CD155

A Type I transmembrane glycoprotein in the immunoglobulin superfamily. CD155 has a dual role in the regulation of cancer development because it promotes cancer invasiveness and proliferation through the loss of contact inhibition but also provides a crucial direct link between intrinsic responses to cellular stress and surveillance by the immune system.

Background


An Overview of CD155

CD155 is a highly glycosylated type I transmembrane glycoprotein belonging to the immunoglobulin superfamily (IgSF) member. As an important tumor-associated protein, its aberrant expression has been confirmed by a large number of studies on tumor invasion and metastasis and the anti-tumor effect of regulating immune cells. The human CD155 molecule was first discovered by Bernhardt et al. in 1989. This molecule can mediate poliovirus (PV) invasion of the body and cause polio, hence it is named poliovirus receptor (PVR). CD155 is involved in cell proliferation, apoptosis and motor processes. IgSF member CD155 belongs to the Nectin family in adhesion molecules. It is involved in the formation of cell adhesion and adhesion junctions (AJs) and plays an important role in mediating the metastasis of malignant cells. Due to the difference between CD155 and Nectins, Takai et al. named CD155 as Necl-5 (Nectin like molecule-5) in 2003. Studies found that CD155 is also involved in the development of the embryonic nervous system.

Inhibition of CD155

TIGIT inhibitors block the binding of CD155 to TIGIT, thereby activating NK cell activity to kill tumor cells. At the same time, NK cell activation can also promote the activity of T cells.

CD155 and diseases

CD155 is expressed at low levels on a variety of normal human cells, but it is highly expressed on a variety of tumor cells. The expression distribution of CD155 molecules on cell lines has a certain regularity. CD155 is not only expressed in human B cell lines, NK cell lines, and monocyte cell lines, but also in T cell lines and megakaryocyte cell lines. Furthermore, CD155 has high levels of expression in endothelial cell lines, epithelial cell lines, epithelial cell-derived cancer cell lines, glioma cell lines, and melanoma cell lines. Therefore, CD155 can be considered as a target for treating tumors with CD155 overexpression. Binding of CD155 to TIGIT (a poliovirus receptor) inhibits NK cell activity, thereby promoting tumor cell invasion and migration.

Reference:

Gao J., Zheng Q., Xin N., Wang W., et al. (2017) CD155, an onco-immunologic molecule in human tumors. Cancer Science. 108 (10): 1934-1938.