CAR T-Cell Therapy in Hematological Malignancies

Cryopreserved leukapheresis material can be transferred from controlled rate freezers to ultracold storage at warmer temperatures without affecting downstream CAR-T cell culture performance and in-vitro functionality

Chimeric antigen receptor (CAR) T-cell therapies are increasingly adopted as a commercially available treatment for hematologic and solid tumor cancers. As CAR-T therapies reach more patients globally, the cryopreservation and banking of patients' leukapheresis materials is becoming imperative to accommodate intra/inter-national shipping logistical delays and provide greater manufacturing flexibility. This study aims to determine the optimal temperature range for transferring cryopreserved leukapheresis materials from two distinct types of controlled rate freezing systems, Liquid Nitrogen (LN2)-based and LN2-free Conduction Cooling-based, to the ultracold LN2 storage freezer (≤-135 °C), and its impact on CAR T-cell production and functionality. Presented findings demonstrate that there is no significant influence on CAR T-cell expansion, differentiation, or downstream in-vitro function when employing a transfer temperature range spanning from -30 °C to -80 °C for the LN2-based controlled rate freezers as well as for conduction cooling controlled rate freezers. Notably, CAR T-cells generated from cryopreserved leukapheresis materials using the conduction cooling controlled rate freezer exhibited suboptimal performance in certain donors at transfer temperatures lower than -60 °C, possibly due to the reduced cooling rate of lower than 1 °C/min and extended dwelling time needed to reach the final temperatures within these systems. This cohort of data suggests that there is a low risk to transfer cryopreserved leukapheresis materials at higher temperatures (between -30 °C and -60 °C) with good functional recovery using either controlled cooling system, and the cryopreserved materials are suitable to use as the starting material for autologous CAR T-cell therapies.

CAR-T cell therapy: Efficacy in management of cancers, adverse effects, dose-limiting toxicities and long-term follow up

Chimeric Antigen Receptor T-cell (CAR-T) therapy has emerged as a groundbreaking and highly promising approach for the management of cancer. This paper reviews the efficacy of CAR-T therapy in the treatment of various hematological malignancies, also, with a mention of its effect on solid tumors, for which they have not received FDA approval yet. Different common and uncommon side effects are also discussed in this paper, with attention to the effect of each drug separately. By reviewing the recommendations of the FDA for CAR-T therapy research, we have extensively discussed dose-limiting toxicities. This further highlights the need for precise dosing strategies, striking a balance between therapeutic benefits and potential risks. Additionally, we reviewed the long-term follow-up of patients receiving CAR-T therapy to gain valuable insights into response durability and late-onset effects.

Endolysosomal transient receptor potential mucolipins and two-pore channels: implications for cancer immunity

Past research has identified that cancer cells sustain several cancer hallmarks by impairing function of the endolysosomal system (ES). Thus, maintaining the functional integrity of endolysosomes is crucial, which heavily relies on two key protein families: soluble hydrolases and endolysosomal membrane proteins. Particularly members of the TPC (two-pore channel) and TRPML (transient receptor potential mucolipins) families have emerged as essential regulators of ES function as a potential target in cancer therapy. Targeting TPCs and TRPMLs has demonstrated significant impact on multiple cancer hallmarks, including proliferation, growth, migration, and angiogenesis both in vitro and in vivo. Notably, endosomes and lysosomes also actively participate in various immune regulatory mechanisms, such as phagocytosis, antigen presentation, and the release of proinflammatory mediators. Yet, knowledge about the role of TPCs and TRPMLs in immunity is scarce. This prompts a discussion regarding the potential role of endolysosomal ion channels in aiding cancers to evade immune surveillance and destruction. Specifically, understanding the interplay between endolysosomal ion channels and cancer immunity becomes crucial. Our review aims to comprehensively explore the current knowledge surrounding the roles of TPCs and TRPMLs in immunity, whilst emphasizing the critical need to elucidate their specific contributions to cancer immunity by pointing out current research gaps that should be addressed.

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

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

Advances in molecular targeted drugs in combination with CAR-T cell therapy for hematologic malignancies

Molecular targeted drugs and chimeric antigen receptor (CAR) T cell therapy represent specific biological treatments that have significantly improved the efficacy of treating hematologic malignancies. However, they face challenges such as drug resistance and recurrence after treatment. Combining molecular targeted drugs and CAR-T cells could regulate immunity, improve tumor microenvironment (TME), promote cell apoptosis, and enhance sensitivity to tumor cell killing. This approach might provide a dual coordinated attack on cancer cells, effectively eliminating minimal residual disease and overcoming therapy resistance. Moreover, molecular targeted drugs can directly or indirectly enhance the anti-tumor effect of CAR-T cells by inducing tumor target antigen expression, reversing CAR-T cell exhaustion, and reducing CAR-T cell associated toxic side effects. Therefore, combining molecular targeted drugs with CAR-T cells is a promising and novel tactic for treating hematologic malignancies. In this review article, we focus on analyzing the mechanism of therapy resistance and its reversal of CAR-T cell therapy resistance, as well as the synergistic mechanism, safety, and future challenges in CAR-T cell therapy in combination with molecular targeted drugs. We aim to explore the benefits of this combination therapy for patients with hematologic malignancies and provide a rationale for subsequent clinical studies.

Applied Cardio-Oncology in Hematological Malignancies: A Narrative Review

Applied cardio-oncology in hematological malignancies refers to the integration of cardiovascular care and management for patients with blood cancer, particularly leukemia, lymphoma, and multiple myeloma. Hematological cancer therapy-related cardiotoxicity deals with the most common cardiovascular complications of conventional chemotherapy, targeted therapy, immunotherapy, chimeric antigen receptor T (CAR-T) cell and tumor-infiltrating lymphocyte therapies, bispecific antibodies, and hematopoietic stem cell transplantation. This narrative review focuses on hematological cancer-therapy-related cardiotoxicity's definition, risk stratification, multimodality imaging, and use of cardiac biomarkers to detect clinical and/or subclinical myocardial dysfunction and electrical instability. Moreover, the most common cardiotoxic profiles of the main drugs and/or therapeutic interventions in patients with hematological malignancies are described thoroughly.

A novel immunogenic cell death-related classification indicates the immune landscape and predicts clinical outcome and treatment response in acute myeloid leukemia

BACKGROUND

Immunogenic cell death (ICD) is closely related to anti-tumor therapy and regulates the tumor microenvironment (TME). This study aims to explore the molecular characteristics of ICD in acute myeloid leukemia (AML) and to analyze the value of ICD-related biomarkers in TME indication, prognosis prediction, and treatment response evaluation in AML.

METHODS

Single-sample gene set enrichment analysis was used to calculate the ICD score. LASSO regression was used to construct a prognostic risk score model. We also analyzed differences in clinical characteristics, immune landscape, immunotherapy response, and chemotherapy sensitivity between high-risk and low-risk patients.

RESULTS

This study identified two ICD-related subtypes and found significant heterogeneity in clinical prognosis, TME, and immune landscape between different ICD subtypes. Subsequently, a novel ICD-related prognostic risk score model was developed, which accurately predicted the prognosis of AML patients and was validated in nine AML cohorts. Moreover, there were significant correlations between risk scores and clinicopathological factors, somatic mutations, TME characteristics, immune cell infiltration, immunotherapy response, and chemosensitivity. We further validated the model gene expression in a clinically real-world cohort.

CONCLUSIONS

The novel ICD-related signatures identified and validated by us can serve as promising biomarkers for predicting clinical outcomes, chemotherapy sensitivity, and immunotherapy response in AML patients, guiding the establishment of personalized and accurate treatment strategies for AML.

Developing CAR-immune cell therapy against SARS-CoV-2: Current status, challenges and prospects

Chimeric antigen receptor (CAR)-immune cell therapy has revolutionized the anti-tumor field, achieving efficient and precise tumor clearance by directly guiding immune cell activity to target tumors. In addition, the use of CAR-immune cells to influence the composition and function of the immune system and ultimately achieve virus clearance and immune system homeostasis has attracted the interest of researchers. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered a global pandemic of coronavirus disease 2019 (COVID-19). To date, the rapidly mutating SARS-CoV-2 continues to challenge existing therapies and has raised public concerns regarding reinfection. In patients with COVID-19, the interaction of SARS-CoV-2 with the immune system influences the course of the disease, and the coexistence of over-activated immune system components, such as macrophages, and severely compromised immune system components, such as natural killer cells, reveals a dysregulated immune system. Dysregulated immune-induced inflammation may impair viral clearance and T-cell responses, causing cytokine storms and ultimately leading to patient death. Here, we summarize the research progress on the use of CAR-immune cells against SARS-CoV-2 infection. Furthermore, we discuss the feasibility, challenges and prospect of CAR-immune cells as a new immune candidate therapy against SARS-CoV-2.

Research progress of immunotherapy against anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is the most aggressive type of thyroid cancer. While ATC is rare, its mortality is high. Standard treatments, such as surgery, radiotherapy, and chemotherapy, have demonstrated limited efficacy in managing ATC. However, the advent of immunotherapy has significantly improved the prognosis for patients with ATC. Immunotherapy effectively targets and eliminates tumor cells by using the power of the body's immune cells. The neoantigen is an atypical protein generated by somatic mutation, is exclusively observed in neoplastic cells, and is devoid of central tolerance. Neoantigens exhibit enhanced specificity towards tumor cells and display robust immunogenic properties. Currently, neoantigen therapy is primarily applied in immune checkpoint inhibitors and cellular immunotherapy, encompassing adoptive immunotherapy and tumor vaccines. This study discusses the mechanism, tumor microenvironment, clinical trials, adverse events, limitations and future directions associated with ATC immunotherapy.

Advancing rare disease treatment: EMA's decade-long insights into engineered adoptive cell therapy for rare cancers and orphan designation

Adoptive cell therapy (ACT), particularly chimeric antigen receptor (CAR)-T cell therapy, has emerged as a promising approach for targeting and treating rare oncological conditions. The orphan medicinal product designation by the European Union (EU) plays a crucial role in promoting development of medicines for rare conditions according to the EU Orphan Regulation.This regulatory landscape analysis examines the evolution, regulatory challenges, and clinical outcomes of genetically engineered ACT, with a focus on CAR-T cell therapies, based on the European Medicines Agency's Committee for Orphan Medicinal Products review of applications evaluated for orphan designation and maintenance of the status over a 10-year period. In total, 30 of 36 applications were granted an orphan status, and 14 subsequently applied for maintenance of the status at time of marketing authorisation or extension of indication. Most of the products were autologous cell therapies using a lentiviral vector and were developed for the treatment of rare haematological B-cell malignancies. The findings revealed that 80% (29/36) of the submissions for orphan designation were supported by preliminary clinical data showing a potential efficacy of the candidate products and an added clinical benefit over currently authorised medicines for the proposed orphan condition. Notably, in 89% (32/36) of the cases significant benefit of the new products was accepted based on a clinically relevant advantage over existing therapies. Twelve of fourteen submissions reviewed for maintenance of the status at time of marketing authorisation or extension of indication demonstrated significant benefit of the products over existing satisfactory methods of treatment within the approved therapeutic indications, but one of the applications was withdrawn during the regulatory evaluation.This article summarises the key findings related to the use of engineered ACT, primarily CAR-T cell therapies, in targeting and treating rare cancers in the EU. It emphasises the importance of use of clinical data in supporting medical plausibility and significant benefit at the stage of orphan designation and highlights the high success rate for these products in obtaining initial orphan designations and subsequent maintaining the status at the time of marketing authorisation or extension of indication.

CAR‑T cell therapy: A breakthrough in traditional cancer treatment strategies (Review)

Chimeric antigen receptor (CAR)‑T cell therapy is an innovative approach to immune cell therapy that works by modifying the T cells of a patient to express the CAR protein on their surface, and thus induce their recognition and destruction of cancer cells. CAR‑T cell therapy has shown some success in treating hematological tumors, but it still faces a number of challenges in the treatment of solid tumors, such as antigen selection, tolerability and safety. In response to these issues, studies continue to improve the design of CAR‑T cells in pursuit of improved therapeutic efficacy and safety. In the future, CAR‑T cell therapy is expected to become an important cancer treatment, and may provide new ideas and strategies for individualized immunotherapy. The present review provides a comprehensive overview of the principles, clinical applications, therapeutic efficacy and challenges of CAR‑T cell therapy.

The significance of targeting lysosomes in cancer immunotherapy

Lysosomes are intracellular digestive organelles that participate in various physiological and pathological processes, including the regulation of immune checkpoint molecules, immune cell function in the tumor microenvironment, antigen presentation, metabolism, and autophagy. Abnormalities or dysfunction of lysosomes are associated with the occurrence, development, and drug resistance of tumors. Lysosomes play a crucial role and have potential applications in tumor immunotherapy. Targeting lysosomes or harnessing their properties is an effective strategy for tumor immunotherapy. However, the mechanisms and approaches related to lysosomes in tumor immunotherapy are not fully understood at present, and further basic and clinical research is needed to provide better treatment options for cancer patients. This review focuses on the research progress related to lysosomes and tumor immunotherapy in these.

Sustained efficacy of chimeric antigen receptor T-cell therapy in central nervous system lymphoma: a systematic review and meta-analysis of individual data

Background: Central nervous system lymphoma (CNSL) is considered an aggressive lymphoma with a poor prognosis. Studies investigating CNSL have shown that chimeric antigen receptor (CAR) T-cell therapy has demonstrated an effective response in limited sample sizes. Therefore, we conducted this systematic review and meta-analysis to clarify the sustained efficacy and factors associated with the sustained efficacy of CAR T-cell therapy in the treatment of CNSL. Methods: We searched studies from PubMed, Embase, Medline, and the Cochrane Center Register of Controlled Trials up to July 2023. Studies that included individual data on the duration of response (DoR) after receiving CAR T-cell therapy were enrolled. Pooled response rates were calculated using fixed-effects or random-effects models. Subgroup analysis was performed to analyze the heterogeneity, and a Cox regression model was performed to identify the factors associated with sustained efficacy. Results: In total, 12 studies including 69 patients were identified and included in this meta-analysis. The pooled relapse rate was 45% [95% CI 35, 56]. Subgroup analyses of relapse rates revealed that CAR T-cells using the CD28/4-1BB domain (CD28/4-1BB vs. CD28 vs. 4-1BB, p = 0.0151), parenchymal or leptomeningeal involvement (parenchymal or leptomeningeal vs. both parenchymal and leptomeningeal, p < 0.0001), and combined treatment with CAR T-cell therapy [Autologous stem cell transplantation (ASCT) plus CAR T-cell therapy vs. CAR T cells with maintenance therapy vs. CAR T-cell therapy alone, p = 0.003] were associated with lower relapse rates in patients. Time-to-event endpoints were assessed using reconstructed individual patient survival data to explore key modulators of DoR. Partial response status at CAR-T infusion and the use of ASCT plus CAR T-cell therapy were associated with longer DoR at the multivariate level, with hazard ratios of 0.25 and 0.26, respectively. Conclusion: CAR T-cell therapy shows promising and sustained efficacy in CNSL patients. However, further prospective large-scale studies are needed to assess these effect modifiers to optimize patient selection and improve the sustained efficacy of CAR T-cell therapy in the treatment of CNSL. Systematic review registration: https://clinicaltrials.gov/, identifier PROSPERO CRD42023451856.

Childhood leukemias in Mexico: towards implementing CAR-T cell therapy programs

Leukemias are the most common type of pediatric cancer around the world. Prognosis has improved during the last decades, and many patients are cured with conventional treatment as chemotherapy; however, many patients still present with a refractory disease requiring additional treatments, including hematopoietic stem cell transplantation. Immunotherapy with monoclonal antibodies or cellular therapy is a promising strategy for treating refractory or relapsed hematological malignancies. Particularly, CAR-T cells have shown clinical efficacy in clinical trials, and different products are now commercially approved by regulatory agencies in the USA and Europe. Many challenges still need to be solved to improve and optimize the potential of these therapies worldwide. Global access to cell therapy is a significant concern, and different strategies are being explored in the middle- and low-income countries. In Mexico, leukemias represent around 50% of total cancer diagnosed in pediatric patients, and the rate of relapsed or refractory disease is higher than reported in other countries, a multi-factorial problem. Although significant progress has been made during the last decades in leukemia diagnosis and treatment, making new therapies available to Mexican patients is a priority, and cell and gene therapies are on the horizon. Efforts are ongoing to make CAR-T cell therapy accessible for patients in Mexico. This article summarizes a general landscape of childhood leukemias in Mexico, and we give a perspective about the current strategies, advances, and challenges ahead to make gene and cell therapies for leukemia clinically available.

Preclinical Evaluation of Novel Folate Receptor 1-Directed CAR T Cells for Ovarian Cancer

Treatment options for ovarian cancer patients are limited, and a high unmet clinical need remains for targeted and long-lasting, efficient drugs. Genetically modified T cells expressing chimeric antigen receptors (CAR), are promising new drugs that can be directed towards a defined target and have shown efficient, as well as persisting, anti-tumor responses in many patients. We sought to develop novel CAR T cells targeting ovarian cancer and to assess these candidates preclinically. First, we identified potential CAR targets on ovarian cancer samples. We confirmed high and consistent expressions of the tumor-associated antigen FOLR1 on primary ovarian cancer samples. Subsequently, we designed a series of CAR T cell candidates against the identified target and demonstrated their functionality against ovarian cancer cell lines in vitro and in an in vivo xenograft model. Finally, we performed additional in vitro assays recapitulating immune suppressive mechanisms present in solid tumors and developed a process for the automated manufacturing of our CAR T cell candidate. These findings demonstrate the feasibility of anti-FOLR1 CAR T cells for ovarian cancer and potentially other FOLR1-expressing tumors.

Chimeric Antigen Receptor T Cell Therapy for Pancreatic Cancer: A Review of Current Evidence

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of malignant and non-malignant disorders. CARs are synthetic transmembrane receptors expressed on genetically modified immune effector cells, including T cells, natural killer (NK) cells, or macrophages, which are able to recognize specific surface antigens on target cells and eliminate them. CAR-modified immune cells mediate cytotoxic antitumor effects via numerous mechanisms, including the perforin and granzyme pathway, Fas and Fas Ligand (FasL) pathway, and cytokine secretion. High hopes are associated with the prospective use of the CAR-T strategy against solid cancers, especially the ones resistant to standard oncological therapies, such as pancreatic cancer (PC). Herein, we summarize the current pre-clinical and clinical studies evaluating potential tumor-associated antigens (TAA), CAR-T cell toxicities, and their efficacy in PC.

Donor-derived stem cell infusion for sustained pancytopenia after CD19 CAR-T therapy for relapsed patients post allogeneic stem cell transplantation

OBJECTIVES

To investigate the effectiveness of donor-derived chimeric antigen receptor T (CAR-T) cells in the treatment of relapsed cases after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and whether donor-derived peripheral blood stem cells (PBSCs) have a therapeutic effect on pancytopenia after CAR-T cell therapy.

METHODS

We analyzed data from five adults with B-cell acute lymphoblastic leukemia (ALL) who had relapse after allo-HSCT and received donor-derived CAR-T cell therapy and donor-derived PBSCs to promote hematopoietic recovery.

RESULTS

All patients had negative minimal residual disease after CAR-T therapy, grade 1-2 cytokine release syndrome, and developed grade 4 hematologic toxicity. During the pancytopenia stage after CAR-T cell therapy, donor-derived PBSCs were transfused without graft-versus-host disease (GVHD) prophylaxis. Four patients had grade I-II acute GVHD (aGVHD). After corticosteroid treatment, aGVHD resolved and hematopoiesis was restored. Although steroids in combination with etanercept and ruxolitinib relieved symptoms in one patient with grade IV aGVHD, complete hematopoietic recovery was not achieved, and the patient died due to severe infection.

CONCLUSIONS

Donor-derived CAR-T cell therapy is safe and effective in patients with relapsed/refractory ALL after allo-HSCT. Donor-derived PBSCs infusion could achieve hematopoietic recovery with controllable aGVHD in patients with persistent pancytopenia.

Insights into the Tumor Microenvironment-Components, Functions and Therapeutics

Similarly to our healthy organs, the tumor tissue also constitutes an ecosystem. This implies that stromal cells acquire an altered phenotype in tandem with tumor cells, thereby promoting tumor survival. Cancer cells are fueled by abnormal blood vessels, allowing them to develop and proliferate. Tumor-associated fibroblasts adapt their cytokine and chemokine production to the needs of tumor cells and alter the peritumoral stroma by generating more collagen, thereby stiffening the matrix; these processes promote epithelial-mesenchymal transition and tumor cell invasion. Chronic inflammation and the mobilization of pro-tumorigenic inflammatory cells further facilitate tumor expansion. All of these events can impede the effective administration of tumor treatment; so, the successful inhibition of tumorous matrix remodeling could further enhance the success of antitumor therapy. Over the last decade, significant progress has been made with the introduction of novel immunotherapy that targets the inhibitory mechanisms of T cell activation. However, extensive research is also being conducted on the stromal components and other cell types of the tumor microenvironment (TME) that may serve as potential therapeutic targets.

A bibliometric and knowledge-map study of CAR-T cell-related cytokine release syndrome (CRS) from 2012 to 2023

CAR-T cell therapy has demonstrated efficacy in treating certain hematological malignancies. However, the administration of CAR-T cells is accompanied by the occurrence of adverse events. Among these, cytokine release syndrome (CRS) has garnered significant attention. In this descriptive study, we set the search criteria to retrieve and obtain articles regarding CAR-T cell-related CRS from the Web of Science Core Collection (WoSCC). The bibliometric and knowledge-map analysis of these documents was conducted using Microsoft Excel 2019, GraphPad Prism 8, CtieSpace, and VOSviewer. 6,623 authors from 295 institutions in 49 countries coauthored a total of 1,001 publications. The leading country in this field was the United States. The most productive institution was the University of Pennsylvania. Carl H. June had the most citations, while Daniel W. Lee had the most co-citations. Research hotspots primarily concentrated on the pathogenesis, serum biomarkers, management, and therapeutic drugs of CRS, alongside neurotoxicity. Emerging topics within this discipline encompassed the following: a. Drugs for effective treatment and intervention of CRS; b. Conducting pertinent clinical trials to acquire real-world data; c. Management of toxicity (CRS and neurotoxicity) associated with CAR-T cell therapy; d. The study of BCMA-CAR-T cells in multiple myeloma (MM); e. Optimizing the CAR framework structure to enhance the effectiveness and safety of CAR-T cells. A bibliometric and scientific knowledge-map analysis provided a unique and objective perspective for exploring the field of CAR-T cell-related CRS, and may provide some new clues and valuable references for researchers.

Granulocyte-Macrophage-Colony-Stimulating-Factor Combined with Prostaglandin E1 Create Dendritic Cells of Leukemic Origin from AML Patients' Whole Blood and Whole Bone Marrow That Mediate Antileukemic Processes after Mixed Lymphocyte Culture

Although several (chemotherapeutic) protocols to treat acute myeloid leukemia (AML) are available, high rates of relapses in successfully treated patients occur. Strategies to stabilize remissions are greatly needed. The combination of the (clinically approved) immune-modulatory compounds Granulocyte-Macrophage-Colony-Stimulating-Factor (GM-CSF) and Prostaglandine E1 (PGE-1) (Kit-M) converts myeloid blasts into dendritic cells of leukemic origin (DCleu). After stimulation with DCleu ex vivo, leukemia-specific antileukemic immune cells are activated. Therefore, Kit-M treatment may be an attractive immunotherapeutic tool to treat patients with myeloid leukemia. Kit-M-mediated antileukemic effects on whole bone marrow (WBM) were evaluated and compared to whole blood (WB) to evaluate the potential effects of Kit-M on both compartments. WB and WBM samples from 17 AML patients at first diagnosis, in persisting disease and at relapse after allogeneic stem cell transplantation (SCT) were treated in parallel with Kit-M to generate DC/DCleu. Untreated samples served as controls. After a mixed lymphocyte culture enriched with patients' T cells (MLC), the leukemia-specific antileukemic effects were assessed through the degranulation- (CD107a+ T cells), the intracellular IFNγ production- and the cytotoxicity fluorolysis assay. Quantification of cell subtypes was performed via flow cytometry. In both WB and WBM significantly higher frequencies of (mature) DCleu were generated without induction of blast proliferation in Kit-M-treated samples compared to control. After MLC with Kit-M-treated vs. not pretreated WB or WBM, frequencies of (leukemia-specific) immunoreactive cells (e.g., non-naive, effector-, memory-, CD3+β7+ T cells, NK- cells) were (significantly) increased, whereas leukemia-specific regulatory T cells (Treg, CD152+ T cells) were (significantly) decreased. The cytotoxicity fluorolysis assay showed a significantly improved blast lysis in Kit-M-treated WB and WBM compared to control. A parallel comparison of WB and WBM samples revealed no significant differences in frequencies of DCleu, (leukemia-specific) immunoreactive cells and achieved antileukemic processes. Kit-M was shown to have comparable effects on WB and WBM samples regarding the generation of DCleu and activation of (antileukemic) immune cells after MLC. This was true for samples before or after SCT. In summary, a potential Kit-M in vivo treatment could lead to antileukemic effects in WB as well as WBM in vivo and to stabilization of the disease or remission in patients before or after SCT. A clinical trial is currently being planned.

Leukapheresis for CAR-T cell production and therapy

Chimeric antigen receptor (CAR) T-cell therapy is an effective, individualized immunotherapy, and novel treatment for hematologic malignancies. Six commercial CAR-T cell products are currently approved for lymphatic malignancies and multiple myeloma. In addition, an increasing number of clinical centres produce CAR-T cells on-site, which enable the administration of CAR-T cells on site. The CAR-T cell products are either fresh or cryopreserved. Manufacturing CAR-T cells is a complicated process that begins with leukapheresis to obtain T cells from the patient's peripheral blood. An optimal leukapheresis product is crucial step for a successful CAR-T cell therapy; therefore, it is imperative to understand the factors that may affect the quality or T cells. The leukapheresis for CAR-T cell production is well tolerated and safe for both paediatric and adult patients and CAR-Τ cell therapy presents high clinical response rate in many studies. CAR-T cell therapy is under continuous improvement, and it has transformed into an almost standard procedure in clinical haematology and stem cell transplantation facilities that provide both autologous and allogeneic stem cell transplantations. In patients suffering from advanced haematological malignancies, CAR-T cell therapy shows incredible antitumor efficacy. Even after a single infusion of autologous CD19-targeting CAR-T cells in patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL) and acute lymphoblastic leukaemia (ALL), long lasting remission is observed, and a fraction of the patients are being cured. Future novel constructs are being developed with better T cell persistence and better expansion. New next-generation CAR-T cells are currently designed to avoid toxicities such as cytokine release syndrome and neurotoxicity.

Assessment and predictive ability of the absolute neutrophil count in peripheral blood for in vivo CAR T cells expansion and CRS

BACKGROUND

Chimeric antigen receptor (CAR) T cell therapy is an advanced and effective immunotherapy for relapsed or refractory B-cell malignancies. High expansion of CAR T cells in vivo and durable antitumor activity indicate a persistent therapeutic response. However, this treatment is linked to a high frequency of adverse events, such as cytokine release syndrome (CRS), which affects its efficacy and can even be life-threatening. At present, a variety of markers associated with clinical response and treatment toxicity after CAR T cells infusion have been reported. Although these biomarkers can act as effective indicators reflecting CAR T cells expansion as well as CRS, they fail to predict the expansion rate of CAR T cells. Hence, further investigation is urgent to find a new biomarker to fill this void.

METHODS

We analyzed the association between the absolute neutrophil count (ANC) and CAR expansion and CRS in 45 patients with B-cell malignancies from two clinical trials. We proposed that ANC could be a practical biomarker for CAR T cells expansion and CRS, and conducted a feasibility analysis on its predictive ability.

RESULTS

In this study, 17 B-cell hematological malignancy patients with anti-B-cell maturation antigen CAR-treated and 28 with CAR19/22 T-cell-treated were enrolled and divided into an ANC-absence group and an ANC-presence group. The results showed that ANC absence correlated positively with CAR expansion and the expansion rate. The ANC can be used as a predictive marker for CAR T cells expansion. Moreover, the patients with ANC absence experienced a more severe CRS, and ANC performed a predictive ability for CRS. In addition, the peak serum concentration of several cytokines involved in CRS was higher in patients with ANC absence.

CONCLUSION

Thus, we suggest ANC as an evaluative and predictive biomarker for CAR expansion and CRS during CAR T cell therapy, which can help to maximize clinical efficacy, reduce treatment-related toxicity and prolong survival.

Managing leukapheresis in adult and pediatric patients eligible for chimeric antigen receptor T-cell therapy: suggestions from an Italian Expert Panel

Chimeric antigen receptor (CAR) T-cell therapy relies on T cells engineered to target specific tumor antigens such as CD-19 in B-cell malignancies. In this setting, the commercially available products have offered a potential long-term cure for both pediatric and adult patients. Yet manufacturing CAR T cells is a cumbersome, multistep process, the success of which strictly depends on the characteristics of the starting material, i.e., lymphocyte collection yield and composition. These, in turn, might be affected by patient factors such as age, performance status, comorbidities, and previous therapies. Ideally, CAR T-cell therapies are a one-off treatment; therefore, optimization and the possible standardization of the leukapheresis procedure is critical, also in view of the novel CAR T cells currently under investigation for hematological malignancies and solid tumors. The most recent Best Practice recommendations for the management of children and adults undergoing CAR T-cell therapy provide a comprehensive guide to their use. However, their application in local practice is not straightforward and some grey areas remain. An Italian Expert Panel of apheresis specialists and hematologists from the centers authorized to administer CAR T-cell therapy took part in a detailed discussion on the following: 1) pre-apheresis patient evaluation; 2) management of the leukapheresis procedure, also in special situations represented by low lymphocyte count, peripheral blastosis, pediatric population <25 kg, and the COVID-19 outbreak; and 3) release and cryopreservation of the apheresis unit. This article presents some of the important challenges that must be faced to optimize the leukapheresis procedure and offers suggestions as to how to improve it, some of which are specific to the Italian setting.

CSPG4 CAR-redirected Cytokine Induced Killer lymphocytes (CIK) as effective cellular immunotherapy for HLA class I defective melanoma

BACKGROUND

Even acknowledging the game-changing results achieved in the treatment of metastatic melanoma with the use of immune checkpoint inhibitors (ICI), a large proportion of patients (40-60%) still fail to respond or relapse due to the development of resistance. Alterations in the expression of Human Leukocyte Antigen class I (HLA-I) molecules are considered to play a major role in clinical resistance to ICI. Cellular immunotherapy with HLA-independent CAR-redirected lymphocytes is a promising alternative in this challenging setting and dedicated translational models are needed.

METHODS

In this study, we propose an HLA-independent therapeutic strategy with Cytokine Induced Killer lymphocytes (CIK) genetically engineered with a Chimeric Antigen Receptor (CAR) targeting the tumor antigen CSPG4 as effector mechanism. We investigated the preclinical antitumor activity of CSPG4-CAR.CIK in vitro and in a xenograft murine model focusing on patient-derived melanoma cell lines (Mel) with defective expression of HLA-I molecules.

RESULTS

We successfully generated CSPG4-CAR.CIK from patients with metastatic melanoma and reported their intense activity in vitro against a panel of CSPG4-expressing patient-derived Mel. The melanoma killing activity was intense, even at very low effector to target ratios, and not influenced by the expression level (high, low, defective) of HLA-I molecules on target cells. Furthermore, CAR.CIK conditioned medium was capable of upregulating the expression of HLA-I molecules on melanoma cells. A comparable immunomodulatory effect was replicated by treatment of Mel cells with exogenous IFN-γ and IFN-α. The antimelanoma activity of CSPG4-CAR.CIK was successfully confirmed in vivo, obtaining a significant tumor growth inhibition of an HLA-defective Mel xenograft in immunodeficient mice.

CONCLUSIONS

In this study we reported the intense preclinical activity of CSPG4-CAR.CIK against melanoma, including those with low or defective HLA-I expression. Our findings support CSPG4 as a valuable CAR target in melanoma and provide translational rationale for clinical studies exploring CAR-CIK cellular immunotherapies within the challenging setting of patients not responsive or relapsing to immune checkpoint inhibitors.

Advances in CAR T Cell Therapy for Non-Small Cell Lung Cancer

Since its first approval by the FDA in 2017, tremendous progress has been made in chimeric antigen receptor (CAR) T cell therapy, the adoptive transfer of engineered, CAR-expressing T lymphocyte. CAR T cells are all composed of three main elements: an extracellular antigen-binding domain, an intracellular signaling domain responsible for T cell activation, and a hinge that joins these two domains. Continuous improvement has been made in CARs, now in their fifth generation, particularly in the intracellular signaling domain responsible for T cell activation. CAR T cell therapy has revolutionized the treatment of hematologic malignancies. Nonetheless, the use of CAR T cell therapy for solid tumors has not attained comparable levels of success. Here we review the challenges in achieving effective CAR T cell therapy in solid tumors, and emerging CAR T cells that have shown great promise for non-small cell lung cancer (NSCLC). A growing number of clinical trials have been conducted to study the effect of CAR T cell therapy on NSCLC, targeting different types of surface antigens. They include epidermal growth factor receptor (EGFR), mesothelin (MSLN), prostate stem cell antigen (PSCA), and mucin 1 (MUC1). Potential new targets such as erythropoietin-producing hepatocellular carcinoma A2 (EphA2), tissue factor (TF), and protein tyrosine kinase 7 (PTK7) are currently under investigation in clinical trials. The challenges in developing CAR T for NSCLC therapy and other approaches for enhancing CAR T efficacy are discussed. Finally, we provide our perspective on imaging CAR T cell action by reviewing the two main radionuclide-based CAR T cell imaging techniques, the direct labeling of CAR T cells or indirect labeling via a reporter gene.

Differences in efficacy and safety among CAR-Ts anti-CD19/CD22, anti-CD19, and anti-CD22, in adult patients with relapse/refractory B-cell acute lymphoblastic leukemia: a meta-analysis and systematic review

Relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) is a challenging disease with low rates of remission and survival in adult patients. Anti-CD19 Chimeric Antigen Receptor T-cells (CAR-Ts) therapies have been approved for these patients. Dual-target CAR-Ts against CD19 and CD22 have recently been developed to improve the efficacy of the single-target therapy; however, extent of the improvement using this dual-target therapy has yet to be determined. We performed a meta-analysis of the outcome and safety of CAR-Ts, comparing anti-CD19 vs anti-CD22 vs dual-target anti-CD19/CD22 CAR-Ts, to elucidate the differences and limitations of these therapies in adult patients with R/R B-ALL. Although the limitations of our study derived from heterogeneity in the included publications, our results suggest that anti-CD19/CD22 CAR-Ts generate lower incidence of relapse and neurotoxicity, but similar results were obtained regarding complete remission, minimal residual disease, overall survival, and cytokine release syndrome compared with single-target anti-CD19 and anti-CD22 CAR-Ts.

Tumor microenvironment-induced tumor cell plasticity: relationship with hypoxic stress and impact on tumor resistance

The role of tumor interaction with stromal components during carcinogenesis is crucial for the design of efficient cancer treatment approaches. It is widely admitted that tumor hypoxic stress is associated with tumor aggressiveness and thus impacts susceptibility and resistance to different types of treatments. Notable biological processes that hypoxia functions in include its regulation of tumor heterogeneity and plasticity. While hypoxia has been reported as a major player in tumor survival and dissemination regulation, the significance of hypoxia inducible factors in cancer stem cell development remains poorly understood. Several reports indicate that the emergence of cancer stem cells in addition to their phenotype and function within a hypoxic tumor microenvironment impacts cancer progression. In this respect, evidence showed that cancer stem cells are key elements of intratumoral heterogeneity and more importantly are responsible for tumor relapse and escape to treatments. This paper briefly reviews our current knowledge of the interaction between tumor hypoxic stress and its role in stemness acquisition and maintenance. Our review extensively covers the influence of hypoxia on the formation and maintenance of cancer stem cells and discusses the potential of targeting hypoxia-induced alterations in the expression and function of the so far known stem cell markers in cancer therapy approaches. We believe that a better and integrated understanding of the effect of hypoxia on stemness during carcinogenesis might lead to new strategies for exploiting hypoxia-associated pathways and their targeting in the clinical setting in order to overcome resistance mechanisms. More importantly, at the present time, efforts are oriented towards the design of innovative therapeutical approaches that specifically target cancer stem cells.

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies in the targeted therapy era

Hepatitis due to hepatitis B virus (HBV) reactivation can be serious and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving chemotherapy, especially rituximab-containing therapy for hematological malignancies and those receiving stem cell transplantation. Patients with inactive and even resolved HBV infection still have persistence of HBV genomes in the liver. The expression of these silent genomes is controlled by the immune system. Suppression or ablation of immune cells, most importantly B cells, may lead to reactivation of seemingly resolved HBV infection. Thus, all patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen. Patients found to be positive for HBsAg should be given prophylactic antiviral therapy. For patients with resolved HBV infection, there are two approaches. The first is pre-emptive therapy guided by serial HBV DNA monitoring, and treatment with antiviral therapy as soon as HBV DNA becomes detectable. The second approach is prophylactic antiviral therapy, particularly for patients receiving high-risk therapy, especially anti-CD20 monoclonal antibody or hematopoietic stem cell transplantation. Entecavir and tenofovir are the preferred antiviral choices. Many new effective therapies for hematological malignancies have been introduced in the past decade, for example, chimeric antigen receptor (CAR)-T cell therapy, novel monoclonal antibodies, bispecific antibody drug conjugates, and small molecule inhibitors, which may be associated with HBV reactivation. Although there is limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBsAg-positive patients receiving novel treatments, including Bruton's tyrosine kinase inhibitors, B-cell lymphoma 2 inhibitors, and CAR-T cell therapy. Further studies are needed to determine the risk of HBV reactivation with these agents and the best prophylactic strategy.

Lipid nanoparticle-mediated messenger RNA delivery for ex vivo engineering of natural killer cells

Natural killer (NK) cells participate in the immune system by eliminating cancer and virally infected cells through germline-encoded surface receptors. Their independence from prior activation as well as their significantly lower toxicity have placed them in the spotlight as an alternative to T cells for adoptive cell therapy (ACT). Engineering NK cells with mRNA has shown great potential in ACT by enhancing their tumor targeting and cytotoxicity. However, mRNA transfection of NK cells is challenging, as the most common delivery methods, such as electroporation, show limitations. Therefore, an alternative non-viral delivery system that enables high mRNA transfection efficiency with preservation of the cell viability would be beneficial for the development of NK cell therapies. In this study, we investigated both polymeric and lipid nanoparticle (LNP) formulations for eGFP-mRNA delivery to NK cells, based on a dimethylethanolamine and diethylethanolamine polymeric library and on different ionizable lipids, respectively. The mRNA nanoparticles based on cationic polymers showed limited internalization by NK cells and low transfection efficiency. On the other hand, mRNA-LNP formulations were optimized by tailoring the lipid composition and the microfluidic parameters, resulting in a high transfection efficiency (∼100%) and high protein expression in NK cells. In conclusion, compared to polyplexes and electroporation, the optimized LNPs show a greater transfection efficiency and higher overall eGFP expression, when tested in NK (KHYG-1) and T (Jurkat) cell lines, and cord blood-derived NK cells. Thus, LNP-based mRNA delivery represents a promising strategy to further develop novel NK cell therapies.

Cell-based medicinal products approved in the European Union: current evidence and perspectives

Advanced Therapy Medicinal Products (ATMPs) are innovative clinical treatments exploiting the pharmacological, immunological, or metabolic properties of cells and/or gene(s) with the aim to restore, correct, or modify a biological function in the recipient. ATMPs are heterogeneous medicinal products, developed mainly as individualized and patient-specific treatments, and represent new opportunities for diseases characterized by a high-unmet medical need, including rare, genetic and neurodegenerative disorders, haematological malignancies, cancer, autoimmune, inflammatory and orthopaedic conditions. Into the European Union (EU) market, the first ATMP has been launched in 2009 and, to date, a total of 24 ATMPs have been approved. This review aims at reporting on current evidence of cell-based therapies authorized in the EU, including Somatic Cell Therapies, Tissue Engineering Products, and Cell-based Gene Therapy Products as Chimeric Antigen Receptor (CAR) T-cells, focusing on the evaluation of efficacy and safety in clinical trials and real-world settings. Despite cell-based therapy representing a substantial promise for patients with very limited treatment options, some limitations for its widespread use in the clinical setting remain, including restricted indications, highly complex manufacturing processes, elevated production costs, the lability of cellular products over time, and the potential safety concerns related to the intrinsic characteristics of living cells, including the risk of severe or life-threatening toxicities, such as CAR-T induced neurotoxicity and cytokine release syndrome (CRS). Although encouraging findings support the clinical use of ATMPs, additional data, comparative studies with a long-term follow-up, and wider real-world evidences are needed to provide further insights into their efficacy and safety profiles.

Combination of CAR‑T cell therapy and radiotherapy: Opportunities and challenges in solid tumors (Review)

Chimeric antigen receptor (CAR) T cell therapy has emerged as a new and breakthrough cancer immunotherapy. Although CAR-T cell therapy has made significant progress clinically in patients with refractory or drug-resistant hematological malignancies, there are numerous challenges in its application to solid tumor therapy, including antigen escape, severe toxic reactions, abnormal vascularization, tumor hypoxia, insufficient infiltration of CAR-T cells and immunosuppression. As a conventional mode of anti-tumor therapy, radiotherapy has shown promising effects in combination with CAR-T cell therapy by enhancing the specific immunity of endogenous target antigens, which promoted the infiltration and expansion of CAR-T cells and improved the hypoxic tumor microenvironment. This review focuses on the obstacles to the application of CAR-T technology in solid tumor therapy, the potential opportunities and challenges of combined radiotherapy and CAR-T cell therapy, and the review of recent literature to evaluate the best combination for the treatment of solid tumors.

Targeting fibroblast activation protein (FAP): advances in CAR-T cell, antibody, and vaccine in cancer immunotherapy

Fibroblast activation protein (FAP) is a serine protease with dual enzymatic activities overexpressed in cancer-associated fibroblasts (CAFs) in several tumor types, while its expression in healthy adult tissues is scarce. FAP overexpression on CAFs is associated with poor prognosis and plays an important role in tumor development, progression, and invasion. Therefore, FAP is considered a robust therapeutic target for cancer therapy. Here, we try to review and highlight the recent advances in immunotherapies for FAP targeting including the anti-FAP antibodies and immunoconjugates, FAP chimeric antigen receptor (CAR)-T cell, and various FAP vaccines in a preclinical and clinical setting. Subsequently, a discussion on the challenges and prospects associated with the development and translation of effective and safe therapies for targeting and depletion of FAP is provided. We proposed that new CAR-T cell engineering strategies and nanotechnology-based systems as well as advanced functional biomaterials can be used to improve the efficiency and safety of CAR-T cells and vaccines against FAP for more personalized immunotherapy. This review emphasizes the immune targeting of FAP as an emerging stromal candidate and one of the crucial elements in immunotherapy and shows the potential for improvement of current cancer therapy. A summary of different immunotherapy approaches to target fibroblast activation protein (FAP) for cancer therapy.

Comprehensive clinical evaluation of CAR-T cell immunotherapy for solid tumors: a path moving forward or a dead end?

INTRODUCTION

Chimeric Antigen Receptor (CAR)-T cell therapy is a form of adoptive cell therapy that has demonstrated tremendous results in the treatment of hematopoietic malignancies, leading to the US Food and Drug Administration (FDA) approval of four CD19-targeted CAR-T cell products. With the unprecedented success of CAR-T cell therapy in hematological malignancies, hundreds of preclinical studies and clinical trials are currently undergoing to explore the translation of this treatment to solid tumors. However, the clinical experience in non-hematologic malignancies has been less encouraging, with only a few patients achieving complete responses. Tumor-associated antigen heterogeneity, inefficient CAR-T cell trafficking and the immunosuppressive tumor microenvironment are considered as the most pivotal roadblocks in solid tumor CAR-T cell therapy.

MATERIALS AND METHODS

We reviewed the relevant literature/clinical trials for CAR-T cell immunotherapy for solid tumors from Pubmed and ClinicalTrials.gov.

CONCLUSION

Herein, we provide an update on solid tumor CAR-T cell clinical trials, focusing on the studies with published results. We further discuss some of the key hurdles that CAR-T cell therapy is encountering for solid tumor treatment as well as the strategies that are exploited to overcome these obstacles.

CAR-T Cells Immunotherapies for the Treatment of Acute Myeloid Leukemia-Recent Advances

In order to increase the effectiveness of cancer therapies and extend the long-term survival of patients, more and more often, in addition to standard treatment, oncological patients receive also targeted therapy, i.e., CAR-T cells. These cells express a chimeric receptor (CAR) that specifically binds an antigen present on tumor cells, resulting in tumor cell lysis. The use of CAR-T cells in the therapy of relapsed and refractory B-type acute lymphoblastic leukemia (ALL) resulted in complete remission in many patients, which prompted researchers to conduct tests on the use of CAR-T cells in the treatment of other hematological malignancies, including acute myeloid leukemia (AML). AML is associated with a poorer prognosis compared to ALL due to a higher risk of relapse caused by the development of resistance to standard treatment. The 5-year relative survival rate in AML patients was estimated at 31.7%. The objective of the following review is to present the mechanism of action of CAR-T cells, and discuss the latest findings on the results of anti-CD33, -CD123, -FLT3 and -CLL-1 CAR-T cell therapy, the emerging challenges as well as the prospects for the future.

Applications of synthetic biology in medical and pharmaceutical fields

Synthetic biology aims to design or assemble existing bioparts or bio-components for useful bioproperties. During the past decades, progresses have been made to build delicate biocircuits, standardized biological building blocks and to develop various genomic/metabolic engineering tools and approaches. Medical and pharmaceutical demands have also pushed the development of synthetic biology, including integration of heterologous pathways into designer cells to efficiently produce medical agents, enhanced yields of natural products in cell growth media to equal or higher than that of the extracts from plants or fungi, constructions of novel genetic circuits for tumor targeting, controllable releases of therapeutic agents in response to specific biomarkers to fight diseases such as diabetes and cancers. Besides, new strategies are developed to treat complex immune diseases, infectious diseases and metabolic disorders that are hard to cure via traditional approaches. In general, synthetic biology brings new capabilities to medical and pharmaceutical researches. This review summarizes the timeline of synthetic biology developments, the past and present of synthetic biology for microbial productions of pharmaceutics, engineered cells equipped with synthetic DNA circuits for diagnosis and therapies, live and auto-assemblied biomaterials for medical treatments, cell-free synthetic biology in medical and pharmaceutical fields, and DNA engineering approaches with potentials for biomedical applications.

CAR-NKT cell therapy: a new promising paradigm of cancer immunotherapy

Today, cancer treatment is one of the fundamental problems facing clinicians and researchers worldwide. Efforts to find an excellent way to treat this illness continue, and new therapeutic strategies are developed quickly. Adoptive cell therapy (ACT) is a practical approach that has been emerged to improve clinical outcomes in cancer patients. In the ACT, one of the best ways to arm the immune cells against tumors is by employing chimeric antigen receptors (CARs) via genetic engineering. CAR equips cells to target specific antigens on tumor cells and selectively eradicate them. Researchers have achieved promising preclinical and clinical outcomes with different cells by using CARs. One of the potent immune cells that seems to be a good candidate for CAR-immune cell therapy is the Natural Killer-T (NKT) cell. NKT cells have multiple features that make them potent cells against tumors and would be a powerful replacement for T cells and natural killer (NK) cells. NKT cells are cytotoxic immune cells with various capabilities and no notable side effects on normal cells. The current study aimed to comprehensively provide the latest advances in CAR-NKT cell therapy for cancers.

A Novel Anti-CD44 Variant 3 Monoclonal Antibody C44Mab-6 Was Established for Multiple Applications

Cluster of differentiation 44 (CD44) promotes tumor progression through the recruitment of growth factors and the acquisition of stemness, invasiveness, and drug resistance. CD44 has multiple isoforms including CD44 standard (CD44s) and CD44 variants (CD44v), which have common and unique functions in tumor development. Therefore, elucidating the function of each CD44 isoform in a tumor is essential for the establishment of CD44-targeting tumor therapy. We have established various anti-CD44s and anti-CD44v monoclonal antibodies (mAbs) through the immunization of CD44v3-10-overexpressed cells. In this study, we established C₄₄Mab-6 (IgG₁, kappa), which recognized the CD44 variant 3-encoded region (CD44v3), as determined via an enzyme-linked immunosorbent assay. C₄₄Mab-6 reacted with CD44v3-10-overexpressed Chinese hamster ovary (CHO)-K1 cells (CHO/CD44v3-10) or some cancer cell lines (COLO205 and HSC-3) via flow cytometry. The apparent K_D of C₄₄Mab-6 for CHO/CD44v3-10, COLO205, and HSC-3 was 1.5 × 10^-9 M, 6.3 × 10^-9 M, and 1.9 × 10^-9 M, respectively. C₄₄Mab-6 could detect the CD44v3-10 in Western blotting and stained the formalin-fixed paraffin-embedded tumor sections in immunohistochemistry. These results indicate that C₄₄Mab-6 is useful for detecting CD44v3 in various experiments and is expected for the application of tumor diagnosis and therapy.

Immunogenic Cell Death in Hematological Malignancy Therapy

Although the curative effect of hematological malignancies has been improved in recent years, relapse or drug resistance of hematological malignancies will eventually recur. Furthermore, the microenvironment disorder is an important mechanism in the pathogenesis of hematological malignancies. Immunogenic cell death (ICD) is a unique mechanism of regulated cell death (RCD) that triggers an intact antigen-specific adaptive immune response by firing a set of danger signals or damage-associated molecular patterns (DAMPs), which is an immunotherapeutic modality with the potential for the treatment of hematological malignancies. This review summarizes the existing knowledge about the induction of ICD in hematological malignancies and the current research on combining ICD inducers with other treatment strategies for hematological malignancies.

Directed targeting of B-cell maturation antigen-specific CAR T cells by bioinformatic approaches: From in-silico to in-vitro

AIMS

Chimeric Antigen Receptor (CAR) T-cell is a breakthrough in cancer immunotherapy. The primary step of successful CAR T cell therapy is designing a specific single-chain fragment variable (scFv). This study aims to verify the designed anti-BCMA (B cell maturation antigen) CAR using bioinformatic techniques with the following experimental evaluations.

MAIN METHODS

Following the second generation of anti-BCMA CAR designing, the protein structure, function prediction, physicochemical complementarity at the ligand-receptor interface, and biding sites analysis of anti-BCMA CAR construct were confirmed using different modeling and docking server, including Expasy, I-TASSER, HDock, and PyMOL software. To generate CAR T-cells, isolated T cells were transduced. Then, anti-BCMA CAR mRNA and its surface expression were confirmed by real-time -PCR and flow cytometry methods, respectively. To evaluate the surface expression of anti-BCMA CAR, anti-(Fab')2 and anti-CD8 antibodies were employed. Finally, anti-BCMA CAR T cells were co-cultured with BCMA+/- cell lines to assess the expression of CD69 and CD107a as activation and cytotoxicity markers.

KEY FINDINGS

In-silico results approved the suitable protein folding, perfect orientation, and correct locating of functional domains at the receptor-ligand binding site. The in-vitro results confirmed high expression of scFv (89 ± 1.15% (and CD8α (54 ± 2.88%). The expression of CD69 (91.97 ± 1.7%) and CD107a (92.05 ± 1.29%) were significantly increased, indicating appropriate activation and cytotoxicity.

SIGNIFICANCE

In-silico studies before experimental assessments are crucial for state-of-art CAR designing. Highly activation and cytotoxicity of anti-BCMA CAR T-cell revealed that our CAR construct methodology would be applicable to define the road map of CAR T cell therapy.

Dynamics and specificities of T cells in cancer immunotherapy

Recent advances in cancer immunotherapy - ranging from immune-checkpoint blockade therapy to adoptive cellular therapy and vaccines - have revolutionized cancer treatment paradigms, yet the variability in clinical responses to these agents has motivated intense interest in understanding how the T cell landscape evolves with respect to response to immune intervention. Over the past decade, the advent of multidimensional single-cell technologies has provided the unprecedented ability to dissect the constellation of cell states of lymphocytes within a tumour microenvironment. In particular, the rapidly expanding capacity to definitively link intratumoural phenotypes with the antigen specificity of T cells provided by T cell receptors (TCRs) has now made it possible to focus on investigating the properties of T cells with tumour-specific reactivity. Moreover, the assessment of TCR clonality has enabled a molecular approach to track the trajectories, clonal dynamics and phenotypic changes of antitumour T cells over the course of immunotherapeutic intervention. Here, we review the current knowledge on the cellular states and antigen specificities of antitumour T cells and examine how fine characterization of T cell dynamics in patients has provided meaningful insights into the mechanisms underlying effective cancer immunotherapy. We highlight those T cell subsets associated with productive T cell responses and discuss how diverse immunotherapies might leverage the pre-existing tumour-reactive T cell pool or instruct de novo generation of antitumour specificities. Future studies aimed at elucidating the factors associated with the elicitation of productive antitumour T cell immunity are anticipated to instruct the design of more efficacious treatment strategies.

CAR-modified immune cells as a rapidly evolving approach in the context of cancer immunotherapies

Nowadays, one of the main challenges clinicians face is malignancies. Through the progression of technology in recent years, tumor nature and tumor microenvironment (TME) can be better understood. Because of immune system involvement in tumorigenesis and immune cell dysfunction in the tumor microenvironment, clinicians encounter significant challenges in patient treatment and normal function recovery. The tumor microenvironment can stop the development of tumor antigen-specific helper and cytotoxic T cells in the tumor invasion process. Tumors stimulate the production of proinflammatory and immunosuppressive factors and cells that inhibit immune responses. Despite the more successful outcomes, the current cancer therapeutic approaches, including surgery, chemotherapy, and radiotherapy, have not been effective enough for tumor eradication. Hence, developing new treatment strategies such as monoclonal antibodies, adaptive cell therapies, cancer vaccines, checkpoint inhibitors, and cytokines helps improve cancer treatment. Among adoptive cell therapies, the interaction between the immune system and malignancies and using molecular biology led to the development of chimeric antigen receptor (CAR) T cell therapy. CAR-modified immune cells are one of the modern cancer therapeutic methods with encouraging outcomes in most hematological and solid cancers. The current study aimed to discuss the structure, formation, subtypes, and application of CAR immune cells in hematologic malignancies and solid tumors.

ErbB- and MUC1-targetted CAR-T cell immunotherapy of oral squamous cell carcinoma

Chimeric antigen receptor T (CAR-T) cell therapy has shown great success in treating B cell malignancies however, there are many challenges which limit their therapeutic efficacy in solid tumours. Immunotherapy of head and neck squamous cell carcinoma (HNSCC), and in particular, oral squamous cell carcinoma (OSCC), presents a unique set of challenges including lack of consistently expressed tumour associated antigens (TAAs) and the immunosuppressive tumour microenvironment (TME). Currently, there are few clinical trials investigating the use of CAR-T cells in HNSCC/OSCC however results from trials investigating similar solid tumours, such as breast cancer, can be adopted to help evaluate the use of CAR-T in this cancer. In this review, the process of CAR-T cell engineering, and different generations of these cells will be summarised, highlighting their potential use in treating HNSCC through targeting ErbB and MUC1; TAAs highly expressed by this solid tumour. Potential strategies including combination therapy, utilising both TAA-targeting CAR-Ts and immune checkpoint inhibitors, such as PD-L1, has been discussed, in an attempt to develop synergistic anti-tumour responses. In addition to this, the use of dual-targeting CAR-T cells, synthetic NOTCH (synNOTCH) receptors and alternative non-tumour targets of the TME have been reviewed. Such combination therapies have been shown to help limit solid tumour progression and enhance both the safety and efficacy of CAR-T cell immunotherapy, which may be adopted for the treatment and management of OSCC.

Recent Emerging Immunological Treatments for Primary Brain Tumors: Focus on Chemokine-Targeting Immunotherapies

Primary brain tumors are a leading cause of death worldwide and are characterized by extraordinary heterogeneity and high invasiveness. Current drug and radiotherapy therapies combined with surgical approaches tend to increase the five-year survival of affected patients, however, the overall mortality rate remains high, thus constituting a clinical challenge for which the discovery of new therapeutic strategies is needed. In this field, novel immunotherapy approaches, aimed at overcoming the complex immunosuppressive microenvironment, could represent a new method of treatment for central nervous system (CNS) tumors. Chemokines especially are a well-defined group of proteins that were so named due to their chemotactic properties of binding their receptors. Chemokines regulate the recruitment and/or tissue retention of immune cells as well as the mobilization of tumor cells that have undergone epithelial–mesenchymal transition, promoting tumor growth. On this basis, this review focuses on the function and involvement of chemokines and their receptors in primary brain tumors, specifically examining chemokine-targeting immunotherapies as one of the most promising strategies in neuro-oncology.

Small-Molecule Compounds Boost CAR-T Cell Therapy in Hematological Malignancies

OPINION STATEMENT

Although chimeric antigen receptor T cell immunotherapy has been successfully applied in patients with hematological malignancies, several obstacles still need to be overcome, such as high relapse rates and side effects. Overcoming the limitations of CAR-T cell therapy and boosting the efficacy of CAR-T cell therapy are urgent issues that must be addressed. The exploration of small-molecule compounds in combination with CAR-T cell therapies has achieved promising success in pre-clinical and clinical studies in recent years. Protein kinase inhibitors, demethylating drugs, HDAC inhibitors, PI3K inhibitors, immunomodulatory drugs, Akt inhibitors, mTOR inhibitors, and Bcl-2 inhibitors exhibited potential synergy in combination with CAR-T cell therapy. In this review, we will discuss the recent application of these combination therapies for improved outcomes of CAR-T cell therapy.

Molecular and therapeutic effect of CRISPR in treating cancer

Cancer has become one of the common causes of mortality around the globe due to mutations in the genome which allows rapid growth of cells uncontrollably without repairing DNA errors. Cancers could arise due alterations in DNA repair mechanisms (errors in mismatch repair genes), activation of oncogenes and inactivation of tumor suppressor genes. Each cancer type is different and each individual has a unique genetic change which leads them to cancer. Studying genetic and epigenetic alterations in the genome leads to understanding the underlying features. CAR T therapy over other immunotherapies such as monoclonal antibodies, immune checkpoint inhibitors, cancer vaccines and adoptive cell therapies has been widely used to treat cancer in recent days and gene editing has now become one of the promising treatments for many genetic diseases. This tool allows scientists to change the genome by adding, removing or altering genetic material of an organism. Due to advance in genetics and novel molecular techniques such as CRISPR, TALEN these genes can be edited in such a way that their original function could be replaced which in turn improved the treatment possibilities and can be used against malignancies and even cure cancer in future along with CAR T cell therapy due to the specific recognition and attacking of tumor.

Tyrosine kinase inhibitors as potential sensitizers of adoptive T cell therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a high-incidence malignant tumor worldwide and lacks effective treatment options. Targeted drugs are the preferred recommendations for the systemic treatment of hepatocellular carcinoma. Immunotherapy is a breakthrough in the systemic treatment of malignant tumors, including HCC. However, either targeted therapy or immunotherapy alone is inefficient and has limited survival benefits on part of HCC patients. Investigations have proved that tyrosine kinase inhibitors (TKIs) have regulatory effects on the tumor microenvironment and immune response, which are potential sensitizers for immunotherapy. Herein, a combination therapy using TKIs and immunotherapy has been explored and demonstrated to improve the effectiveness of treatment. As an effective immunotherapy, adoptive T cell therapy in solid tumors is required to improve tumor infiltration and killing activity which can be possibly achieved by combination with TKIs.

Update on immunotherapy in the management of gallbladder cancer

Gallbladder cancer (GBC) is a relatively infrequent but highly lethal cancer with a poor prognosis. Management remains challenging and controversial, and most patients are diagnosed at an advanced stage. However, with the progressive advances in the use of immunotherapies, new treatment modalities are being implemented. In September 2022, the US FDA approved durvalumab (a PD-L1 inhibitor) in combination with chemotherapy for adult patients with locally advanced or metastatic GBC. This groundbreaking news is the first FDA approval for the use of immunotherapy in biliary tract cancers. This article reviews the newest advances and trials regarding immunotherapy for GBC.

Exploiting the Endogenous Ubiquitin Proteasome System in Targeted Cancer Treatment

To overcome the lack of specificity of cancer therapeutics and thus create a more potent and effective treatment, we developed a novel chimeric protein, IL2-Smurf2. Here, we describe the production of this chimeric IL2-Smurf2 protein and its variants, with inactive or over-active killing components. Using Western blots, we demonstrated the chimeric protein's ability to specifically enter target cells alone. After entering the cells, the protein showed biological activity, causing cell death that was not seen with an inactive variant, and that was shown to be apoptotic. The chimeric protein also proved to be active as an E3 ligase, as demonstrated by testing total ubiquitination levels along with targeted ubiquitination for degradation. Finally, we tested IL2-Smurf2 and its variants in an in vivo mouse model of leukemia and demonstrated its potential as a drug for the targeted treatment of cancer cells. In the course of this work, we established for the first time the feasibility of the use of Smurf2 as a killing component in chimeric targeting proteins. Utilizing the IL2 cytokine to target cells overexpressing IL-2R and Smurf2 to cause protein degradation, we were able to produce a chimeric protein with dual functionality which causes targeted cell death.

Adoptive Cell Therapy for T-Cell Malignancies

T-cell malignancies are often aggressive and associated with poor prognoses. Adoptive cell therapy has recently shown promise as a new line of therapy for patients with hematological malignancies. However, there are currently challenges in applying adoptive cell therapy to T-cell malignancies. Various approaches have been examined in preclinical and clinical studies to overcome these obstacles. This review aims to provide an overview of the recent progress on adoptive cell therapy for T-cell malignancies. The benefits and drawbacks of different types of adoptive cell therapy are discussed. The potential advantages and current applications of innate immune cell-based adoptive cell therapy for T cell malignancies are emphasized.