title: egc-Encoded superantigens from Staphylococcus aureus are neutralized by human sera much less efficiently than are classical staphylococcal enterotoxins or toxic shock syndrome toxin.
abstract: PCR was employed to determine the presence of all known superantigen genes (sea, seq, and tst) and of the exotoxin-like gene cluster (set) in 40 Staphylococcus aureus isolates from blood cultures and throat swabs; 28 isolates harbored superantigen genes, five on average, and this strictly correlated with their ability to stimulate T-cell proliferation. In contrast, the set gene cluster was detected in every S. aureus strain, suggesting a nonredundant function for these genes which is different from T-cell activation. No more than 10% of normal human serum samples inhibited the T-cell stimulation elicited by egc-encoded enterotoxins (staphylococcal enterotoxins G, I, M, N, and O), whereas between 32 and 86% neutralized the classical superantigens. Similarly, intravenous human immunoglobulin G preparations inhibited egc-encoded superantigens with 10- to 100-fold-reduced potency compared with the classical enterotoxins. Thus, there are surprisingly large gaps in the capacity of human serum samples to neutralize S. aureus superantigens.
authors.affiliation: Institut für Immunologie und Transfusionsmedizin, Ernst-Moritz-Arndt-Universität Greifswald, Diagnostikzentrum Sauerbruchstrasse, D-17487 Greifswald, Germany.
authors.forename: Silva
authors.initials: S
authors.lastname: Holtfreter
authors.forename: Kristin
authors.initials: K
authors.lastname: Bauer
authors.forename: Damien
authors.initials: D
authors.lastname: Thomas
authors.forename: Christine
authors.initials: C
authors.lastname: Feig
authors.forename: Vera
authors.initials: V
authors.lastname: Lorenz
authors.forename: Katharina
authors.initials: K
authors.lastname: Roschack
authors.forename: Erika
authors.initials: E
authors.lastname: Friebe
authors.forename: Kathleen
authors.initials: K
authors.lastname: Selleng
authors.forename: Sandra
authors.initials: S
authors.lastname: Lövenich
authors.forename: Timm
authors.initials: T
authors.lastname: Greve
authors.forename: Andreas
authors.initials: A
authors.lastname: Greinacher
authors.forename: Brigitte
authors.initials: B
authors.lastname: Panzig
authors.forename: Susanne
authors.initials: S
authors.lastname: Engelmann
authors.forename: Gérard
authors.initials: G
authors.lastname: Lina
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Bröker
mesh_terms: D000328:Adult; D001427:Bacterial Toxins / Q000276:immunology*; D004768:Enterotoxins / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D044967:Serum / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology*; D018089:Superantigens / Q000276:immunology*
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal