Detection of Staphylococcal Superantigenic Toxins by a CD69-Specific Cytofluorimetric Assay Measuring T-Cell Activation

The presence of staphylococcal superantigenic toxins in the supernatants of liquid cultures was detected by an easy and rapid method assessing the activation of T lymphocytes by cytofluorimetric measurement of CD69 expression. Staphylococcus aureus cells were grown in Eagle’s minimum essential medium supplemented with 5% heat-inactivated fetal calf serum. Supernatant fluids from all S. aureus strains producing superantigen-related toxins, including enterotoxins A to E, toxic shock syndrome toxin, and exfoliative toxins A and B, induced CD69 expression in a significantly higher number of T cells than a cutoff of 2%. This CD69 assay might be used for initial detection of superantigens from S. aureus strains isolated in the context of staphylococcal toxemia or related chronic human diseases such as atopic dermatitis or Kawasaki syndrome.

Download Full-text

Inhibition of Toxic Shock Syndrome Toxin-I-Induced Cytokine Production and T Cell Activation by Interleukin-IO, Interleukin-4, and Dexamethasone

The Journal of Infectious Diseases ◽

10.1093/infdis/172.4.988 ◽

1995 ◽

Vol 172 (4) ◽

pp. 988-992 ◽

Cited By ~ 42

Author(s):

T. Krakauer

Keyword(s):

T Cell ◽

T Cell Activation ◽

Toxic Shock Syndrome ◽

Cell Activation ◽

Cytokine Production ◽

Interleukin 4 ◽

Toxic Shock ◽

Toxic Shock Syndrome Toxin

Download Full-text

A toxic shock syndrome toxin 1 mutant that defines a functional site critical for T-cell activation.

Infection and Immunity ◽

10.1128/iai.63.6.2141-2146.1995 ◽

1995 ◽

Vol 63 (6) ◽

pp. 2141-2146 ◽

Cited By ~ 13

Author(s):

C M Cullen ◽

L R Blanco ◽

P F Bonventre ◽

E Choi

Keyword(s):

T Cell ◽

T Cell Activation ◽

Toxic Shock Syndrome ◽

Cell Activation ◽

Functional Site ◽

Toxic Shock ◽

Toxic Shock Syndrome Toxin

Download Full-text

The Superantigen Toxic Shock Syndrome Toxin 1 Alters Human Aortic Endothelial Cell Function

Infection and Immunity ◽

10.1128/iai.00848-17 ◽

2017 ◽

Vol 86 (3) ◽

Cited By ~ 2

Author(s):

Katarina Kulhankova ◽

Kyle J. Kinney ◽

Jessica M. Stach ◽

Françoise A. Gourronc ◽

Isabella M. Grumbach ◽

...

Keyword(s):

Endothelial Cell ◽

Toxic Shock Syndrome ◽

Cell Activation ◽

Current Evidence ◽

Toxic Shock ◽

Endothelial Cell Activation ◽

Content Type ◽

Toxic Shock Syndrome Toxin ◽

Stimulation Of ◽

Aortic Endothelial

ABSTRACTStaphylococcus aureusinfective endocarditis (IE) is a fast-progressing and tissue-destructive infection of the cardiac endothelium. The superantigens (SAgs) toxic shock syndrome toxin 1 (TSST-1), staphylococcal enterotoxin C (SEC), and the toxins encoded by the enterotoxin gene cluster (egc) play a novel and essential role in the etiology ofS. aureusIE. Recent studies indicate that SAgs act at the infection site to cause tissue pathology and promote vegetation growth. The underlying mechanism of SAg involvement has not been clearly defined. In SAg-mediated responses, immune cell priming is considered a primary triggering event leading to endothelial cell activation and altered function. Utilizing immortalized human aortic endothelial cells (iHAECs), we demonstrated that TSST-1 directly activates iHAECs, as documented by upregulation of vascular and intercellular adhesion molecules (VCAM-1 and ICAM-1). TSST-1-mediated activation results in increased monolayer permeability and defects in vascular reendothelialization. Yet stimulation of iHAECs with TSST-1 fails to induce interleukin-8 (IL-8) and IL-6 production. Furthermore, simultaneous stimulation of iHAECs with TSST-1 and lipopolysaccharide (LPS) inhibits LPS-mediated IL-8 and IL-6 secretion, even after pretreatment with either of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and IL-1β. IL-8 suppression is not mediated by TSST-1 binding to its canonical receptor major histocompatibility complex class II (MHC-II), supporting current evidence for a nonhematopoietic interacting site on SAgs. Together, the data suggest that TSST-1 differentially regulates cell-bound and secreted markers of endothelial cell activation that may result in dysregulated innate immune responses duringS. aureusIE. Endothelial changes resulting from the action of SAgs can therefore directly contribute to the aggressive nature ofS. aureusIE and development of life-threatening complications.

Download Full-text

Protection against lethal toxic shock by targeted disruption of the CD28 gene.

Journal of Experimental Medicine ◽

10.1084/jem.183.6.2675 ◽

1996 ◽

Vol 183 (6) ◽

pp. 2675-2680 ◽

Cited By ~ 57

Author(s):

B Saha ◽

D M Harlan ◽

K P Lee ◽

C H June ◽

R Abe

Keyword(s):

T Cell ◽

T Cell Activation ◽

Toxic Shock Syndrome ◽

Cell Activation ◽

Dose Effect ◽

Tnf Alpha ◽

Toxic Shock ◽

Costimulatory Signals ◽

Toxigenic Strains

Toxic shock syndrome (TSS) is a multi system disorder resulting from superantigen-mediated cytokine production. Nearly 90% of the clinical cases of TSS arise due to an exotoxin, toxic shock syndrome toxin-1 (TSST-1), elaborated by toxigenic strains of Staphylococcus aureus. It is clearly established that besides antigen-specific signals a variety of costimulatory signals are required for full T cell activation. However, the nature and potential redundancy of costimulatory signals are incompletely understood, particularly with regards to superantigen-mediated T cell activation in vivo. Here we report that CD28-deficient mice (CD28-/-) are completely resistant to TSST-1-induced lethal TSS while CD28 (+/-) littermate mice were partially resistant to TSST-1. The mechanism for the resistance of the CD28 (-/-) mice was a complete abrogation of TNF-alpha accumulation in the serum and a nearly complete (90%) impairment of IFN-gamma secretion in response to TSST-1 injection. In contrast, the serum level of IL-2 was only moderately influenced by the variation of CD28 expression. CD28 (-/-) mice retained sensitivity to TNF-alpha as demonstrated by equivalent lethality after cytokine injection. These findings establish an essential requirement for CD28 costimulatory signals in TSST-1-induced TSS. The hierarchy of TSST-1 resistance among CD28 wild-type (CD28+/+), CD28 heterozygous (CD28+/-), and CD28-/- mice suggests a gene-dose effect, implying that the levels of T cell surface CD28 expression critically regulate superantigen-mediated costimulation. Finally, as these results demonstrate the primary and non-redundant role of CD28 receptors in the initiation of the in vivo cytokine cascade, they suggest therapeutic approaches for superantigen-mediated immunopathology.

Download Full-text

High Titer Persistent Neutralizing Antibodies Induced by TSST-1 Variant Vaccine Against Toxic Shock Cytokine Storm

Toxins ◽

10.3390/toxins12100640 ◽

2020 ◽

Vol 12 (10) ◽

pp. 640

Author(s):

Andreas Roetzer ◽

Norbert Stich ◽

Nina Model ◽

Michael Schwameis ◽

Christa Firbas ◽

...

Keyword(s):

T Cell ◽

T Cell Activation ◽

Neutralizing Antibodies ◽

Cell Activation ◽

High Titer ◽

Neutralizing Antibody ◽

Cytokine Storm ◽

Toxic Shock ◽

Antibody Titers ◽

Toxic Shock Syndrome Toxin

Staphylococcal superantigen toxins lead to a devastating cytokine storm resulting in shock and multi-organ failure. We have previously assessed the safety and immunogenicity of a recombinant toxic shock syndrome toxin 1 variant vaccine (rTSST-1v) in clinical trials (NCT02971670 and NCT02340338). The current study assessed neutralizing antibody titers after repeated vaccination with escalating doses of rTSST-1v. At study entry, 23 out of 34 subjects (67.6%) had neutralizing antibody titers inhibiting T cell activation as determined by 3H-thymidine incorporation at a serum dilution of ≤1:100 with similar figures for inhibition of IL-2 activation (19 of 34 subjects, 55.9%) as assessed by quantitative PCR. After the first vaccination, numbers of subjects with neutralization titers inhibiting T cell activation (61.7% ≥ 1:1000) and inhibiting IL-2 gene induction (88.2% ≥ 1:1000) increased. The immune response was augmented after the second vaccination (inhibiting T cell activation: 78.8% ≥ 1:1000; inhibiting IL-2 induction: 93.9% ≥ 1:1000) corroborated with a third immunization months later in a small subgroup of subjects. Assessment of IFNγ, TNFα and IL-6 inhibition revealed similar results, whereas neutralization titers did not change in placebo participants. Antibody titer studies show that vaccination with rTSST-1v in subjects with no/low neutralizing antibodies can rapidly induce high titer neutralizing antibodies persisting over months.

Download Full-text

Involvement of Enterotoxins G and I in Staphylococcal Toxic Shock Syndrome and Staphylococcal Scarlet Fever

Journal of Clinical Microbiology ◽

10.1128/jcm.37.8.2446-2449.1999 ◽

1999 ◽

Vol 37 (8) ◽

pp. 2446-2449 ◽

Cited By ~ 122

Author(s):

Sophie Jarraud ◽

Grégoire Cozon ◽

François Vandenesch ◽

Michèle Bes ◽

Jerome Etienne ◽

...

Keyword(s):

T Cell Activation ◽

Scarlet Fever ◽

Toxic Shock Syndrome ◽

Cell Activation ◽

Target Genes ◽

Pcr Amplification ◽

Toxic Shock ◽

Specific Flow ◽

Staphylococcal Enterotoxins ◽

Staphylococcal Toxic Shock Syndrome

We investigated the involvement of the recently described staphylococcal enterotoxins G and I in toxic shock syndrome. We reexamined Staphylococcus aureus strains isolated from patients with menstrual and nonmenstrual toxic shock syndrome (nine cases) or staphylococcal scarlet fever (three cases). These strains were selected because they produced none of the toxins known to be involved in these syndromes (toxic shock syndrome toxin 1 and enterotoxins A, B, C, and D), enterotoxin E or H, or exfoliative toxin A or B, despite the fact that superantigenic toxins were detected in a CD69-specific flow cytometry assay measuring T-cell activation. Sets of primers specific to the enterotoxin G and I genes (seg andsei, respectively) were designed and used for PCR amplification. All of the strains were positive for seg andsei. Sequence analysis confirmed that the PCR products, corresponded to the target genes. We suggest that staphylococcal enterotoxins G and I may be capable of causing human staphylococcal toxic shock syndrome and staphylococcal scarlet fever.

Download Full-text