Portal de Periódicos da CAPES

Crucial amino acid residues of mouse CD1d for glycolipid ligand presentation to Vα14 NKT cells

2001; Oxford University Press; Volume: 13; Issue: 7 Linguagem: Inglês

10.1093/intimm/13.7.853

1460-2377

Noriaki Kamada, Hiroshi Iijima, Kaname Kimura, Michishige Harada, Eiji Shimizu, Shinichiro Motohashi, Tetsu Kawano, Hiroshi Shinkai, Toshinori Nakayama, Teruyuki Sakai, Laurent Brossay, Mitchell Kronenberg, Masaru Taniguchi,

T-cell and B-cell Immunology

A novel lymphocyte, NKT cells bearing an invariant Vα14 antigen receptor, specifically recognizes α-galactosylceramide (α-GalCer) exclusively presented by mouse CD1d (mCD1d). However, the precise molecular interaction remains unclear. For the basis of functional analyses, a docking model of α-GalCer with the crystal structure of mCD1d was constructed. Possible residues involved in the α-GalCer–mCD1d interaction were found to be Arg79, Glu83 and Asp80 for carbohydrate recognition, and Asp153 for interaction with the amide group on the fatty acyl chain. The α-GalCer-presenting ability of various transfectants expressing mutant mCD1d was completely abrogated if a single amino acid mutation was induced at positions 79, 80, 83 or 153, suggesting that the polar amino acids above the F′ pocket are crucial for α-GalCer presentation to activate Vα14 NKT cells. The possibility that Glu83 is a contact site for the NKT cell receptor is also discussed.