Cytotoxicity is one of the major defence mechanisms against both virus-infected and tumor cells. Radioactive (51)chromium ((51)Cr) release assay is a "gold standard" for assessment of natural killer (NK) cytolytic activity in vitro. Several disadvantages of this assay led us to design alternative tools based on flow cytometry analysis. Four different fluorescent dyes, calcein acetoxymethyl ester (CAM), carboxyfluorescein succinimidyl ester (CFSE), Vybrant DiO (DiO) and MitoTracker Green (MTG) were tested for labeling of NK target K-562 cells. Target staining stability, spontaneous release of fluorochromes and subsequent accumulation in bystander unstained cells were measured using fluorimetry and flow cytometry. Healthy donor peripheral blood mononuclear cells and affinity column purified NK cells were used as effectors coincubated with target K-562 cells at different E:T ratios for 3h and 90 min, respectively. Fluorescent probe 7-amino-actinomycin D was used for live and dead cell discrimination. Bland-Altman statistical method was applied to measure true agreement for all CAM-(51)Cr, CFSE-(51)Cr, DiO-(51)Cr and MTG-(51)Cr pairs analyzed. Based on the data, none of the four proposed methods can be stated equivalent to the standard (51)Cr release assay. Considering linear relationships between data obtained with four fluorochromes and (51)Cr release assay as well as linear regression analysis with R(2)=0.9393 value for CAM-(51)Cr pair, we found the CAM assay to be the most closely related to the (51)Cr assay.
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http://dx.doi.org/10.1016/j.imbio.2008.02.006 | DOI Listing |
Heliyon
September 2024
Department of Hematology-Oncology, Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, 400030, China.
The red blood cell (RBC) lifespan is a crucial indicator used in clinical diagnostics, treatment, and disease monitoring. This biomarker quantifies the duration that red blood cells (RBCs) circulate within the bloodstream after being released from the bone marrow, serving as a sensitive and direct indicator of red blood cell turnover. Conventional techniques for RBC lifespan measurement, including differential agglutination, Cr labeling, and N glycine labeling, each present their own set of challenges, such as complexity, radioactive exposure, and potential allergic reaction.
View Article and Find Full Text PDFMethods Mol Biol
April 2024
Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam, the Netherlands.
T cells are instrumental in protecting the host against invading pathogens and the development of cancer. To do so, they produce effector molecules such as granzymes, interleukins, interferons, and perforin. For the development and immunomonitoring of therapeutic applications such as cell-based therapies and vaccines, assessing T cell effector function is paramount.
View Article and Find Full Text PDFMethods Cell Biol
April 2024
Department of Pharmacology, Physiology, & Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States; Department of Microbiology & Immunology, Thomas Jefferson University, Philadelphia, PA, United States; Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States. Electronic address:
This chapter introduces four commonly used in vitro chimeric antigen receptor (CAR)-T cell cytotoxicity assays (lactate dehydrogenase release assay, Cr release assay, IncuCyte live cell killing assay, and xCELLigence real-time analysis) and provides a detailed protocol for xCELLigence real-time analysis. Focusing on in vitro assays, this chapter starts with explaining the mechanisms and discussing the utilization of each assay to quantify T-cell-induced cytotoxicity. Due to the high-throughput quantification and straightforward workflow of xCELLigence real-time analysis, a protocol entailing reagents and equipment, a 3-day step-by-step procedure, and instructions for data analysis are provided.
View Article and Find Full Text PDFFront Immunol
January 2024
Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, TX, United States.
Reliable and sensitive characterization assays are important determinants of the successful clinical translation of immunotherapies. For the assessment of cytolytic potential, the chromium 51 (Cr) release assay has long been considered the gold standard for testing effector cells. However, attaining the approvals to access and use radioactive isotopes is becoming increasingly complex, while technical aspects [i.
View Article and Find Full Text PDFJ Clin Immunol
January 2024
School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia.
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