title: Real-time imaging reveals the dynamics of leukocyte behaviour during experimental cerebral malaria pathogenesis.
abstract: During experimental cerebral malaria (ECM) mice develop a lethal neuropathological syndrome associated with microcirculatory dysfunction and intravascular leukocyte sequestration. The precise spatio-temporal context in which the intravascular immune response unfolds is incompletely understood. We developed a 2-photon intravital microscopy (2P-IVM)-based brain-imaging model to monitor the real-time behaviour of leukocytes directly within the brain vasculature during ECM. Ly6C(hi) monocytes, but not neutrophils, started to accumulate in the blood vessels of Plasmodium berghei ANKA (PbA)-infected MacGreen mice, in which myeloid cells express GFP, one to two days prior to the onset of the neurological signs (NS). A decrease in the rolling speed of monocytes, a measure of endothelial cell activation, was associated with progressive worsening of clinical symptoms. Adoptive transfer experiments with defined immune cell subsets in recombinase activating gene (RAG)-1-deficient mice showed that these changes were mediated by Plasmodium-specific CD8(+) T lymphocytes. A critical number of CD8(+) T effectors was required to induce disease and monocyte adherence to the vasculature. Depletion of monocytes at the onset of disease symptoms resulted in decreased lymphocyte accumulation, suggesting reciprocal effects of monocytes and T cells on their recruitment within the brain. Together, our studies define the real-time kinetics of leukocyte behaviour in the central nervous system during ECM, and reveal a significant role for Plasmodium-specific CD8(+) T lymphocytes in regulating vascular pathology in this disease.
authors.affiliation: Immune Imaging Laboratory, The Centenary Institute, Newtown, Sydney, New South Wales, Australia; Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Saparna
authors.initials: S
authors.lastname: Pai
authors.affiliation: Immune Imaging Laboratory, The Centenary Institute, Newtown, Sydney, New South Wales, Australia.
authors.forename: Jim
authors.initials: J
authors.lastname: Qin
authors.affiliation: Immune Imaging Laboratory, The Centenary Institute, Newtown, Sydney, New South Wales, Australia; Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Lois
authors.initials: L
authors.lastname: Cavanagh
authors.affiliation: Immune Imaging Laboratory, The Centenary Institute, Newtown, Sydney, New South Wales, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mitchell
authors.affiliation: Vascular Immunology Unit, Discipline of Pathology, Sydney Medical School, University of Sydney, Camperdown, Sydney, New South Wales, Australia.
authors.forename: Fatima
authors.initials: F
authors.lastname: El-Assaad
authors.affiliation: Immune Imaging Laboratory, The Centenary Institute, Newtown, Sydney, New South Wales, Australia; Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Rohit
authors.initials: R
authors.lastname: Jain
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia; Vascular Immunology Unit, Discipline of Pathology, Sydney Medical School, University of Sydney, Camperdown, Sydney, New South Wales, Australia.
authors.forename: Valery
authors.initials: V
authors.lastname: Combes
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia; Molecular Immunopathology Unit, Discipline of Pathology, Sydney Medical School and Bosch Institute, University of Sydney, Camperdown, Sydney, New South Wales, Australia.
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Hunt
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia; Vascular Immunology Unit, Discipline of Pathology, Sydney Medical School, University of Sydney, Camperdown, Sydney, New South Wales, Australia.
authors.forename: Georges E R
authors.initials: GE
authors.lastname: Grau
authors.affiliation: Immune Imaging Laboratory, The Centenary Institute, Newtown, Sydney, New South Wales, Australia; Discipline of Dermatology, University of Sydney, Sydney, New South Wales, Australia; Department of Dermatology, Royal Prince Alfred Hospital, Camperdown, Sydney, New South Wales, Australia.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weninger
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D016779:Malaria, Cerebral / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence; D009000:Monocytes / Q000378:metabolism / Q000473:pathology; D010962:Plasmodium berghei / Q000378:metabolism*