By studying starfish, Metschnikow was the first to see cells digesting bacteria, a process he called phagocytosis (the eating of cells by other cells). Phagocytosis, it turns out, is an important immune defence in all living things. Since Metschnikow's work, scientists have studied the immune systems of simpler organisms (such as invertebrates) in the hope of understanding the immune systems of more complex organisms, like us.
However, invertebrates' immune systems are more elaborate than we expected. "We have underestimated the complexity of invertebrate immunity," says Dr. Paul Schmid-Hempel, an evolutionary ecologist at the ETH Zurich in Switzerland. By studying the immune systems of fruit flies, mosquitoes and other invertebrates (including bed bugs, moths, crustaceans, worms, sponges and bees), scientists are finding new molecules involved in defences against pathogens (microbes that cause disease).
One molecule found in fruit flies, Dscam, is capable of folding itself in 18,000 different ways. Computer models that predict the structure of this molecule have led scientists to suggest that this folding creates different shapes, each capable of binding to different structures on the pathogen's surface. "These molecules can be used very flexibly by assembling their components in many ways," says Schmid-Hempel. Until now, this ability to recognize specific pathogens was thought to be limited to vertebrates.
In another exciting area of research, scientists showed the sophisticated ways that invertebrates manage their immune systems. "Insects recognise peptidoglycan [a component of bacterial cell wall] and this triggers a rapid immune response" explains Schmid-Hempel. However, once the bacteria have been killed, molecules digest peptidoglycans and therefore dampen down the immune response. Regulating the immune response in this way is important because immune systems, if left unchecked, can harm an individual by mistakenly attacking cells in the body.
In humans, the failure of the body to recognise itself results in autoimmune diseases. For example, Crohn's disease is the failure of the body to recognize intestinal cells, resulting in an immune response against these cells. Understanding these autoimmune processes in invertebrates might help us to better engineer drugs to tackle these debilitating diseases in humans.
Insects can also boost their immune systems ready for a pathogen invasion. Female bedbugs, which are often wounded during mating, enhance their immune system prior to mating in anticipation of pathogen invasion. Similarly, bumblebees maintain their immune systems in an enhanced state following a pathogen attack to counter future infections. "This can even cross generations, with mothers transferring immunity to their offspring" says Schmid-Hempel. This delicate management of immune responses has until now been regarded as a characteristic of vertebrates.
Schmid-Hempel thinks that the molecular mechanisms found in invertebrate immune systems may rival those seen in the vertebrate world. He says: "Insects use different cells and molecules, but follow very similar principles for detecting pathogens as vertebrates."
And scientists are only beginning to understand the elaborate ways that invertebrates respond to pathogens. As they discover new molecules, the invertebrate immune system could turn out to be much more like that of vertebrates - making it an even better model for the study of our own immune system.
The impact on innate immunity: at the defence frontier - the biology of innate immunity conference was organised by the ESF Research Conferences Scheme and was attended by 90 immunologists and evolutionary ecologists. It was held at the University of Innsbruck Conference Centre in Obergurgl, Ötz Valley, Austria on 19-24 May 2007. The conference appealed to an international audience, drawing scientists from mainland Europe (Kenneth Söderhäll, Uppsala University, Sweden), Britain (Andrew Read, University of Edinburgh, Scotland), and the Canada (Shelley Adamo, Dalhousie University, Nova Scotia, CA). This conference was organised by ESF in partnership with the Fonds zur Förderung der wissenschaftlichen Forschung in Österreich (FWF) and the Leopold-Franzens-Universität Innsbruck (LFUI).
The European Science Foundation, which is based in Strasbourg, France, is an association of 75 member organisations from 30 European countries. Since its inception in 1974, it has co-ordinated a wide range of pan-European scientific initiatives.
Thomas Lau | alfa
Seeing on the Quick: New Insights into Active Vision in the Brain
15.08.2018 | Eberhard Karls Universität Tübingen
New Approach to Treating Chronic Itch
15.08.2018 | Universität Zürich
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Materials Sciences
15.08.2018 | Life Sciences