Pathology of fatal and resolving Plasmodium berghei cerebral malaria in mice

CBA/T6 and Balb/c mice inoculated with Plasmodium berghei ANKA strain (PbA) died from cerebral malaria 6-8 days post-inoculation. DBA/2J mice similarly inoculated developed a non-fatal cerebral malaria, with mild temporary cerebral symptoms, and died between days 15 and 22 from other malaria-related complications. When inoculated with P. berghei K173 (Pb) these mouse strains did not develop a cerebral malaria but died between days 15 and 22 from other malaria-related complications. These mouse strain/parasite strain combinations allow for detailed examination of factors critical in the pathology of murine cerebral malaria. Monastral Blue, a colloid dye, when injected intravascularly between days 0 and 2 into PbA-inoculated CBA (PbA-CBA) or Balb/c (PbA-Balb/c) mice prevented death from cerebral malaria. There was no evidence of increased vascular permeability at this stage. When Monastral Blue was injected between days 5 and 8, there was increased vascular permeability in the kidney, liver, lung, spleen and brain of PbA-CBA and PbA-Balb/c mice. Injection of Monastral Blue into these animals at this time also precipitated cerebral symptoms and death, but not in Pb-infected mice. Endothelial and mononuclear cells phagocytosed, and were coated with, the Monastral Blue particles when the dye was injected between days 5 and 8 into PbA-CBA and PbA-Balb/c mice. Control, uninfected mice did not demonstrate either of these features. Pb-infected mice only demonstrated coated mononuclear cells. Mononuclear cell attachment to the endothelium, increased vascular permeability and increased association of Monastral Blue particles with monocytes and endothelial cells were correlated with cerebral symptoms and death. Monastral Blue is thus a useful agent for studying the roles of mononuclear cells and endothelium in murine cerebral malaria.