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

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