Staphylococcus aureus and Streptococcus pyogenes colonize mucosal surfaces of the human body to cause disease. A group of virulence factors known as superantigens are produced by both of these organisms that allows them to cause serious diseases from the vaginal (staphylococci) or oral mucosa (streptococci) of the body. Superantigens interact with T cells and APCs to cause massive cytokine rele...

Bacterial superantigens, a diverse family of toxins, induce an inflammatory cytokine storm that can lead to lethal shock. CD28 is a homodimer expressed on T cells that functions as the principal costimulatory ligand in the immune response through an interaction with its B7 coligands, yet we show here that to elicit inflammatory cytokine gene expression and toxicity, superantigens must bind dire...

Staphylococcus aureus is widely prevalent in the nasopharynges of healthy individuals (carriers) but can also cause serious infections. S. aureus can elaborate a variety of superantigen exotoxins in "carrier" or "pathogenic" states. Streptococcus pyogenes can also colonize the nasopharynx and elaborate superantigens. Unlike the acute effects of superantigen exotoxins absorbed through the gut or...

Superantigens are a group of bacterial and viral proteins that are characterized by their capacity to stimulate a large number of T cells. They bind directly to the major histocompatibility complex class II molecule on the antigen-presenting cell and cross-link the antigen-presenting cell with T cells expressing certain T-cell receptors, leading to polyclonal T-cell activation. They have been s...

BACKGROUND Group A streptococcus (GAS) causes invasive disease, superficial disease, and can asymptomatically colonize humans. Superantigens are one virulence factor found in GAS. Previous studies found associations between the genes that encode superantigens and emm type of GAS. It is unknown if these associations are due to underlying biological factors that limit the distribution of superant...

The excessive immunological response triggered by microbial superantigens has been implicated in the etiology of a wide range of human diseases but has been most clearly defined for the staphylococcal and streptococcal toxic shock syndromes. Because MHC class II presentation of superantigens to T cells is not MHC-restricted, the possibility that HLA polymorphisms could influence superantigenici...

Staphylococcus aureus infection plays an important role in atopic eczema (AE) because of its ability to produce virulence factors such as superantigens. Epicutaneous application of superantigens induces eczema. Superantigens also induce corticosteroid resistance, and subvert T-regulatory cell activity, thereby increasing AE severity. Increased binding of S. aureus to skin is driven by underlyin...

The special issue “Enterotoxins: Microbial Proteins and Host Cell Dysregulation” is comprised of research articles and reviews covering a diverse group of toxins that affect the gut and dysregulate host immune response in mechanistically different ways. Excellent in-depth reviews of staphylococcal superantigens and Clostridium perfringens toxins are the cornerstones of this issue. The present e...

BACKGROUND Accurate and rapid diagnosis of bacterial arthritis is not always possible in unvaccinated (Streptococcus pneumoniae and Haemophilus influenzae type B) children in Iran. OBJECTIVES Searching the staphylococcal superantigen (entrotoxin A, B, C and TSST1) in synovial fluid of cases with inflammatory arthritis. PATIENTS AND METHODS This cross sectional study was implemented in the p...