In vitro activation of feline immunodeficiency virus in ramified microglial cells from asymptomatically infected cats.
Intravenous infection of cats with feline immunodeficiency virus was used as a model system to study activation of virus replication in brain-resident microglial cells in vitro. Virus release by ramified microglial cells isolated from subclinically infected animals was detectable in cell-free tissue culture supernatant only by reverse transcription and nested PCR of gag-specific RNA sequences and not by virion-associated reverse transcriptase activity. In contrast, cocultivation of in vivo-infected microglial cells with mitogen-activated peripheral blood mononuclear cells (PBMC) regularly allows detection of high virus yields in cell-free tissue culture fluid. Besides uptake and multiplication of microglia-derived virus in PBMC, release of virus from microglia is stimulated by cell contact with PBMC. The data suggest that T lymphocytes patrolling the central nervous system could reactivate the semilatent state of lentiviruses in microglial cells in the course of clinically silent central nervous system infection.
Hein
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Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Mannheim, Ruprecht-Karls-Universität Heidelberg, Mannheim, Germany. andreas.hein@imh.ma.uni-heidelberg.de
Martin
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JP
Dörries
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D000818:Animals; D002415:Cats; D002460:Cell Line; D018920:Coculture Techniques; D016089:Immunodeficiency Virus, Feline / Q000254:growth & development*; D016180:Lentivirus Infections / Q000821:virology*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000821:virology; D008213:Lymphocyte Activation; D017628:Microglia / Q000166:cytology / Q000821:virology*; D014771:Virion / Q000502:physiology; D014775:Virus Activation; D014779:Virus Replication