Severe adult malaria is associated with specific PfEMP1 adhesion types and high parasite biomass

Proc Natl Acad Sci U S A. 2016 Jun 7;113(23):E3270-9. doi: 10.1073/pnas.1524294113. Epub 2016 May 16.


The interplay between cellular and molecular determinants that lead to severe malaria in adults is unexplored. Here, we analyzed parasite virulence factors in an infected adult population in India and investigated whether severe malaria isolates impair endothelial protein C receptor (EPCR), a protein involved in coagulation and endothelial barrier permeability. Severe malaria isolates overexpressed specific members of the Plasmodium falciparum var gene/PfEMP1 (P. falciparum erythrocyte membrane protein 1) family that bind EPCR, including DC8 var genes that have previously been linked to severe pediatric malaria. Machine learning analysis revealed that DC6- and DC8-encoding var transcripts in combination with high parasite biomass were the strongest indicators of patient hospitalization and disease severity. We found that DC8 CIDRα1 domains from severe malaria isolates had substantial differences in EPCR binding affinity and blockade activity for its ligand activated protein C. Additionally, even a low level of inhibition exhibited by domains from two cerebral malaria isolates was sufficient to interfere with activated protein C-barrier protective activities in human brain endothelial cells. Our findings demonstrate an interplay between parasite biomass and specific PfEMP1 adhesion types in the development of adult severe malaria, and indicate that low impairment of EPCR function may contribute to parasite virulence.

Keywords: EPCR; PfEMP1; Plasmodium falciparum; malaria; var.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antigens, CD / genetics
  • Antigens, CD / metabolism
  • Biomass
  • Endothelial Protein C Receptor
  • Female
  • Humans
  • Machine Learning
  • Malaria, Falciparum / genetics
  • Malaria, Falciparum / metabolism
  • Malaria, Falciparum / parasitology*
  • Male
  • Middle Aged
  • Plasmodium falciparum / genetics*
  • Plasmodium falciparum / pathogenicity*
  • Protein C / metabolism
  • Protein Domains
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / genetics*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism
  • Virulence
  • Young Adult


  • Antigens, CD
  • Endothelial Protein C Receptor
  • PROCR protein, human
  • Protein C
  • Protozoan Proteins
  • Receptors, Cell Surface
  • erythrocyte membrane protein 1, Plasmodium falciparum

Associated data

  • GENBANK/KU843600
  • GENBANK/KU843604