The global eradication of malaria could be a step closer, according to The Independent.
The newspaper reported that scientists have identified a key mechanism in the way that malaria-causing parasites attack red blood cells and spread through the body.
The widely reported research has revealed how a range of malarial parasites exploit a protein called basigin on the surface of blood cells, using the protein to identify and infect the cells. The scientists were able to show that several types of malaria parasites use basigin in this way, and that the process can be blocked during lab experiments. If all malaria parasites use this mechanism then the findings could have far-reaching consequences, as they could allow the development of a single drug or vaccine that blocks all strains of the infection.
Like the recent results of a malaria vaccine trial, this research could lead to a genuine breakthrough in the fight against malaria, which affects hundreds of millions of people around the world. However, this is only an initial step towards developing a universal malaria treatment, and the technology will still need extensive development and research before we can tell if it provides a safe and effective treatment.
Where did the story come from?
The study was carried out by researchers from the Wellcome Trust Sanger Institute in Cambridge and other institutions in Japan, Senegal and the US. The research was funded by the Wellcome Trust.
The research was published in the peer-reviewed scientific journal Nature. The story was widely reported, with the media generally providing good accounts of the research and useful background information about malaria. The Independent provided a particularly thorough and accurate description of the research.
What kind of research was this?
Malaria is caused by a type of parasitic organism called a plasmodium that can enter the bloodstream when a mosquito bites a person. After the plasmodia have taken hold in the person’s liver they begin seeking out and entering the red blood cells. Once inside red blood cells, the plasmodia begin multiplying until they eventually cause the blood cells to burst, re-entering the bloodstream to infect more blood cells.
This laboratory study was designed to identify a protein required for malaria infection that was common to all strains of the Plasmodium falciparum parasite, the most deadly malaria-causing parasite. The researchers initially identified a candidate protein, and then tested it to determine whether or not it was essential for malaria infection to occur. They then sought to determine whether manipulating this protein could keep the parasites from invading the red blood cells.
This research used standard laboratory techniques to identify target proteins, test their interaction with the parasite, and determine if the protein was essential for malaria infection.
What did the research involve?
In order to infect a person with malaria, the parasites must get inside their red blood cells. To do this they must first recognise the cell by interacting with the proteins on its surface. Thus far, research has identified multiple different proteins that allow this to happen, but none that is used by all strains of the parasite. This has made the process of developing a single treatment to prevent infection difficult.
The researchers identified proteins that appear on the surface of, or are secreted by, red blood cells, and screened these proteins in order to select those that interact with the parasite.
The researchers selected a candidate red blood cell protein called basigin. They then carried out a series of experiments to see if they could interfere with the binding of the red blood cell and parasite proteins, and whether this could prevent the parasites from infecting the cells. These experiments included attempts to physically block the interaction of the two proteins by introducing other molecules that would bind to the proteins instead. The researchers also used genetic techniques to prevent the red blood cell-parasite interaction from occurring.
The researchers carried out experiments in parasite strains produced in the laboratory, as well as in strains obtained from the field.
What were the basic results?
The researchers found that the basigin red blood cell protein interacted with an essential parasite protein.
When the researchers introduced a form of basigin that was not attached to the red blood cells, they found that parasite invasion of the cells was prevented in a “dose-response” manner; in other words, the more free floating basigin they used, the fewer parasites invaded the red blood cells. This prevention was found to occur across multiple strains of the parasite. A similar result was found when the researchers introduced antibody proteins that would bind to the target red blood cell proteins.
When the researchers repeated their tests using parasites obtained from the field, they achieved similar results to those seen in laboratory-developed parasites.
How did the researchers interpret the results?
The researchers conclude that they have identified a single red blood cell protein that is essential for malaria infection, regardless of the specific parasite strain of Plasmodium falciparum tested. They said that using modest amounts of antibodies to bind to this protein kept the parasites from invading the red blood cells. They said that the identification of this protein “may provide new possibilities for therapeutic intervention.”
The researchers appear to have identified a human protein that is key to malaria parasites’ ability to infect red blood cells. This could prove to be an extremely important discovery in the global fight against malaria, a disease that affects hundreds of millions of people and kills around one million people every year. The knowledge gained from this research could be put towards future anti-malaria therapies, or even vaccines.
However, it is important to put this research into context, as it is still at an early stage: the study has identified a mechanism used by the malaria parasite, but researchers will still need to design and optimise possible therapies based around these findings. These would then need testing in people to ensure that they are safe to use in a real-world setting.
For many years, malaria prevention has focused on environmental and physical interventions such as mosquito nets and insecticide to prevent mosquitoes from biting people and infecting them with malaria-causing parasites. Research into therapies and vaccines to fight the parasites themselves has often been frustrated by the multiple strains of the parasite that cause the illness, and the various ways they invade cells.
However, this study appears to have identified a promising target for future research that may apply to most strains of the parasite. Together with the recent news of a potential malaria vaccine, it seems this is a promising step forward in the battle against malaria, which is still one of the world’s greatest health problems.
- Crosnier C, Bustamante LY, Josefin Bartholdson S et al. Basigin is a receptor essential for erythrocyte invasion by Plasmodium falciparum. Nature 2011