Superantigens could be behind several illnesses

November 29, 2010
Karin Lindkvist and Maria Saline are two of the researchers who have studied how superantigens activate the immune system. Credit: University of Gothenburg

Superantigens, the toxins produced by staphylococcus bacteria, are more complex than previously believed, reveals a team of researchers from the University of Gothenburg in an article published today in the scientific journal Nature Communications. Their discovery shows that the body's immune system can cause more illnesses than realised.

"Superantigens have a real talent for disrupting the body's ," says Karin Lindkvist from the University of Gothenburg's Department of Cell- and Molecular Biology, one of the authors of the article. "If you're infected with bacteria that secrete superantigens, your immune system will respond so strongly that it'll make you ill. Our study shows that superantigens activate the immune system in more ways than previously thought."

We are all exposed daily to various types of foreign organism that can harm us. The human body has therefore developed whose role it is to "kill" and remove all foreign invaders that find their way in – the immune system.

Antibiotic-resistant bacteria have become increasingly common with the more widespread use of different types of antibiotics. Yellow staphylococci (Staphylococcus aureus) are one of the most common bacteria in the world around us, with most children and adults carrying them at some point. One strain, MRSA (methicillin-resistant Staphylococcus aureus), has developed resistance to penicillin and other penicillin-like antibiotics that are normally used to treat infections caused by staphylococci. Staphylococci can cause a variety of conditions such as long-term wound infections and abscesses, and can also lead to food poisoning.

The toxins produced by staphylococci are also known as superantigens. A normal viral infection will trigger the activation of around 0.0001% of the body's natural killer cells (T cells), which is enough to destroy the virus. However, contracting bacteria that secrete superantigens leads to the activation of 5-20% of the body's T cells. Such a strong immune response will often result in illness, which generally involves fever and extreme nausea. Superantigens are also well-known for causing toxic symptoms, as in toxic shock syndrome. There is also some speculation as to whether superantigens can cause autoimmune disorders such as rheumatoid arthritis.

"By investigating how superantigens activate the immune system via its T cells, we've been able to show that they bind to more than one part of the T cell receptor," says Lindkvist. "This is an important discovery for our understanding of superantigens' biological function, and for the future development of a vaccine against superantigens. We haven't yet looked at whether other superantigens can activate T cells in the same complex way, but it's reasonable to assume that they can."

More information: The study The structure of superantigen complexed with TCR and MHC reveals novel insights into superantigenic T cell activation has been published in the scientific journal Nature Communications.

Related Stories

Recommended for you

Scientists find key to regenerating blood vessels

November 23, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) identifies a signaling pathway that is essential for angiogenesis, the growth of new blood vessels from pre-existing vessels. The ...

Researchers find infectious prions in Creutzfeldt-Jakob disease patient skin

November 22, 2017
Creutzfeldt-Jakob disease (CJD)—the human equivalent of mad cow disease—is caused by rogue, misfolded protein aggregates termed prions, which are infectious and cause fatal damages in the patient's brain. CJD patients ...

Surprising roles for muscle in tissue regeneration, study finds

November 22, 2017
A team of researchers at Whitehead has illuminated an important role for different subtypes of muscle cells in orchestrating the process of tissue regeneration. In a paper published in the November 22 issue of Nature, they ...

Study reveals new mechanisms of cell death in neurodegenerative disorders

November 22, 2017
Researchers at King's College London have discovered new mechanisms of cell death, which may be involved in debilitating neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Cinnamon turns up the heat on fat cells

November 21, 2017
New research from the University of Michigan Life Sciences Institute has determined how a common holiday spice—cinnamon—might be enlisted in the fight against obesity.

How rogue immune cells cross the blood-brain barrier to cause multiple sclerosis

November 21, 2017
Drug designers working on therapeutics against multiple sclerosis should focus on blocking two distinct ways rogue immune cells attack healthy neurons, according to a new study in the journal Cell Reports.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.