Immune Checkpoint Proteins

Immune checkpoint proteins are regulators of the immune system that prevent foreign antigens and preferably the host’s immune cells from attacking, thereby regulating self-tolerance, immune homeostasis and prevent autoimmunity.

The checkpoint proteins can send two types of signals to express these immune responses

1.     Co-stimulatory checkpoints deliver positive signals to T cells following their binding to ligands and receptors on antigen-presenting cells (APCs). They can stimulate immune responses, including CD27, CD40, OX40, GITR, 4-1BB, CD28, ICOS and many more.

2.     Co-inhibitory checkpoints deliver negative signals to T cells upon interaction with their counterparts on the APCs. They can inhibit immune responses, including PD1, PD-L1, CTLA-4, VISTA, CD155/TIGIT, TIM-3, and more.

Figure 2: The main immune checkpoints that relate to T cells

In recent years, immune checkpoint proteins have attracted greater attention in cancer development since tumour cells can hijack the checkpoint proteins by stimulating the binding of immune checkpoint targets to prevent attack from the hosts immune system. Therefore, many believe that by disabling the checkpoints using immune checkpoint inhibitors, the T cells can be switched on to regulate adaptive responses to fight against cancers.

Inhibitors like anti-CTLA4 and anti-PD1 monoclonal antibodies have already demonstrated anti-tumour activities in patients. Encouraged by this early success, researchers have expanded their investigations into other immune checkpoint proteins to find better treatments of cancer.

Further developments are underway in looking at therapeutic approaches for autoimmune diseases. In autoimmune diseases, impaired tolerance leads to the pathological autoimmune conditions resulting in diseases such as systemic lupus erythematosus, rheumatoid arthritis and Sjogren’s syndrome. Emerging evidence has shown that by transferring an inhibitory signal or suppressing a stimulatory signal to gain endogenous immunosuppression is essential in autoimmune diseases management. For example, Abatacept (CTLA4-Ig), an immune checkpoint inhibitor has made major advancement in the treatment of rheumatoid arthritis patients who have failed to respond to csDMARDs or TNF-α inhibitor.

More checkpoint inhibitors and stimulators are under active development as promising targets for disease therapy and anti-cancer therapy.

Therefore, 2BScientific has partnered with established suppliers to offer an exclusive collection of immune checkpoint proteins and antibodies that includes:

• Biotinylated conjugated Checkpoint Proteins with His, Fc Tag
• Checkpoint Proteins with different His, Fc, Llama IgG2b Tags to perform variety of bioassay analysis
• Range of Antibodies for Checkpoint Inhibitor detection
• Range of Antibodies for Checkpoint Stimulator detection
• Checkpoint detection ELISA kits
• Inhibitor Screening Kits    

Next wave of Checkpoint Proteins for Cancer Immunotherapy:

Beyond well-characterised immune checkpoint proteins as described above; recent studies also identified a series of novel immune regulators. These proteins hold the promise of becoming the next wave of cancer drug targets.
 

• CD73 a novel cancer immunotherapy target