Superantigen Recognition by γδ T Cells SEA Recognition Site for Human Vγ2 T Cell Receptors

AbstractHuman γδ T cells expressing the Vγ2Vδ2 antigen receptors recognize nonpeptide prenyl pyrophosphate and alkylamine antigens. We find that they also recognize staphylococcal enterotoxin A superantigens in a manner distinct from the recognition of nonpeptide antigens. Using chimeric and mutant toxins, SEA amino acid residues 20–27 were shown to be required for γδ TCR recognition of SEA. Residues at 200–207 that are critical for specific αβ TCR recognition of SEA do not affect γδ TCR recognition. SEA residues 20–27 are located in an area contiguous with the binding site of V β chains. This study defines a superantigen recognition site for a γδ T cell receptor and demonstrates the differences between Vγ2Vδ2+ T cell recognition of superantigens and nonpeptide antigens