GM mosquitoes, new vaccine against malaria--study

Researchers at the Jichi Medical University in Shimotsuki, Japan have genetically modified the anopheles mosquito to produce a natural vaccine protein in its saliva, which when injected into the bloodstream will act like vaccination.

The archetype mosquito also carries vaccination against Leishmania--lethal mosquito disease spread by sand flies.

Lead researcher, Professor Shigeto Yoshida, Jichi Medical University said, “Blood-sucking arthropods including mosquitoes, sand flies and ticks transmit numerous infectious agents during blood feeding. This includes malaria, which kills between 1-2 million people, mostly African children, a year.”

“The lack of an effective vaccine means control of the carrier has become a crucial objective to combating the disease,” added Yoshida.

Details of the study
The research team identified a region called stephensi-a malaria, in the set of chromosomes of anopheles mosquito. This genome acted as a promoter that activates genes in the insects’ saliva.

For the examination, the team attached SP15 --a promising inoculation against leishmania-- to the stephensi, a malaria promoter.

Further, the research involved lab mice being bitten by the genetically modified mosquito to determine the working of the promoter.

Results of the study
Analysis revealed that mice bitten off by the ‘flying vaccinators’, as they were called, bred antibodies, proteins that fight infection, against Leishmania, which was indicative of vaccination.

This also led the researchers to conclude that the GM mosquitoes certainly produced SP15 in their saliva which led to the production of antibodies.

Yoshida stated, “Following bites, protective immune responses are induced, just like a conventional vaccination but with no pain and no cost.”

“What’s more, continuous exposure to bites will maintain high levels of protective immunity, through natural boosting, for a life time. So the insect shifts from being a pest to being beneficial,” added Yoshida.

It was also made known that though the mice were bitten some 1,500 times during the experiment, researchers clarified that in places with widespread malaria, people get bitten more than a hundred times a night.

David O’Brochta, insect molecular geneticist, University of Maryland, College Park, said, “It is a fascinating proof of concept.”

However, researchers added, “Such a strategy would involve the mass delivery of a vaccine without first obtaining the consent of patients or monitoring dosages.”

The study appears in the journal Insect Molecular Biology.