Immune Checkpoints
The process of immune regulation involves several pathways related to T-cell and B-cell activation, proliferation, foreign antigen elimination, and induction of tumor cell death. Cytotoxic T-lymphocyte associated protein 4 (CTLA4) is a cell-surface receptor expressed on CD4+ and CD8+ T-cells, and programmed cell death 1 (PD-1) is a cell surface receptor expressed on T-cells and pro-B-cells. Both are components of the immune checkpoint that functions in blocking the activation of a T-cell response.
Figure 1. CTLA4 receptor stimulation negatively regulates the immune system by switching off the T-cell response, preventing the further activation of the adaptive immune response by inhibiting AKT. PD-1 receptor stimulation (PD-L1 and PD-L2 expressed on Antigen-Presenting cells) negatively regulates the immune system by switching off the T-cell responseópreventing further activation of the adaptive immune response. Specific nodes in the pathway that are therapeutically actionable are noted. Click here to open a larger version of this image in a new window.
Diseases in Which Pathway is Deregulated
- Bladder cancer
- Hodgkin lymphoma
- Melanoma
- Non-small cell lung cancer
- Renal cell carcinoma
- Small cell lung cancer
Therapies That Target This Pathway
Genes Involved in the Pathway
Last Updated: May 24, 2016