The malaria pathogen Plasmodium falciparum is a parasite consisting of a single cell. It is transmitted to humans by the bite of an Anopheles mosquito. In the human body the pathogen invades the red blood cells, digests them - and thus causes a life-threatening disease.
The parasite's sexual reproduction takes place in the gut of the mosquito: When mosquitoes bite an infected person, they not only take up the blood, but also the parasite. In the gut, the plasmodia transform into generative cells of different sizes, which can, in principle, be compared to human egg and sperm cells. They fuse, leave the midgut and migrate into the mosquito's salivary glands. During the next blood meal, the mosquito infects another human, and thus completes the parasite?s life cycle.
A protein layer covers the generative cells of the malaria parasite
A Würzburg research team around Gabriele Pradel and Nina Simon made an astonishing discovery: During maturation of of its generative cells, the pathogen expresses six special proteins, which assemble to form larger complexes. These protein complexes can later be found on the surface of the "egg" and form a sticky cover. These findings have now been published in the Journal of Biological Chemistry.
Why is this such hot news? "The sticky cover might function to capture the 'sperm' cells. But it is also possible that the egg protects itself against the aggressive environment of the mosquito midgut", Gabriele Pradel speculates.
A protective mechanism would in fact be plausible. In the mosquito gut the malaria parasites initially live protected inside the human red blood cells. However, these rupture as soon as the generative cells are mature - from this moment on a new protective shield would be useful for the survival of the pathogen.
A new target for a vaccine?
This sticky shield might be a weak point of the malaria parasite. If essential for malaria reproduction, the proteins would be an attractive target for so-called transmission blocking vaccines. But first of all, Gabriele Pradel and her team have to identify the real purpose of the layer. And this can take several years.
New measures against malaria are needed urgently: All around the world, an estimated one to three million people die of this infection every year. The pathogens are getting more and more resistant against existing drugs; a possible vaccine is being clinically tested. Other prospective vaccines have all proved to be without effect.
Break through by breeding mosquitoes
The Würzburg research group studies the development of the malaria parasites in the Anopheles mosquito in a high security lab. Here, they rear the mosquitoes, from the eggs, to the larvae and the pupae, and finally to the adult insects. For their experiments, the scientists take the freshly hatched mosquitoes and have them suck human blood to which they added plasmodia.
The breeding of Anopheles mosquitoes in the so-called insectory is Gabriele Pradel's pride and joy: "Within Germany, similar research opportunities only exist in Hamburg and Heidelberg." Even globally, they are rare: Only a total of about ten laboratories have one.
About Gabriele Pradel
The microbiologist Gabriele Pradel is heading a young investigator group at the Würzburg Research Center for Infectious Diseases since 2005. The German Research Foundation (DFG) sponsors her work in the framework of the Emmy Noether Program.
"Sexual Stage Adhesion Proteins Form Multi-protein Complexes in the Malaria Parasite Plasmodium falciparum", Nina Simon, Sabrina M. Scholz, Cristina K. Moreira, Thomas J. Templeton, Andrea Kuehn, Marie-Adrienne Dude, and Gabriele Pradel. The Journal of Biological Chemistry, Vol. 284, Issue 21, 14537-14546, MAY 22, 2009. DOI 10.1074/jbc.M808472200
Contact: PD Dr. Gabriele Pradel; phone ++ 49 (931) 31-2174, email@example.com
Robert Emmerich | idw
Regulation of root growth from afar: How genes from leaf cells affect root growth.
22.07.2019 | Max-Planck-Institut für Molekulare Pflanzenphysiologie
If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
19.07.2019 | Physics and Astronomy
19.07.2019 | Physics and Astronomy
19.07.2019 | Earth Sciences