Immune checkpoints are important regulators for maintaining immune homeostasis and preventing autoimmunity. Targeting immune checkpoints to treat cancer has been extensively studied in the field of immuno-oncology. Although the immune checkpoint targets that have been studied the most are inhibitory pathways, identification of novel stimulatory pathways also encourage scientists to develop drugs targeting these pathways.
Immune checkpoints represent a group of extracellular membrane-binding proteins expressed on immune effector cells, such as T cells, B cells, and NK cells, which can inhibit or stimulate effector cell proliferation. They are involved in eliminating foreign pathogens while maintaining self-tolerance, playing a vital role in immunomodulation. Nowadays, the production of therapeutic antibodies designed to block or activate immune checkpoints has become a new powerful approach for the treatment of cancer and other diseases.
At Creative Bioarray, we help customers develop their immune checkpoint inhibitors, whether they are antibodies, peptides, or small molecules. We can help to design a roadmap that begins with binding assays to screen for good candidates, proceeds to interaction assays with the selected candidates, and then progresses finally to functional assays to determine immunomodulatory function. With this roadmap, we can demonstrate the binding and functional properties of your compound, as well as its potential mechanism of action.
As part of this roadmap, checkpoint inhibitors have to be tested for immunomodulatory activities using functional assays, in which Creative Bioarray has extensive expertise. In most of the experiments we performed, we begin by stimulating T cells in the presence of the checkpoint inhibitor using a variety of activating reagents. After stimulation, at least one of the following functional assays is performed: T cell proliferation assay, cytokine production assay, and T cell cytotoxicity assay. These functional assays are all provided in a high-throughput method, so multiple compound and conditions can be incorporated.
Creative Bioarray can also perform a unique immune checkpoint functional assay that uses a special reporter cell line to determine whether your inhibitor can restore immune cell function. Here, the reporter cell line expresses the checkpoint protein, while the target cell expresses its ligand. Blocking their interaction will result in the activation of the reporter cell line and the expression of luciferase. The substrate is then added to the culture to measure luciferase expression. This is an extremely reliable, high-throughput method to screen a large number of compounds for blocking activity.