“New Discovery: Two Drugs Increase Blood Filtration to Stop Malaria Transmission”

Malaria is a disease transmitted to humans by the bite of a mosquito which is itself infected with a parasite. This parasite settles in the liver, then infects the red blood cells and destroys them. A Paris Cité University – Inserm team, led by Pr Pierre Buffet, medical director of the Institut Pasteur, has identified two drugs likely to increase the efficiency of blood filtration by the spleen tenfold. This can stop the transmission of the disease between red blood cells.

Malaria is a disease caused by parasites of the genus Plasmodium. This infectious disease is potentially fatal. According to the World Health Organization (WHO), it affected approximately 241 million people worldwide in 2020, and caused 627,000 deaths (see our malaria disease sheet).

Transmitted to humans by the bite of a mosquito that is itself infected, 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 director of the Institut Pasteur (UMRS 1134 Université Paris Cité – Inserm), is interested in the proportions of red blood cells infected by the malaria parasite present in the blood and the spleen. In a recent study published in the journal Nature Communications, the team explains the mechanisms of blood filtration by the spleen and identifies two drugs likely to increase the efficiency of this filtration tenfold. 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 tempo of research could be faster than for standard development,” emphasizes Professor Pierre Buffet.

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The human spleen, cemetery and sanctuary for the malaria parasite

In the body, the spleen is the organ simultaneously responsible for generating an immune response to microbes in the blood and for filtering the blood to destroy and eliminate abnormal red blood cells that are too old or infected. “From the beginning of the 2000s, with Geneviève Milon, Peter David and other members of Odile Puijalon’s unit at the Pasteur Institute, we began to study the role of the spleen in the face of red blood cells infected with malaria parasite »explains Professor Pierre Buffet.

Already in a previous study in 2021, the UMRS 1134 team of Professor Pierre Buffet (Inserm – Université Paris Cité), in close collaboration with the team of Professor Fabrice Chrétien (Institut Pasteur) and an Australian-Indonesian team led by Professor Nick Anstey, observed at 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 modifying the understanding of malaria.

Source

Safe drugs with high potential to block malaria transmission revealed by a spleen mimetic screening, Nature Communications15 mars 2023

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