title: Transmission of Toxoplasma gondii from infected dendritic cells to natural killer cells.
abstract: The obligate intracellular parasite Toxoplasma gondii can actively infect any nucleated cell type, including cells from the immune system. In the present study, we observed that a large number of natural killer (NK) cells were infected by T. gondii early after intraperitoneal inoculation of parasites into C57BL/6 mice. Interestingly, one mechanism of NK cell infection involved NK cell-mediated targeting of infected dendritic cells (DC). Perforin-dependent killing of infected DC led to active egress of infectious parasites that rapidly infected adjacent effector NK cells. Infected NK cells were not efficiently targeted by other NK cells. These results suggest that rapid transfer of T. gondii from infected DC to effector NK cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection.
authors.affiliation: Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, F59, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Catrine M
authors.initials: CM
authors.lastname: Persson
authors.forename: Henrik
authors.initials: H
authors.lastname: Lambert
authors.forename: Polya P
authors.initials: PP
authors.lastname: Vutova
authors.forename: Isabel
authors.initials: I
authors.lastname: Dellacasa-Lindberg
authors.forename: Joanna
authors.initials: J
authors.lastname: Nederby
authors.forename: Hideo
authors.initials: H
authors.lastname: Yagita
authors.forename: Hans-Gustaf
authors.initials: HG
authors.lastname: Ljunggren
authors.forename: Alf
authors.initials: A
authors.lastname: Grandien
authors.forename: Antonio
authors.initials: A
authors.lastname: Barragan
authors.forename: Benedict J
authors.initials: BJ
authors.lastname: Chambers
mesh_terms: D000818:Animals; D003713:Dendritic Cells / Q000276:immunology / Q000469:parasitology*; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology / Q000469:parasitology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D014122:Toxoplasma / Q000276:immunology; D014123:Toxoplasmosis / Q000276:immunology / Q000635:transmission*