Plasmodium falciparum-infected erythrocytes increase intercellular adhesion molecule 1 expression on brain endothelium through NF-kappaB

Infect Immun. 2006 Jun;74(6):3262-70. doi: 10.1128/IAI.01625-05.

Abstract

Sequestration of Plasmodium falciparum-infected erythrocytes (Pf-IRBC) in postcapillary brain endothelium is a hallmark of cerebral malaria (CM) pathogenesis. There is a correlation between adherent Pf-IRBC and increased expression of intercellular cell adhesion molecule 1 (ICAM-1), which is also a receptor for Pf-IRBC on human brain microvascular endothelial cells (HBMEC). The underlying mechanism for the increased ICAM-1 expression has not been clearly defined. Therefore, we investigated the mechanisms of ICAM-1 expression on isolated HBMEC after exposure to Pf-IRBC. Ultrastructural characterization of the model confirmed that there was attachment through both Pf-IRBC knobs and HBMEC microvillus protrusions. Pf-IRBC induced a dose- and time-dependent increase in ICAM-1 expression on HBMEC that was specific for human brain endothelium and was not observed with human umbilical vein endothelium. Involvement of both membrane-associated Pf-IRBC proteins and parasite-derived soluble factors with the increase in ICAM-1 expression was demonstrated by surface trypsinization and fractionation. Pf-IRBC exposure induced nuclear translocation of NF-kappaB in HBMEC, which was linked to ICAM-1 expression, as shown by use of specific inhibitors of the transcription factor NF-kappaB and immunocytochemistry. In addition, inhibition of reactive oxygen species decreased Pf-IRBC-induced ICAM-1 expression on HBMEC. Parasite-induced ICAM-1 expression explains the localization of this molecule on brain endothelium in postmortem CM brain samples. By increasing ICAM-1 expression, Pf-IRBC may increase their sequestration, thereby perpetuating CM.

Publication types

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

MeSH terms

  • Active Transport, Cell Nucleus
  • Animals
  • Artemisinins / pharmacology
  • Blood-Brain Barrier
  • Brain / metabolism*
  • Endothelium, Vascular / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Erythrocytes / parasitology*
  • Humans
  • Intercellular Adhesion Molecule-1 / analysis*
  • NF-kappa B / physiology*
  • Plasmodium falciparum / pathogenicity*
  • Reactive Oxygen Species
  • Sesquiterpenes / pharmacology

Substances

  • Artemisinins
  • NF-kappa B
  • Reactive Oxygen Species
  • Sesquiterpenes
  • Intercellular Adhesion Molecule-1
  • artemisinin