Table 4.

Effect of IFN-γ treatment on B. suis-infected VD3-THP-1 cellsa

Cell treatment%b of:
Apoptotic VD3-THP-1 cellsInfected VD3-THP-1 cellsApoptotic cells in the infected-cell population
Medium4 ± 1
IFN-γ66 ± 10
GFP-B. suisinfection3 ± 214 ± 21 ± 1
GFP-B. suis infection + IFN-γ23 ± 516 ± 315 ± 4
  • a VD3-THP-1 cells were infected (or not) with opsonized GFP-B. suis in eight-chamber culture slides (as described in Materials and Methods) and then cultured (or not) with 10,000 U of IFN-γ per ml after gentamicin had killed extracellular bacteria. Forty-eight hours later for each condition, the percentage of apoptotic cells (red fluorescence), infected cells (green fluorescence), or apoptotic cells in the infected-cell population (green plus red fluorescence) was determined by fluorescence microscopy with phycoerythrin-labeled annexin V as described in the legend to Fig.5.

  • b Percentages were determined by analyzing at least 800 cells; values are means and standard deviations from seven different experiments.