CD137


CD137 is a member of the tumor necrosis factor receptor family. Its alternative names are tumor necrosis factor receptor superfamily member 9, 4-1BB and induced by lymphocyte activation. It is of interest to immunologists as a co-stimulatory immune checkpoint molecule.

Expression

CD137 is expressed by activated T cells of both the CD4+ and CD8+ lineages. Although it is thought to function mainly in co-stimulating those cell types to support their activation by antigen presenting cells expressing its ligand, CD137 is also expressed on dendritic cells, B cells, NK cells, neutrophils and macrophages.

Specific effects on cells

The best characterized activity of CD137 is its costimulatory activity for activated T cells. Crosslinking of CD137 enhances T cell proliferation, IL-2 secretion, survival and cytolytic activity. Further, it can enhance immune activity to eliminate tumors in mice.

Interactions

CD137 has been shown to interact with TRAF2.

As a drug target

Utomilumab

targets this receptor to stimulate a more intense immune system attack on cancers. It is a fully human IgG2 monoclonal antibody. It is in early clinical trials. 5 clinical trials are active.