Burnet Institute scientists have played a key role in an Oxford-led study that’s identified the human antibodies that prevent the malaria parasite from entering blood cells.
Co-author, Burnet Director and CEO Professor Brendan Crabb AC, regards the work, published in the prestigious journal, Cell, as a highly significant step forward in the field of malaria, and a potential key to creating a highly effective malaria vaccine.
The study focuses on a protein called RH5 produced by the malaria parasite, which must bind to a human protein on red blood cells called basigin in order to infect them.
The researchers were able to demonstrate which human antibodies effectively block RH5 from binding with basigin, thus preventing the parasite from spreading through the blood.
The study was done as part of a clinical trial in Oxford of the first vaccine that targets the RH5 malaria protein.
“When someone is vaccinated, they make many different types of antibodies against the same RH5 target,” co-author and researcher Dr Daniel Alanine said.
“This study is key to understanding which specific antibodies are actually effective against malaria, and which are not.”
Another key finding of the study is the identification of an exciting new antibody, which works by slowing down the speed in which RH5 binds to red blood cells.
The parasite can still invade, but this antibody slows down the invasion. This gives the antibodies that do block RH5 more time to act, helping them become more effective.
“This is an exciting finding because it shows that antibodies that do not prevent the parasite from getting into red blood cells might still be useful, by making the protective antibodies more potent,” co-author Matthew Higgins, Professor of Molecular Parasitology at the Department of Biochemistry, University of Oxford, said.
Through the deployment of state-of-the art imaging technologies, Burnet’s Dr Paul Gilson, Dr Rasika Kumarasingha, and Professor Crabb played a key role in the identification of this antibody and explaining its enhancing effect.
“We now know that this idea is indeed quite likely and not only that, but we have a tool to slow invasion so that protective antibodies can work effectively.”
“Enhancing RH5 antibodies like this provides a surprising and potentially powerful avenue for greatly improving a number of vaccine and therapeutic approaches.”
There remains an urgent need to develop an effective malaria vaccine. Despite the increasing use of bed nets, insecticides and drugs in malaria-endemic regions, malaria still kills approximately 430,000 people each year.
Scientists have yet been unsuccessful at creating a vaccine that works against the malaria parasite in the blood.
This work was done in collaboration with researchers at the Center for Global Infectious Disease Research at the Seattle Children’s Research Institute (USA), Laboratory of Malaria and Vector Research (USA), Cell Surface Signalling Laboratory at the Wellcome Trust Sanger Institute (Cambridge), and ExpreS2ion Biotechnologies (Denmark).