Infect Immun. 2009 Jan 12. [Epub ahead of print]
Transmission of Toxoplasma gondii from Infected Dendritic Cells to Natural Killer Cells
Persson CM, Lambert H, Vutova PP, Dellacasa-Lindberg I, Nederby J, Yagita H, Ljunggren HG, Grandien A, Barragan A, Chambers BJ.
Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden; Department of Parasitology, Mycology and Environmental Microbiology, Swedish Institute for Infectious Disease Control, 171 82 Solna, Sweden; Juntendo University School of Medicine, Tokyo, 113-8421, Japan.
The obligate intracellular parasite Toxoplasma gondii (T. 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 i.p. 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.
PMID: 19139191 [PubMed - as supplied by publisher]