Rescuing APC assay on low expressing cell line fluorescence-based cell sorting

The K_V1.3 channel is a voltage-activated K⁺ channel that belongs to the Shaker-related subfamily. It plays an essential role in human T cell proliferation and activation by regulating their membrane potential and Ca²⁺ signaling. Hence, K_V1.3 is considered a promising target for treating autoimmune disorders. Additionally, K_V1.3 exhibits high expression levels in several types of cancer cells, possibly promoting cancer formation and growth, and it seems to play a role in the development of inflammation-mediated neurological disorders. Therefore, studying this ion channel and its pharmacological modulation will hopefully lead to discovering novel therapeutic agents. Consequently, having a high current expression in APC studies is fundamental for obtaining high throughput and reliability in drug screening and development.

In this report, we investigated the possibility of applying the fluorescence-activated cell sorting (FACS) method to make sure that the majority of the cell population used for APC experiments expresses the K_V1.3 channel. For this purpose, we performed cell staining using fluorescent-labelled antibodies followed by cell sorting. We demonstrated that the cell staining and sorting procedure greatly improves the success rate of APC experiments.