Different effect of Toxoplasma gondii infection on adhesion capacity of fibroblasts and monocytes

This study investigated the effect of infection with the apicomplexan parasite Toxoplasma gondii , in combination with the concomitant cytokine environment (IFN-γ/TNF-α), on adhesion of THP-1 monocytic cells to MRC-5 fibroblasts. Surprisingly, infection of THP-1 cells decreased their adhesion to the MRC-5 cell monolayer. This decrease was compensated by IFN-γ/TNF-α stimulation. In contrast, infection of MRC-5 cells significantly increased adhesion, which was synergistically augmented by cytokine stimulation. Levels of ICAM-1 (CD54) on MRC-5 cells, as well as LFA-1 (CD11a) on THP-1 cells, were not changed by infection, neither in resting, nor in cytokine stimulated cells. These results show that T. gondii infection alters adhesion properties and reactivity to cytokine stimulation in a cell-specific way.