User:HWu21/4-1BB ligand

The interaction between 4-1BB and 4-1BBL provide costimulatory signals to a variety of T cells, which can be used to discover cancer immunotherapy. The 4-1BB/4-1BBL complex together with a signal provided by a T-cell receptor can provide costimulatory signals to CD4+ and CD8+ T cells in mice, leading to the activation of CD4+ and CD8+ T cells. The activation of CD8+ T cells is essential in antitumor immunity. The 4-1BB/4-1BBL complex with the help of T-cell receptor signals can co-stimulate human CD28- T cells and trigger the increase in CD28- T cells. Unlike the activation of CD8+ T cells, the proliferation of CD28- T cells can negatively affect cancer state and other diseases. Therefore, this pathway can be targeted for immunotherapy.

The 4-1BB/4-1BBL complex consists of three monomeric 4-1BBs and a trimeric 4-1BBL. Each 4-1BB monomer binds to two 4-1BBLs via cysteine-rich domains (CRDs). The interaction between 4-1BB and the second 4-1BBL is required to stabilize their interactions.