Nav: Home

Lack of plasmodium surface-protein blocks mosquito infection

November 09, 2016

A previously unknown feature of the malaria parasite development has just been published in the journal Cell Host&Microbe. An international research team, led by a parasitologist at University of São Paulo and Pasteur Institute, Paris, has shown that, contrary to what has been assumed so far, a Plasmodium surface-protein plays an essential role at a stage of its life cycle that occurs not in the body of the host, but in the guts of the Anopheles mosquito. The finding has consequences for the search for vaccines or drugs that could alleviate the suffering caused by malaria. By 2015, 214 million people were affected by the parasite, especially in Africa.

Throughout its life cycle, the malaria parasite assumes different forms, at different points in the host and vector bodies. The infected female of the mosquito, when it bites a human, inoculates the parasite present in its saliva in the form called sporozoite. Through the bloodstream, sporozoites reach the liver of the host, where they invade a class of cells called hepatocytes. Inside them, they become merozoites, the form of the parasite that invades the red blood cells. It is when the red blood cells break because they are full of parasites that the typical fever attacks of the disease occur. Typically, the stages of the life cycle that happen inside de host are assexual. Part of the merozoites, however, remains inside the erythrocytes and differs in gametocytes, male and female. The next stages of the life of the parasite now occur in the body of the mosquito which, by sucking the blood of the host, brings into its body the blood cells laden with parasites, now sexually differentiated.

It is in this comeback to the mosquito organism that lies the discovery published in Cell Host and Microbe. To continue their development, the gametocytes need to leave the vacuole in which they are harboured inside the red cell. In cells modified to not express the surface protein (called MTRAP), the team has verified, gametocytes cannot leave the vacuole. As a result, the life cycle of the plasmodium is interrupted and the mosquito can no longer transmit it. Until now, parasitologists have attributed to this protein the ability of merozoites to invade red blood cells still within the host's body. The experiments also showed that for this step, the MTRAP protein is innocuous.

"The experiments allow a new approach to influence the life cycle of plasmodium," says parasitologist Daniel Bargieri of the Institute of Biomedical Sciences at USP. "We now have yet another target to be studied to block transmission of the parasite, which increases the potential for achieving the ambitious goal of eradicating malaria."

Plasmodium Merozoite TRAP Family Protein Is Essential for Vacuole Membrane Disruption and Gamete Egress from Erythrocytes Bargieri et al., 2016, Cell Host & Microbe 20, 618-630 November 9, 2016 ª 2016 The Authors. Corresponding Author:

Published by Elsevier Inc.

University of Sao Paulo Scientific Outreach Unit

Related Malaria Articles:

New tool in fight against malaria
Modifying a class of molecules originally developed to treat the skin disease psoriasis could lead to a new malaria drug that is effective against malaria parasites resistant to currently available drugs.
Malaria expert warns of need for malaria drug to treat severe cases in US
The US each year sees more than 1,500 cases of malaria, and currently there is limited access to an intravenously administered (IV) drug needed for the more serious cases.
Monkey malaria breakthrough offers cure for relapsing malaria
A breakthrough in monkey malaria research by two University of Otago scientists could help scientists diagnose and treat a relapsing form of human malaria.
Getting to zero malaria cases in zanzibar
New research led by the Johns Hopkins Center for Communication Programs, Ifakara Health Institute and the Zanzibar Malaria Elimination Program suggests that a better understanding of human behavior at night -- when malaria mosquitoes are biting -- could be key to preventing lingering cases.
Seeking better detection for chronic malaria
In people with chronic malaria, certain metabolic systems in the blood change to support a long-term host-parasite relationship, a finding that is key to eventually developing better detection, treatment and eradication of the disease, according to research published today in the Journal of Clinical Investigation Insight.
Widely used malaria treatment to prevent malaria in pregnant women
A global team of researchers, led by a research team at the Liverpool School of Tropical Medicine (LSTM), are calling for a review of drug-based strategies used to prevent malaria infections in pregnant women, in areas where there is widespread resistance to existing antimalarial medicines.
Protection against Malaria: A matter of balance
A balanced production of pro and anti-inflammatory cytokines at two years of age protects against clinical malaria in early childhood, according to a study led by ISGlobal, an institution supported by ''la Caixa'' Foundation.
The math of malaria
A new mathematical model for malaria shows how competition between parasite strains within a human host reduces the odds of drug resistance developing in a high-transmission setting.
Free malaria tests coupled with diagnosis-dependent vouchers for over-the-counter malaria treatment
Coupling free diagnostic tests for malaria with discounts on artemisinin combination therapy (ACT) when malaria is diagnosed can improve the rational use of ACTs and boost testing rates, according to a cluster-randomized trial published this week in PLOS Medicine by Wendy Prudhomme O'Meara of Duke University, USA, and colleagues.
Certain antibodies against a sugar are associated with malaria protection
Certain type of antibodies against α-Gal- a carbohydrate expressed by many organisms including the malaria parasite- could protect against malaria, according to a new study led by ISGlobal, an institution supported by 'la Caixa' Foundation.
More Malaria News and Malaria Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.