Belatacept in clinical and experimental transplantation - progress and promise

Belatacept is a fusion protein composed of the Fc fragment of a human IgG(1) immunoglobulin linked to the extracellular domain of cytotoxic T-lymphocyte-associated antigen 4 (CTLA4). CTLA4 is a molecule crucial for T-cell costimulation, selectively blocking the process of T-cell activation. Belatacept binds surface costimulatory ligands (CD80 and CD86) of antigen-presenting cells. Studies on nonhuman primates, as well as phase II and III clinical trials are here reviewed. Belatacept is a promising therapy in organ transplantation and in the future can be used to induce tolerance.