The study found that the two enzymes - which have distinct functions - work together to hamper the body's efforts to fight off the disease. Together they repair damage done to the meningitis bacteria's DNA by the body's white blood cells, which are sent to fight the infection.
Understanding the part these enzymes play in the process that enables the bacteria to elude the body's natural defences could eventually help scientists develop novel new treatments for meningitis and the septicaemia it can cause. Both are extremely serious conditions with a high mortality rate, which take hold quickly and are difficult to treat - sometimes resulting in extreme measures such as limb amputation.
When the meningitis bacteria enter the bloodstream, the body's natural defences send white blood cells to fight the infection. They ingest the bacteria and subject them to oxidative stress. Oxidative stress damages the base chemical compounds of the bacteria's DNA. This should lead to cell death and the defeat of the bacteria. However, the virulent meningitis bacteria are able to repair this harmful damage and are therefore unaffected by the body's defences.
The research team found that the two enzymes essential to the bacteria's repair mechanism are AP endonuclease and 3'-phosphodiesterase. Contrary to the scientists' expectations, these two enzymes carry out separate functions in the DNA repair process.
Professor Paul Freemont from Imperial's Division of Molecular Biosciences explains: "Scientists have long understood that the secret of meningitis' virulence lies in its ability to rearrange its DNA and thus change its external appearance to the body's immune system. Significantly our research has now demonstrated that the ability of meningitis to repair its DNA is important for its ability to survive attack from the body's immune system. This work provides an insight into the precise roles of two enzymes in mending DNA and gives us a greater understanding than ever before into why these infections are so hard for the body to fight.
"We have also discovered that this novel combination of enzymes is present in a wide variety of bacteria and that it has a direct impact on the infectivity of human pathogens."
Dr Geoff Baldwin from Imperial's Division of Molecular Biosciences added: "The wide importance of DNA repair to the viability of all organisms is well established. However, for the first time this research shows an important role for DNA repair in meningitides fighting off the attack of the body's immune system.
"We have examined two enzymes from a family that are known to cut the DNA during its repair. To our surprise we discovered that in the meningitis bacteria, one of the enzymes does not cut the DNA. Instead, it removes damaged DNA ends that prevent the DNA from being remade during the repair process. This has an important impact for our understanding of the precise pathways of DNA repair and the significance of the two separate functionalities that act in different DNA repair pathways within the pathogen."
Professor Christoph Tang from Imperial's Division of Investigative Science added: "After realising that the two enzymes had distinct roles repairing different types of DNA damage, were able show the pathogen can 'fend off' different types of DNA damage while in the bloodstream. In theory, finding some way of disabling these enzymes would render the bacteria unable to repair itself, and therefore vulnerable to attack and defeat by the body's immune system."
Danielle Reeves | alfa
New technique unveils 'matrix' inside tissues and tumors
29.06.2017 | University of Copenhagen The Faculty of Health and Medical Sciences
Designed proteins to treat muscular dystrophy
29.06.2017 | Universität Basel
Computer scientists use wave packet theory to develop realistic, detailed water wave simulations in real time. Their results will be presented at this year’s SIGGRAPH conference.
Think about the last time you were at a lake, river, or the ocean. Remember the ripples of the water, the waves crashing against the rocks, the wake following...
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
29.06.2017 | Physics and Astronomy
29.06.2017 | Life Sciences
29.06.2017 | Health and Medicine