Description: Transforming growth factor β3 (TGF-β3) is the third member of the transforming growth factor family of cytokines, which also includes TGF-β1 and -β2. These cytokines are secreted in precursor form consisting of a bioactive C-terminal domain attached to an N-terminal domain known as latency associated protein (LAP). Cleavage of LAP results in the mature protein, which functions as a disulfide-linked homodimer. As with all members of the family, TGF bet ;3 is highly conserved across species, with mouse and human TGF beta 3 demonstrating 100% sequence homology and cross-species activity.
The members of this family can be expressed by most cell types and exert pleiotropic effects, which include the suppression of B- and T-cell effector activity, mediation of tissue healing, and suppression of tumor proliferation. The promotion of CD4+CD25+ T-cell expansion is a newly discovered function of the TGF-β cytokines, and indicates an important role in the protection against autoimmunity.
