Malaria is a disease transmitted to humans by a mosquito bite, itself infected with a parasite. This parasite settles in the liver, then infects the red blood cells and destroys them. A Université Paris Cité - Inserm team, led by Prof. Pierre Buffet, Medical Vice-President of the Institut Pasteur, identifies two drugs likely to increase the efficiency of blood filtration by the spleen. This can stop the transmission of the disease between red blood cells.
Malaria is a disease caused by Plasmodium parasites. This infectious disease is potentially fatal. According to the World Health Organization (WHO), 241 million people were affected worldwide in 2020, and this caused 627,000 deaths (see our malaria disease fact sheet).
Transmitted to humans by the bite of an infected mosquito, the parasite settles in the liver, then multiplies after a few days in the red blood cells and causes them to burst. It can then disperse and gradually infect more and more red blood cells.
Improve blood filtration by the spleen to stop the disease
The team of Professor Pierre Buffet, current Medical Vice-President of the Institut Pasteur (UMRS 1134 Université Paris Cité – Inserm), studies the proportions - in blood and spleen - of red blood cells infected with the malaria parasite. In a recent study published in Nature Communications journal, the team explains the mechanisms of blood filtration by spleen and identifies two drugs likely to increase the efficiency of this filtration. The infected red blood cells would then be retained in the spleen to be destroyed and eliminated there, thus stopping the transmission of the disease. “We could go into a clinical trial within two years with a main result a year later. As these are already existing drugs, the pace of research could be faster than for standard development,” emphasizes Prof. Pierre Buffet.
The human spleen, cemetery and sanctuary for the malaria parasite
In the body, the spleen is the organ simultaneously responsible for generating in the blood an immune response to microbes and for filtering the blood to destroy and eliminate abnormal, too old or infected red blood cells. "From the beginning of the 2000s, with Geneviève Milon, Peter David and other members of Odile Puijalon’s unit at the Institut Pasteur, we began to study the role of the spleen with red blood cells infected with malaria parasite", explains Professor Pierre Buffet.
In a previous study in 2021 (in French), three teams* already observed in patients with chronic malaria a concentration of infected red blood cells 20 to 4000 times higher in the human spleen than in the circulating blood. These results confirmed that most of the parasite cycle would in fact occur almost entirely in the spleen, thus profoundly changing the understanding of malaria.
*Prof. Pierre Buffet team (UMRS 1134, Inserm – Université Paris Cité), with Prof. Fabrice Chrétien team (Institut Pasteur) and an Australian-Indonesian team led by the Prof. Nick Anstey.
At the Institut Pasteur, many studies focus on malaria. Among some recent successes:
June 2022 _ A New Drug Target against Malaria
Safe drugs with high potential to block malaria transmission revealed by a spleen mimetic screening, Nature Communications, 15 mars 2023