Recombinant PfEMP1 peptide inhibits and reverses cytoadherence of clinical Plasmodium falciparum isolates in vivo

Blood. 2003 Jan 1;101(1):331-7. doi: 10.1182/blood-2002-06-1725. Epub 2002 Aug 15.

Abstract

The parasite ligand Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) and host endothelial receptors represent potential targets for antiadhesive therapy for cytoadherence. In the present study, the major host receptor CD36 was targeted in vitro and in vivo with a recombinant peptide, PpMC-179, corresponding to the minimal CD36-binding domain from the cysteine-rich interdomain region 1 (CIDR1) within the MCvar1 PfEMP1. The in vitro inhibitory effect of PpMC-179 on human dermal microvascular endothelial cells (HDMECs) expressing multiple relevant adhesion molecules was investigated using a parallel-plate flow chamber. Pretreatment of endothelial monolayers with PpMC-179 (2 microM) inhibited the adhesion of infected erythrocytes (IRBCs) from all clinical isolates tested by 84.4% on resting and 62.8% on tumor necrosis factor alpha (TNF-alpha)-stimulated monolayers. Adhesion to stimulated cells was further inhibited (90.4%) when PpMC-179 was administered with an inhibitory anti-intercellular adhesion molecule 1 (ICAM-1) monoclonal antibody 84H10 (5 microg/mL). To determine the in vivo effectiveness of PpMC-179, we used a human/severe combined immunodeficiency (SCID) mouse chimeric model that allowed direct visualization of cytoadherence on intact human microvasculature. In unstimulated skin grafts, PpMC-179 inhibited adhesion by 86.3% and by 84.6% in TNF-alpha-stimulated skin grafts. More importantly, PpMC-179 administration resulted in the detachment of already adherent IRBCs by 80.7% and 83.3% on resting and stimulated skin grafts, respectively. The antiadhesive effect of PpMC-179 was rapid and sustained in vivo for at least 30 minutes. Our data indicate that targeting cytoadhesion in vivo is feasible and may offer a rapid antimalarial therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesiveness / drug effects
  • Animals
  • Endothelium, Vascular / metabolism
  • Humans
  • Mice
  • Mice, Transgenic
  • Microcirculation
  • Microscopy, Video
  • Plasmodium falciparum / drug effects*
  • Plasmodium falciparum / pathogenicity
  • Protozoan Proteins / isolation & purification
  • Protozoan Proteins / pharmacology*
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / pharmacology

Substances

  • Protozoan Proteins
  • Recombinant Proteins
  • erythrocyte membrane protein 1, Plasmodium falciparum