title: High-throughput screening platform identifies small molecules that prevent sequestration of Plasmodium falciparum-infected erythrocytes.
abstract: BACKGROUND
  We developed a 2-step approach to screen molecules that prevent and/or reverse Plasmodium falciparum-infected erythrocyte (IE) binding to host receptors. IE adhesion and sequestration in vasculature causes severe malaria, and therefore antiadhesion therapy might be useful as adjunctive treatment. IE adhesion is mediated by the polymorphic family (approximately 60 members) of P. falciparum EMP1 (PfEMP1) multidomain proteins.
  
  
  METHODS
  We constructed sets of PfEMP1 domains that bind ICAM-1, CSA, or CD36, receptors that commonly support IE binding. Combinations of domain-coated beads were assayed by Bio-Plex technology as a high-throughput molecular platform to screen antiadhesion molecules (antibodies and small molecules). Molecules identified as so-called hits in the screen (first step) then could be assayed individually for inhibition of binding of live IE to receptors (second step).
  
  
  RESULTS
  In proof-of-principle studies, the antiadhesion activity of several antibodies was concordant in Bio-Plex and live IE assays. Using this 2-step approach, we identified several molecules in a small molecule library of 10 000 compounds that could inhibit and reverse binding of IEs to ICAM-1 and CSA receptors.
  
  
  CONCLUSIONS
  This 2-step screening approach should be efficient for identification of antiadhesion drug candidates for falciparum malaria.
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington.
authors.forename: Justin
authors.initials: J
authors.lastname: Gullingsrud
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington.
authors.forename: Neta
authors.initials: N
authors.lastname: Milman
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington.
authors.forename: Tracy
authors.initials: T
authors.lastname: Saveria
authors.affiliation: Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton.
authors.forename: Olga
authors.initials: O
authors.lastname: Chesnokov
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Williamson
authors.affiliation: Inserm UMR 1134 Université Paris Diderot, Sorbonne Paris Cité, UMR S1134 Institut National de la Transfusion Sanguine, Paris, France.
authors.forename: Anand
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: Inserm UMR 1134 Université Paris Diderot, Sorbonne Paris Cité, UMR S1134 Institut National de la Transfusion Sanguine, Paris, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Gamain
authors.affiliation: Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health, Bethesda, Maryland.
authors.forename: Patrick E
authors.initials: PE
authors.lastname: Duffy
authors.affiliation: Seattle Biomedical Research Institute, Seattle, Washington Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton.
authors.forename: Andrew V
authors.initials: AV
authors.lastname: Oleinikov
mesh_terms: D018955:CD36 Antigens / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism / Q000469:parasitology*; D057166:High-Throughput Screening Assays; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D016778:Malaria, Falciparum / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000276:immunology; D015800:Protozoan Proteins / Q000378:metabolism*; D054852:Small Molecule Libraries
chemical_list: D018955:CD36 Antigens; D015815:Cell Adhesion Molecules; D015800:Protozoan Proteins; D054852:Small Molecule Libraries; C085731:erythrocyte membrane protein 1, Plasmodium falciparum; D018799:Intercellular Adhesion Molecule-1
keywords: CD36; CSA; ICAM-1; PfEMP1 proteins; Plasmodium falciparum; antiadhesion therapy; high-throughput screening; host receptors; malaria; sequestration of parasites; small molecules