Development of a screening method to identify regulators of MICA shedding

作者：Kishikawa Takahiro; Otsuka Motoyuki^*; Ohno Motoko; Yoshikawa Takeshi; Sato Masaya; Koike Kazuhiko

来源：Biochemical and Biophysical Research Communications, 2015, 465(4): 764-768.

DOI：10.1016/j.bbrc.2015.08.081

• MICA
• Compound screening
• Shedding assay
• Reporter

Immune cells, such as natural killer (NK) cells, recognize virally infected and transformed cells, and eliminate them through the interaction between NKG2D receptors on NK cells and NKG2D ligands on pathogenic cells. Shedding of NKG2D ligands is thought to be a type of counter-mechanism employed by pathogenic cells to evade from NKG2D-mediated immune surveillance. MHC class I polypeptide-related sequence A (MICA) is a prototypical NKG2D ligand. We previously reported that, in soluble form, MICA expression levels are significantly associated with hepatitis virus-induced hepatocellular carcinoma. Here, we report a MICA shedding assay that utilizes membrane-bound MICA tagged at its N-terminus with a nano-luciferase reporter to quantify MICA shedding into culture media. Using this method, we screened a compound library and identified putative regulators of MICA shedding that have the potential to enhance the immune reaction by simultaneously increasing cell surface MICA levels and decreasing soluble MICA levels. This shedding assay may be useful for screening regulators of cell surface molecule shedding.

• 出版日期2015-10-2