Vaccine made from complex of two malaria proteins protects mice from lethal infection

June 23, 2014
Credit: CDC

An experimental vaccine designed to spur production of antibodies against a key malaria parasite protein, AMA1, was developed more than decade ago by scientists from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. It showed promise in test-tube and animal experiments and in early-stage clinical trials, but returned disappointing results in recent human trials conducted in malaria-endemic countries.

Now, the NIAID scientists have improved on their original vaccine with a new candidate that delivers AMA1 protein together with part of a second parasite protein called RON2. In a natural infection, malaria parasites use the AMA1-RON2 complex to attach to and invade . When injected into mice as a complex, the AMA1-RON2 vaccine prompted robust antibody production and protected the animals from a lethal form of mouse malaria.

Moreover, when produced in response to AMA1-RON2 vaccine were administered to other, non-vaccinated mice, those animals received some protection from infection as well. Further analysis showed that the improved antibody response following AMA1-RON2 vaccination was due to an increased proportion of antibodies aimed directly at the AMA1-RON2 junction, which made them better at inhibiting parasite invasion.

The researchers note that this strategy of vaccination with the functional protein AMA1-RON2 complex could be tested in the next generation of human malaria vaccines. Such vaccines, which would contain multiple AMA1 sequences in complex with RON2, might induce antibodies targeted to a range of genetically diverse malaria parasites.

Explore further: Building a better malaria vaccine: Mixing the right cocktail

More information: P Srinivasan et al. Immunization with a functional protein complex required for erythrocyte invasion protects against lethal malaria. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1409928111 (2014).

Related Stories

A new target to inhibit malaria and toxoplasmosis infection

July 25, 2011

Maryse Lebrun, Research Director at Inserm, and her fellow researchers at the Laboratoire Dynamique des interactions membranaires normales et pathologiques (CNRS, France), have characterised a protein complex that allows ...

Malaria, toxoplasmosis: Toward new lines of research?

October 10, 2013

A study realized by teams from the Institut Pasteur, the Institut Cochin and the Wellcome Trust Centre for Molecular Parasitology of the University of Glasgow, could redefine part of the present lines of research toward a ...

Recommended for you

What causes sleepiness when sickness strikes

January 19, 2017

It's well known that humans and other animals are fatigued and sleepy when sick, but it's a microscopic roundworm that's providing an explanation of how that occurs, according to a study from researchers at the Perelman School ...

Soft robot helps the heart beat

January 18, 2017

Harvard University and Boston Children's Hospital researchers have developed a customizable soft robot that fits around a heart and helps it beat, potentially opening new treatment options for people suffering from heart ...

0 comments

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.