Figure 4.

BCG and LVS co-infection in J774 cell lines. J774 cell lines (5 × 10⁵) were seeded in wells on cover slips and IL-4 expression induced with 50 ng/ml doxycycline for 12 h. Cells were then infected with either (a) LVS (5 × 10⁶) or (b) BCG (5 × 10⁶) for 24 h, followed by LVS (5 × 10⁶). At 1 and 4 h post-LVS inoculation, cells were fixed, treated with either Dig or Sap, and stained for LVS. The cytosolic (LVS-Dig and BCG + LVS-Dig) and total intracellular (LVS-Sap and BCG + LVS-Sap) LVS quantifications were determined as described in the Materials and methods. Concurrently, J774 cell lines (5 × 10⁵ per well) were induced with doxycycline, infected with BCG or mock treated with medium for 48 h, and infected with LVS. Uptake and replication of LVS were measured at 3 and 24 h post-LVS inoculation (c), and NO levels in culture medium were measured prior to and 24 h after LVS inoculation using the Griess reagent (d). *P < 0.05 between indicated groups. ǂP < 0.05 between the indicated J774.IL4 and respective J774 and J774.vec groups.

BCG: Bacillus Calmette Guẻrin; Dig: digoxin; LVS: live vaccine strain; Sap: saponin.