Su.50. Distinct Regulatory T-Cells Induced By Repeated Injection of Toxic Shock Syndrome Toxin-1: a Comparative Study with Staphylococcal Enterotoxin a

2006 ◽  
Vol 119 ◽  
pp. S177
Author(s):  
Haowei Li ◽  
Anthony Chow
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Comparative Study ◽  
Toxic Shock Syndrome ◽  
Staphylococcal Enterotoxin ◽  
Repeated Injection ◽  
Staphylococcal Enterotoxin A ◽  
Toxic Shock ◽  
Toxic Shock Syndrome Toxin

Staphylococcus aureusisogenic mutant, deficient in toxic shock syndrome toxin-1 but not staphylococcal enterotoxin A production, exhibits attenuated virulence in a tampon-associated vaginal infection model of toxic shock syndrome

1999 ◽  
Vol 45 (3) ◽  
pp. 250-256
Author(s):  
Monica L De Boer ◽  
Winnie WS Kum ◽  
Anthony W Chow
Keyword(s):  
Weight Loss ◽  
Toxic Shock Syndrome ◽  
Staphylococcal Enterotoxin ◽  
Aureus Strain ◽  
Infection Model ◽  
Staphylococcal Enterotoxin A ◽  
Toxic Shock ◽  
Vaginal Infection ◽  
Toxic Shock Syndrome Toxin

Since menstrual toxic shock syndrome (MTSS) is associated with a predominant clone of Staphylococcus aureus which produces both toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin A (SEA), we sought to clarify the role of TSST-1 in a tampon-associated vaginal infection model in New Zealand White (NZW) rabbits, using isogenic tst+/sea+S. aureus mutants in which tst was inactivated by allelic replacement. Rabbits infected with the tst-/sea+strain became ill within 3 days, with fever, weight loss, conjunctival hyperemia, and lethargy. Mortality was significantly higher with the tst+/sea+strain compared to its tst-/sea+isogenic derivative (4/13 vs. 0/14; p < 0.05, Fisher's exact test, 2-tailed). Mean fever index was higher (p < 0.005; t test, 2-tailed) and weight loss more sustained among survivors in the tst+/sea+group. Furthermore, culture filtrates from the tst+/sea+strain induced a significantly greater response in mitogenesis and TNFalpha secretion from rabbit splenocytes in vitro compared to the tst-/sea+isogenic derivative. Thus, regardless of the role of SEA, TSST-1 significantly contributed to both morbidity and mortality in this tampon-associated vaginal infection model in NZW rabbits. This is the first demonstration of the potential role of TSST-1 and SEA in the pathogenesis of MTSS with a MTSS-associated clinical S. aureus strain in a relevant animal model.Key words: toxic-shock syndrome toxin-1, superantigens, rabbit model.

Receptors for toxic shock syndrome toxin-1 and staphylococcal enterotoxin A on human blood monocytes

1992 ◽  
Vol 38 (9) ◽  
pp. 937-944 ◽  
Author(s):  
Raymond H. See ◽  
Gerald Krystal ◽  
Anthony W. Chow
Keyword(s):  
T Lymphocytes ◽  
Toxic Shock Syndrome ◽  
Staphylococcal Enterotoxin ◽  
Human Monocytes ◽  
Staphylococcal Enterotoxin A ◽  
Blood Monocytes ◽  
Toxic Shock ◽  
Hla Dr ◽  
Toxic Shock Syndrome Toxin ◽  
Staphylococcal Toxic Shock Syndrome

Staphylococcal toxic shock syndrome toxin-1 (TSST-1) as well as staphylococcal enterotoxin A (SEA) and B (SEB) have recently been shown to bind directly to the class II major histocompatibility antigen, HLA-DR. Whereas others have characterized TSST-1 and SEA binding to HLA-DR on transfected L cells or B lymphoma cell lines, we sought evidence for direct binding of TSST-1 and SEA to HLA-DR on purified human monocytes. A single class of high-affinity receptors was found for both TSST-1 (dissociation constant (Kd) 40 nM, 3.4 × 104 receptors per cell) and SEA (Kd 12 nM, 3.2 × 104 receptors per cell) on normal human monocytes. Affinity cross-linking of 125I-labeled toxins to monocytes revealed the presence of two membrane protein subunits with molecular masses consistent with the α and β chains of human HLA-DR (35 and 28 kDa, respectively). The anti-HLA-DR monoclonal antibody L243, but not L203 or 2.06, inhibited radiolabeled toxin binding to human monocytes and neutralized the mitogenic response of human T lymphocytes to both toxins. However, L243 was consistently more effective in blocking radiolabeled TSST-1 than SEA binding to human monocytes from the same donors, suggesting that TSST-1 and SEA may be binding to overlapping epitopes rather than to the same epitope on HLA-DR. Because TSST-1 and SEB bind to distinct epitopes on HLA-DR and because SEA cross competes with both TSST-1 and SEB on the HLA-DR receptor, we postulate that SEA occupies a binding site within HLA-DR that overlaps both TSST-1 and SEB. Future studies focused on receptor-mediated binding of these toxins to human monocytes and T lymphocytes from normal donors and toxic shock syndrome patients may reveal the underlying anomalies that predispose particular individuals to toxic shock syndrome. Key words: monocytes, staphylococcal toxic shock syndrome toxin-1, receptors, HLA-DR, staphylococcal enterotoxin A.

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