Getting the message through; signal transduction and integration in T helper cell lineage commitment

Abstract

Helper T lymphocytes are master regulators of the adaptive immune response. Recent years have demonstrated the existence of four functionally distinct effector subsets: type 1, type 2, regulatory and IL-17 producing T helper cells. Manipulation of T helper cell differentiation may prove useful for effective vaccine development and treatment of allergic and autoimmune diseases. Here, I discuss which signals control T helper cell lineage commitment, how these multiple signals are integrated during the polarisation process and subsequent cross-regulatory mechanisms that effectuate lineage stabilisation, affording new insights into the role of T cell receptor-mediated and co-stimulatory signals in T helper cell polarisation and the role of suppressors of cytokine signalling (SOCS) family members in lineage stabilisation.