Zonal human hepatocytes are differentially permissive to Plasmodium falciparum malaria parasites

Abstract

Plasmodium falciparum (Pf) is a major cause of human malaria and is transmitted by infected Anopheles mosquitoes. The initial asymptomatic infection is characterized by parasite invasion of hepatocytes, followed by massive replication generating schizonts with blood-infective merozoites. Hepatocytes can be categorized by their zonal location and metabolic functions within a liver lobule. To understand specific host conditions that affect infectivity, we studied Pf parasite liver stage development in relation to the metabolic heterogeneity of fresh human hepatocytes. We found selective preference of different Pf strains for a minority of hepatocytes, which are characterized by the particular presence of glutamine synthetase (hGS). Schizont growth is significantly enhanced by hGS uptake early in development, showcasing a novel import system. In conclusion, Pf development is strongly determined by the differential metabolic status in hepatocyte subtypes. These findings underscore the importance of detailed understanding of hepatocyte host-Pf interactions and may delineate novel pathways for intervention strategies.

A portfolio of geographically distinct laboratory-adapted Plasmodium falciparum clones with consistent infection rates in Anopheles mosquitoes

“…An additional limitation is that the current study stopped when oocysts were detected in the mosquito midgut. For a number of isolates data on sporozoite production are also available [ 13 , 14 ], but comparing sporozoite production or infectivity between individual isolates was beyond the scope of this manuscript. A last limitation of the current work is that no images of non-viable gametocytes were made and expert judgement regularly informed the timing of feeding experiments.…”

“…Given the importance of genetic variation for vaccine and drug efficacy, reliance on a single parasite isolate fails to give a comprehensive insight into intervention potency in natural infections [ 10 ]. Similarly, relevant inter-strain variation in parasite growth rates [ 11 ], gametocyte production [ 12 ] and sporozoite invasion capacity [ 13 , 14 ] warrant further examination. The current portfolio of laboratory isolates for studies on sexual and sporogonic stages is very limited.…”

Dissection-independent production ofPlasmodiumsporozoites from whole mosquitoes

“…For P. falciparum infections, HC-04 cells (media composition according to Yang et al [ 73 ]) were plated on 96 well plates (MatTek Corporation) coated with a 1 μg/cm 2 mix of collagen, fibronectin, and laminin (see above) at a seeding density of 17,000 cells per well. Sporozoites were added to cells at a ratio of 5:1 (i.e., 85,000 sporozoites per well).…”

Mid-Liver Stage Arrest of Plasmodium falciparum Schizonts in Primary Porcine Hepatocytes

“…Fresh porcine hepatocytes were isolated based on human protocols as described previously Yang et al (2021) (Yang et al, 2021). Different seeding densities were compared, and the viability of each density was assessed using brightfield microscopy and mitochondrial enzymatic activity (MTT) from day of invasion up to day five (Figures 1A, B).…”