Natural killer T (NKT) cells are a unique T cell subset with features of both innate and adaptive immunity. Several subsets of NKT cells exist, the most known is characterized by an invariant Valpha14-Jalpha18 T cell receptor alpha chain and a restricted Vbeta repertoire, also called invariant NKT (iNKT) cells. From a functional perspective, iNKT cells are unique given their ability to rapidly produced copious amounts of Th1, Th2 or Th17 cytokines upon recognition of cognate glycolipid ligands. A variety of microbially derived ligands have been described including glycolipids from Strep. Pneumonia or Borrelia Burgdorferi. iNKT cells also directly respond to certain cytokines such as IL-12, thereby mimicking innate cells. We have recently described an important regulatory role for iNKT cells in dampening combined gut and joint inflammation in spondyloarthritis (SpA). In men, iNKT cells are also expanded within the inflamed joint of SpA patients where they seem to undergo some degree of functional impairment by upregulation of coinhibitory molecules. Together with other regulatory T cell subsets, iNKT cells establish a naturaly regulatory feedback loop that acts to dowmodulate inflammation and aims to resolve ongoing inflammation.

Disclosure of Interest None Declared