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
At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History
New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy