egc-Encoded superantigens from Staphylococcus aureus are neutralized by human sera much less efficiently than are classical staphylococcal enterotoxins or toxic shock syndrome toxin.
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.
Holtfreter
Silva
S
Institut für Immunologie und Transfusionsmedizin, Ernst-Moritz-Arndt-Universität Greifswald, Diagnostikzentrum Sauerbruchstrasse, D-17487 Greifswald, Germany.
Bauer
Kristin
K
Thomas
Damien
D
Feig
Christine
C
Lorenz
Vera
V
Roschack
Katharina
K
Friebe
Erika
E
Selleng
Kathleen
K
Lövenich
Sandra
S
Greve
Timm
T
Greinacher
Andreas
A
Panzig
Brigitte
B
Engelmann
Susanne
S
Lina
Gérard
G
Bröker
Barbara M
BM
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*
D001427:Bacterial Toxins; D004768:Enterotoxins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal