Prolonged extracellular development of Plasmodium falciparum and the favoring effect of carnitine

Cultivation of Asexual Intraerythrocytic Stages of Plasmodium falciparum

Successfully developed in 1976, the continuous in vitro culture of Plasmodium falciparum has many applications in the field of malaria research. It has become an important experimental model that directly uses a human pathogen responsible for a high prevalence of morbidity and mortality in many parts of the world and is a major source of biological material for immunological, biochemical, molecular, and pharmacological studies. Until present, the basic techniques described by Trager and Jensen and Haynes et al. remain unchanged in many malaria research laboratories. Nonetheless, different factors, including culture media, buffers, serum substitutes and supplements, sources of erythrocytes, and conditions of incubation (especially oxygen concentration), have been modified by different investigators to adapt the original technique in their laboratories or enhance the in vitro growth of the parasites. The possible effects and benefits of these modifications for the continuous cultivation of asexual intraerythrocytic stages of P. falciparum, as well as future challenges in developing a serum-free cultivation system and axenic cultures, are discussed.

Transport proteins of Plasmodium falciparum: defining the limits of metabolism

In this review we give an account of transport processes occurring at the membrane interface that separates the asexual stage of Plasmodium falciparum from its host, the infected erythrocyte, and also describe proteins whose activities may be important at this location. We explain the potential clinical value of such studies in the light of the current spread of parasite resistance to conventional antimalarial strategies. We discuss the uptake of substrates critical to the survival of the intracellular malaria parasite, and also the parasite's homeostatic and disposal mechanisms. The use of the Xenopus laevis expression system in the characterisation of a hexose transporter ("PfHT1") and a Ca(2+) ATPase ("PfATP4") of the parasite plasma membrane are described in detail.