Recognition of bacterial glycosphingolipids by natural killer T cells.
Natural killer T (NKT) cells constitute a highly conserved T lymphocyte subpopulation that has the potential to regulate many types of immune responses through the rapid secretion of cytokines. NKT cells recognize glycolipids presented by CD1d, a class I-like antigen-presenting molecule. They have an invariant T-cell antigen receptor (TCR) alpha-chain, but whether this invariant TCR recognizes microbial antigens is still controversial. Here we show that most mouse and human NKT cells recognize glycosphingolipids from Sphingomonas, Gram-negative bacteria that do not contain lipopolysaccharide. NKT cells are activated in vivo after exposure to these bacterial antigens or bacteria, and mice that lack NKT cells have a marked defect in the clearance of Sphingomonas from the liver. These data suggest that NKT cells are T lymphocytes that provide an innate-type immune response to certain microorganisms through recognition by their antigen receptor, and that they might be useful in providing protection from bacteria that cannot be detected by pattern recognition receptors such as Toll-like receptor 4.
Kinjo
Yuki
Y
Division of Developmental Immunology, La Jolla Institute for Allergy and Immunology, San Diego, 10355 Science Center Drive, San Diego, California 92121, USA.
Wu
Douglass
D
Kim
Gisen
G
Xing
Guo-Wen
GW
Poles
Michael A
MA
Ho
David D
DD
Tsuji
Moriya
M
Kawahara
Kazuyoshi
K
Wong
Chi-Huey
CH
Kronenberg
Mitchell
M
D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000276:immunology*; D018949:Antigens, CD1 / Q000737:chemistry / Q000276:immunology; D055610:Antigens, CD1d; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology; D006028:Glycosphingolipids / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D006825:Hybridomas; D007694:Killer Cells, Natural / Q000276:immunology*; D008099:Liver / Q000166:cytology / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D020578:Sphingomonas / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D000942:Antigens, Bacterial; D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human; D006028:Glycosphingolipids