scholarly journals Flow cytometry and pharmacokinetic studies

2019 ◽  
Vol 4 (3) ◽  
pp. IPK06
Author(s):  
Vellalore N Kakkanaiah

Biography Vellalore Kakkanaiah, PhD serves as the director of the flow cytometry group, which is part of the Biomarker Laboratories at PPD Richmond, VA. His team is focused on the development of flow cytometry methods to support drug development. Recently, his team developed a simple whole blood assay to study the cellular kinetics of CAR-T cells after adoptive cell therapy in multiple myeloma patients. Prior to joining PPD, Dr Kakkanaiah was a senior scientist at SurroMed, Inc. where he developed micro volume laser scanning cytometry assays. He earned a doctorate in immunology from Madurai Kamaraj University in India and then served as a postdoctoral fellow at Virginia Tech. His postdoctoral training involved the first identification of mature CD4-CD8 T cells by flow cytometry from the thymus of an autoimmune mouse model. He was also a fellow of the Arthritis Foundation at the UNC-Chapel Hill. Vellalore N Kakkanaiah speaks to the International Journal of Pharmacokinetics about his experience in developing flow cytometry assays for measuring cellular kinetics in adoptive cell therapies. Flow cytometry is new to bioanalysis and is being used for measuring the cellular kinetics of infused cells from adoptive cell therapy. Here, he discusses the challenges in developing flow cytometry methods for monitoring the infused CAR-T cells.

2021 ◽  
Vol 12 ◽  
Author(s):  
Ratchapong Netsrithong ◽  
Methichit Wattanapanitch

Adoptive cell therapy (ACT) using chimeric antigen receptor (CAR) T cells holds impressive clinical outcomes especially in patients who are refractory to other kinds of therapy. However, many challenges hinder its clinical applications. For example, patients who undergo chemotherapy usually have an insufficient number of autologous T cells due to lymphopenia. Long-term ex vivo expansion can result in T cell exhaustion, which reduces the effector function. There is also a batch-to-batch variation during the manufacturing process, making it difficult to standardize and validate the cell products. In addition, the process is labor-intensive and costly. Generation of universal off-the-shelf CAR T cells, which can be broadly given to any patient, prepared in advance and ready to use, would be ideal and more cost-effective. Human induced pluripotent stem cells (iPSCs) provide a renewable source of cells that can be genetically engineered and differentiated into immune cells with enhanced anti-tumor cytotoxicity. This review describes basic knowledge of T cell biology, applications in ACT, the use of iPSCs as a new source of T cells and current differentiation strategies used to generate T cells as well as recent advances in genome engineering to produce next-generation off-the-shelf T cells with improved effector functions. We also discuss challenges in the field and future perspectives toward the final universal off-the-shelf immunotherapeutic products.


Author(s):  
Christopher DeRenzo ◽  
Giedre Krenciute ◽  
Stephen Gottschalk

Adoptive cell therapy with genetically modified T cells holds the promise to improve outcomes for children with recurrent/refractory solid tumors and has the potential to reduce treatment complications for all patients. Although T cells that express chimeric antigen receptors (CARs) specific for CD19 have had remarkable success for B-cell–derived malignancies, which has led to their approval by the U.S. Food and Drug Administration, CAR T cells have been less effective for solid tumors and brain tumors. Lack of efficacy is most likely multifactorial, but heterogeneous antigen expression; limited migration of T cells to tumor sites; and the immunosuppressive, hostile tumor microenvironment have emerged as major roadblocks that must be addressed. In this review, we summarize the clinical experience with CAR T-cell therapy for pediatric solid tumors, including brain tumors. In addition, we review strategies that have been and are being developed to enhance their antitumor activity.


2022 ◽  
Vol 23 (2) ◽  
pp. 903
Author(s):  
Avinoam Reichman ◽  
Alexander Kunz ◽  
Jara J. Joedicke ◽  
Uta E. Höpken ◽  
Anna Keib ◽  
...  

Chimeric-antigen-receptor (CAR)-T-cell therapy is already widely used to treat patients who are relapsed or refractory to chemotherapy, antibodies, or stem-cell transplantation. Multiple myeloma still constitutes an incurable disease. CAR-T-cell therapy that targets BCMA (B-cell maturation antigen) is currently revolutionizing the treatment of those patients. To monitor and improve treatment outcomes, methods to detect CAR-T cells in human peripheral blood are highly desirable. In this study, three different detection reagents for staining BCMA-CAR-T cells by flow cytometry were compared. Moreover, a quantitative polymerase chain reaction (qPCR) to detect BCMA-CAR-T cells was established. By applying a cell-titration experiment of BCMA-CAR-T cells, both methods were compared head-to-head. In flow-cytometric analysis, the detection reagents used in this study could all detect BCMA-CAR-T cells at a similar level. The results of false-positive background staining differed as follows (standard deviation): the BCMA-detection reagent used on the control revealed a background staining of 0.04% (±0.02%), for the PE-labeled human BCMA peptide it was 0.25% (±0.06%) and for the polyclonal anti-human IgG antibody it was 7.2% (±9.2%). The ability to detect BCMA-CAR-T cells down to a concentration of 0.4% was similar for qPCR and flow cytometry. The qPCR could detect even lower concentrations (0.02–0.01%). In summary, BCMA-CAR-T-cell monitoring can be reliably performed by both flow cytometry and qPCR. In flow cytometry, reagents with low background staining should be preferred.


2016 ◽  
Vol 8 (7) ◽  
pp. 702-711 ◽  
Author(s):  
Chuan Jin ◽  
Grammatiki Fotaki ◽  
Mohanraj Ramachandran ◽  
Berith Nilsson ◽  
Magnus Essand ◽  
...  

2018 ◽  
Vol 10 (3) ◽  
pp. 203-16
Author(s):  
Anna Meiliana ◽  
Nurrani Mustika Dewi ◽  
Andi Wijaya

BACKGROUND: Current cancer drugs and treatments are aiming at eradicating tumor cells, but often are more toxic then effective, killing also the normal cells and not selectively the tumor cells. There is good personalized cancer therapy that involves administration to the cancer-bearing host of immune cells with direct anticancer activity, which called adoptive cell therapy (ACT). A review of the unique biology of T cell therapy and of recent clinical experience compels a reassessment of target antigens that traditionally have been viewed from the perspective of weaker immunotherapeutic modalities.CONTENT: Chimeric antigen receptors (CAR) are recombinant receptors which provide both antigen-binding and T cell-activating functions. Many kind of CARs has been reported for the past few years, targeting an array of cell surface tumor antigens. Their biologic functions have extremely changed following the introduction of tripartite receptors comprising a costimulatory domain, termed second-generation CARs. The combination of CARs with costimulatory ligands, chimeric costimulatory receptors, or cytokines can be done to further enhance T cell potency, specificity and safety. CARs reflects a new class of drugs with exciting potential for cancer immunotherapy.SUMMARY: CAR-T cells have been arising as a new modality for cancer immunotherapy because of their potent efficacy against terminal cancers. They are known to exert higher efficacy than monoclonal antibodies and antibodydrug conjugates, and act via mechanisms distinct from T cell receptor-engineered T cells. These cells are constructed by transducing genes encoding fusion proteins of cancer antigen-recognizing single-chain Fv linked to intracellular signaling domains of T cell receptors.KEYWORDS: chimeric antigen receptor, CAR T cells, adoptive cell therapy, ACT, T cell receptor, TCR, cancer, immunotherapy


2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Hiroshi Sugimoto ◽  
Susan Chen ◽  
Jean-Pierre Minembe ◽  
Johara Chouitar ◽  
Xingyue He ◽  
...  

AbstractCharacterizing in vivo cellular kinetics and biodistribution of chimeric antigen receptor T (CAR-T) cells is critical for toxicity assessment, nonclinical and clinical efficacy studies. To date, the standardized assay to characterize CAR-T cell distribution, expansion, contraction, and persistence profiles is not readily available. To overcome this limitation and increase comparability among studies, we have established a universal protocol for analysis. We established a duplexing ddPCR protocol for the CAR-T transgene and reference gene to normalize the genomic DNA input prepared from mouse blood and tissues. The high-throughput gDNA extraction method enabled highly reproducible gDNA extraction while eliminating labor-intensive steps. The investigational CAR-T cells were intravenously injected into immunodeficient mice bearing human colorectal cancer xenografts. The blood and tissue samples were collected to measure the cellular kinetics by ddPCR and flow cytometry. The standard curves were linear throughout the calibration range with acceptable intra- and inter-day precision and accuracy. The gDNA recovery study performed by spiking in the exo-gene plasmid DNA or CAR-T cells revealed that the recovery ranged from 60 to 100% in blood and tissue homogenates. The use of both units of copy/μg gDNA and copy/μL blood met the current regulatory requirement and allowed for a systematic understanding of CAR-T cell expansion and a direct comparison with the flow cytometry data. A standardized ddPCR assay, including automated gDNA extraction procedures, has been established for evaluating cellular kinetics and biodistribution in CAR-T cell therapies.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Laura Castelletti ◽  
Dannel Yeo ◽  
Nico van Zandwijk ◽  
John E. J. Rasko

AbstractMalignant mesothelioma (MM) is a treatment-resistant tumor originating in the mesothelial lining of the pleura or the abdominal cavity with very limited treatment options. More effective therapeutic approaches are urgently needed to improve the poor prognosis of MM patients. Chimeric Antigen Receptor (CAR) T cell therapy has emerged as a novel potential treatment for this incurable solid tumor. The tumor-associated antigen mesothelin (MSLN) is an attractive target for cell therapy in MM, as this antigen is expressed at high levels in the diseased pleura or peritoneum in the majority of MM patients and not (or very modestly) present in healthy tissues. Clinical trials using anti-MSLN CAR T cells in MM have shown that this potential therapeutic is relatively safe. However, efficacy remains modest, likely due to the MM tumor microenvironment (TME), which creates strong immunosuppressive conditions and thus reduces anti-MSLN CAR T cell tumor infiltration, efficacy and persistence. Various approaches to overcome these challenges are reviewed here. They include local (intratumoral) delivery of anti-MSLN CAR T cells, improved CAR design and co-stimulation, and measures to avoid T cell exhaustion. Combination therapies with checkpoint inhibitors as well as oncolytic viruses are also discussed. Preclinical studies have confirmed that increased efficacy of anti-MSLN CAR T cells is within reach and offer hope that this form of cellular immunotherapy may soon improve the prognosis of MM patients.


2021 ◽  
Vol 9 (3) ◽  
pp. e001877
Author(s):  
Irfan N Bandey ◽  
Jay R T Adolacion ◽  
Gabrielle Romain ◽  
Melisa Martinez Paniagua ◽  
Xingyue An ◽  
...  

BackgroundAdoptive cell therapy based on the infusion of chimeric antigen receptor (CAR) T cells has shown remarkable efficacy for the treatment of hematologic malignancies. The primary mechanism of action of these infused T cells is the direct killing of tumor cells expressing the cognate antigen. However, understanding why only some T cells are capable of killing, and identifying mechanisms that can improve killing has remained elusive.MethodsTo identify molecular and cellular mechanisms that can improve T-cell killing, we utilized integrated high-throughput single-cell functional profiling by microscopy, followed by robotic retrieval and transcriptional profiling.ResultsWith the aid of mathematical modeling we demonstrate that non-killer CAR T cells comprise a heterogeneous population that arise from failure in each of the discrete steps leading to the killing. Differential transcriptional single-cell profiling of killers and non-killers identified CD137 as an inducible costimulatory molecule upregulated on killer T cells. Our single-cell profiling results directly demonstrate that inducible CD137 is feature of killer (and serial killer) T cells and this marks a different subset compared with the CD107apos (degranulating) subset of CAR T cells. Ligation of the induced CD137 with CD137 ligand (CD137L) leads to younger CD19 CAR T cells with sustained killing and lower exhaustion. We genetically modified CAR T cells to co-express CD137L, in trans, and this lead to a profound improvement in anti-tumor efficacy in leukemia and refractory ovarian cancer models in mice.ConclusionsBroadly, our results illustrate that while non-killer T cells are reflective of population heterogeneity, integrated single-cell profiling can enable identification of mechanisms that can enhance the function/proliferation of killer T cells leading to direct anti-tumor benefit.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1229
Author(s):  
Ali Hosseini Rad S. M. ◽  
Joshua Colin Halpin ◽  
Mojtaba Mollaei ◽  
Samuel W. J. Smith Bell ◽  
Nattiya Hirankarn ◽  
...  

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized adoptive cell therapy with impressive therapeutic outcomes of >80% complete remission (CR) rates in some haematological malignancies. Despite this, CAR T cell therapy for the treatment of solid tumours has invariably been unsuccessful in the clinic. Immunosuppressive factors and metabolic stresses in the tumour microenvironment (TME) result in the dysfunction and exhaustion of CAR T cells. A growing body of evidence demonstrates the importance of the mitochondrial and metabolic state of CAR T cells prior to infusion into patients. The different T cell subtypes utilise distinct metabolic pathways to fulfil their energy demands associated with their function. The reprogramming of CAR T cell metabolism is a viable approach to manufacture CAR T cells with superior antitumour functions and increased longevity, whilst also facilitating their adaptation to the nutrient restricted TME. This review discusses the mitochondrial and metabolic state of T cells, and describes the potential of the latest metabolic interventions to maximise CAR T cell efficacy for solid tumours.


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