Malaria immunity trigger found for multiple mosquito species

March 13, 2009

( -- Researchers at the Johns Hopkins Bloomberg School of Public Health have for the first time identified a molecular pathway that triggers an immune response in multiple mosquito species capable of stopping the development of Plasmodium falciparum-the parasite that causes malaria in humans.

By silencing the gene, caspar, the researchers were able to block the development of the malaria-causing parasite in Anopheles gambiae, A. stephensi and A. albimanus mosquitoes-three mosquito species that spread in Africa, Asia and the Americas. Their findings were published March 13 in PLoS Pathogens.

According to the study, the transcription factor Rel 2 is a key molecule involved in regulating several potent anti-Plasmodium that attack the parasite in the mosquito gut. Rel 2 is activated by the immune deficiency pathway (Imd) which, in turn, is negatively regulated by the caspar gene; when caspar is silenced the Rel 2 is activated. The researchers found that silencing of the caspar gene through the manipulation of resulted in that successfully blocked the development of Plasmodium falciparum in the . Silencing the gene known as cactus, which is part of another pathway called Toll, was shown to have similar effect in controlling the development of Plasmodium berghei, which causes malaria in rodents.

"When a mosquito is feeding on malaria-infected blood, the parasite will be recognized by the mosquito's immune system through receptors that then start the . In the wild, this response is believed to occur too late to mount an efficient immune defense that would kill all . At least a few will successfully develop inside the mosquito and enable transmission of malaria," explained George Dimopoulos, PhD, senior author of the study and associate professor at the Johns Hopkins Malaria Research Institute.

"In the lab we activated this immune response in advance of infection, giving the mosquito a head start in defeating the invading parasite."

Dimopoulos and his colleagues Lindsey Graver and Yuemei Dong also found that Rel 2 activation did not affect the survival and egg laying fitness of the modified mosquitoes.

"This came as a pleasant surprise since it essentially means that we one day could spread this trait in natural mosquito populations using genetic modification. Furthermore, by activating Rel 2, the genetically modified mosquitoes will attack the malaria parasite with several independent immune factors, and this will make it very difficult for Plasmodium to develop resistance," said Dimopoulos.

More information: "Caspar controls resistance to Plasmodium falciparum in diverse Anopheline species," PLoS Pathogens

Source: Johns Hopkins University Bloomberg School of Public Health

Related Stories

Recommended for you

Zika virus infection alters human and viral RNA

October 20, 2016

Researchers at University of California San Diego School of Medicine have discovered that Zika virus infection leads to modifications of both viral and human genetic material. These modifications—chemical tags known as ...

Food-poisoning bacteria may be behind Crohn's disease

October 19, 2016

People who retain a particular bacterium in their gut after a bout of food poisoning may be at an increased risk of developing Crohn's disease later in life, according to a new study led by researchers at McMaster University.

Neurodevelopmental model of Zika may provide rapid answers

October 19, 2016

A newly published study from researchers working in collaboration with the Regenerative Bioscience Center at the University of Georgia demonstrates fetal death and brain damage in early chick embryos similar to microcephaly—a ...

Scientists uncover new facets of Zika-related birth defects

October 17, 2016

In a study that could one day help eliminate the tragic birth defects caused by Zika virus, scientists from the Florida campus of The Scripps Research Institute (TSRI) have elucidated how the virus attacks the brains of newborns, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.