Brain Endothelium: The "Innate Immunity Response Hypothesis" in Cerebral Malaria Pathogenesis

Front Immunol. 2019 Jan 29:9:3100. doi: 10.3389/fimmu.2018.03100. eCollection 2018.

Abstract

Cerebral malaria (CM) is a life-threatening neurological syndrome caused by Plasmodium falciparum infection afflicting mainly children in Africa. Current pathogenesis models implicate parasite and host-derived factors in impairing brain vascular endothelium (BVE) integrity. Sequestration of Plasmodium-infected red blood cells (iRBCs) in brain microvessels is a hallmark of CM pathology. However, the precise mechanisms driving loss of blood-brain barrier (BBB) function with consequent brain injury are still unsettled and it is plausible that distinct pathophysiology trajectories are involved. Studies in humans and in the mouse model of CM indicate that inflammatory reactions intertwined with microcirculatory and coagulation disturbances induce alterations in vascular permeability and impair BBB integrity. Yet, the role of BVE as initiator of immune responses against parasite molecules and iRBCs is largely unexplored. Brain endothelial cells express pattern recognition receptors (PRR) and are privileged sensors of blood-borne infections. Here, we focus on the hypothesis that innate responses initiated by BVE and subsequent interactions with immune cells are critical to trigger local effector immune functions and induce BBB damage. Uncovering mechanisms of BVE involvement in sensing Plasmodium infection, recruiting of immune cells and directing immune effector functions could reveal pharmacological targets to promote BBB protection with potential applications in CM clinical management.

Keywords: PAMPs; PRRs; blood-brain barrier; cerebral malaria; endothelial cells; innate immunity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Antimalarials / pharmacology
  • Antimalarials / therapeutic use
  • Blood-Brain Barrier / cytology
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / immunology*
  • Capillary Permeability / drug effects
  • Capillary Permeability / immunology
  • Disease Models, Animal
  • Endothelial Cells / immunology
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / immunology*
  • Host-Parasite Interactions / immunology
  • Humans
  • Immunity, Innate*
  • Malaria, Cerebral / drug therapy
  • Malaria, Cerebral / immunology*
  • Malaria, Cerebral / parasitology
  • Microcirculation / immunology
  • Plasmodium falciparum / immunology*

Substances

  • Antimalarials