Researcher at University of Leicester has discovered how a protein in the blood - linked to defence against meningitis - plays a more vital role than previously understood in the body's immune defence system.

The study also reveals that the same protein, Properdin can also harm internal organs under certain circumstances.

Lack of the protein in the human body has previously been linked to susceptibility to meningitis.

"I have a broad interest in immune mechanisms of health and disease, though recently, I have focused on a particular component of the first line immune defence, a protein called Properdin," said Dr Cordula Stover, of the Department of Infection, Immunity and Inflammation at the University of Leicester.

"Properdin deficiency in families, though rare, predisposes people to develop meningococcal meningitis, usually with poor outcome of the infection.

"I hypothesized that the importance of Properdin extends beyond this particular infectious disease, and that indeed it is an important player in health generally, and that its importance becomes apparent in conditions involving both acute and chronic states of inflammation," said Stover.

Now two of Dr Stover's papers, published in the Journal of Immunology, demonstrate that Properdin plays a significant role in the survival of conditions relating to surgical perforation of the gut and activation of the immune system by wall components of bacteria.

In conditions relating to multi-organ dysfunction, a complication which can occur in response to severe sepsis, Properdin however aggravates organ damage.

Dr Stover added: "So far, the system Properdin is a part of - the so-called complement system - is classified as a first line, innate, acutely effective immune activation mechanism.

"My work shows that the activity of Properdin extends beyond the acute phase and, importantly, that Properdin is stepping onto the stage as an important player in different inflammatory conditions.

"As the worldwide burden of chronic inflammatory disease increases, it is of practical relevance to understand the contribution of this immune protein."