Why do cancer cells express PD-L1?
In addition, PD-L1 is expressed by tumor cells as an “adaptive immune mechanism” to escape anti-tumor responses . PD-L1 is associated with an immune environment rich in CD8 T cells, production of Th1 cytokines and chemical factors, as well as interferons and specific gene expression characteristics .
Do tumor cells express PD-L1?
PD-L1 also termed B7H1 or CD274, is primarily expressed by tumor cells and tumor-infiltrating immune cells (17), whereas PD-L2, also known as B7-DC or CD273, is expressed mainly by dendritic cells and macrophages (18).
What causes PD-L1 expression?
The PD–L1 adaptive expression is a consequence of the presence of tumor antigen–specific T cells that recognized the cancer cells leading to the production of interferon-γ.
Do cancer cells express PD-L1?
PD-L1 is expressed on the surface of tumor cells and it is able to bind to PD-1 on the surface of activated T cells and B cells. The binding of PD-L1 to PD-1 leads to an immunosuppressive effect and allows the tumor to evade immune destruction (Swaika et al., 2015).
What does PD-L1 stand for?
Programmed death-ligand 1 (PD-L1) is a 40kDa type 1 transmembrane protein that has been speculated to play a major role in suppressing the adaptive arm of immune systems during particular events such as pregnancy, tissue allografts, autoimmune disease and other disease states such as hepatitis.
What is PD-L1 in cancer?
A protein that acts as a kind of “brake” to keep the body’s immune responses under control. PD-L1 may be found on some normal cells and in higher-than-normal amounts on some types of cancer cells.
Is PD-L1 expressed on cancer cells?
Programmed death-ligand 1 (PD-L1) is the primary ligand of PD-1 and is constitutively expressed on antigen presenting cells, mesenchymal stem cells and bone marrow-derived mast cells. In addition, PD-L1 is also expressed on a wide range of tumor cells, including lung cancer, breast cancer and melanoma.
What types of cells express PD-L1?
PD-L1, also known as CD274 and B7-H1, is a transmembrane protein commonly expressed on the surface of antigen presenting cells and tumor cells. PD-L1 specifically binds to its receptor, PD-1, which is expressed on the surface of immune-related lymphocytes, such as T cells, B cells, and myeloid cells (11, 12).
How is PD-L1 expression measured?
PD-L1 expression is routinely measured using immunohistochemistry, an assay which stains tissue specimens according to the presence or absence of a biomarker, and how much of that biomarker is expressed (for example, darker staining indicates higher expression).
What is a high level of PD-L1?
Some cancer cells have high amounts of PDL1. This allows the cancer cells to “trick” the immune system, and avoid being attacked as foreign, harmful substances. If your cancer cells have a high amount of PDL1, you may benefit from a treatment called immunotherapy.