title: Hierarchical Cluster Analysis of Three-Dimensional Reconstructions of Unbiased Sampled Microglia Shows not Continuous Morphological Changes from Stage 1 to 2 after Multiple Dengue Infections in Callithrix penicillata.
abstract: It is known that microglial morphology and function are related, but few studies have explored the subtleties of microglial morphological changes in response to specific pathogens. In the present report we quantitated microglia morphological changes in a monkey model of dengue disease with virus CNS invasion. To mimic multiple infections that usually occur in endemic areas, where higher dengue infection incidence and abundant mosquito vectors carrying different serotypes coexist, subjects received once a week subcutaneous injections of DENV3 (genotype III)-infected culture supernatant followed 24 h later by an injection of anti-DENV2 antibody. Control animals received either weekly anti-DENV2 antibodies, or no injections. Brain sections were immunolabeled for DENV3 antigens and IBA-1. Random and systematic microglial samples were taken from the polymorphic layer of dentate gyrus for 3-D reconstructions, where we found intense immunostaining for TNFα and DENV3 virus antigens. We submitted all bi- or multimodal morphological parameters of microglia to hierarchical cluster analysis and found two major morphological phenotypes designated types I and II. Compared to type I (stage 1), type II microglia were more complex; displaying higher number of nodes, processes and trees and larger surface area and volumes (stage 2). Type II microglia were found only in infected monkeys, whereas type I microglia was found in both control and infected subjects. Hierarchical cluster analysis of morphological parameters of 3-D reconstructions of random and systematic selected samples in control and ADE dengue infected monkeys suggests that microglia morphological changes from stage 1 to stage 2 may not be continuous.
authors.affiliation: Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federal do Pará, Hospital Universitário João de Barros BarretoBelém, Brasil; Experimental Neuropathology Laboratory, Department of Pharmacology, University of OxfordOxford, UK.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Diniz
authors.affiliation: Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federal do Pará, Hospital Universitário João de Barros Barreto Belém, Brasil.
authors.forename: Geane O
authors.initials: GO
authors.lastname: Silva
authors.affiliation: Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federal do Pará, Hospital Universitário João de Barros Barreto Belém, Brasil.
authors.forename: Thaís B
authors.initials: TB
authors.lastname: Naves
authors.affiliation: Curso de Graduação em Biologia, Universidade da Amazônia Belém, Brasil.
authors.forename: Taiany N
authors.initials: TN
authors.lastname: Fernandes
authors.affiliation: Departamento de Microscopia Eletrônica, Instituto Evandro Chagas Belém, Brasil.
authors.forename: Sanderson C
authors.initials: SC
authors.lastname: Araújo
authors.affiliation: Departamento de Microscopia Eletrônica, Instituto Evandro Chagas Belém, Brasil.
authors.forename: José A P
authors.initials: JA
authors.lastname: Diniz
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará Belém, Brasil.
authors.forename: Luis H S
authors.initials: LH
authors.lastname: de Farias
authors.affiliation: Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federal do Pará, Hospital Universitário João de Barros Barreto Belém, Brasil.
authors.forename: Marcia C K
authors.initials: MC
authors.lastname: Sosthenes
authors.affiliation: Laboratório de Biologia Molecular e Ambiental, Instituto Federal de Educação Ciência e Tecnologia do Pará, Campus de Bragança, Bragança Pará, Brasil.
authors.forename: Cristovam G
authors.initials: CG
authors.lastname: Diniz
authors.affiliation: Experimental Neuropathology Laboratory, Department of Pharmacology, University of Oxford Oxford, UK.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Anthony
authors.affiliation: Departamento de Arbovirologia e Febres Hemorrágicas, Instituto Evandro Chagas Ananindeua, Brasil.
authors.forename: Pedro F
authors.initials: PF
authors.lastname: da Costa Vasconcelos
authors.affiliation: Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Universidade Federal do Pará, Hospital Universitário João de Barros BarretoBelém, Brasil; Experimental Neuropathology Laboratory, Department of Pharmacology, University of OxfordOxford, UK.
authors.forename: Cristovam W
authors.initials: CW
authors.lastname: Picanço Diniz
keywords: Callithrix penicillata; dengue virus infection; dentate gyrus; hierarchical cluster analysis; microglial morphological subtleties