From Circulation to Cultivation: Plasmodium In Vivo versus In Vitro.

Research on Plasmodium parasites has driven breakthroughs in reducing malaria morbidity and mortality. Experimental analysis of in vivo/ex vivo versus in vitro samples serve unique roles in Plasmodium research. However, these distinctly different environments lead to discordant biology between parasites in host circulation and those under laboratory cultivation. Here, we review how in vitro factors, such as nutrient levels and physical forces, differ from those in the human host and the resulting implications for parasite growth, survival, and virulence. Additionally, we discuss the current utility of direct-from-host methodologies, which avoid the potentially confounding effects of in vitro cultivation. Finally, we make the case for methodological improvements that will drive research progress of physiologically relevant phenotypes.