Algae researchers at the University of California, San Diego have engineered potential edible vaccine candidates for malaria. The proof-of-principle experiments could pave the way to the development of an inexpensive, edible vaccine to prevent transmission of malaria, one of the world’s most prevalent and debilitating diseases.
The mosquito-borne disease that affects more than 225 million people worldwide is caused by protozoan parasites from the genus Plasmodium. Malaria results in fever, headaches and even death in seere cases. Antimalarial medications are available but an effective vaccine has not been developed.
Blocking malaria transmission
The scientists used algae to produce Plasmodium proteins that elicited antibodies against the parasite in mice and the antibodies prevented malaria transmission. The study was published in PLoS ONE. Biologists at UC San Diego collaborated with the San Diego Center for Algae Biotechnology, which is busy engineering algae to produce biofuels and other products.
Any effective malaria vaccine would need to include proteins very similar to those made by the parasite, thus disrupting transmission of the disease from the bite of mosquitoes that carry the parasite. Such proteins made by specially engineered bacteria are coated with sugar molecules. However the parasite doesn’t add sugars to its proteins, which explains why antibodies made against lab-produced malaria proteins don’t work against the real thing.
Initial proof-of-principle experiments at UC San Diego suggest that a vaccine made from proteins made by algae could prevent malaria transmission. Video: UC San Diego Biological Sciences
The biologists thought an edible green alga, Chlamydomonas reinhardtii, that expresses malaria proteins without coating them with sugar molecules would be worth a try.
Stephen Mayfield, a professor of biology at UC San Diego, headed the research effort at UCSD’s Division of Biological Sciences. Mayfield also is director of the San Diego Center for Algae Biotechnology, a research consortium seeking to develop transportation fuels from algae.
Earlier, Mayfield published a landmark study demonstrating that many complex human proteins could be produced by Chlamydomonas.
James Gregory, a postdoctoral researcher in Mayfield’s lab, wondered if Chlamydomonas could also produce a malarial protein.
“It’s too costly to vaccinate two billion people using current technologies,” Mayfield said in a news release. “Realistically, the only way a malaria vaccine will ever be used is if it can be produced at a fraction of the cost of current vaccines. Algae have this potential because you can grow algae any place on the planet in ponds or even in bathtubs.”