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

AN Tikhonova, F Van Laethem, K Hanada, J Lu… - Immunity, 2012 - cell.com
AN Tikhonova, F Van Laethem, K Hanada, J Lu, LA Pobezinsky, C Hong, TI Guinter…
Immunity, 2012cell.com
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 …
Summary
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. Ligand recognition was via the αβTCR combining site and involved the identical germline-encoded residues that have been thought to uniquely impose MHC specificity, demonstrating that these residues do not only promote MHC binding. This study demonstrates that, without MHC-specific thymic selection, αβTCRs can resemble antibodies in recognizing conformational epitopes on MHC-independent ligands.
cell.com