Migratory responses of leukocytes infected with Toxoplasma gondii.

Recently, monocytic cells were suggested to systemically transport Toxoplasma tachyzoites during acute infection in mice. The mechanism underlying this shuttling function may partly be explained by dramatically enhanced host-cell motility upon parasite invasion. Here, we report that infection of human and murine macrophages in vitro resulted in augmented migration across a transwell membrane, linked to host-cell differentiation and to the parasite genotype. The hypermotility phenotype was absent in infected monocytes, NK, B or T-cells. In contrast to previous observations with dendritic cells, adoptive transfer of infected macrophages or lymphocytes did not exacerbate infection in mice compared to inoculation with free parasites.