title: Two adjacent residues in staphylococcal enterotoxins A and E determine T cell receptor V beta specificity.
abstract: The T cell receptor (TCR) V beta-determining region of two bacterial superantigens, staphylococcal enterotoxin A (SEA) and SEE, has been mapped to the COOH-terminal region of SEA and SEE using a panel of recombinant SEA/SEE hybrids. Total TCR V beta mRNA enrichment in human peripheral blood T cell cultures was determined by a novel single-tube amplification technique using a redundant V beta-specific primer. SEA routinely enriched mRNA coding for hV beta 1.1, 5.3, 6.3, 6.4, 6.9, 7.3, 7.4, and 9.1, while SEE, which is 83% homologous to SEA, enriched hV beta 5.1, 6.3, 6.4, 6.9, and 8.1 mRNA. Exchanging residues 206 and 207 was sufficient to convert in toto the TCR V beta response of human peripheral T lymphocytes. In addition, an SEA-reactive murine T cell line, SO3 (mV beta 17), unresponsive to wild-type SEE responded to SEE-S206N207, while an SEE-specific human T cell line, Jurkat (hV beta 8.1), unresponsive to SEA was stimulated strongly by SEA-P206D207. Exchanging all other regions of SEA and SEE except residues 206 and 207 did little to change the V beta response. Thus, the V beta binding region appears to be a stable, discrete domain localized within the COOH-terminal region that is largely unaffected by the considerable amino acid variability between SEA and SEE. This region may interact directly with TCR V beta.
authors.affiliation: Department of Molecular Medicine, University of Auckland, New Zealand.
authors.forename: K R
authors.initials: KR
authors.lastname: Hudson
authors.forename: H
authors.initials: H
authors.lastname: Robinson
authors.forename: J D
authors.initials: JD
authors.lastname: Fraser
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D004768:Enterotoxins / Q000737:chemistry / Q000276:immunology*; D005784:Gene Amplification; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology*; D013211:Staphylococcus aureus / Q000472:pathogenicity*; D013329:Structure-Activity Relationship
chemical_list: D004768:Enterotoxins; D012333:RNA, Messenger; D016693:Receptors, Antigen, T-Cell, alpha-beta; C049463:enterotoxin E, Staphylococcal; C026066:enterotoxin A, Staphylococcal