Altered plasma membrane phospholipid organization in Plasmodium
falciparum-infected human erythrocytes
RS Schwartz, JA Olson, C Raventos-Suarez, M Yee, RH Heath, B Lubin and RL Nagel
The intraerythrocytic development of the malaria parasite is accompanied by
distinct morphological and biochemical changes in the host cell membrane,
yet little is known about development-related alterations in the
transbilayer organization of membrane phospholipids in parasitized cells.
This question was examined in human red cells infected with Plasmodium
falciparum. Normal red cells were infected with strain FCR3 or with clonal
derivatives that either produce (K+) or do not produce (K-) knobby
protuberances on the infected red cells. Parasitized cells were harvested
at various stages of parasite development, and the bilayer orientation of
red cell membrane phospholipids was determined chemically using
2,4,6-trinitrobenzene sulphonic acid (TNBS) or enzymatically using bee
venom phospholipase A2 (PLA2) and sphingomyelinase C (SMC). We found that
parasite development was accompanied by distinct alterations in the red
cell membrane transbilayer distribution of phosphatidylcholine (PC),
phosphatidylethanolamine (PE), and phosphatidylserine (PS). Increases in
the exoplasmic membrane leaflet exposure of PE and PS were larger in the
late-stage parasitized cells than in the early-stage parasitized cells.
Similar results were obtained for PE membrane distribution using either
chemical (TNBS) or enzymatic (PLA2 plus SMC) methods, although changes in
PS distribution were observed only with TNBS. Uninfected cohort cells
derived from mixed populations of infected and uninfected cells exhibited
normal patterns of membrane phospholipid organization. The observed
alterations in P falciparum-infected red cell membrane phospholipid
distribution, which is independent of the presence or absence of knobby
protuberances, might be associated with the drastic changes in cell
membrane permeability and susceptibility to early hemolysis observed in the
late stages of parasite development.
Volume 69,
Issue 2,
pp. 401-407,
02/01/1987
Copyright © 1987 by The American Society of Hematology
