Antibody-Based CAR T Cells Produced by Lentiviral Transduction

Optimizing viral transduction in immune cell therapy manufacturing: key process design considerations

Immune cell therapies have revolutionized the treatment of cancers, autoimmune disorders, and infectious diseases. A critical step in their manufacturing is viral transduction, which enables the delivery of therapeutic genes into immune cells. However, the complexity of this process presents significant challenges for optimization and scalability. This review provides a comprehensive analysis of viral transduction process in immune cell therapy manufacturing, highlighting key design considerations to support the development of safe, effective, and scalable production methods. Additionally, it examines current technological challenges in immune cell transduction and explores future innovations poised to advance the field.

Migration Dynamics of Human NK Cell Preparations in Microchannels and Their Invasion Into Patient-Derived Tissue

Natural killer (NK) cells are characterised by their ability to attack cancer cells without prior antigen stimulation. Additionally, clinical trials revealed great potential of NK cells expressing chimeric antigen receptors (CARs). Successful anti-tumour efficacy remains limited by migration and infiltration to the tumour site by NK cell preparations, which is linked to the scarcity in the knowledge of migration dynamics and invasion potential. Here, we applied a recently reported innovative microfluidic microchannel technology to gain insight into the intrinsic motility of NK cells. We assessed the baseline activated and proliferating NK cells in direct comparison with T cells and investigated their motility patterns in the presence of tumour cells. Additionally, we performed high-resolution 4D confocal imaging in patient-derived hyperplastic lymphatic tissues to assess their invasive capacity. Our data revealed that the invasion potential of NK cells was greater than that of T cells, despite their similar velocities. The flexibility of the NK cell nucleus may have contributed to the higher invasion potential. The motility of CD19-CAR-NK cell preparations was similar to that of non-transduced NK cells in hyperplastic lymphoid tissue, with improved targeted migration in tumour tissue, suggesting the suitability of genetically engineered NK cells for difficult-to-reach tumour tissues.

Gene and Cell Therapy for Sarcomas: A Review

Background: The heterogeneity of sarcomas and resulting distinct sub-type specific characteristics, their high recurrence rates, and tendency for distant metastasis, continue to present significant challenges to providing optimal treatments. Objective: To provide a comprehensive review of current literature and clinical trials in gene and cell therapies for sarcomas. Methods: A comprehensive literature search was conducted utilizing the following databases: PubMed, Medline, Google Scholar and clinicaltrials.gov. Search terms included "gene therapy", "cell therapy", "NK cell therapy, "CAR-T therapy", "virotherapy", "sarcoma", "gene therapy", and "solid tumors". Additional sources were identified through manual searching for references of relevant studies. No language restrictions were set. The NCT number, study status, condition, and phase were noted for clinical trials. Results: There are only three gene and cell therapies for sarcomas that have been approved by a federal regulatory agency. Rexin-G: the first tumor-targeted gene therapy vector designed to target all advanced solid malignancies, including chemo-refractory osteosarcomas and soft tissue sarcomas, was approved by the Philippine FDA in 2007. Gendicine was the first oncolytic virus approved for intratumoral delivery in China in 2003. Afami-cel, an innovative chimeric antigen receptor (CAR) T cell therapy, was approved for synovial sarcoma in the United States in 2024. Other promising therapies are discussed in the text. Conclusions: The future of gene and cell therapy for sarcomas holds great promise, as research moves to late-stage clinical development. The integration of gene and cell therapies into standard sarcoma treatment protocols has the potential to significantly improve the quality of life and outcomes for patients with this rare and challenging group of cancers.

Cell-based immunotherapy in oesophageal cancer

Oesophageal cancer (EC) is among the most common illnesses globally, and its prognosis is unfavourable. Surgery, radiotherapy and chemotherapy are the primary therapy options for EC. Despite the occasional efficacy of these traditional treatment modalities, individuals with EC remain at a significant risk for local recurrence and metastasis. Consequently, innovative and efficacious medicines are required. In recent decades, clinical practice has effectively implemented cell therapy, which includes both stem cell and non-stem cell-based approaches, as an innovative tumour treatment, offering renewed hope to patients with oesophageal squamous cell carcinoma (ESCC). This paper examines the theoretical framework and contemporary advancements in cell treatment for individuals with EC. We further described current clinical studies and summarised essential data related to survival and safety assessments.

Innovative PBMC-derived humanized mouse model reveals CD8+ T cell-intrinsic regulation during antitumor immunity

The PBMC-derived humanized mouse model (PBMC model) may serve as an excellent tool in the field of immunology for both preclinical research and personalized therapeutic strategy development. However, single transplantation of complete PBMCs without modifications prevents the identification of cell type-specific factors that are potentially involved in modulating cell-intrinsic functions for the immune response. Here, we establish an innovative strategy for PBMC model generation, where two-step transplantations coupled with cell type-specific gene manipulation were conducted to evaluate the potential role of CD8+ T cell-intrinsic factors in regulating antitumor immunity toward PDX-based tumors. This method readily yields over 10 % of human CD45+ cells within the PBMCs of humanized mice with high editing efficiency of gene expression in CD8+ T cells that can be subsequently detected in the tumor microenvironment (TME). Our work provides a new method to generate a PBMC-derived humanized mouse model for investigating regulators of interest during antitumor immunity in a cell type-specific manner.

T cell receptor-directed antibody-drug conjugates for the treatment of T cell-derived cancers

T cell-derived cancers are hallmarked by heterogeneity, aggressiveness, and poor clinical outcomes. Available targeted therapies are severely limited due to a lack of target antigens that allow discrimination of malignant from healthy T cells. Here, we report a novel approach for the treatment of T cell diseases based on targeting the clonally rearranged T cell receptor displayed by the cancerous T cell population. As a proof of concept, we identified an antibody with unique specificity toward a distinct T cell receptor (TCR) and developed antibody-drug conjugates, precisely recognizing and eliminating target T cells while preserving overall T cell repertoire integrity and cellular immunity. Our anti-TCR antibody-drug conjugates demonstrated effective receptor-mediated cell internalization, associated with induction of cancer cell death with strong signs of apoptosis. Furthermore, cell proliferation-inhibiting bystander effects observed on target-negative cells may contribute to the molecules' anti-tumor properties precluding potential tumor escape mechanisms. To our knowledge, this represents the first anti-TCR antibody-drug conjugate designed as custom-tailored immunotherapy for T cell-driven pathologies.

Nanomaterials Boost CAR-T Therapy for Solid Tumors

T cell engineering, particularly via chimeric antigen receptor (CAR) modifications for enhancing tumor specificity, has shown efficacy in treating hematologic malignancies. The extension of CAR-T cell therapy to solid tumors, however, is impeded by several challenges: The absence of tumor-specific antigens, antigen heterogeneity, a complex immunosuppressive tumor microenvironment, and physical barriers to cell infiltration. Additionally, limitations in CAR-T cell manufacturing capacity and the high costs associated with these therapies restrict their widespread application. The integration of nanomaterials into CAR-T cell production and application offers a promising avenue to mitigate these challenges. Utilizing nanomaterials in the production of CAR-T cells can decrease product variability and lower production expenses, positively impacting the targeting and persistence of CAR-T cells in treatment and minimizing adverse effects. This review comprehensively evaluates the use of various nanomaterials in the production of CAR-T cells, genetic modification, and in vivo delivery. It discusses their underlying mechanisms and potential for clinical application, with a focus on improving specificity and safety in CAR-T cell therapy.

Generation of Murine Chimeric Antigen Receptor-Modified T Cells for In Vivo Studies in Syngeneic Tumor Models

CAR-T cell therapy has emerged as a potent and effective tool in the immunotherapy of refractory cancers. However, challenges exist in their clinical application, necessitating extensive preclinical research to optimize their function. Various preclinical in vitro and in vivo models have been proposed for such purpose; among which immunocompetent mouse models serve as an invaluable tool in studying host immune interactions within a more realistic simulation of the tumor milieu. We hereby describe a standardized protocol for the generation of high-titer γ-retroviral vectors through transfection of the HEK293T packaging cell line. The virus-containing supernatant is further concentrated using an inhouse concentrator solution, titrated, and applied to mouse T cells purified via a convenient and rapid method by nylon-wool columns. Using the method presented here, we were able to achieve high titer γ-retrovirus and highly pure mouse T cells with desirable CAR transduction efficiency. The mouse CAR T cells produced through this protocol demonstrate favorable CAR expression and viability, thus making them suitable for further in vitro/in vivo assays. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Production of γ-retroviral vectors from retrovirus-backbone plasmids Basic Protocol 2: Concentration of γ-retrovirus-containing supernatants Basic Protocol 3: Titration of concentrated γ-retrovirus Basic Protocol 4: Isolation and activation of mouse T cells Basic Protocol 5: Transduction of activated mouse T cells, assessment of CAR expression, and expansion of CAR T cells for further in vitro/in vivo studies Support Protocol: Surface staining of cells for flow cytometric assessment of CAR expression.

Continuous manufacturing of lentiviral vectors using a stable producer cell line in a fixed-bed bioreactor

Continuous manufacturing of lentiviral vectors (LVs) using stable producer cell lines could extend production periods, improve batch-to-batch reproducibility, and eliminate costly plasmid DNA and transfection reagents. A continuous process was established by expanding cells constitutively expressing third-generation LVs in the iCELLis Nano fixed-bed bioreactor. Fixed-bed bioreactors provide scalable expansion of adherent cells and enable a straightforward transition from traditional surface-based culture vessels. At 0.5 vessel volume per day (VVD), the short half-life of LVs resulted in a low total infectious titer at 1.36 × 104 TU cm-2. Higher perfusion rates increased titers, peaking at 7.87 × 104 TU cm-2 at 1.5 VVD. The supernatant at 0.5 VVD had a physical-to-infectious particle ratio of 659, whereas this was 166 ± 15 at 1, 1.5, and 2 VVD. Reducing the pH from 7.20 to 6.85 at 1.5 VVD improved the total infectious yield to 9.10 × 104 TU cm-2. Three independent runs at 1.5 VVD and a culture pH of 6.85 showed low batch-to-batch variability, with a coefficient of variation of 6.4% and 10.0% for total infectious and physical LV yield, respectively. This study demonstrated the manufacture of high-quality LV supernatant using a stable producer cell line that does not require induction.

Mutation-specific CAR T cells as precision therapy for IGLV3-21R110 expressing high-risk chronic lymphocytic leukemia

The concept of precision cell therapy targeting tumor-specific mutations is appealing but requires surface-exposed neoepitopes, which is a rarity in cancer. B cell receptors (BCR) of mature lymphoid malignancies are exceptional in that they harbor tumor-specific-stereotyped sequences in the form of point mutations that drive self-engagement of the BCR and autologous signaling. Here, we use a BCR light chain neoepitope defined by a characteristic point mutation (IGLV3-21R110) for selective targeting of a poor-risk subset of chronic lymphocytic leukemia (CLL) with chimeric antigen receptor (CAR) T cells. We develop murine and humanized CAR constructs expressed in T cells from healthy donors and CLL patients that eradicate IGLV3-21R110 expressing cell lines and primary CLL cells, but neither cells expressing the non-pathogenic IGLV3-21G110 light chain nor polyclonal healthy B cells. In vivo experiments confirm epitope-selective cytolysis in xenograft models in female mice using engrafted IGLV3-21R110 expressing cell lines or primary CLL cells. We further demonstrate in two humanized mouse models lack of cytotoxicity towards human B cells. These data provide the basis for advanced approaches of resistance-preventive and biomarker-guided cellular targeting of functionally relevant lymphoma driver mutations sparing normal B cells.

Automated production of gene-modified chimeric antigen receptor T cells using the Cocoon Platform

Autologous cell-based therapeutics have gained increasing attention in recent years because of their efficacy at treating diseases with limited therapeutic options. Chimeric antigen receptor (CAR) T-cell therapy has demonstrated clinical success in hematologic oncology indications, providing critically ill patients with a potentially curative therapy. Although engineered cell therapies such as CAR T cells provide new options for patients with unmet needs, the high cost and complexity of manufacturing may hinder clinical and commercial translation. The Cocoon Platform (Lonza, Basel, Switzerland) addresses many challenges, such as high labor demand, process consistency, contamination risks and scalability, by enabling efficient, functionally closed and automated production, whether at clinical or commercial scale. This platform is customizable and easy to use and requires minimal operator interaction, thereby decreasing process variability. We present two processes that demonstrate the Cocoon Platform's capabilities. We employed different T-cell activation methods-OKT3 and CD3/CD28 Dynabeads (Thermo Fisher Scientific, Waltham, MA, USA)-to generate final cellular products that meet the critical quality attributes of a clinical autologous CAR T-cell product. This study demonstrates a manufacturing solution for addressing challenges with manual methods of production and facilitating the scale-up of autologous cell therapy.

CAR-T Cell Therapy: From the Shop to Cancer Therapy

Cancer is a worldwide health problem. Nevertheless, new technologies in the immunotherapy field have emerged. Chimeric antigen receptor (CAR) technology is a novel biological form to treat cancer; CAR-T cell genetic engineering has positively revolutionized cancer immunotherapy. In this paper, we review the latest developments in CAR-T in cancer treatment. We present the structure of the different generations and variants of CAR-T cells including TRUCK (T cells redirected for universal cytokine killing. We explain the approaches of the CAR-T cells manufactured ex vivo and in vivo. Moreover, we describe the limitations and areas of opportunity for this immunotherapy and the current challenges of treating hematological and solid cancer using CAR-T technology as well as its constraints and engineering approaches. We summarize other immune cells that have been using CAR technology, such as natural killer (NK), macrophages (M), and dendritic cells (DC). We conclude that CAR-T cells have the potential to treat not only cancer but other chronic diseases.

Engagement of an optimized lentiviral vector enhances the expression and cytotoxicity of CAR in human NK cells

Adoptive chimeric antigen receptor (CAR)-modified T or NK cells (CAR-T/NK) have emerged as a novel form of disease treatment. Lentiviral vectors (LVs) are commonly employed to engineer NK cells for the efficient expression of CARs. This study reported the influence of single-promoter and dual-promoter LVs on the CAR expression and cytotoxicity of engineered NK cells. We constructed a third-generation NKG2D-based CAR that kills cancer cells by targeting up to eight stress-induced ligands (NKG2DLs). Our results demonstrated that the CAR exhibits both a higher expression level and a higher coexpression concordance with the GFP reporter in HEK-293T or NK92 cells by utilizing the optimized single-promoter pCDHsp rather than the original dual-promoter pCDHdp. After puromycin selection, the pCDHsp produces robust CAR expression and enhanced in vitro cytotoxicity of engineered NK cells. Therefore, infection with a single-promoter pCDHsp lentivector is recommended to prepare CAR-engineered NK cells. This research helps to optimize the production of CAR-NK cells and enhance their functional activity, to provide CAR-NK cell products with better and more uniform quality.

Antigen-Multimers: Specific, Sensitive, Precise, and Multifunctional High-Avidity CAR-Staining Reagents

Although chimeric antigen receptor (CAR) T-cell therapy has transformed cancer treatment, high-quality and universal CAR-staining reagents are urgently required to manufacture CAR T cells, predict therapy response, decipher CAR biology, and engineer new CARs. Here, we developed tetrameric and dodecameric forms of a multifunctional and extensible category of high-avidity CAR-staining reagents: antigen-multimers. Antigen-multimers detected CARs against CD19, HER2, and Tn-glycoside with significantly higher specificity, sensitivity, and precision than existing reagents. In addition to accurate CAR T-cell detection by flow cytometry, antigen-multimers also enabled ≥100-fold magnetic enrichment of rare CAR T cells, selective CAR T-cell stimulation, and high-dimensional CAR T-cell profiling by single-cell multi-omics analyses. Finally, antigen-multimers accurately captured clinical anti-CD19 CAR T cells from patients' cellular infusion products, post-infusion peripheral blood, and tumor biopsies. Antigen-multimers can be readily extended to other CAR systems by switching its antigen ligand. As such, antigen-multimers have broad clinical and research applications.