Immune checkpoints and their modulation have become the subjects of considerable interest for immuno-oncology.
Expressed by T cells and their matching cellular partners, these proteins can be inhibitory or stimulatory. To escape destruction by the immune system, tumor cells over-express inhibitory checkpoints like PD-L1, Gal9 or HVEM, thus effectively switching off the T cells infiltrated at the tumor site.
Thus strategies for immuno-oncology can be two-fold: inhibition of checkpoint blockade to restore T cell activity, or activation of stimulatory checkpoints to stimulate T cell activity. Assessing the effect of a therapeutic antibody or a small molecule on the immune checkpoint interaction is now a major challenge for Research and Drug Discovery.