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, firstname.lastname@example.org
Robert Emmerich | idw
Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society
127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Power and Electrical Engineering
18.01.2017 | Materials Sciences
18.01.2017 | Life Sciences