Nav: Home

Scientists effectively disrupt communication between parasites that spread disease

March 09, 2017

Prof. Shulamit Michaeli, Dean of Bar-Ilan's Mina and Everard Goodman Faculty of Life Sciences, and member of the Bar-Ilan Institute of Nanotechnology and Advanced Materials (BINA), has demonstrated how parasite migration can be controlled by creating an unfavorable environment or by damaging cell health, since parasites under stress secrete vesicles that disrupt their socially coordinated movement in groups. This research has just been published in the peer-reviewed journal PLOS Pathogens.

Traveling from host to host Michaeli's team, including students Dror Eliaz and Sriram Kannan, study trypanosomatids, single-cell parasites which cause major diseases such as African sleeping sickness, leishmaniosis and Chagas' disease, affecting millions of people. Leishmaniasis, for example, is found in 88 countries and over 300 million people are at risk of infection. African trypanosomes infect cattleand the annual economic loss due to this disease is estimated at about US$2 billion. The American Chagas' disease causes major heart and intestinal malfunction. Around 90 million are at risk of infection, with five to eight million people affected annually.

Trypanosome parasites are transmitted to mammals by the blood-sucking tsetse fly. The parasites' stopover in the insect-host has two stages. They live in the insect's gut for two to three weeks and then migrate to the saliva glands. When the fly has its next meal, the parasites are transferred via the saliva to the prey, infecting its bloodstream. In this way the mammal now becomes host to the parasite, and the disease is spread. To complete their two-stage stay in the insect, the parasites must undertake an epic journey of active migration fraught with perils, such as the fly's digestive enzymes, immune system and the need to cross the intestinal barrier.

With a little help from my friends Research has shown that these insect-stage parasites are capable of group behavior, using cell-cell signaling to promote collective migration. By moving in numbers they are better able to transverse the fly's intestines, complete the journey to the saliva glands, and proliferate the disease. But how do these parasites communicate in order to coordinate their movements in response to signals from neighboring parasites? Until now, the signaling mechanism has been unclear. Prof. Michaeli's new study describes a novel process demonstrating that under stress the parasites secrete exosomes which communicate a message to neighboring cells that something is wrong. Exosomes are small vesicles secreted by cells, implicated in cell-cell communication and the transmission of disease. Depending on the type and physiological state of the secreting cell, exosome interaction with recipient cells may help ward off disease or, alternatively, exacerbate it. For example, they have recently been shown to influence the proliferation and metastasis of melanoma tumor cells.

Keep your distance

Michaeli's team interfered with the parasite communication system by inducing "stress" in parasite cells causing them to release exosomes. They found that the presence of these exosome-secreting cells disrupted the normal migration of the parasite cells. Parasite "scouts" which monitor the environment in the insect-host pick up "keep away" messages from these damaged cells, and, in turn, communicate with the migrating parasite population, messaging them to avoid contact with the "unfit" ones. When exosome secretion was inhibited no effect on the migration was observed. Michaeli's results strongly suggest that exosomes act as a repellent that drives the fit parasites away from either damaged cells or an unfavorable environment.

Prof. Michaeli explains the importance of these findings. "A Biblical story relates the collapse of the Tower of Babel because the people lost the common language with which to communicate with each other. Uncovering how to shut down the parasites' communication system may lead to the development of drugs to treat and prevent the spread of these devastating diseases."
-end-
Prof. Michaeli's research was supported by the Israel Science Foundation, the Binational Science Foundation, and the Applebaum Foundation. She is the incumbent of the David and Inez Myers Chair in Gene Expression and Infectious Disease at Bar-Ilan University.

Bar-Ilan University

Related Parasites Articles:

Feeding bluebirds helps fend off parasites
If you feed the birds in your backyard, you may be doing more than just making sure they have a source of food: you may be helping baby birds give parasites the boot.
Scientists discover how malaria parasites import sugar
Researchers at Stockholm University has established how sugar is taken up by the malaria parasite, a discovery with the potential to improve the development of antimalarial drugs.
How malaria parasites become resistant to artemisinin antimalarial drugs
Malaria parasite mutations that inhibit the endocytoic appetite for a host's red blood cells may render them resistant to artemisinin, a widely used frontline antimalarial drug, according to a new study, which reveals a key molecular mechanism of drug resistance.
Study shows interactions between bacteria and parasites
A team at the Technical University of Munich (TUM) has completed the first study of the effects of a simultaneous infection with blood flukes (schistosomes) and the bacterium Helicobacter pylori -- a fairly common occurrence in some parts of the world.
Evolution designed by parasites
In 'Invisible Designers: Brain Evolution Through the Lens of Parasite Manipulation,' published in the September 2019 issue of The Quarterly Review of Biology, Marco Del Giudice explores an overlooked aspect of the relationship between parasites and their hosts by systematically discussing the ways in which parasitic behavior manipulation may encourage the evolution of mechanisms in the host's nervous and endocrine systems.
Airless worms: A new hope against drug-resistant parasites
Toronto scientists have uncovered a metabolic pathway that only exists in parasitic worms.
Parasites dampen beetle's fight or flight response
Beetles infected with parasitic worms put up less of a fight against simulated attacks from predators and rival males, according to a study by Felicia Ebot-Ojong, Andrew Davis and Elizabeth Jurado at the University of Georgia, USA, publishing May 22, 2019 in the open-access journal PLOS ONE.
Genome structure of malaria parasites linked to virulence
An international research team led by scientists at the University of California, Riverside, and the La Jolla Institute for Immunology has found that malaria parasite genomes are shaped by parasite-specific gene families, and that this genome organization strongly correlates with the parasite's virulence.
Parasites discovered in fossil fly pupae
Parasitic wasps existed as early as several million years ago.
Migratory animals carry more parasites, says study
Every year, billions of animals migrate across the globe, carrying parasites with them and encountering parasites through their travels.
More Parasites News and Parasites Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Uncharted
There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 1: Numbers
In a recent Radiolab group huddle, with coronavirus unraveling around us, the team found themselves grappling with all the numbers connected to COVID-19. Our new found 6 foot bubbles of personal space. Three percent mortality rate (or 1, or 2, or 4). 7,000 cases (now, much much more). So in the wake of that meeting, we reflect on the onslaught of numbers - what they reveal, and what they hide.  Support Radiolab today at Radiolab.org/donate.