Standardization of flow cytometric detection of antigen expression

Integrin β2 Plays a Significant Role in Therapeutic Angiogenesis Through Hematopoietic Stem Cell Transplantation

The efficacy of hematopoietic stem cell (HSC) therapy for cerebral infarction has been previously demonstrated. However, the lack of response in some patients has hindered its widespread use. To establish HSC therapy as a standard treatment, it is important to examine the causes of non-responsiveness. In this study, we aimed to identify the specifications of transplanted cells based on their therapeutic mechanisms to predict treatment success. We found that HSC therapy activates injured cerebral endothelial cells via gap junctions because cell adhesion between HSCs and the endothelium plays an essential role in cellular communication via gap junctions. The expression of the adhesion molecule integrin β2 (CD18) in CD34-positive (CD34+) cells was identified as critical for the therapeutic effect on cerebral infarction in a murine model. Cells with low CD18 expression exhibited a weaker therapeutic effect than cells with high CD18 expression, even when the same number of HSCs was administered. The expression of CD18 in CD34+ cells can be used as a specification marker for transplanted HSCs and is useful for identifying non-responders. Furthermore, quantification of CD18 expression is crucial for evaluating the cellular potential of cell-based therapies for diseases where therapeutic effects are mediated through cell adhesion.

Using Spectral Flow Cytometry for CAR T-Cell Clinical Trials: Game Changing Technologies Enabling Novel Therapies

Monitoring chimeric antigen redirected (CAR) T-cells post-infusion in clinical trials is a specialized application of flow cytometry. Unlike the CAR T-cell monitoring for individual patients conducted in clinical laboratories, the data generated during a clinical trial will be used not only to monitor the therapeutic response of a single patient, but determine the success of the therapy itself, or even of an entire class of therapeutic compounds. The data, typically acquired at multiple testing laboratories, will be compiled into a single database. The data may also be used for mathematical modeling of cellular kinetics or to identify predictive biomarkers. With the expanded context of use, a robust, standardized assay is mandatory in order to generate a valuable and reliable data set. Hence, the requirements for assay validation, traceable calibration, technology transfer, cross-instrument standardization and regulatory compliance are high.