title: A role for CD1d-restricted NKT cells in injury-associated T cell suppression.
abstract: Natural killer T (NKT) cells are known to modulate T cell responses during autoimmunity, tolerance, and antitumor immunity; however, their potential role in regulating the immune response to injury has not been reported. Using a murine model of burn injury, we investigated whether CD1d-restricted NKT cells played a role in the T cell suppression that occurs early after injury. A functional role for CD1d stimulation of NKT cells in the injury-related immune suppression was demonstrated by experiments in which the suppression of antigen (Ag)-specific delayed-type hypersensitivity and in vitro T cell-proliferative responses were prevented if mice were given anti-CD1d monoclonal antibody (mAb) systemically just before injury. The CD1d-NKT cell-dependent suppression of the T cell response after injury occurred in the absence of quantitative changes in NKT cells themselves or CD1d(+) Ag-presenting cells. We observed that elevated production of the immunosuppressive cytokine interleukin (IL)-4 correlated with burn-induced immune dysfunction, and we found that NKT cells but not conventional T cells were the source of IL-4 early after injury. Lastly, we observed that the injury-induced production of NKT cell-derived IL-4 could be blocked by systemic treatment of burn-injured mice with anti-CD1d mAb. Together, our results reveal a novel mechanism involving CD1d stimulation of NKT cells in the onset of T cell suppression that occurs subsequent to injury.
authors.affiliation: The Burn and Shock Trauma Institute, Department of Surgery, Loyola University Medical Center, Maywood, Illinois, USA. dfaunce@lumc.edu
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Faunce
authors.forename: Richard L
authors.initials: RL
authors.lastname: Gamelli
authors.forename: Mashkoor A
authors.initials: MA
authors.lastname: Choudhry
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Kovacs
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D018949:Antigens, CD1 / Q000502:physiology*; D055610:Antigens, CD1d; D002056:Burns / Q000276:immunology*; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007108:Immune Tolerance; D015847:Interleukin-4 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D015398:Signal Transduction; D013154:Spleen / Q000166:cytology / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D018949:Antigens, CD1; D055610:Antigens, CD1d; D015847:Interleukin-4