CD137

CD137 is a member of the tumor necrosis factor (TNF) receptor family. Its alternative names are tumor necrosis factor receptor superfamily member 9 (TNFRSF9), 4-1BB and induced by lymphocyte activation (ILA). It is currently of interest to immunologists as a co-stimulatory is_associated_with::immune checkpoint molecule.

Expression
CD137 can be expressed by activated is_associated_with::T cells, but to a larger extent on is_associated_with::CD8 than on is_associated_with::CD4 is_associated_with::T cells. In addition, CD137 expression is found on is_associated_with::dendritic cells, follicular dendritic cells, natural killer cells, granulocytes and cells of blood vessel walls at sites of is_associated_with::inflammation.

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 is_associated_with::TRAF2.