title: First-trimester Plasmodium falciparum infections display a typical "placental" phenotype.
abstract: BACKGROUND
  Plasmodium falciparum-infected erythrocytes (IEs) adhere to host cell receptors, allowing parasites to sequester into deep vascular beds of various organs. This defining phenomenon of malaria pathogenesis is key to the severe clinical complications associated with cerebral and placental malaria. The principal ligand associated with the binding to chondroitin sulfate A (CSA) that allows placental sequestration of IEs is a P. falciparum erythrocyte membrane protein 1 (PfEMP1) family member encoded by the var2csa gene.
  
  
  METHODS
  Here, we investigated the transcription pattern of var genes by real-time polymerase chain reaction, the expression of VAR2CSA, protein by flow cytometry, and the CSA-binding ability of IEs collected at different stages of pregnancy using a static-based Petri dish assay.
  
  
  RESULTS
  Through comparison with the profiles of isolates from nonpregnant hosts, we report several lines of evidence showing that parasites infecting women during pregnancy preferentially express VAR2CSA protein, and that selection for the capacity to adhere to CSA via VAR2CSA expression occurs early in pregnancy.
  
  
  CONCLUSIONS
  Our data suggest that the placental tropism of P. falciparum is already established in the first trimester of pregnancy, with consequent implications for the development of the pathology associated with placental malaria.
authors.affiliation: PRES Sorbonne Paris Cité, Faculté de Pharmacie, Université Paris Descartes, Paris, France.
authors.forename: Justin
authors.initials: J
authors.lastname: Doritchamou
authors.forename: Gwladys
authors.initials: G
authors.lastname: Bertin
authors.forename: Azizath
authors.initials: A
authors.lastname: Moussiliou
authors.forename: Pascal
authors.initials: P
authors.lastname: Bigey
authors.forename: Firmine
authors.initials: F
authors.lastname: Viwami
authors.forename: Sem
authors.initials: S
authors.lastname: Ezinmegnon
authors.forename: Nadine
authors.initials: N
authors.lastname: Fievet
authors.forename: Achille
authors.initials: A
authors.lastname: Massougbodji
authors.forename: Philippe
authors.initials: P
authors.lastname: Deloron
authors.forename: Nicaise
authors.initials: N
authors.lastname: Tuikue Ndam
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000096:biosynthesis; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D008288:Malaria / Q000469:parasitology* / Q000473:pathology; D008297:Male; D010920:Placenta / Q000469:parasitology*; D010963:Plasmodium falciparum / Q000472:pathogenicity*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000469:parasitology* / Q000473:pathology; D011261:Pregnancy Trimester, First; D014158:Transcription, Genetic; D055815:Young Adult
chemical_list: D000953:Antigens, Protozoan; C512601:VAR2CSA protein, Plasmodium falciparum