title: Synchronous versus asynchronous oscillations for antigenically varying Plasmodium falciparum with host immune response.
abstract: We consider a deterministic intra-host model for Plasmodium falciparum (Pf) malaria infection, which accounts for antigenic variation between n clonal variants of PfEMP1 and the corresponding host immune response (IR). Specifically, the model separates the IR into two components, specific and cross-reactive, respectively, in order to demonstrate that the latter can be a mechanism for the sequential appearance of variants observed in actual Pf infections. We show that a strong variant-specific IR relative to the cross-reactive IR favours the asynchronous oscillations (sequential dominance) over the synchronous oscillations in a number of ways. The decay rate of asynchronous oscillations is smaller than that for the synchronous oscillations, allowing for the parasite to survive longer. With the introduction of a delay in the stimulation of the IR, we show that only a small delay is necessary to cause persistent asynchronous oscillations and that a strong variant-specific IR increases the amplitude of the asynchronous oscillations.
authors.affiliation: Department of Mathematics, Southern Methodist University, Dallas, TX 75275-0156, USA.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Mitchell
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Carr
mesh_terms: D000818:Animals; D000940:Antigenic Variation / Q000235:genetics* / Q000276:immunology*; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology; D006790:Host-Parasite Interactions / Q000235:genetics* / Q000276:immunology*; D007109:Immunity / Q000235:genetics / Q000276:immunology*; D018448:Models, Immunological; D009716:Numerical Analysis, Computer-Assisted; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan