Type of in vitro cultivation influences cytoadhesion, knob structure, protein localization and transcriptome profile of Plasmodium falciparum

Abstract

In vitro cultivation of Plasmodium falciparum is critical for studying the biology of this parasite. However, it is likely that different in vitro cultivation conditions influence various aspects of the parasite’s life cycle. In the present study two P. falciparum isolates were cultivated using the two most common methods, in which AlbuMAX or human serum as additives are used, and the results were compared. The type of cultivation influenced the knob structure of P. falciparum-infected erythrocytes (IEs). IEs cultivated with AlbuMAX had fewer knobs than those cultivated with human serum. Furthermore, knob size varied between isolates and is also depended on the culture medium. In addition, there was a greater reduction in the cytoadhesion of IEs to various endothelial receptors in the presence of AlbuMAX than in the presence of human serum. Surprisingly, cytoadhesion did not correlate with the presence or absence of knobs. Greater numbers of the variant surface antigen families RIFIN, STEVOR, and PfMC-2TM were found at the IE membrane when cultivated in the presence of AlbuMAX. Moreover, the type of cultivation had a marked influence on the transcriptome profile. Compared with cultivation with human serum, cultivation with AlbuMAX increased the expression of approximately 500–870 genes.

Adhesion between P. falciparum infected erythrocytes and human endothelial receptors follows alternative binding dynamics under flow and febrile conditions

“…Finally, adherent IEs are counted manually. These experiments demonstrated that laboratory-adapted trophozoite-stage IT4 and 3D7 isolates show different binding capacities to various ECRs under static conditions 31,33 . The main objective of this study was to characterize the binding behavior of erythrocytes infected with P. falciparum to the ECRs CD36, ICAM-1, P-selectin, CD9, and CSA under controlled flow and temperature conditions.…”

“…Experimental setup. Endothelial cytoadhesion and the binding capacities of various laboratory strains and patient isolates of P. falciparum have been mainly investigated under static conditions 6,31,32 . This is classically achieved by directly incubating IEs with cells or recombinant receptors of interest 8,16,33,34 .…”

Proteome and Structural Organization of the Knob Complex on the Surface of the Plasmodium Infected Red Blood Cell

“…Keeping in mind the above‐mentioned challenges, we first decided to use the parasite cultivation method that allows formation of maximum numbers of knobs on the erythrocyte membrane. It has been demonstrated that long‐term in vitro cultivated parasites form a lower number of knobs, and that the use of the medium supplement AlbuMAX alone in the culture media results in fewer knobs on the surface of iRBC as compared to 10% human serum . Therefore, we used a 3D7 knobby line (validated by punctate staining of KAHRP on the infected erythrocyte membrane by immunofluorescence; Supporting Information Figure S1) that was in culture for a short while and maintained it in media containing 10% human serum instead of AlbuMAX.…”

CD47-SIRPα Interactions Regulate Macrophage Uptake of Plasmodium falciparum-Infected Erythrocytes and Clearance of Malaria In Vivo

“…In this study, Albumax (Life Technologies, Paisley, United Kingdom) was used to grow the parasites. Compared to the use of human serum, parasites grown with Albumax display altered expression of over 500 genes (31). For example, the cytoadhesion of infected RBCs to various endothelial receptors is greatly reduced in the presence of Albumax compared to human serum.…”