title: Agonist properties of a microbial superantigen peptide.
abstract: Staphylococcal enterotoxin A (SEA) binds to class II major histocompatibility complex (MHC) molecules and stimulates monocytes to produce tumor necrosis factor alpha (TNF alpha) and interleukin one (IL-1). We have examined the monocyte stimulatory activity of individual synthetic peptides encompassing the entire sequence of the SEA molecule. Only one peptide, SEA(121-149), induced both TNF alpha and IL-1 production at a concentration as low as 30 microM. Consistent with its effects on monocyte function, SEA(121-149) was shown to bind directly to class II MHC molecules on the surface of both monocytes and B cells, and its binding was inhibited specifically by native SEA. Further, polyclonal antibody to SEA(121-149) inhibited induction of TNF alpha by both SEA and toxic shock syndrome toxin one. Thus, we have identified SEA(121-149) as a peptide agonist of SEA monocyte stimulatory activity.
authors.affiliation: Dept. Micro. & Cell Science, Univ. of Florida, Gainesville 32611.
authors.forename: C H
authors.initials: CH
authors.lastname: Pontzer
authors.forename: N D
authors.initials: ND
authors.lastname: Griggs
authors.forename: H M
authors.initials: HM
authors.lastname: Johnson
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001427:Bacterial Toxins; D002478:Cells, Cultured; D004768:Enterotoxins / Q000378:metabolism* / Q000494:pharmacology*; D006681:HLA-D Antigens / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis*; D007739:L Cells; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D013211:Staphylococcus aureus; D013329:Structure-Activity Relationship; D018089:Superantigens; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D000906:Antibodies; D001427:Bacterial Toxins; D004768:Enterotoxins; D006681:HLA-D Antigens; D007375:Interleukin-1; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D018089:Superantigens; D014409:Tumor Necrosis Factor-alpha; C030107:enterotoxin F, Staphylococcal; C026066:enterotoxin A, Staphylococcal