The Specificity of a Weak γδ TCR Interaction Can Be Modulated by the Glycosylation of the Ligand

Abstract

The γδ T cell clone LBK5 recognizes the MHC molecule IEk. Here, we demonstrate that the affinity of this interaction is weaker than those typically reported for αβ TCRs that recognize peptide/MHC complexes. Consistent with our previous finding that peptide bound to the IE molecule does not confer specificity, we show that the entire epitope for LBK5 is contained within the polypeptide chains of the molecule, centered around the polymorphic residues 67 and 70 of the IE β-chain. However, LBK5 recognition is profoundly influenced by the N-linked glycosylation at residue 82 of the IE α-chain. Since infected, stressed, or transformed cells often change the posttranslational modifications of their surface glycoproteins, this finding suggests a new way in which γδ T cell Ag recognition can be regulated.