Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery could help stop malaria at its source -- the mosquito

31.08.2007
As summer temperatures cool in the United States, fewer mosquitoes whir around our tiki torches. But mosquitoes swarming around nearly 40 percent of the world’s population will continue to spread a deadly parasitic disease — malaria. Now an interdisciplinary team led by researchers from Rensselaer Polytechnic Institute has found a key link that causes malarial infection in both humans and mosquitoes.

If this link in the chain of infection can be broken at its source — the mosquito — then the spread of malaria could be stopped without any man, woman, or child needing to a take a drug. The researchers’ discovery will be published in the Aug. 31 edition of the Journal of Biological Chemistry.

The team found that humans and the mosquitoes that carry the malaria parasite share the same complex carbohydrate, heparan sulfate. In both humans and mosquitoes, heparan sulfate is a receptor for the malaria parasite, binding to the parasite and giving it quick and easy transport through the body. The team was led by Robert J. Linhardt, the Ann and John H. Broadbent Jr. ’59 Senior Constellation Professor of Biocatalysis and Metabolic Engineering at Rensselaer.

“The discovery allows us to think differently about preventing the disease,” Linhardt said. “If we can stop heparan sulfate from binding to the parasite in mosquitoes, we will not just be treating the disease, we will be stopping its spread completely.”

Malaria parasites are extremely finicky about their hosts, Linhardt explained. Birds, rodents, humans, and primates all can be infected with malaria, but each species is infected by a different species of mosquito — and each of those mosquitoes is infected by a different malaria parasite. In other words, there needs to be a perfect match at the molecular basis for malaria to spread from one species to another, Linhardt said. Researchers have long understood this deadly partnership, but the molecular basis for the match had never been determined.

“The discovery marks a paradigm shift in stopping malaria,” Linhardt said “Now, we can work to develop an environmentally safe, inexpensive way to block infection in mosquitoes and not have to worry about drug side effects in humans.”

Malaria kills over one million people around the world, mostly young children. And the problem is growing, Linhardt noted. As the Earth heats up due to global warming, outbreaks of malaria are being reported higher up the coast of South America and Mexico each year, he said.

“Unfortunately, there is little direct funding on malaria in this country outside of the Bill and Melinda Gates Foundation, because it is not considered a major threat in this country,” Linhardt noted. “We do our research on a shoestring. Malaria research funding needs to move higher up on the scientific priority list.”

Linhardt and his collaborators were the first to discover the link between the spread of malaria in humans and heparan sulfate in 2003. Those findings were also published in the Journal of Biological Chemistry. In this earlier study, Linhardt compared the receptors in the liver of humans to those of rodents. The liver is the first organ to be infected by the malaria parasite in mammals. The researchers found that heparan sulfate in the human liver was the unwitting transporter of the disease to the human bloodstream. The receptor found in rodents was a different heparan sulfate.

The next step for Linhardt, outlined in the current research, was to determine if heparan sulfate was also present in the species of mosquito known to spread malaria to humans, Anopheles stephensi. To make this key link, Linhardt and his current research team, which includes Rensselaer doctoral students Melissa Kemp and Jin Xie, enlisted the help of New York University physician and entomologist Photini Sinnis. Sinnis and her team at NYU provided their entomological expertise and the ill-fated mosquitoes needed for the experiments.

After finding heparan sulfate in mashed mosquitoes, the researchers needed to determine if heparan sulfate was in the mosquito organs known to host the malaria parasite. If so, it was likely that heparan sulfate was the reason malaria spreads from mosquito to human and human to mosquito.

In mosquitoes, the malaria parasite infects the digestive tract. A mosquito bites a human who carries the malaria parasite in his or her bloodstream. The parasites move into the bug’s gut and then to their salivary glands, allowing the mosquito to infect another human during its next blood meal. To isolate a two-microgram salivary gland and the four-microgram digestive tract from each mosquito required the extreme skill of Sinnis and her team, which included Alida Coppi. Once isolated, the guts and glands were analyzed by internationally renowned microanalysts Toshihiko Toida, Hidenao Toyoda, and Akiko Kinoshita-Toyoda at Chiba University in Japan. Heparan sulfate was found in both mosquito organs.

As a final step, the Rensselaer team proved that the heparan sulfate in the mosquito bound to the same malaria parasite that heparan sulfate found in the human liver did. It was an unfortunate perfect match.

Gabrielle DeMarco | EurekAlert!
Further information:
http://www.rpi.edu

Further reports about: Linhardt Malaria Organ gland heparan infected malaria parasite parasite sulfate

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

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...

Im Focus: Studying fundamental particles in materials

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...

Im Focus: Designing Architecture with Solar Building Envelopes

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>