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!
New type of photosynthesis discovered
17.06.2018 | Imperial College London
New ID pictures of conducting polymers discover a surprise ABBA fan
17.06.2018 | University of Warwick
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
15.06.2018 | Materials Sciences
15.06.2018 | Ecology, The Environment and Conservation
15.06.2018 | Power and Electrical Engineering