We all know of the link between malaria and watery habitats – but scientists have been looking at another link between the mosquito-borne disease and pond-dwelling photosynthetic blooms.
The malaria parasite produces very complex, 3D proteins that are difficult and expensive to reproduce in traditional recombinant systems. Hence researchers have been looking for cheaper ways to produce these proteins, but could algae really be used to create an effective edible malarial vaccine?
Well, it seems like a bit of a tentative ânot at the moment', unfortunately, according to researchers at the University of California, San Diego. They looked at using algae to produce a malarial vaccine that can orally delivered, and did so by engineering the choloroplast of Chlamydomonas reinhardtii algae to produce the Pfs25 Plasmodium falciparum surface protein fused to the Î² subunit of the cholera toxin (CtxB). The genetically-engineered fusion-protein-producing algae were then freeze-dried and fed to mice. Incredibly, upon being fed the algae, the mice developed IgA antibodies specific for both the malarial parasite and CtxB. However, the IgA was produced only in the gut and mucosal linings – and thus won't protect against the malarial parasites.
All is not lost, though. This method has shown it might be possible to use edible freeze-dried algae to protect against infectious diseases that affect mucosal linings.
"What this study shows is that you can get a really good immune response from a recombinant protein in algae that you feed to a mammal," said Stephen Mayfield, professor of biology at UC San Diego. "In this case, it happens to be a mouse, but presumably it would also work in a human. That's really encouraging for the potential for algae-based vaccines in the future."
Edible vaccines against salmonella, E. coli, and possibly even cholera itself, could be grown anywhere and at any time. "It's too costly to vaccinate two billion people using current technologies," explained Mayfield. "Realistically, the only way a malaria vaccine will ever be used in the developing world 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."
Read the journal article >> Applied and Environmental Microbiology
What do you think about edible freeze-dried algae as vaccines? Do you think they have potential? You can join our discussion on LinkedIn or leave a comment below, I'd love to hear what you think.
If you want to know more about strategy and innovation in vaccines, you might be interested in attending the World Vaccine Congress Asia 2013, 17-20 June 2013, Singapore.
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