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
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences