Natural killer (NK) T cells (of which type I and type II exist) are a small group of T cells in the blood that recognize and bind self- and foreign lipids.
They rapidly release cytokines that can promote or suppress different immune responses, however the regulation of these responses is not well understood.
In a study appearing online on July 19 in advance of publication in the August print issue of the Journal of Clinical Investigation, Vipin Kumar and colleagues from the Torrey Pines Institute for Molecular Studies examined the responses of these cells following their recognition of a self-glycolipid, sulfatide, and their relevance to inflammatory liver disease. They show that activation of sulfatide-reactive type II NKT cells caused recruitment of type I NKT cells into the liver in mice. These recruited type I NKT cells were anergic (ie. they were not able to mount a normal immune response against this self antigen) and as such were able to prevent experimentally-induced hepatitis in these animals.
The authors went on to show that secretion of the cytokine IL-12 by dendritic cells in the liver and interaction of these dendritic cells with type II NKT cells was able to regulate the activity of type I NKT cells. The authors suggest that this activity could be exploited for the purpose of devising therapeutic interventions for inflammatory disease, including autoimmune diseases and asthma.
TITLE: Type II NKT cell?mediated anergy induction in type I NKT cells prevents inflammatory liver disease