Benefits of using Flow Cytometry in CAR-T Cell Therapeutic Development

Adoptive cell therapy (ACT) is a personalized treatment approach against cancer.  ACT relies on genetic modification of a patient’s own T cells to target antigens selectively expressed on cancer cells. Successful applications of ACT include T cells expressing receptors of chimeric antigen receptors (CAR-T) for cancer treatment.

Chimeric antigen receptor T-cell (CAR-T) therapy involves isolation by removing healthy T cells from the blood of the patient, ex vivo culturing, then genetically modifying them to express a chimeric antigen receptor that is specific to a selected tumor (ex: CD19 in leukemias), then transfusion of autologous or allogeneic cells back  into patients where they circulate throughout the body to find and kill cells expressing that CAR-T target antigen.   Each drug is unique as it comes from an individual.  An advantage of CAR-T cell therapy is that this therapeutic can develop into persistent memory T cells that will survey the patient for possible relapse of the same cancer. Should a relapse occur, the CAR-T cells become active again and proceed to destroy the re-occurring cancer cells. Therefore, the need for long term follow-up of the patient involves monitoring the persistence of the CAR-T cells in the memory compartment of the cellular immune system. Once infused, tracking of CAR-T cells by flow cytometry requires utilization of well-characterized assays that allow for in-depth analysis of the cellular behavior of the patient’s immune cells.

Since CAR-T research focuses on various immune cell types and their behavior in cancer, flow cytometry represents a powerful and versatile technology for the interrogation of immune cell responses and their effects on cancer cells. An example of such a flow assay is the quantification and characterization of specific subsets of circulating T cells. This type of analysis provides a platform to better gauge the immunogenicity of the therapy and the ability of the immune cells to successfully identify and attack cancer cells.

The use of flow cytometry is at the forefront of this medical revolution in immuno-oncology, as an empowering and versatile technology enabling in-depth analysis of cellular behavior of CAR-T cells and their potential role in cancer biology and effective therapeutic intervention.