FIG. 7.

Interactions of B. pseudomallei ΔsctU_Bp3, ΔsctU_Bp1,2,₃, and DD503 with RAW 264.7 cells. Monolayers were infected at an MOI of 10 (A to D). (A) Bacterial uptake (open bars) and survival (filled bars) in RAW 264.7 cells were determined at 3 and 18 h postinfection, respectively. (B) Culture supernatants were assayed for IL-1β production at 18 h. (C) Percent cytotoxicity was determined by assaying for LDH release in culture supernatants at 18 h. The values are the means and standard deviations of three independent experiments performed in duplicate. (D) Light micrograph of ΔsctU_Bp1,2,₃-infected RAW 264.7 cells at 18 h. Bar = 50 μm. (E and F) Confocal micrographs of RAW 264.7 cells infected with ΔsctU_Bp1,2,₃ at an MOI of 40 at 18 h postinfection. Bacteria were stained red with rabbit anti-B. thailandensis polyclonal sera and anti-rabbit IgG Alexa Fluor 568, actin was stained green with Alexa Fluor 488 phalloidin, and nuclei were stained blue with DRAQ5. The micrographs are representative of at least two independent experiments.