3RZC

Structure of the self-antigen iGb3 bound to mouse CD1d and in complex with the iNKT TCR

Summary for 3RZC

• Entry DOI: 10.2210/pdb3rzc/pdb
• Descriptor: Antigen-presenting glycoprotein CD1d1, Beta-2-microglobulin, Valpha14, ... (8 entities in total)
• Functional Keywords: antigen presentation, glycolipid, nkt cells, immune system
• Biological source: Mus musculus (mouse); More
• Total number of polymer chains: 4
• Total formula weight: 97121.71

Authors

Yu, E.D.,Girardi, E.,Wang, J.,Zajonc, D.M. (deposition date: 2011-05-11, release date: 2011-08-24, Last modification date: 2024-11-20)

Primary citation

Yu, E.D.,Girardi, E.,Wang, J.,Zajonc, D.M.
Cutting Edge: Structural Basis for the Recognition of {beta}-Linked Glycolipid Antigens by Invariant NKT Cells.
J.Immunol., 187:2079-2083, 2011

PubMed Abstract: Invariant NKT (iNKT) cells expressing a semi-invariant Vα14 TCR recognize self and foreign lipid Ags when presented by the nonclassical MHCI homolog CD1d. Whereas the majority of known iNKT cell Ags are characterized by the presence of a single α-linked sugar, mammalian self Ags are β-linked glycosphingolipids, posing the interesting question of how the semi-invariant TCR can bind to such structurally distinct ligands. In this study, we show that the mouse iNKT TCR recognizes the complex β-linked Ag isoglobotrihexosylceramide (iGb3; Galα1-3-Galβ1-4-Glcβ1-1Cer) by forcing the proximal β-linked sugar of the trisaccharide head group to adopt the typical binding orientation of α-linked glycolipids. The squashed iGb3 orientation is stabilized by several interactions between the trisaccharide and CD1d residues. Finally, the formation of novel contacts between the proximal and second sugar of iGb3 and CDR2α residues of the TCR suggests an expanded recognition logic that can possibly distinguish foreign Ags from self Ags.

PubMed: 21810611
DOI: 10.4049/jimmunol.1101636

Experimental method

X-RAY DIFFRACTION (2.8 Å)