Cellular Therapeutics Research Articles

Regulatory T cells as a therapeutic approach for inflammatory bowel disease.

Foxp3+ T regulatory (Treg) cells suppress inflammation and are essential for maintaining tissue homeostasis. A growing appreciation of tissue-specific Treg functions has built interest in leveraging the endogenous suppressive mechanisms of these cells into cellular therapeutics in organ-specific diseases. Notably, Treg cells play a critical role in maintaining the intestinal environment. As a barrier site, the gut requires Treg cells to mediate interactions with the microbiota, support barrier integrity, and regulate the immune system. Without fully functional Treg cells, intestinal inflammation and microbial dysbiosis ensue. Thus, there is a particular interest in developing Treg cellular therapies for intestinal inflammatory disease, such as inflammatory bowel disease (IBD). This article reviews some of the critical pathways that are dysregulated in IBD, Treg cell mechanisms of suppression, and the efforts and approaches in the field to develop these cells as a cellular therapy for IBD.

AQAFI: a bioanalytical method for automated KPIs quantification of fluorescent images of human leukocytes and micro-nano particles.

Micro-nanoparticle and leukocyte imaging find significant applications in the areas of infectious disease diagnostics, cellular therapeutics, and biomanufacturing. Portable fluorescence microscopes have been developed for these measurements, however, quantitative assessment of the quality of images (micro-nanoparticles, and leukocytes) captured using these devices remains a challenge. Here, we present a novel method for automated quality assessment of fluorescent images (AQAFI) captured using smartphone fluorescence microscopes (SFM). AQAFI utilizes novel feature extraction methods to identify and measure multiple features of interest in leukocyte and micro-nanoparticle images. For validation of AQAFI, fluorescent particles of different diameters (8.3, 2, 1, 0.8 μm) were imaged using custom-designed SFM at a range of excitation voltages (3.8-4.5 V). Particle intensity, particle vicinity intensity, and image background noise were chosen as analytical parameters of interest and measured by the AQAFI algorithm. A control method was developed by manual calculation of these parameters using ImageJ which was subsequently used to validate the performance of the AQAFI method. For micro-nanoparticle images, correlation coefficients with R2 > 0.95 were obtained for each parameter of interest while comparing AQAFI vs. control (ImageJ). Subsequently, key performance indicators (KPIs) i.e., signal difference to noise ratio (SDNR) and contrast to noise ratio (CNR) were defined and calculated for these micro-nano particle images using both AQAFI and control methods. Finally, we tested the performance of the AQAFI method on the fluorescent images of human peripheral blood leukocytes captured using our custom SFM. Correlation coefficients of R2 = 0.99 were obtained for each parameter of interest (leukocyte intensity, vicinity intensity, background noise) calculated using AQAFI and control (ImageJ). A high correlation was also found between the CNR and SDNR values calculated using both methods. The developed AQAFI method thus presents an automated and precise way to quantify and assess the quality of fluorescent images (micro-nano particles and leukocytes) captured using portable SFMs. Similarly, this study finds broader applicability and can also be employed with benchtop microscopes for the quantitative assessment of their imaging performance.

Defined Differentiation of Human Pluripotent Stem Cells to Brain Microvascular Endothelial-Like Cells for Modeling the Blood-Brain Barrier.

The blood-brain barrier (BBB) comprises brain microvascular endothelial cells (BMECs) that form a high-resistance cellular interface that separates the blood compartment from the brain parenchyma. An intact BBB is pivotal to maintaining brain homeostasis but also impedes the entry of neurotherapeutics. There are limited options for human-specific BBB permeability testing, however. Human pluripotent stem cell models offer a powerful tool for dissecting components of this barrier in vitro, including understanding mechanisms of BBB function, and developing strategies to improve the permeability of molecular and cellular therapeutics targeting the brain. Here, we provide a detailed, step-by-step protocol for differentiation of human pluripotent stem cells (hPSCs) to cells exhibiting key characteristics of BMECs, including paracellular and transcellular transport resistance and transporter function that enable modeling the human BBB.

Human iPS Cells for Clinical Applications and Cellular Products.

Human induced pluripotent stem cells (iPSCs), since their discovery in 2007, have rapidly become a starting cell type of choice for the differentiation of many mature cell types. Their flexibility, amenability to gene editing and functional equivalence to embryonic stem cells ensured their subsequent adoption by many manufacturing processes for cellular products. In this chapter, we will discuss the process whereby iPSCs are generated, key quality control steps which should be considered during manufacturing, the application of good manufacturing practice to production processes and iPSC-derived cellular products which are already undergoing clinical trials. iPSCs provide a new avenue for the next generation of cellular therapeutics and by combining new differentiation protocols, quality control and reproducible manufacturing, iPSC-derived cellular products could provide treatments for many currently untreatable diseases, allowing the large-scale manufacture of high-quality cell therapies.

Comprehensive narrative review on the analysis of outcomes from cell transplantation clinical trials for discogenic low back pain

BackgroundIntervertebral disc (IVD) degeneration is one of the primary causes of low back pain (LBP) and despite a prominent prevalence, present treatment options remain inadequate for a large portion of LBP patients. New developments in regenerative therapeutics offer potentially powerful medical tools to modify this pathology, with specific focus on (stem) cell transplantations. Multiple clinical trials have since reported overall beneficial outcomes favoring cell therapy. Nonetheless, the significance of these improvements is often not (clearly) discussed. As such, this narrative review aims to summarize the significance of the reported improvements from human clinical trials on IVD-targeted cell therapy. MethodsThrough a comprehensive narrative review we discuss the improvements in pain, disability, quality of life, and imaging modalities and reported adverse events following cell therapy for discogenic pain. ResultsMost clinical trials were able to report clear and significant improvements in pain and disability outcomes. Imaging and quality of life improvements however were not as clearly reported but did present some enhancements for a select number of patients. Finally, whether cell therapy can outperform placebo treatment remains intangible. ConclusionsOur review highlights the clinical significance of observed trends in pain and disability improvement. Nevertheless, reporting quality was found unsatisfactory and large-scale randomized controlled studies remain small in number. Future studies and articles should put more emphasis on improvements in imaging modalities and compare outcomes to (placebo) control groups to fully elucidate the efficacy and safety of cellular therapeutics against LBP.

The consequences of recurrent genetic and epigenetic variants in human pluripotent stem cells.

It is well established that human pluripotent stem cells (hPSCs) can acquire genetic and epigenetic changes during culture invitro. Given the increasing use of hPSCs in research and therapy and the vast expansion in the number of hPSC lines available for researchers, the International Society for Stem Cell Research has recognized the need to reassess quality control standards for ensuring the genetic integrity of hPSCs. Here, we summarize current knowledge of the nature of recurrent genetic and epigenetic variants in hPSC culture, the methods for their detection, and what is known concerning their effects on cell behavior invitro or invivo. We argue that the potential consequences of low-level contamination of cell therapy products with cells bearing oncogenic variants are essentially unknown at present. We highlight the key challenges facing the field with particular reference to safety assessment of hPSC-derived cellular therapeutics.

Regenerative medicine applications: An overview of clinical trials.

Insights into the use of cellular therapeutics, extracellular vesicles (EVs), and tissue engineering strategies for regenerative medicine applications are continually emerging with a focus on personalized, patient-specific treatments. Multiple pre-clinical and clinical trials have demonstrated the strong potential of cellular therapies, such as stem cells, immune cells, and EVs, to modulate inflammatory immune responses and promote neoangiogenic regeneration in diseased organs, damaged grafts, and inflammatory diseases, including COVID-19. Over 5,000 registered clinical trials on ClinicalTrials.gov involve stem cell therapies across various organs such as lung, kidney, heart, and liver, among other applications. A vast majority of stem cell clinical trials have been focused on these therapies' safety and effectiveness. Advances in our understanding of stem cell heterogeneity, dosage specificity, and ex vivo manipulation of stem cell activity have shed light on the potential benefits of cellular therapies and supported expansion into clinical indications such as optimizing organ preservation before transplantation. Standardization of manufacturing protocols of tissue-engineered grafts is a critical first step towards the ultimate goal of whole organ engineering. Although various challenges and uncertainties are present in applying cellular and tissue engineering therapies, these fields' prospect remains promising for customized patient-specific treatments. Here we will review novel regenerative medicine applications involving cellular therapies, EVs, and tissue-engineered constructs currently investigated in the clinic to mitigate diseases and possible use of cellular therapeutics for solid organ transplantation. We will discuss how these strategies may help advance the therapeutic potential of regenerative and transplant medicine.

Multiplexed engineering and precision gene editing in cellular immunotherapy.

The advent of cellular immunotherapy in the clinic has entirely redrawn the treatment landscape for a growing number of human cancers. Genetically reprogrammed immune cells, including chimeric antigen receptor (CAR)-modified immune effector cells as well as T cell receptor (TCR) therapy, have demonstrated remarkable responses across different hard-to-treat patient populations. While these novel treatment options have had tremendous success in providing long-term remissions for a considerable fraction of treated patients, a number of challenges remain. Limited in vivo persistence and functional exhaustion of infused immune cells as well as tumor immune escape and on-target off-tumor toxicities are just some examples of the challenges which restrain the potency of today's genetically engineered cell products. Multiple engineering strategies are being explored to tackle these challenges.The advent of multiplexed precision genome editing has in recent years provided a flexible and highly modular toolkit to specifically address some of these challenges by targeted genetic interventions. This class of next-generation cellular therapeutics aims to endow engineered immune cells with enhanced functionality and shield them from immunosuppressive cues arising from intrinsic immune checkpoints as well as the hostile tumor microenvironment (TME). Previous efforts to introduce additional genetic modifications into immune cells have in large parts focused on nuclease-based tools like the CRISPR/Cas9 system or TALEN. However, nuclease-inactive platforms including base and prime editors have recently emerged and promise a potentially safer route to rewriting genetic sequences and introducing large segments of transgenic DNA without inducing double-strand breaks (DSBs). In this review, we discuss how these two exciting and emerging fields-cellular immunotherapy and precision genome editing-have co-evolved to enable a dramatic expansion in the possibilities to engineer personalized anti-cancer treatments. We will lay out how various engineering strategies in addition to nuclease-dependent and nuclease-inactive precision genome editing toolkits are increasingly being applied to overcome today's limitations to build more potent cellular therapeutics. We will reflect on how novel information-rich unbiased discovery approaches are continuously deepening our understanding of fundamental mechanisms governing tumor biology. We will conclude with a perspective of how multiplexed-engineered and gene edited cell products may upend today's treatment paradigms as they evolve into the next generation of more potent cellular immunotherapies.

Cardiovascular Complications of CD 19 Chimeric Antigen Receptor-T Cell Therapy: A Systematic Review

Corresponding Author: Muhammad Umair Mushtaq, MD Assistant Professor of Medicine Division of Hematologic Malignancies and Cellular Therapeutics University of Kansas Medical Center 2330 Shawnee Mission Parkway, Suite 210, MS 5003, Westwood, KS 66205 Email: mmushtaq@kumc.edu Background: Anti CD19 chimeric antigen receptor (CAR) T cell therapy is being utilized for the treatment of patients with refractory and relapsing hematologic malignancies with propitious results. It has resulted in a significant increase in overall survival and reduced relapse rate. However, a multitude of cardiac complications has been observed with this therapy. This systematic review aims at cardiovascular complications of CD 19 CAR-T cell therapy. Methodology: Following the preferred reporting items for systemic reviews and Meta-analysis (PRISMA) guidelines, a comprehensive literature search was performed on three databases (PubMed, Cochrane Register of Controlled Trials, and Clinicaltrials.gov) using MeSH terms and keywords for "cardiovascular complications" AND "CAR-T Cell therapy" from the date of inception to May 16, 2022. Our search produced 354 results, and duplicates were removed. After excluding irrelevant and review articles during primary and secondary screening, ten studies were included which mentioned cardiovascular side effects of CAR-T cell therapy. Results: A total of 3004 patients from ten studies were included for this systematic review. The median age of patients was 57 (2-72) years, and 62% were male. (Table 1) All included studies used CD19 CAR-T cell therapy except Qi et al. which used CD20 and CD22 in addition to CD19. Eight studies were retrospective, and two were clinical trials. As per the available data, Troponemia was the most commonly reported cardiac side effect of CART therapy with an incidence of 18.3% (n=54), followed by arrhythmias at 4.9% (n=138), new onset of congestive heart failure 4.8% (n=144), and acute coronary syndrome (ACS) 4.1% (n=11). CHF decompensation, cardiogenic shock, venous thromboembolism, and myocarditis was observed in 3.2% (n=20), 3.1% (n=76), 1.5%(n=35), 0.8% (n=4) of the patients, respectively. Cardiac arrest due to CAR-T cell therapy occurred in 1.5% (n=8) of patients, while death due to cardiac causes occurred in 1.9% (n=48) of the patients. Conclusion: The overall rate of cardiotoxicity associated with CAR-T cell therapy is low and further studies are need of the hour to consolidate these findings. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Tales, tips & teachable moments from applications support veterans

Charlotte Barker, Editor, BioInsights speaks to three Field Application Scientist Managers at Corning Life Sciences: Chris Suarez, Catherine Siler & Austin Mogen Dr Chris Suarez is the Manager of the Field Application Scientist team at Corning Life Sciences. He received his PhD in Medicinal Chemistry and Molecular Pharmacology from Purdue University working on viral production, cell line engineering, and cancer biology. Dr Suarez has held positions in academia focusing on translational research to overcome mechanisms of therapeutic resistance in breast and prostate cancer using 3D tumor organoid models. Dr Suarez works extensively with process development groups, optimizing production capabilities and cellular scale-up conditions from viral production to cellular therapeutics. In addition, he focuses on collaborations utilizing 3D technology like the Corning spheroid and Elplasia® microplates, Transwell® inserts and extracellular matrices to provide more predictive models for therapeutic response.Dr Catherine Siler is an accomplished Field Application Scientist for Corning Life Sciences, with a PhD in Biology from Johns Hopkins University. Dr Siler enables scientists and researchers in the life science industry to overcome challenges with cell culture and scale-up for clinical manufacturing of advanced therapies. She also utilizes her research and teaching experience to drive the adoption of an industry-leading global product portfolio of innovative single-use consumables for research, process development and bioprocessing applications.Dr Austin Mogen is a Field Application Scientist Manager for Western United States and Latin America at Corning Life Sciences. He received his doctorate from the University of Florida and gained industry experience as a Senior Scientist of upstream process development and manufacturing supervisor for viral vector manufacturing. In this position he focused on bioprocess development, closed system solutions for cell culture scale-up, and viral vector production. Since joining Corning Dr Mogen works extensively with academic researchers and process development groups, optimizing cell culture assays and cellular scale-up conditions for viral production, cellular therapeutics, and biologics.

Delivering the CRISPR/Cas9 system for engineering gene therapies: Recent cargo and delivery approaches for clinical translation.

Clustered Regularly Interspaced Short Palindromic Repeats associated protein 9 (CRISPR/Cas9) has transformed our ability to edit the human genome selectively. This technology has quickly become the most standardized and reproducible gene editing tool available. Catalyzing rapid advances in biomedical research and genetic engineering, the CRISPR/Cas9 system offers great potential to provide diagnostic and therapeutic options for the prevention and treatment of currently incurable single-gene and more complex human diseases. However, significant barriers to the clinical application of CRISPR/Cas9 remain. While in vitro, ex vivo, and in vivo gene editing has been demonstrated extensively in a laboratory setting, the translation to clinical studies is currently limited by shortfalls in the precision, scalability, and efficiency of delivering CRISPR/Cas9-associated reagents to their intended therapeutic targets. To overcome these challenges, recent advancements manipulate both the delivery cargo and vehicles used to transport CRISPR/Cas9 reagents. With the choice of cargo informing the delivery vehicle, both must be optimized for precision and efficiency. This review aims to summarize current bioengineering approaches to applying CRISPR/Cas9 gene editing tools towards the development of emerging cellular therapeutics, focusing on its two main engineerable components: the delivery vehicle and the gene editing cargo it carries. The contemporary barriers to biomedical applications are discussed within the context of key considerations to be made in the optimization of CRISPR/Cas9 for widespread clinical translation.

Learning from pediatric CAR-T development: insights from manufacturing unique patient doses

Chris Brown is the Director of GMP Manufacturing within the Therapeutic Cell Production Core, Seattle Children’s Therapeutics’ GMP cell manufacturing facility. He leads the facility’s manufacturing/process development team and played a key role in initial design, stand-up, and ongoing development of the TCPC facilities, team, and manufacturing methodologies. He has more than 20 years’ experience in the manufacturing of cellular products for Phase 1 and 2 clinical trials, with a focus in translating cutting-edge research into first-in-human cellular therapeutics. He joined Seattle Children’s Research Institute from the Fred Hutchinson Cancer Research Center in 2010, where he led the manufacturing team within the Cellular Production Facility cleanroom. He holds a BA in Biology from Carleton College in Northfield, Minnesota.Sean Werner is the Chief Technology Officer – Cell Processing at BioLife Solutions, a leading provider of bioproduction tools and services to the cell and gene therapy and broader biopharma markets. BioLife acquired Sexton Biotechnologies in 2021 where Sean was President of the company known for providing processing and handling solutions for the CGT industry. Sean received his PhD from Purdue University in Biology followed by post-doctoral positions at the Indiana University School of Medicine and Eli Lilly. Sean has previous experience filling various roles in the global regulatory and general management functions supporting medical devices, autologous cell therapy, and single use disposable development programs. In his 15 years working in the life science industry, he has guided pre-clinical and clinical testing and submission strategies leading to global commercialization of multiple medical devices and bioprocessing tools.

Conglomeration of T- and B-Cell Matrix Responses Determines the Potency of Human Bone Marrow Mesenchymal Stromal Cells.

Cell manufacturing facilities need to define the potency of mesenchymal stromal cells (MSCs) as cellular therapeutics in advanced clinical trials or marketing approval. Since MSCs' mechanism of action in humans is not well defined, more than a single functional property of MSCs needs to be captured as a surrogate measure of potency utilizing assay matrix technologies. However, the current limitation is the sole investigation of MSC-mediated T-cell suppression as a surrogate measure of potency. We investigated the effect of MSCs on B-cell matrix responses to be incorporated into the assay matrix potency analytical system. Our results demonstrate that MSCs inhibit B-cell differentiation and block pan-antibody secretion upon activation of B cells in the PBMCs. In contrast, MSCs are inferior in blocking B-cell matrix responses when purified B cells are used. Mechanistic analysis has demonstrated that MSC-mediated inhibition of B-cell matrix responses is non-contact dependent and Tryptophan metabolic pathway plays a major role, akin to the mechanism of MSC-mediated T-cell suppression. MSCs also inhibit both T-cell and B-cell responses when both of these lymphoid populations are concurrently activated in the PBMCs. Secretome analysis of MSC and T/B cell-activated PBMC cocultures identified direct and inverse correlative matrix signatures between humoral antibody isotypes and secretory molecules. The current analysis of the combined and concomitant investigation of T-cell and B-cell matrix responses fulfills the potency assay matrix strategy by incorporating MSCs' interaction with more than a single inflammatory immune responder.

DLL4 and VCAM1 enhance the emergence of T cell-competent hematopoietic progenitors from human pluripotent stem cells.

T cells show tremendous efficacy as cellular therapeutics. However, obtaining primary T cells from human donors is expensive and variable. Pluripotent stem cells (PSCs) have the potential to provide a renewable source of T cells, but differentiating PSCs into hematopoietic progenitors with T cell potential remains an important challenge. Here, we report an efficient serum- and feeder-free system for differentiating human PSCs into hematopoietic progenitors and T cells. This fully defined approach allowed us to study the impact of individual proteins on blood emergence and differentiation. Providing DLL4 and VCAM1 during the endothelial-to-hematopoietic transition enhanced downstream progenitor T cell output by ~80-fold. These two proteins synergized to activate notch signaling in nascent hematopoietic stem and progenitor cells, and VCAM1 additionally promoted an inflammatory transcriptional program. We also established optimized medium formulations that enabled efficient and chemically defined maturation of functional CD8αβ+, CD4−, CD3+, TCRαβ+ T cells with a diverse TCR repertoire.

CAR-T Engager proteins optimize anti-CD19 CAR-T cell therapies for lymphoma

ABSTRACT B cell lymphoma therapy has been transformed by CD19-targeting cellular therapeutics that induce high clinical response rates and impressive remissions in relapsed and refractory patients. However, approximately half of all patients who respond to CD19-directed cell therapy relapse, the majority within 6 months. One characteristic of relapse is loss or reduction of CD19 expression on malignant B cells. We designed a unique therapeutic to prevent and reverse relapses due to lost or reduced CD19 expression. This novel biologic, a CAR T Engager, binds CD20 and displays the CD19 extracellular domain. This approach increases the apparent CD19 antigen density on CD19-positive/CD20-positive lymphoma cells, and prevents antigen-loss induced relapse, as CD19 bound to CD20 remains present on the cell surface. We demonstrate that this novel therapeutic prevents and reverses lymphoma relapse in vitro and prevents CD19-negative lymphoma growth and relapse in vivo.

KIR2DS2 Expression Identifies NK Cells With Enhanced Anticancer Activity.

NK cells are promising cellular therapeutics against hematological and solid malignancies. Immunogenetic studies have identified that various activating killer cell Ig-like receptors (KIRs) are associated with cancer outcomes. Specifically, KIR2DS2 has been associated with reduced incidence of relapse following transplant in hematological malignancies and improved outcomes in solid tumors, but the mechanism remains obscure. Therefore, we investigated how KIR2DS2 expression impacts NK cell function. Using a novel flow cytometry panel, we show that human NK cells with high KIR2DS2 expression have enhanced spontaneous activation against malignant B cell lines, liver cancer cell lines, and primary chronic lymphocytic leukemia cells. Surface expression of CD16 was increased on KIR2DS2high NK cells, and, accordingly, KIR2DS2high NK cells had increased activation against lymphoma cells coated with the clinically relevant anti-CD20 Abs rituximab and obinutuzumab. Bulk RNA sequencing revealed that KIR2DS2high NK cells have upregulation of NK-mediated cytotoxicity, translation, and FCGR gene pathways. We developed a novel single-cell RNA-sequencing technique to identify KIR2DS2+ NK cells, and this confirmed that KIR2DS2 is associated with enhanced NK cell-mediated cytotoxicity. This study provides evidence that KIR2DS2 marks a population of NK cells primed for anticancer activity and indicates that KIR2DS2 is an attractive target for NK-based therapeutic strategies.

Parkin-mediated mitophagy protects against TNF-α-induced stress in bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BMSCs) have been investigated as cellular therapeutics for intervertebral disc degeneration. However, transplanted BMSCs are prone to be damaged. TNF-α is reported to extensively promote degeneration process. Nevertheless, the relationship between BMSCs senescence and TNF-α-induced stress has not been elucidated. Previous studies showed that mitophagy is a crucial factor in maintaining cellular homeostasis. Hence, we sought to clarify the role and mechanism of mitophagy in TNF-α-induced biological changes of BMSCs. Here, we found that TNF-α caused transient senescent damage in the early stage. Meanwhile, Parkin-mediated mitophagy was initiated and weakened the damage through maintaining mitochondria homeostasis. After inhibiting mitophagy by knockdown of Parkin, TNF-α irreversibly caused cellular senescence. These results suggested that Parkin-mediated mitophagy played protective role in BMSCs in response to TNF-α, which could be a crucial therapeutic target in the future.

Stem cells, cell therapies, and bioengineering in lung biology and disease 2021.

The 9th biennial conference titled "Stem Cells, Cell Therapies, and Bioengineering in Lung Biology and Diseases" was hosted virtually, due to the ongoing COVID-19 pandemic, in collaboration with the University of Vermont Larner College of Medicine, the National Heart, Lung, and Blood Institute, the Alpha-1 Foundation, the Cystic Fibrosis Foundation, and the International Society for Cell & Gene Therapy. The event was held from July 12th through 15th, 2021 with a pre-conference workshop held on July 9th. As in previous years, the objectives remained to review and discuss the status of active research areas involving stem cells (SCs), cellular therapeutics, and bioengineering as they relate to the human lung. Topics included 1) technological advancements in the in situ analysis of lung tissues, 2) new insights into stem cell signaling and plasticity in lung remodeling and regeneration, 3) the impact of extracellular matrix in stem cell regulation and airway engineering in lung regeneration, 4) differentiating and delivering stem cell therapeutics to the lung, 5) regeneration in response to viral infection, and 6) ethical development of cell-based treatments for lung diseases. This selection of topics represents some of the most dynamic and current research areas in lung biology. The virtual workshop included active discussion on state-of-the-art methods relating to the core features of the 2021 conference, including in situ proteomics, lung-on-chip, induced pluripotent stem cell (iPSC)-airway differentiation, and light sheet microscopy. The conference concluded with an open discussion to suggest funding priorities and recommendations for future research directions in basic and translational lung biology.

Abstract 5506: CD30 co-stimulatory domain enhances the efficacy of chimeric antigen receptor-engineered γδT cells

Abstract Adoptive transfer of immune killer cells genetically engineered to express chimeric antigen receptors (CARs) has demonstrated a feasible and effective approach against numerous types of cancers. Among the killer cells, γδT cells possessing a wide range of antigen-independent tumor recognition and low risk of developing GVHD offer a chance to develop CAR-engineered allogenic ‘off-the-shelf’ cellular therapeutics. Successful tumor eradication primarily depends on providing optimized signals affecting the proliferation, persistence, antitumor activity and cytokine secretion of CAR-γδT cells. We describe here a novel CD30 costimulatory domain for CAR signaling, which is known to be involved in cell anti-apoptosis, activation and proliferation. Conventional αβT cells and innate γδT cells activated by a CD30-ζ signaling-CAR displayed similar levels of cytolytic efficacies and cytokine secretion against antigen-expressing cancer cell lines as those of other CAR containing commonly used costimulatory domains CD28, CD27, 4-1BB, OX40, and ICOS. Furthermore, the third-generation CARs including the CD30 costimulatory domain retained potent antitumor efficacies independent of their position or type of partner costimulatory domain. More significantly, CAR-γδT cells containing CD30-ζ signaling revealed effective cytolytic activities against several solid cancer cell lines based on its antigen-recognizing antibody fragments. Our findings suggest that the CD30 costimulatory domain could be an attractive candidate for developing CAR-engineered killer cell therapeutics and may be applicable for the design of numerous antigen-recognizing CAR constructs, with an emphasis on targeting solid tumors. Citation Format: Hyun-Il Cho, Chung-Hyo Kang, Sang-Eun Lee, In-Sil Song, Jung-Min Ha, Seon-Duk Lee, Hyun-Jung Sohn, Tai-Gyu Kim. CD30 co-stimulatory domain enhances the efficacy of chimeric antigen receptor-engineered γδT cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5506.

Abstract 2889: Novel bispecific humanized BCMA-CD3 antibodies specifically target multiple myeloma cells

Abstract BCMA antigen is overexpressed in multiple myeloma cells and has been shown to be a promising target for novel cellular and antibody therapeutics. The humanized BCMA (clone 4C8A) antibody that effectively targeted multiple myeloma in a CAR (chimeric antigen receptor) format was used for designing several formats of bispecific BCMA-CD3 antibodies. Several different designs including univalent and bivalent BCMA-CD3 CrossMAB; triple chain BCMA-FAB-CD3 ScFv-Fc and tetravalent BCMA ScFv-CD3 ScFv-Fc antibodies were tested for affinity and binding with BCMA-positive cells and T cells. Real time cytotoxic activity (RTCA) and IFN-gamma secretion were also tested with multiple myeloma and CHO-BCMA target cells. All BCMA bispecific antibody designs demonstrated specific affinity with CHO-BCMA but not CHO cells in the nanoM range of 0.3-33 nM; all designs bound to T cells by FACS. The triple chain BCMA-FAB-CD3 ScFv-Fc designs had the highest Kd of binding with CHO-BCMA cells (Kd=0.3 nM) and with multiple myeloma MM1S, and H929 cells (0.1 and 0.3 nM, respectively). All antibodies with T cells specifically killed CHO-BCMA and multiple myeloma cells in a dose-dependent manner but not CHO or K562 cells, measured by RTCA assay. The bivalent BCMA-CD3 CrossMAB and triple chain BCMA FAB CD3scFv-Fc antibodies with T cells secreted IFN-gamma with EC50 =0.01-0.02 nM. In addition, the BCMA bispecific antibodies had high in vivo efficacy using a MM1S xenograft NSG mouse model. Significance: This data demonstrates high efficacy of novel hBCMA-CD3 antibodies with multiple myeloma cells and provides a basis for future pre-clinical and clinical development. Citation Format: Yanwei Huang, John Sienkiewicz, Jinying Sun, Liselle Guiang, Feng Li, Liming Yang, Lijun Wu, Vita M. Golubovskaya. Novel bispecific humanized BCMA-CD3 antibodies specifically target multiple myeloma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2889.