Altruistic Immunity Could be an Interesting Approach to Tackle Malaria
Malaria kills roughly twice as many people worldwide as AIDS, drugs no longer work against some strains, and mosquitoes in diverse parts of the United States now carry the disease.
When the malaria-causing Plasmodium falciparum enters the body through female anopheles mosquito, a subsequent immune response can result in the production of anti-parasitic antibodies. These acquired antibodies could be ingested by other Plasmodium-harboring mosquitoes, inhibiting the survival and transmission of the parasite.
Attributable to this pathway, an estimated 1 in 25 malaria patients are able to stop the spread of malaria, conferring a type of altruistic immunity- says a recent study by scientists led by researcher Teun Bousema at Radboud university medical center. This is observed more prominently among missionaries who had been infected with malaria several times.
“This is the first time that we have been able to produce direct evidence that human antibodies against malaria parasite proteins are able to prevent the spread of malaria” said Bousema.
This study examined blood from more than 600 malaria patients, testing their ability to inhibit mosquito infection and their immune response to over 300 malaria proteins: Antibodies targeting 45 of these proteins were
linked with people’s ability to inhibit the spread of malaria, and people with these antibodies were ten times less infectious for mosquitoes.The results mean better understanding of how people contribute to the spread of malaria. The team is now investigating roles of a number of proteins as to their potential in the transmission blocking malaria vaccine.
Bousema: “We have developed a malaria parasite that expresses a firefly gene, allowing us to see just by looking at the mosquito whether or not it has been infected.”
PhD student Will Stone who has studied people’s immune response to over 300 malaria proteins says, “We saw that our test subjects produced antibodies that are able to slow the spread of malaria in response to 45 of these proteins. People with these antibodies were ten times less likely to infect mosquitos.”
Bousema concludes, “This research enables us to better understand which patients prevent the spread of malaria. We are now looking at whether it is possible to develop a malaria vaccine using some of these proteins. A vaccine that prevents the spread of malaria would help reduce the disease burden of malaria worldwide.”
