Malaria is a parasitic disease caused by Plasmodium and results in more than 750,000 deaths annually, but what if there was a more effective approach to curing it? Malaria is transported from one person to another by an infected mosquito. When the mosquito bites a human, a parasite called sporozoite is deposited in the skin. It then travels to the liver cells and multiplies to the point of affecting red blood cells and causing clinical symptoms. Common symptoms of malaria are: high fevers, shaking chills, flu-like symptoms, and anemia.
A new study recently uncovered a powerful strategy for eliciting an immune response in the body that can combat the parasite during multiple stages of its lifestyle. This may be the most effective next-generation approach to malaria we’ve seen.
Dr. Stefan Kappe, co-author of the study from the Seattle Biomedical Research Institute was quoted saying, “Unfortunately, the complexity of the parasite and the diverse types of protection needed against malaria are the main reason why, despite decades of effort, no fully protective vaccine is ready for licensing.”
By exposing the parasite to radiation, DNA damage is caused that arrests the parasite in an early stage in the liver. This also provides the immune system with an opportunity to develop an immune response that can combat the parasite. Dr. John Harty from the University of Iowa and co-author of the study examined whether it was a better vaccine option to genetically weakened parasites that were generated by target gene deletions to truncate replication in the liver-stage development.
By using mice as malaria models, researchers discovered that immunization with late-liver-stage arresting GAP (genetically attenuated parasites) provided long lasting protection at the blood stag of infection. These findings suggest that by weakening and arresting the parasite as late in the liver as possible may provide a large and diverse array of immune cells that are effective for neutralizing the native parasite.
Dr. Kappe and Dr. Harty were quoted saying, “Collectively, our data indicates that late-liver-stage-arresting GAP constitutes a superior vaccination strategy. This underscores the potential utility of late-arresting GAP as broadly protective second-generation live-attenuated malaria vaccine candidates and a powerful model to find new parasite protein-based vaccine candidates that protect against infection in the liver and the blood.”
SOURCE: Cell Host and Microbe, June 14, 2011