Anti-CTLA-4 Unleashing the Power of T Cells in Combination Immunotherapy

www.assaygenie.com/anti-ctla-4-unl…therapy-cf2a03/
www.cancer.gov/publications/dict…-terms/def/ctla-4
www.assaygenie.com/anti-mouse-cd80…-low-endotoxin/
www.assaygenie.com/human-cd86-phar…enie-elisa-kit/

Immune Checkpoint Inhibitors in Cancer Immunotherapy
This briefing document reviews the mechanisms of action and clinical applications of three key immune checkpoint inhibitors in cancer immunotherapy: anti-CTLA-4, anti-PD-1, and anti-PD-L1. The information is based on three articles published by Assay Genie:

Anti-CTLA-4: Unleashing the Power of T Cells in Combination Immunotherapy
Anti-PD-1: Restoring T Cell Function in Cancer Immunotherapy
Anti-PD-L1: Targeting Tumor Evasion with Immune Checkpoint Blockade
Introduction
Cancer immunotherapy harnesses the power of the immune system to fight malignancies. Immune checkpoint inhibitors are a type of immunotherapy that block proteins on immune cells that normally prevent them from attacking cancer cells. This allows the immune system to recognize and destroy cancer cells more effectively.

Key Immune Checkpoints and Their Mechanisms
1. CTLA-4 (Cytotoxic T-lymphocyte-associated protein 4):

CTLA-4 is expressed on T cells and competes with the costimulatory molecule CD28 for binding to B7 molecules (CD80 and CD86) on antigen-presenting cells (APCs).
Mechanism: CTLA-4 binding delivers an inhibitory signal, dampening the immune response and preventing autoimmunity.
Tumor Evasion: Cancer cells can overexpress CTLA-4 to suppress T cell activation and evade immune surveillance.
Anti-CTLA-4 therapy: Monoclonal antibodies like ipilimumab block CTLA-4, reactivating T cells to attack tumor cells.
Quote: "Anti-CTLA-4 antibodies work by blocking this inhibitory interaction, thereby reactivating T cells to recognize and attack tumor cells." (Anti-CTLA-4 article)
2. PD-1 (Programmed cell death protein 1):

PD-1 is an inhibitory receptor expressed on T cells.
Mechanism: Binding of its ligand PD-L1 (programmed death-ligand 1), often expressed on tumor cells, suppresses T cell activity.
Quote: "By expressing PD-L1, tumor cells engage PD-1 on T cells, effectively shutting down their activity and allowing the tumor to grow unchecked." (Anti-PD-1 article)
Anti-PD-1 therapy: Monoclonal antibodies like nivolumab and pembrolizumab block PD-1, restoring T cell function.
3. PD-L1 (Programmed death-ligand 1):

PD-L1 is a ligand for PD-1, primarily expressed on tumor and immune cells.
Mechanism: Binding to PD-1 on T cells triggers intracellular signals that suppress T cell activation and promote T cell exhaustion.
Quote: "When PD-L1 binds to the PD-1 receptor on T cells, it triggers a cascade of intracellular signals that ultimately reduce T-cell activation, proliferation, and cytokine production." (Anti-PD-L1 article)
Anti-PD-L1 therapy: Monoclonal antibodies like atezolizumab, durvalumab, and avelumab block PD-L1, preventing the inhibitory signal to T cells.
Conclusion:
Immune checkpoint inhibitors have revolutionized cancer treatment, providing durable responses and improved survival outcomes for many patients. Continued research and development of these therapies hold immense promise for the future of cancer immunotherapy.