PD-L1 TN-cyclon™ ELISA K​it

​PD-L1 is a protein molecule that has immunosuppressive functions by binding to its receptor, PD-1, which either suppresses or halts T-cell activity. While PD-L1 is normally expressed on the surface of antigen-presenting cells, it is also known to be expressed on the surface of tumor cells and non-transformed cells within the tumor microenvironment. Blocking the interaction between PD-1 and PD-L1 with immune checkpoint inhibitors has been shown to inhibit the growth of tumor cells, and the expression level of PD-L1 in tumor tissue, as well as its release into the blood, is a useful candidate biomarker for predicting efficacy.
PD-L1 is also found in serum (as soluble PD-L1) and exosomes. Exosomes, particularly in cancer, play a crucial role in mechanisms such as horizontal transmission, which is linked to cancer metastasis. Furthermore, a small amount of PD-L1 is present in the serum of healthy individuals, making it important to understand how the quantity changes when transitioning from a healthy state to cancer. This knowledge can contribute to the re-evaluation of the significance of immune checkpoints and improve the effectiveness of inhibitors.
However, since exosomes are limited in quantity and PD-L1 levels in the serum of healthy individuals are also low, it is essential to measure ultra-small amounts of PD-L1 when distinguishing between healthy individuals and early cancer patients.
The measurement of PD-L1 with this kit is based on TN-cyclon™, a proprietary technology that combines the sandwich ELISA and enzymatic cycling methods. This method enables highly sensitive quantification of human PD-L1 in samples containing serum or exosomes.