αβ T cell receptors that do not undergo major histocompatibility complex-specific thymic selection possess antibody-like recognition specificities.

Major histocompatibility complex (MHC) restriction is the cardinal feature of T cell antigen recognition and is thought to be intrinsic to αβ T cell receptor (TCR) structure because of germline-encoded residues that impose MHC specificity. Here, we analyzed αβTCRs from T cells that had not undergone MHC-specific thymic selection. Instead of recognizing peptide-MHC complexes, the two αβTCRs studied here resembled antibodies in recognizing glycosylation-dependent conformational epitopes on a native self-protein, CD155, and they did so with high affinity independently of MHC molecules.