Superantigenic activity of toxic shock syndrome toxin-1 is resistant to heating and digestive enzymes.
OBJECTIVE
To elucidate the stability of superantigenic activity and pathogenesis of toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxin A (SEA) against heating and digestive enzymes.


RESULTS
Purified TSST-1 and SEA were treated with heating, pepsin and trypsin that are related to food cooking, stomach and intestine conditions. The integrity, superantigenic activity and toxicity of treated TSST-1 and SEA were analysed by Western blotting, spleen cell culture, cytokine assay and toxic shock models. Both TSST-1 and SEA showed strong resistance to heating, pepsin and trypsin digestion. Furthermore, the treated TSST-1 showed significant higher induction of interferon-γ and toxic shock compared with that of SEA. Pepsin- or trypsin-digested TSST-1 fragments still showed significant superantigenic and lethal shock toxicities.


CONCLUSIONS
The superantigenic activity of TSST-1 was stable to heating and digestive enzymes. Pepsin- and trypsin-digested TSST-1 fragments still showed superantigenic and lethal shock activities, indicating that digested TSST-1 could cross epithelial cells and induce systemic toxicity.


CONCLUSIONS
This study found, for the first time, that pepsin- or trypsin-digested smaller TSST-1 retained significant superantigenic and lethal shock activities. The different resistance of TSST-1 and SEA participates in the different pathogenic activities during food poisoning and toxic shock syndrome.
Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
S-J
SJ
Li
D-L
DL
Hu
E K
EK
Maina
K
K
Shinagawa
K
K
Omoe
A
A
Nakane
D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004768:Enterotoxins / Q000378:metabolism / Q000494:pharmacology*; D006358:Hot Temperature; D051379:Mice; D008810:Mice, Inbred C57BL; D010434:Pepsin A / Q000378:metabolism*; D055550:Protein Stability; D018089:Superantigens / Q000378:metabolism / Q000494:pharmacology*; D014357:Trypsin / Q000378:metabolism*
D001427:Bacterial Toxins; D004768:Enterotoxins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal; C026066:enterotoxin A, Staphylococcal; D014357:Trypsin; D010434:Pepsin A