Parasitology Seminar Series
Title: “Plasmodium falciparum dry season survival strategies"
Speaker: Silvia Portugal, PhD
Max Planck Institute for Infectious Biology
Date: Monday, November 09, 2020
Time: 12 - 1 pm
The dry season is a major challenge for Plasmodium falciparum parasites in many malaria endemic regions, where water availability limits mosquito vectors to only part of the year. How P. falciparum bridges two transmission seasons months apart, without being cleared by the human host or compromising host survival is poorly understood. Now we show that low levels of P. falciparum parasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of subjects with febrile malaria in the transmission season reflecting longer circulation within each replicative cycle of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication, but rather increased splenic clearance of longer-circulating infected erythrocytes, which likely maintain parasitaemias below clinical and immunological radar. We propose that P. falciparum virulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence that enables transmission as the rainy season ensues and mosquitoes return.
About Dr. Portugal:
After the Ph.D in Maria Mota’s lab (IMM Lisbon, Portugal) studying Plasmodium superinfection in mouse models or malaria, and a postDoc in Pete Crompton’s lab (NIH, USA) investigating naturally acquired immunity to malaria in the seasonal setting of Mali, I became an independent group Leader in Heidelberg University Hospital in 2016 aiming to understand how Plasmodium falciparum survives the dry season when no mosquitoes are available. This Fall my lab moved to the Max Planck Institute for Infection Biology in Berlin where we will continue to study the dry season reservoir of Plasmodium falciparum and possible ways to target it for malaria elimination.
Questions: Please contact Sue Waddington-Pilder (email@example.com).