Superantigen recognition by gamma delta T cells: SEA recognition site for human V gamma 2 T cell receptors

Human gamma delta T cells expressing the V gamma 2V delta2 antigen receptor s recognize nonpeptide prenyl pyrophosphate and alkylamine antigens. We fin d 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 gamma delta TCR recognition of SEA. Residues at 200-207 that are criti cal for specific alpha beta TCR recognition of SEA do not affect gamma delt a TCR recognition. SEA residues 20-27 are located in an area contiguous wit h the binding site of V beta chains. This study defines a superantigen reco gnition site for a gamma delta T cell receptor and demonstrates the differe nces between V gamma 2V delta2(+) T cell recognition of superantigens and n onpeptide antigens.