title: Red blood cell membrane dynamics during malaria parasite egress.
abstract: Precisely how malaria parasites exit from infected red blood cells to further spread the disease remains poorly understood. It has been shown recently, however, that these parasites exploit the elasticity of the cell membrane to enable their egress. Based on this work, showing that parasites modify the membrane's spontaneous curvature, initiating pore opening and outward membrane curling, we develop a model of the dynamics of the red blood cell membrane leading to complete parasite egress. As a result of the three-dimensional, axisymmetric nature of the problem, we find that the membrane dynamics involve two modes of elastic-energy release: 1), at short times after pore opening, the free edge of the membrane curls into a toroidal rim attached to a membrane cap of roughly fixed radius; and 2), at longer times, the rim radius is fixed, and lipids in the cap flow into the rim. We compare our model with the experimental data of Abkarian and co-workers and obtain an estimate of the induced spontaneous curvature and the membrane viscosity, which control the timescale of parasite release. Finally, eversion of the membrane cap, which liberates the remaining parasites, is driven by the spontaneous curvature and is found to be associated with a breaking of the axisymmetry of the membrane.
authors.affiliation: Laboratoire Charles Coulomb UMR 5221, CNRS, Laboratoire Charles Coulomb UMR 5221, Université Montpellier 2, F-34095 Montpellier, France. andrew.callan-jones@univ-montp2.fr
authors.forename: Andrew
authors.initials: A
authors.lastname: Callan-Jones
authors.forename: Octavio Eduardo
authors.initials: OE
authors.lastname: Albarran Arriagada
authors.forename: Gladys
authors.initials: G
authors.lastname: Massiera
authors.forename: Vladimir
authors.initials: V
authors.lastname: Lorman
authors.forename: Manouk
authors.initials: M
authors.lastname: Abkarian
mesh_terms: D001696:Biomechanical Phenomena; D004910:Erythrocyte Membrane / Q000378:metabolism* / Q000469:parasitology*; D008288:Malaria / Q000469:parasitology*; D052940:Merozoites / Q000254:growth & development / Q000502:physiology; D008954:Models, Biological; D010963:Plasmodium falciparum / Q000254:growth & development* / Q000502:physiology