The human immune system is a complex network that is composed of co-inhibitory and co-stimulatory pathways to maintain homeostasis and avoid autoimmunity. In general, the immune checkpoints allow the proper immune responses against various tumors while also protecting healthy tissues. The combined use of co-inhibitory and co-stimulatory present great potential for the effectiveness of T-cell mediated antitumor immune responses and the efficacy of immunotherapy.
The inhibitory immune checkpoint receptors expressed on activated T cells and B cells play important roles in immune response regulation. The binding of these receptors with their ligands would inhibit the T-cell receptor (TCR) signaling and TCR-mediated proliferation, transcriptional activation, and cytokine production. In this case, the design of therapeutic antibodies would block the binding of receptor-ligand, resulting in promising clinical trials for tumor treatment.
As a revolutionary milestone in immuno-oncology, the development of immune checkpoint inhibitors (ICIs) aims to interrupt co-inhibitory signaling pathways to enhance the immune responses and promote immune-mediated elimination of tumor cells. In the past decades, a series of ICIs have been discovered, and the combination therapies that target multiple co-signaling pathways, as well as the tumor microenvironment, would further improve the success rate of cancer treatment.
Fig.1 Immune checkpoints in the tumor microenvironment.
Classification of Co-Inhibitory Pathways
The rapid understanding of the mechanism of action (MOA) for the co-inhibitory pathways would be helpful for human tumor treatment. Here, we describe the normal co-inhibitory pathways for our clients.
Creative Biolabs has been a long-term expert in the field of immune checkpoint inhibitors (ICIs) discovery and development. Based on our extensive experience and advanced platforms, now we can provide a series of services include but are not limited to: