Protein kinase C theta: a new essential superstar on the T-cell stage

Recent studies have identified protein kinase C theta (PKC theta), a member of the Ca2+-independent PKC family as an essential component of the T-cell synapse that cooperates with calcineurin to activate the interleukin-2 (IL -2) gene. Several selective functions of PKC theta involved in the activati on and survival of T cells are reviewed herein. Among these, the nuclear fa ctor-kappaB (NF-kappaB) signaling cascade appears to be the most critical t arget of PKC theta in the T-cell receptor/CD28 costimulatory pathway that l eads to T-cell activation.