Crystal Structures of Two H-2D^b/Glycopeptide Complexes Suggest a Molecular Basis for CTL Cross-Reactivity

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• 作者：Ann Glithero ; Jose Tormo ; John S. Haurum ; Gemma Arsequell ; Gregorio Valencia ; Jon Edwards ; Sebastian Springer ; Alain Townsend ; Ya-Lan Pao ; Mark Wormald ; Raymond A. Dwek ; E. Yvonne Jones ; Tim Elliott
• 刊名：Immunity
• 出版年：1999
• 出版时间：1 January 1999
• 年：1999
• 卷：10
• 期：1
• 页码：63-74
• 全文大小：492 K

文摘

Two synthetic O-GlcNAc-bearing peptides that elicit H-2D^b-restricted glycopeptide-specific cytotoxic T cells (CTL) have been shown to display nonreciprocal patterns of cross-reactivity. Here, we present the crystal structures of the H-2D^b glycopeptide complexes to 2.85 Å resolution or better. In both cases, the glycan is solvent exposed and available for direct recognition by the T cell receptor (TCR). We have modeled the complex formed between the MHC-glycopeptide complexes and their respective TCRs, showing that a single saccharide residue can be accommodated in the standard TCR-MHC geometry. The models also reveal a possible molecular basis for the observed cross-reactivity patterns of the CTL clones, which appear to be influenced by the length of the CDR3 loop and the nature of the immunizing ligand.