Gene against bacterial attack unravelledOctober 29, 2008Dutch researcher Joost Wiersinga from AMC Medical Centre in Amsterdam has unravelled a genetic defence mechanism against the lethal bacteria Burkholderia pseudomallei. The research is the next step towards a vaccine against this bacterium suitable for bioweapons. Humans have an innate defence system against deadly bacteria. However, how the step from gene to anti-bacterial effect occurs in the body is not yet known. To date, B. Pseudomallei, a bacterium suitable for bioweapons, had managed to elude medics. It can remain hidden in the human body for many years without being detected by the immune system. The bacteria can suddenly become activated and spread throughout the body, resulting in the patient dying from blood poisoning. AMC physician Joost Wiersinga and the Laboratory for Experimental Internal Medicine discovered which gene-protein combination renders the lethal bacteria B. pseudomallei harmless. Immune system fooled Wiersinga focussed on the so-called Toll-like receptors. These are the proteins that initiate the fight against pathogens. There are currently ten known Toll-like receptors which are located on the outside of immune cells, our body's defence system. The toll-like receptors jointly function as a 10-figure alarm code. Upon coming into contact with the immune cell each bacterium enters its own Toll code. For known pathogens this sets off an alarm in the immune system and the defence mechanism is activated. Yet B. pseudomallei fools the system by entering the code of a harmless bacterium. As a result the body's defence system remains on standby. Yet some people are resistant: they become infected but not ill. Wiersinga found a genetic cause for this resistance. He discovered which toll receptor can fend off B. pseudomallei. He did this by rearing mice DNA in which the gene for Toll2 production was switched on and off. 'The group where the gene for Toll2 was switched off, survived the bacterial infection', says Wiersinga. 'The other receptor that we investigated, Toll4, had no effect - even though for the past ten years medics had regarded this as the most important receptor.' The ultimate aim of this study is to develop a vaccine. Wiersinga and his colleagues are working together with the Wellcome Trust in Oxford and a clinic in Thailand. B. pseudomallei is endemic in Asia and claims thousands of victims each year. The research was published in PloS Medicine, and Science and Nature Reviews also ran articles on it. NWO funded the work. The Netherlands Organisation for Scientific Research (NWO) |
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| Related Pseudomallei Current Events and Pseudomallei News Articles Pathogenic soil bacterium is influenced by land management practices Researchers from Menzies School of Health Research in Darwin, Australia have found that the soil bacterium Burkholderia pseudomallei, which causes the emerging infectious disease melioidosis in humans and animals, is associated with land management changes such as livestock husbandry or residential gardening. Helping Cystic Fibrosis Patients Beat Bugs People with weakened immune systems, including patients with cystic fibrosis, could be better protected in future from a highly resilient bacteria thanks to work by medical scientists from the University of Leeds. The research is presented today, Wednesday 10 September 2003, at the Society for General Microbiology's meeting at UMIST in Manchester. "British soldiers stationed in South East Asia and North Australia, as well as local people, can be exposed to infection by a dangerous bacterium called Burkholderia pseudomallei which causes pneumonia and septicaemia. This bacterium is resistant to many antibiotics and, as treatment can take nine months with frequent relapses, we urgently need New research sheds light on bacterial firework display Scientists at the Institute for Animal Health have revealed how a tropical bacterium is able invade cells, and ultimately trigger its escape using a homemade rocket. Their work is published in the November issue of Molecular Microbiology. A group of scientists led by Dr Ed Galyov and Dr Mark Stevens have discovered that Burkholderia pseudomallei, which causes a disease called melioidosis, uses a special set of `effector` proteins to invade host cells. Their discovery has revealed surprising similarities with Salmonella, which use similar invasion tactics. B. pseudomallei, along with Salmonella, Shigella, and Yersinia, has the ability to invade cells in the intestine and spread to deeper tiss More Pseudomallei Current Events and Pseudomallei News Articles |
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