V-CAR Ts (276.MG.CD28HD/TM.CD28CSD.3ζ) showed the strongest killing of RMS cells, and the highest release of IFN-γ and Granzyme B in vitro. FGFR4.V-CAR Ts (F8-FR4.CD28HD/TM.CD28CSD.3ζ) showed the most specific killing. CD276-CAR Ts successfully eradicated RD- and Rh4-derived RMS tumors in vivo, achieving complete remission in 3/5 and 5/5 mice, respectively. In CD276low JR-tumors, however, they achieved complete remission in only 1/5 mice. FGFR4 CAR Ts instead delayed Rh4 tumor growth. Dual-CAR Ts promoted Rh4-tumors clearance in 5/5 mice.

CONCLUSIONS

CD276- and CD276/FGFR4-directed CAR Ts showed effective RMS cell killing in vitro and eradication of CD276high RMS tumors in vivo. CD276low tumors escaped the therapy highlighting a correlation between antigen density and effectiveness. FGFR4-CAR Ts showed specific killing in vitro but could only delay RMS growth in vivo. Our results demonstrate that combined expression of CD276-CAR with other CAR does not reduce its benefit. Introducing immunotherapy with CD276-CAR Ts in RMS seems to be feasible and promising, although CAR constructs design and target combinations have to be further improved to eradicate tumors with low target expression.

Cell-based therapies for the treatment of rheumatoid arthritis

Autoimmune diseases, including rheumatoid arthritis that is the most prevalent rheumatic autoimmune disorder, affect autologous connective tissues caused by the breakdown of the self-tolerance mechanisms of the immune system. During the last two decades, cell-based therapy, including stem cells and none-stem cells has been increasingly considered as a therapeutic option in various diseases. This is partly due to the unique properties of stem cells that divide and differentiate from the specialized cells in the damaged tissue. Moreover, stem cells and none-stem cells, impose immunomodulatory properties affecting the diseases caused by immunological abnormalities such as rheumatic autoimmune disorders. In the present review, the efficacy of cell-based therapy with four main types of stem cells, including mesenchymal stem cells, hematopoietic stem cells, embryonic stem cells, and human amniotic membrane cells, as well as none-stem cells, including regulatory T cells, chimeric antigen receptor T cells, and tolerogenic dendritic cells will be evaluated. Moreover, other related issues, including safety, changes in immunological parameters, suitable choice of stem cell and none-stem cell origin, conditioning regimen, limitations, and complications will be discussed.

Development of a bicistronic anti-CD19/CD20 CAR construct including abrogation of unexpected nucleic acid sequence deletions

To address CD19 loss from lymphoma after anti-CD19 chimeric antigen receptor (CAR) T cell therapy, we designed a bicistronic construct encoding an anti-CD19 CAR and an anti-CD20 CAR. We detected deletions from the expected bicistronic construct sequence in a minority of transcripts by mRNA sequencing. Loss of bicistronic construct transgene DNA was also detected. Deletions of sequence were present at much higher frequencies in transduced T cell mRNA versus gamma-retroviral vector RNA. We concluded that these deletions were caused by intramolecular template switching of the reverse transcriptase enzyme during reverse transcription of gamma-retroviral vector RNA into transgene DNA of transduced T cells. Intramolecular template switching was driven by repeated regions of highly similar nucleic acid sequence within CAR sequences. We optimized the sequence of the bicistronic CAR construct to reduce repeated regions of highly similar sequences. This optimization nearly eliminated sequence deletions. This work shows that repeated regions of highly similar nucleic acid sequence must be avoided in complex CAR constructs. We further optimized the bicistronic construct by lengthening the linker of the anti-CD20 single-chain variable fragment. This modification increased CD20-specific interleukin-2 release and reduced CD20-specific activation-induced cell death. We selected an optimized anti-CD19/CD20 bicistronic construct for clinical development.

Insight into the Progress in CAR-T Cell Therapy and Combination with Other Therapies for Glioblastoma

Glioblastoma (GBM) is the most common malignant primary brain cancer in adults. It is always resistant to existing treatments, including surgical resection, postoperative radiotherapy, and chemotherapy, which leads to a dismal prognosis and a high relapse rate. Therefore, novel curative therapies are urgently needed for GBM. Chimeric antigen receptor T (CAR-T) cell therapy has significantly improved life expectancy for hematological malignancies patients, and thus it increases the interest in applying CAR-T cell therapy for solid tumors. In the recently published research, it is indicated that there are numerous obstacles to achieve clinical benefits for solid tumors, especially for GBM, because of GBM anatomical characteristics (the blood-brain barrier and suppressive tumor microenvironment) and the tumor heterogeneity. CAR-T cells are difficult to penetrate blood-brain barrier, and immunosuppressive tumor microenvironment (TME), which induces CAR-T cell exhaustion, impairs CAR-T cell therapy response. Moreover, under the pressure of CAR-T cell therapy, the tumor heterogeneity and tumor plasticity drive tumor evolution and therapy resistance, such as antigen escape. Nonetheless, scientists strive for strategies to overcome these hurdles, including novel CAR-T cell designs and regional delivery. For instance, the structure of multi-antigen-targeted CAR-T cells can enrich CAR-T accumulation in tumor TME and eliminate abundant tumor cells to avoid tumor antigen heterogeneity. Additionally, paired with an immune modifier and one or more stimulating domains, different generation of innovations in the structure and manufacturing of CAR-T cells have improved efficacy and persistence. While single CAR-T cell therapy receives limited clinical survival benefit. Compared with single CAR-T cell therapy, the combination therapies have supplemented the treatment paradigm. Combinatorial treatment methods consolidate the CAR-T cells efficacy by regulating the tumor microenvironment, optimizing the CAR structure, targeting the CAR-T cells to the tumor cells, reversing the tumor-immune escape mechanisms, and represent a promising avenue against GBM, based on multiple impressive research. Moreover, exciting results are also reported to be realized through combining effective therapies with CAR-T cells in preclinical and clinical trials samples, have aroused inspiration to explore the antitumor function of combination therapies. In summary, this study aims to summarize the limitation of CAR-T cell therapies and introduces novel strategies to enhance CAR-T cell function as well as prospect the potential of the therapeutic combination.

ICOS and OX40 tandem co-stimulation enhances CAR T-cell cytotoxicity and promotes T-cell persistence phenotype

Chimeric Antigen Receptor (CAR) T-cell therapies have emerged as an effective and potentially curative immunotherapy for patients with relapsed or refractory malignancies. Treatment with CD19 CAR T-cells has shown unprecedented results in hematological malignancies, including heavily refractory leukemia, lymphoma, and myeloma cases. Despite these encouraging results, CAR T-cell therapy faces limitations, including the lack of long-term responses in nearly 50-70% of the treated patients and low efficacy in solid tumors. Among other reasons, these restrictions are related to the lack of targetable tumor-associated antigens, limitations on the CAR design and interactions with the tumor microenvironment (TME), as well as short-term CAR T-cell persistence. Because of these reasons, we developed and tested a chimeric antigen receptor (CAR) construct with an anti-ROR1 single-chain variable-fragment cassette connected to CD3ζ by second and third-generation intracellular signaling domains including 4-1BB, CD28/4-1BB, ICOS/4-1BB or ICOS/OX40. We observed that after several successive tumor-cell in vitro challenges, ROR1.ICOS.OX40ζ continued to proliferate, produce pro-inflammatory cytokines, and induce cytotoxicity against ROR1+ cell lines in vitro with enhanced potency. Additionally, in vivo ROR1.ICOS.OX40ζ T-cells showed anti-lymphoma activity, a long-lasting central memory phenotype, improved overall survival, and evidence of long-term CAR T-cell persistence. We conclude that anti-ROR1 CAR T-cells that are activated by ICOS.OX40 tandem co-stimulation show in vitro and in vivo enhanced targeted cytotoxicity associated with a phenotype that promotes T-cell persistence.

Harnessing Nanomaterials for Cancer Sonodynamic Immunotherapy

Immunotherapy has made remarkable strides in cancer therapy over the past decade. However, such emerging therapy still suffers from the low response rates and immune-related adverse events. Various strategies have been developed to overcome these serious challenges. Therein, sonodynamic therapy (SDT), as a non-invasive treatment, has received ever-increasing attention especially in the treatment of deep-seated tumors. Significantly, SDT can effectively induce immunogenic cell death to trigger systemic anti-tumor immune response, termed sonodynamic immunotherapy. The rapid development of nanotechnology has revolutionized SDT effects with robust immune response induction. As a result, more and more innovative nanosonosensitizers and synergistic treatment modalities are established with superior efficacy and safe profile. In this review, the recent advances in cancer sonodynamic immunotherapy are summarized with a particular emphasis on how nanotechnology can be explored to harness SDT for amplifying anti-tumor immune response. Moreover, the current challenges in this field and the prospects for its clinical translation are also presented. It is anticipated that this review can provide rational guidance and facilitate the development of nanomaterials-assisted sonodynamic immunotherapy, helping to pave the way for next-generation cancer therapy and eventually achieve a durable response in patients.

B7-H3-targeted CAR T cell activity is enhanced by radiotherapy in solid cancers

Adoptive cell therapy utilizing T cells genetically modified to express a chimeric antigen receptor (CAR) has demonstrated promising clinical results in hematological malignancies. However, solid cancers have not seen a similar success due to multiple obstacles. Investigating these escape mechanisms and designing strategies to counteract such limitations is crucial and timely. Growing evidence in the literature supports the hypothesis that radiotherapy has the potential to enhance the susceptibility of solid tumors to CAR T cell therapy, by overcoming mechanisms of resistance. Radiation treatment can increase the susceptibility of different types of solid cancers (TNBC, HNSCC, PDAC) to B7-H3 CAR T cell-mediated eradication. Multiple mechanisms, including reduced cancer cell proliferation, upregulation of the targeted antigen, modulation of apoptotic molecules may contribute to this signal. The information in the literature and the results we describesupport the ability of radiotherapy to improve the efficacy of CAR T cell therapy in solid tumors.