Objective(s): Streptococcus pyogenes, a notorious human pathogen is responsible to cause a wide range of infections varies from superficial common clinical illness to severe and life threatening infections. To our knowledge this is the first report exploring the emm types and superantigen/exotoxin gene profile of S. pyogenes from Pakistan. Materials a...

Bacterial superantigens are Gram-positive exotoxins that induce proinflammatory cytokine release in vitro, cause lethal shock in vivo, and can be detected in the bloodstream of critically ill patients. They also have a powerful priming effect on the TLR4 agonist LPS. The aim of this study was to investigate the relationship between superantigens and the TLR2 agonist bacterial lipoprotein (BLP)....

A nationwide laboratory-based surveillance study of invasive S. pyogenes infections was conducted in Germany. Invasive isolates (n = 719) were obtained between 2009 and 2014. Most isolates were obtained from blood (92.1%). The proportions of isolates from cerebrospinal fluid, pleural fluid, synovial fluid and peritoneal fluid were 3.9%, 1.8%, 1.7% and 0.6%, respectively. The most common emm typ...

Every adaptive immune response requires costimulation through the B7/CD28 axis, with CD28 on T-cells functioning as principal costimulatory receptor. Staphylococcal and streptococcal superantigen toxins hyperstimulate the T-cell-mediated immune response by orders of magnitude, inducing a lethal cytokine storm. We show that to elicit an inflammatory cytokine storm and lethality, superantigens mu...

background rheumatoid arthritis (ra) is the most common chronic inflammatory disease. the staphylococcal superantigens are considered as the causative agent of ra disease. objectives this study aimed to assess the presence of staphylococcal enterotoxin d in synovial fluid and blood of patients with ra. patients and methods a total of 120 blood and sf samples of patients with ra were studied. ba...

BACKGROUND AND OBJECTIVES Mycoplasma arthritidis mitogen (MAM) superantigen has been shown to induce chronic arthritis, which resembles human rheumatoid arthritis (RA) in a rodent model. However, its role as a causative agent in human RA is not well understood yet. The aim of this study was to investigate the presence of MAM superantigen gene in the synovial fluid (SF) of RA patients. MATERIA...

The functional activity of superantigens is based on capacity of these microbial proteins to bind to both the β-chain of the T cell receptor (TcR) and the major histocompatibility complex (MHC) class II dimer. We have previously shown that a subset of the bacterial superantigens also binds to a membrane protein, designated p85, which is expressed by renal epithelial cells. This binding activity...

Superantigens stimulate T-lymphocyte proliferation and cytokine production, but the effects of superantigen exposure on cell function within a complex, highly regulated immune response remain to be determined. In this study, we demonstrate that superantigen exposure significantly alters the murine host response to bacterial antigens in an in vitro coculture system. Two days after exposure to th...

Group C streptococci have been reported to cause invasive disease similar to that classically associated with group A streptococcus (GAS). We describe a fatal case of toxic shock-like syndrome due to Streptococcus equi subsp. zooepidemicus. The causative organism did not possess any known GAS superantigen exotoxin genes but did show evidence of superantigen production.

In addition to the usual retroviral promoter, the mouse mammary tumor virus (MMTV) long terminal repeat carries a second promoter located in the U3 region. Here we show that both of these promoters are independently able to give rise to superantigen activity in transgenic mice. The ability of multiple MMTV promoters to drive superantigen expression underscores its importance in the virus life c...