Toll-like receptor 3 ligand dampens liver inflammation by stimulating Valpha 14 invariant natural killer T cells to negatively regulate gammadeltaT cells.

Valpha14 invariant natural killer T (Valpha14iNKT) cells are at the interface between the innate and adaptive immune responses and are thus critical for providing full engagement of host defense. We investigated the role of polyriboinosinic:polycytidylic acid (poly I:C), a replication-competent viral double-stranded RNA mimic and a specific agonist that recognizes the cellular sensor Toll-like receptor 3 (TLR3), in regulating Valpha14iNKT cell activation. We established for the first time that hepatic Valpha14iNKT cells up-regulate TLR3 extracellularly after poly I:C treatment.