IL-21 Optimizes the CAR-T Cell Preparation Through Improving Lentivirus Mediated Transfection Efficiency of T Cells and Enhancing CAR-T Cell Cytotoxic Activities

An integrated perspective on measuring cytokines to inform CAR-T bioprocessing

Chimeric antigen receptor (CAR)-T cells are emerging as a generation-defining therapeutic however their manufacture remains a major barrier to meeting increased market demand. Monitoring critical quality attributes (CQAs) and critical process parameters (CPPs) during manufacture would vastly enrich acquired information related to the process and product, providing feedback to enable real-time decision making. Here we identify specific CAR-T cytokines as value-adding analytes and discuss their roles as plausible CPPs and CQAs. High sensitivity sensing technologies which can be easily integrated into manufacture workflows are essential to implement real-time monitoring of these cytokines. We therefore present biosensors as enabling technologies and evaluate recent advancements in cytokine detection in cell cultures, offering promising translatability to CAR-T biomanufacture. Finally, we outline emerging sensing technologies with future promise, and provide an overall outlook on existing gaps to implementation and the optimal sensing platform to enable cytokine monitoring in CAR-T biomanufacture.

Universal CAR 2.0 to overcome current limitations in CAR therapy

Chimeric antigen receptor (CAR) T cell therapy has effectively complemented the treatment of advanced relapsed and refractory hematological cancers. The remarkable achievements of CD19- and BCMA-CAR T therapies have raised high expectations within the fields of hematology and oncology. These groundbreaking successes are propelling a collective aspiration to extend the reach of CAR therapies beyond B-lineage malignancies. Advanced CAR technologies have created a momentum to surmount the limitations of conventional CAR concepts. Most importantly, innovations that enable combinatorial targeting to address target antigen heterogeneity, using versatile adapter CAR concepts in conjunction with recent transformative next-generation CAR design, offer the promise to overcome both the bottleneck associated with CAR manufacturing and patient-individualized treatment regimens. In this comprehensive review, we delineate the fundamental prerequisites, navigate through pivotal challenges, and elucidate strategic approaches, all aimed at paving the way for the future establishment of multitargeted immunotherapies using universal CAR technologies.

The dilemmas and possible solutions for CAR-T cell therapy application in solid tumors

Chimeric antigen receptor T (CAR-T) cell therapy, as an adoptive immunotherapy, is playing an increasingly important role in the treatment of malignant tumors. CAR-T cells are referred to as "living drugs" as they not only target tumor cells directly, but also induce long-term immune memory that has the potential to provide long-lasting protection. CD19.CAR-T cells have achieved complete response rates of over 90 % for acute lymphoblastic leukemia and over 60 % for non-Hodgkin's lymphoma. However, the response rate of CAR-T cells in the treatment of solid tumors remains extremely low and the side effects potentially severe. In this review, we discuss the limitations that the solid tumor microenvironment poses for CAR-T application and the solutions that are being developed to address these limitations, in the hope that in the near future, CAR-T cell therapy for solid tumors can attain the same success rates as are now being seen clinically for hematological malignancies.

Adoptive cell immunotherapy for breast cancer: harnessing the power of immune cells

Breast cancer is the most prevalent malignant neoplasm worldwide, necessitating the development of novel therapeutic strategies owing to the limitations posed by conventional treatment modalities. Immunotherapy is an innovative approach that has demonstrated significant efficacy in modulating a patient's innate immune system to combat tumor cells. In the era of precision medicine, adoptive immunotherapy for breast cancer has garnered widespread attention as an emerging treatment strategy, primarily encompassing cellular therapies such as tumor-infiltrating lymphocyte therapy, chimeric antigen receptor T/natural killer/M cell therapy, T cell receptor gene-engineered T cell therapy, lymphokine-activated killer cell therapy, cytokine-induced killer cell therapy, natural killer cell therapy, and γδ T cell therapy, among others. This treatment paradigm is based on the principles of immune memory and antigen specificity, involving the collection, processing, and expansion of the patient's immune cells, followed by their reintroduction into the patient's body to activate the immune system and prevent tumor recurrence and metastasis. Currently, multiple clinical trials are assessing the feasibility, effectiveness, and safety of adoptive immunotherapy in breast cancer. However, this therapeutic approach faces challenges associated with tumor heterogeneity, immune evasion, and treatment safety. This review comprehensively summarizes the latest advancements in adoptive immunotherapy for breast cancer and discusses future research directions and prospects, offering valuable guidance and insights into breast cancer immunotherapy.

Therapeutic potential of interleukin-21 in cancer

Interleukin-21 (IL-21) is an immunostimulatory cytokine which belongs to the common gamma-chain family of cytokines. It plays an import role in the development, differentiation, proliferation, and activation of immune cells, in particular T and natural killer (NK) cells. Since its discovery in 2000, IL-21 has been shown to regulate both adaptive and immune responses associates with key role in antiviral and antitumor responses. Recent advances indicate IL-21 as a promising target for cancer treatment and encouraging results were obtained in preclinical studies which investigated the potency of IL-21 alone or in combination with other therapies, including monoclonal antibodies, checkpoint inhibitory molecules, oncolytic virotherapy, and adoptive cell transfer. Furthermore, IL-21 showed antitumor effects in the treatment of patients with advanced cancer, with minimal side effects in several clinical trials. In the present review, we will outline the recent progress in IL-21 research, highlighting the potential of IL-21 based therapy as single agent or in combination with other drugs to enhance cancer treatment efficiency.

Sánchez E, Ivanova M, Pastora K, Alcántara-Sánchez C, García-Martínez J, Martín-Antonio B, Ramírez M, González-Murillo Á. Choosing T-cell sources determines CAR-T cell activity in neuroblastoma

Introduction

The clinical success of chimeric antigen receptor-modified T cells (CAR-T cells) for hematological malignancies has not been reproduced for solid tumors, partly due to the lack of cancer-type specific antigens. In this work, we used a novel combinatorial approach consisting of a versatile anti-FITC CAR-T effector cells plus an FITC-conjugated neuroblastoma (NB)-targeting linker, an FITC-conjugated monoclonal antibody (Dinutuximab) that recognizes GD2.

Methods

We compared cord blood (CB), and CD45RA-enriched peripheral blood leukapheresis product (45RA) as allogeneic sources of T cells, using peripheral blood (PB) as a control to choose the best condition for anti-FITC CAR-T production. Cells were manufactured under two cytokine conditions (IL-2 versus IL-7+IL-15+IL-21) with or without CD3/CD28 stimulation. Immune phenotype, vector copy number, and genomic integrity of the final products were determined for cell characterization and quality control assessment. Functionality and antitumor capacity of CB/45RA-derived anti-FITC CAR-T cells were analyzed in co-culture with different anti-GD2-FITC labeled NB cell lines.

Results

The IL-7+IL-15+IL-21 cocktail, in addition to co-stimulation signals, resulted in a favorable cell proliferation rate and maintained less differentiated immune phenotypes in both CB and 45RA T cells. Therefore, it was used for CAR-T cell manufacturing and further characterization. CB and CD45RA-derived anti-FITC CAR-T cells cultured with IL-7+IL-15+IL-21 retained a predominantly naïve phenotype compared with controls. In the presence of the NB-FITC targeting, CD4+ CB-derived anti-FITC CAR-T cells showed the highest values of co-stimulatory receptors OX40 and 4-1BB, and CD8+ CAR-T cells exhibited high levels of PD-1 and 4-1BB and low levels of TIM3 and OX40, compared with CAR-T cells form the other sources studied. CB-derived anti-FITC CAR-T cells released the highest amounts of cytokines (IFN-γ and TNF-α) into co-culture supernatants. The viability of NB target cells decreased to 30% when co-cultured with CB-derived CAR-T cells during 48h.

Conclusion

CB and 45RA-derived T cells may be used as allogeneic sources of T cells to produce CAR-T cells. Moreover, ex vivo culture with IL-7+IL-15+IL-21 could favor CAR-T products with a longer persistence in the host. Our strategy may complement the current use of Dinutuximab in treating NB through its combination with a targeted CAR-T cell approach.

Interleukin-21 as an adjuvant in cancer immunotherapy: Current advances and future directions

Immunotherapy has revolutionized cancer treatment. However, it's well-recognized that a considerable proportion of patients fail to benefit from immunotherapy, and to improve immunotherapy response is clinically urgent. Insufficient immune infiltration and immunosuppressive tumor microenvironments (TME) are main contributors to immunotherapy resistance. Thus sustaining functional self-renewal capacity for immune cells and subverting immune-suppressive signals are potential strategies for boosting the efficacy of immunotherapy. Interleukin-21 (IL-21), a crucial cytokine, which could enhance cytotoxic function of immune cells and reduces immunosuppressive cells enrichment in TME, shows promising orientations as an immunoadjuvant in tumor immunotherapy. This review focuses on IL-21 in cancer treatment, including function and mechanisms of IL-21, preclinical and clinical studies, and future directions for IL-21-assisted therapies.

Generation and optimization of off-the-shelf immunotherapeutics targeting TCR-Vβ2+ T cell malignancy

Current treatments for T cell malignancies encounter issues of disease relapse and off-target toxicity. Using T cell receptor (TCR)Vβ2 as a model, here we demonstrate the rapid generation of an off-the-shelf allogeneic chimeric antigen receptor (CAR)-T platform targeting the clone-specific TCR Vβ chain for malignant T cell killing while limiting normal cell destruction. Healthy donor T cells undergo CRISPR-induced TRAC, B2M and CIITA knockout to eliminate T cell-dependent graft-versus-host and host-versus-graft reactivity. Second generation 4-1BB/CD3zeta CAR containing high affinity humanized anti-Vβ scFv is expressed efficiently on donor T cells via both lentivirus and adeno-associated virus transduction with limited detectable pre-existing immunoreactivity. Our optimized CAR-T cells demonstrate specific and persistent killing of Vβ2+ Jurkat cells and Vβ2+ patient derived malignant T cells, in vitro and in vivo, without affecting normal T cells. In parallel, we generate humanized anti-Vβ2 antibody with enhanced antibody-dependent cellular cytotoxicity (ADCC) by Fc-engineering for NK cell ADCC therapy.

The Expression of LDL-R in CD8+ T Cells Serves as an Early Assessment Parameter for the Production of TCR-T Cells

BACKGROUND/AIM

The quantity and the phenotypes of desired T cell receptor engineered T (TCR-T) cells in the final cell product determine their in vivo anti-tumor efficacy. Optimization of key steps in the TCR-T cell production process, such as T cell activation, has been shown to improve cell quality.

MATERIALS AND METHODS

Using a modified TCR (mTCR) derived from mice transducing PBMCs, we assessed the proportions of low-density lipoprotein receptor (LDL-R) and mTCR expressing cells under the various activation conditions of CD3/CD28-Dynabeads or OKT3 via flow cytometry.

RESULTS

We demonstrate that the proportion of T cells expressing LDL-R post activation is positively correlated with the percentage of mTCR+CD8+ T cells with their less differentiated subtypes in the final product. In addition, we show that shifting the CD3/CD28-Dynabeads activation duration from a typical 48 h to 24 h can significantly increase the production of the desired mTCR+CD8+ T cells. Importantly, the percentages of TCR-T cells with less-differentiated phenotypes, namely mTCR central memory T cells (TCM), were found to be preserved with markedly higher efficiency when T cell activation was optimized.

CONCLUSION

Our findings suggest that the proportion of LDL-R+ T cells may serve as an early assessment parameter for evaluating TCR-T cell quality, possibly facilitating the functional and economical improvement of current adoptive therapy.

T follicular helper cells in cancer, tertiary lymphoid structures, and beyond

With the emergence and success of checkpoint blockade immunotherapy, immuno-oncology has primarily focused on CD8 T cells, whose cytotoxic programs directly target tumor cells. However, the limited response rate of current immunotherapy regimens has prompted investigation into other types of tumor-infiltrating immune cells, such as CD4 T cells and B cells, and how they interact with CD8 T cells in a coordinated network. Recent studies have demonstrated the potential therapeutic benefits of CD4 T follicular helper (TFH) cells and B cells in cancer, highlighting the important role of their crosstalk and interactions with other immune cell components in the tumor microenvironment. These interactions also occur in tumor-associated tertiary lymphoid structures (TLS), which resemble secondary lymphoid organs (SLOs) with orchestrated vascular, chemokine, and cellular infrastructures that support the developmental pathways of functional immune cells. In this review, we discuss recent breakthroughs on TFH biology and T cell-B cell interactions in tumor immunology, and their potential as novel therapeutic targets to advance cancer treatment.

PEG Gels Significantly Improve the Storage Stability of Nucleic Acid Preparations

Currently, nucleic acid preparations have gained much attention due to their unique working principle and application value. However, as macromolecular drugs, nucleic acid preparations have complex construction and poor stability. The current methods to promote stability face problems such as high cost and inconvenient operatios. In this study, the hydrophilic pharmaceutical excipient PEG was used to gelate nucleic acid preparations to avoid the random movements of liquid particles. The results showed that PEG gelation significantly improved the stability of PEI25K-based and liposome-based nucleic acid preparations, compared with nucleic acid preparations without PEG gelation. After being stored at 4 °C for 3 days, non-PEG gelled nucleic acid preparations almost lost transfection activity, while PEGylated preparations still maintained high transfection efficiency. Fluorescence experiments showed that this effect was caused by inhibiting particle aggregation. The method described in this study was simple and effective, and the materials used had good biocompatibility. It is believed that this study will contribute to the better development of gene therapy drugs.

Role of Metabolism in Adoptive T Cell Therapy: Strategies and Challenges

Significance: Immune cell therapy involves the administration of immune cells into patients, and it has emerged as one of the most common type of immunotherapy for cancer treatment. Knowledge on the biology and metabolism of the adoptively transferred immune cells and the metabolic requirements of different cell types in the tumor is fundamental for the development of immune cell therapy with higher efficacy. Recent Advances: Adoptive T cell therapy has been shown to be effective in limited types of cancer. Different types and generations of adoptive T cell therapies have evolved in the recent decade. This review covers the basic principles and development of these therapies in cancer treatment. Critical Issues: Our review provides an overview on the basic concepts on T cell metabolism and highlights the metabolic requirements of T and adoptively transferred T cells. Future Directions: Integrating the knowledge just cited will facilitate the development of strategies to maximize the expansion of adoptively transferred T cells ex vivo and in vivo and to promote their durability and antitumor effects. Antioxid. Redox Signal. 37, 1303-1324.

Combination strategies to optimize the efficacy of chimeric antigen receptor T cell therapy in haematological malignancies

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the therapeutic landscape of haematological malignancies. However, resistance and relapse remain prominent limitations, and they are related to the limited persistence and efficacy of CAR T cells, downregulation or loss of tumour antigens, intrinsic resistance of tumours to death signalling, and immune suppressive microenvironment. Rational combined modality treatments are regarded as a promising strategy to further unlock the antitumor potential of CAR T cell therapy, which can be applied before CAR T cell infusion as a conditioning regimen or in ex vivo culture settings as well as concomitant with or after CAR T cell infusion. In this review, we summarize the combinatorial strategies, including chemotherapy, radiotherapy, haematopoietic stem cell transplantation, targeted therapies and other immunotherapies, in an effort to further enhance the effectiveness of this impressive therapy and benefit more patients.

The landscape of chimeric antigen receptor T cell therapy in breast cancer: Perspectives and outlook

Chimeric antigen receptor-T (CAR-T) cell therapy is a revolutionary adoptive cell therapy, which could modify and redirect T cells to specific tumor cells. Since CAR-T cell therapy was first approved for B cell-derived malignancies in 2017, it has yielded unprecedented progress in hematological tumors and has dramatically reshaped the landscape of cancer therapy in recent years. Currently, cumulative evidence has demonstrated that CAR-T cell therapy could be a viable therapeutic strategy for solid cancers. However, owing to the immunosuppressive tumor microenvironment (TME) and heterogenous tumor antigens, the application of CAR-T cell therapy against solid cancers requires circumventing more challenging obstacles. Breast cancer is characterized by a high degree of invasiveness, malignancy, and poor prognosis. The review highlights the underlying targets of CAR-T cell therapy in breast cancer, summarizes the challenges associated with CAR-T cell therapy, and proposes the strategies to overcome these challenges, which provides a novel approach to breast cancer treatment.

Impact of Manufacturing Procedures on CAR T Cell Functionality

The field of chimeric antigen receptor (CAR) modified T cell therapy has rapidly expanded in the past few decades. As of today, there are six CAR T cell products that have been approved by the FDA: KYMRIAH (tisagenlecleucel, CD19 CAR T cells), YESCARTA (axicabtagene ciloleucel, CD19 CAR T cells), TECARTUS (brexucabtagene autoleucel, CD19 CAR T cells), BREYANZI (lisocabtagene maraleucel, CD19 CAR T cells), ABECMA (idecabtagene vicleucel, BCMA CAR T cells) and CARVYKTI (ciltacabtagene autoleucel, BCMA CAR T cells). With this clinical success, CAR T cell therapy has become one of the most promising treatment options to combat cancers. Current research efforts focus on further potentiating its efficacy in non-responding patients and solid tumor settings. To achieve this, recent evidence suggested that, apart from developing next-generation CAR T cells with additional genetic modifications, ex vivo culture conditions could significantly impact CAR T cell functionality – an often overlooked aspect during clinical translation. In this review, we focus on the ex vivo manufacturing process for CAR T cells and discuss how it impacts CAR T cell function.

The Immune Landscape of Breast Cancer: Strategies for Overcoming Immunotherapy Resistance

Simple Summary

Immunotherapy is a rapidly advancing field in breast cancer treatment, however, it encounters many obstacles that leave open gateways for breast cancer cells to resist novel immunotherapies. It is believed that the tumor microenvironment consisting of cancer, stromal, and immune cells as well as a plethora of tumor-promoting soluble factors, is responsible for the failure of therapeutic strategies in cancer, including breast tumors. Therefore, an in-depth understanding of key barriers to effective immunotherapy, focusing the research efforts on harnessing the power of the immune system, and thus, developing new strategies to overcome the resistance may contribute significantly to increase breast cancer patient survival. In this review, we discuss the latest reports regarding the strategies rendering the immunosuppressive tumor microenvironment more sensitive to immunotherapy in breast cancers, HER2-positive and triple-negative types of breast cancer, which are attractive from an immunotherapeutic point of view.

Abstract

Breast cancer (BC) has traditionally been considered to be not inherently immunogenic and insufficiently represented by immune cell infiltrates. Therefore, for a long time, it was thought that the immunotherapies targeting this type of cancer and its microenvironment were not justified and would not bring benefits for breast cancer patients. Nevertheless, to date, a considerable number of reports have indicated tumor-infiltrating lymphocytes (TILs) as a prognostic and clinically relevant biomarker in breast cancer. A high TILs expression has been demonstrated in primary tumors, of both, HER2-positive BC and triple-negative (TNBC), of patients before treatment, as well as after treatment with adjuvant and neoadjuvant chemotherapy. Another milestone was reached in advanced TNBC immunotherapy with the help of the immune checkpoint inhibitors directed against the PD-L1 molecule. Although those findings, together with the recent developments in chimeric antigen receptor T cell therapies, show immense promise for significant advancements in breast cancer treatments, there are still various obstacles to the optimal activity of immunotherapeutics in BC treatment. Of these, the immunosuppressive tumor microenvironment constitutes a key barrier that greatly hinders the success of immunotherapies in the most aggressive types of breast cancer, HER2-positive and TNBC. Therefore, the improvement of the current and the demand for the development of new immunotherapeutic strategies is strongly warranted.

Gene-Edited Interleukin CAR-T Cells Therapy in the Treatment of Malignancies: Present and Future

In recent years, chimeric antigen receptor T cells (CAR-T cells) have been faced with the problems of weak proliferation and poor persistence in the treatment of some malignancies. Researchers have been trying to perfect the function of CAR-T by genetically modifying its structure. In addition to the participation of T cell receptor (TCR) and costimulatory signals, immune cytokines also exert a decisive role in the activation and proliferation of T cells. Therefore, genetic engineering strategies were used to generate cytokines to enhance tumor killing function of CAR-T cells. When CAR-T cells are in contact with target tumor tissue, the proliferation ability and persistence of T cells can be improved by structurally or inductively releasing immunoregulatory molecules to the tumor region. There are a large number of CAR-T cells studies on gene-edited cytokines, and the most common cytokines involved are interleukins (IL-7, IL-12, IL-15, IL-18, IL-21, IL-23). Methods for the construction of gene-edited interleukin CAR-T cells include co-expression of single interleukin, two interleukin, interleukin combined with other cytokines, interleukin receptors, interleukin subunits, and fusion inverted cytokine receptors (ICR). Preclinical and clinical trials have yielded positive results, and many more are under way. By reading a large number of literatures, we summarized the functional characteristics of some members of the interleukin family related to tumor immunotherapy, and described the research status of gene-edited interleukin CAR-T cells in the treatment of malignant tumors. The objective is to explore the optimized strategy of gene edited interleukin-CAR-T cell function.