PKCtheta: A potential therapeutic target for T-cell-mediated diseases.

Protein kinase (PK)Ctheta belongs to the calcium-independent novel subfamily of PKCs, which itself is a member of the cAMP-dependent, cGMP-dependent PKC kinase superfamily. As a critical regulator of T-cell receptor (TCR) signaling, PKCtheta is required for mature T-cell activation. PKCtheta regulates helper T-cell (Th)2-dependent pulmonary inflammation and airway hyperresponsiveness following immunization and lung challenge with ovalbumin in vivo, and controls Th1 cells in experimental autoimmune encephalomyelitis. Its selective role in T-cell effector function and the TCR signalosome, although not in T-cell development, makes PKCtheta an attractive therapeutic target in T-cell-mediated disease processes. This review discusses the regulation and role of PKCtheta in T-cell-mediated diseases.