Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4)(CD152) is a protein receptor found on T cells. Both CTLA-4 and CD28 bind to B7-1/2 on antigen-presenting cells (APCs) such as dendritic cells and B cells. CTLA-4 has been shown to bind B7-1/2 with a higher affinity than CD28 does. This means that CTLA-4 'hijacks' B7 proteins away from T cell co-stimulatory CD28 receptors, resulting in T cells remaining in a resting state.
CTLA-4 functions as an immune checkpoint and it downregulates the immune response through repression of T cell proliferation and cytokine production. Mice deficient in CTLA-4 develop spontaneous lymphoproliferative disease with multiorgan infiltration within 3–4 weeks of birth, which suggests an aberrant regulation of T cell activation or proliferation.
Cancer can arise when proteins produced by tumour cells express antigens that are not normally seen by the immune system, resulting in an immune response. Cancer cells commonly use CTLA-4 to escape the adaptive immune response and it is found on roughly one third of metastatic cancer cells.
Anti-CTLA-4 monoclonal antibodies such as Yervoy® (Ipilimumab) are used for treating cancer by blocking the inhibitory effects of CTLA-4 on T cells. Ipilimumab can be used for the treatment of melanoma on it's own or else it can be used in combination with Opdivo® (nivolumab).
By activating T cells to recognize tumor cell antigens, anti-CTLA-4 therapy has shown great therapeutic potential in the treatment of melanoma, non-small cell lung cancer, prostate cancer, renal cancer, gastroesophageal carcinoma, pancreatic cancer and many others.
Related tools for research
Related Immunology Content
- Adhesion Molecules in Atherosclerosis - ICAM1
- Adaptive Immunity
- B Cells
- Brown Fat Macrophages
- Carbon Dioxide Signalling in Immune Cells
- Cortisol and the immune response
- Chemokines & Chemokine Receptors
- Dendritic Cells
- Immunometabolism Assays
- Inflammation & Aging Review
- Inflammation & Obesity Review
- Glycolysis Assay Kits
- Heterogeneity of Type 1 diabetes in children
- Natural Killer (NK) Cells
- Natural Killer Cells & Metabolism Review
- NLRP3 Inflammasome
- Mononuclear Phagocytes Review
- Multiple Sclerosis and Stem Cells
- Platelet reactivity & Diet Review
- SOCS proteins review
- TCA assay Kits
- T Cell assay types
- T Cells & Acute Leukemia Review
- T Cells & Hepatitis Review
- T Cell Metabolism
- T Cell responses in Diabetes
- TNF alpha & Inflammation
- TLR mediated Inflammation Review
- TLR Signalling & Neurodegeneration Review
- Trauma Immunology
- Wnt Signalling Pathway in Immunity
- What is Sepsis?