New malaria vaccine candidates identified

July 30, 2014
Children and guardians present to a local dispensary for sampling for the detection of anti-malarial antibodies. Credit: Juliana Wambua

Researchers have discovered new vaccine targets that could help in the battle against malaria. Taking a new, large-scale approach to this search, researchers tested a library of proteins from the Plasmodium falciparum parasite with antibodies produced by the immune systems of a group of infected children.

The tests measured which proteins the children's immune systems responded to, revealing antigens that had not previously been identified as possible vaccine targets and new insights into the ways antigens could be used in combination to increase protection.

"Resistance to drugs is an increasing problem so vaccines are desperately needed to battle the Plasmodium falciparum parasite before it has a chance to make people sick," says Dr Faith Osier, first author from the Kenya Medical Research Institute. "This study presents us with a large number of new vaccine candidates that offer real hope for the future."

A group of children infected with malaria were followed over a six-month period by scientists at the Kenya Medical Research Institute (KEMRI). While some patients became sick, others were protected by naturally occurring antibodies that stopped the malaria parasite from penetrating their during the blood stage of the disease, which produces severe symptoms such as fever and anaemia. Researchers used samples taken from these children to identify combinations of antibodies that provided up to 100 per cent protection against clinical episodes of malaria.

The study used a library of parasite proteins that was generated using an approach developed at the Wellcome Trust Sanger Institute by Dr Gavin Wright and Dr Julian Rayner. These researchers had previously developed a new approach to express large panels of correctly folded, full-length proteins from the Plasmodium falciparum parasite, targeting proteins involved in the invasion of human red blood cells. In this study, Sanger Institute scientists collaborated with colleagues in Kenya to see which of them the children's immune systems had developed antibodies against.

"The use of these proteins by the Sanger Institute's Malaria Programme is helping to zero in on and exploit the weakest point in the 's life cycle," says Dr Julian Rayner, an author from the Sanger Institute. "Trials for vaccines in the past have focussed on one target at a time and have had limited success; with this approach, we can systematically test larger numbers of targets and identify targets that might work in combination."

The findings of this research add further weight to the theory that a successful blood-stage vaccine needs to target multiple antigens. The next step in this research will be to generate antibodies against all of the proteins in the library and test them in the laboratory in different combinations to see whether combinations that appear to protect individuals in the field are able to directly prevent parasite invasion. Such studies are now underway at the Sanger Institute. At KEMRI, Dr Faith Osier's team is working on validating these findings in other African countries.

"Each year, hundreds of thousands of people die from malaria; but hundreds of millions are infected, many of whom are protected from severe symptoms by their immune response," says Dr Kevin Marsh, Director of the KEMRI Wellcome Trust Research Programme at the Kenya Medical Research Institute. "Collaborating with our colleagues at the Sanger Institute helps to bring the latest technological advances to the field, which in this case has highlighted combinations of naturally occurring antibodies that could contribute to the design of new vaccines."

Explore further: Improving human immunity to malaria

More information: Science Translational Medicine. DOI: 10.1126/scitranslmed.3008705

Related Stories

Improving human immunity to malaria

August 1, 2012
The deadliest form of malaria is caused the protozoan Plasmodium falciparum. During its life-cycle in human blood, the parasite P. falciparum expresses unique proteins on the surface on infected blood cells.

Scientists identify potential vaccine candidate for pediatric malaria

May 22, 2014
Researchers have identified a substance, or antigen, that generates antibodies that can hinder the ability of malaria parasites to multiply, which may protect against severe malaria infection.

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

June 23, 2014
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 ...

Major breakthrough in quest for new malaria drugs

July 17, 2014
Victorian scientists have made a major breakthrough in the race to find new drugs to fight malaria, one of the world's most devastating diseases.

New candidate vaccine neutralizes all tested strains of malaria parasite

December 20, 2011
A new candidate malaria vaccine with the potential to neutralise all strains of the most deadly species of malaria parasite has been developed by a team led by scientists at the University of Oxford. The results of this new ...

What makes the deadliest form of malaria specific to people?

December 2, 2013
Researchers have discovered why the parasite that causes the deadliest form of malaria only infects humans.

Recommended for you

Post-stroke patients reach terra firma with new exosuit technology

July 26, 2017
Upright walking on two legs is a defining trait in humans, enabling them to move very efficiently throughout their environment. This can all change in the blink of an eye when a stroke occurs. In about 80% of patients post-stroke, ...

Brain cells found to control aging

July 26, 2017
Scientists at Albert Einstein College of Medicine have found that stem cells in the brain's hypothalamus govern how fast aging occurs in the body. The finding, made in mice, could lead to new strategies for warding off age-related ...

Molecular hitchhiker on human protein signals tumors to self-destruct

July 24, 2017
Powerful molecules can hitch rides on a plentiful human protein and signal tumors to self-destruct, a team of Vanderbilt University engineers found.

Researchers develop new method to generate human antibodies

July 24, 2017
An international team of scientists has developed a method to rapidly produce specific human antibodies in the laboratory. The technique, which will be described in a paper to be published July 24 in The Journal of Experimental ...

New vaccine production could improve flu shot accuracy

July 24, 2017
A new way of producing the seasonal flu vaccine could speed up the process and provide better protection against infection.

A sodium surprise: Engineers find unexpected result during cardiac research

July 20, 2017
Irregular heartbeat—or arrhythmia—can have sudden and often fatal consequences. A biomedical engineering team at Washington University in St. Louis examining molecular behavior in cardiac tissue recently made a surprising ...

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.