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.

Immune Checkpoint

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

Disclaimer: The information presented at padiracinnovation.org is compiled from sources believed to be reliable. Extensive efforts have been made to make this information as accurate and as up-to-date as possible. However, the accuracy and completeness of this information cannot be guaranteed. Despite our best efforts, this information may contain typographical errors and omissions. The contents are to be used only as a guide, and health care providers should employ sound clinical judgment in interpreting this information for individual patient care.