New Synthetic Protein May Be Key to Curing Malaria
Australian scientists at the QIMR Berghofer Medical Research Institute in Brisbane have identified and isolated a protein called PD-L2 that plays a major role in immune system function to help ward off malarial infection. PD-L2 proteins are naturally found on dendritic cells—a form of antigen-presenting cells that initiate a larger immune response by activating T cells—and are thus responsible for T cells attacking pathogens, as well as overriding any ‘stop attack’ signals when the pathogen still exists. The Australian team noticed in severe malaria cases, PD-L2 levels were diminished, and T cells were given ‘stop attack’ signals by dendritic cells, resulting in severe disease. The scientists manufactured a synthetic version of PD-L2, and when tested in mice, revealed curing malaria can be a reality soon.
According to the World Health Organization (WHO), there were 438,000 deaths by malaria last year, and 3.2 billion—half the world’s population—is at risk. Malaria is caused by Plasmodium species, or parasites transmitted through mosquitoes. Malaria is currently treatable and preventable with medications; however, drug resistance is an issue that frequently arises with medications. Even with treatment, malaria can recur without new exposure as the parasite can lie dormant in organs and replicate without alerting the immune system—a factor that has proven difficult for scientists to come up with an effective vaccine.
The scientists infected mice with a large fatal dose of malaria, and they were then administered three doses of synthetic PD-L2. All the mice were cured. Five months later, the same mice were reinfected with malaria-causing parasites, but more doses of PD-L2 were unneeded as the mice did not develop malaria.
The key to curing malaria may not exist in a fancy new drug or even a vaccine but by stimulating our natural immune response to fight harder. More research needs to be conducted before human trials but scientists remain hopeful.