title: Characterization of a novel staphylococcal enterotoxin-like superantigen, a member of the group V subfamily of pyrogenic toxins.
abstract: Staphylococcus aureus is an important human pathogen, causing a variety of diseases. Major virulence factors of this organism include staphylococcal enterotoxins (SEs) that cause food poisoning and toxic shock syndrome. Our study identified a novel enterotoxin-like protein that is a member of the new subfamily (group V) of pyrogenic toxin superantigens (PTSAgs) and examined its biochemical and immunobiological properties. The gene encoding the SE-like protein is directly 5' of another recently identified PTSAg, SEK. The SE-like protein had a molecular weight of 26000 and an experimentally determined isoelectric point between 7.5 and 8.0. We demonstrated that the PTSAg had many of the biological activities associated with SEs, including superantigenicity, pyrogenicity, and ability to enhance endotoxin shock, but lacked both lethality in rabbits when administered in subcutaneous miniosmotic pumps and emetic activity in monkeys. Recombinant protein stimulated human CD4 and CD8 T cells in a T cell receptor variable region, beta chain (TCRVbeta) specific manner. T cells bearing TCRVbeta 2, 5.1, and 21.3 were significantly stimulated.
authors.affiliation: Department of Microbiology, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, Minnesota 55455, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Orwin
authors.forename: Donald Y M
authors.initials: DY
authors.lastname: Leung
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Tripp
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Bohach
authors.forename: Cathleen A
authors.initials: CA
authors.lastname: Earhart
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Ohlendorf
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Schlievert
mesh_terms: D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011749:Pyrogens / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000737:chemistry; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000235:genetics / Q000472:pathogenicity; D018089:Superantigens / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D014774:Virulence
chemical_list: D001427:Bacterial Toxins; D017931:DNA Primers; D011749:Pyrogens; D011994:Recombinant Proteins; C469942:SEQ protein, Staphylococcus aureus; D018089:Superantigens