Fig 2.

Lipid rafts are required for CR3-dependent, but not CR3-independent, phagocytosis of B. burgdorferi. (A) RAW 264.7 cells were pretreated with 1 mM of MβCD for 30 min or left untreated, followed by incubation with 10 μg/mL of an anti-CD16/CD32 mAb and an anti-rat IgG for 30 min (top panels) or Bb914 (m.o.i. = 25) for 1 h (bottom panels). After extensive washing, the cells were fixed and those incubated with B. burgdorferi were stained with CTxB Alexa Fluor 594. RAW 264.7 cells (B), WT (C) and CD11b-deficient BMMs (D) and CHO-CR3/CD14 cells (E) were pretreated with 5 mM of MβCD for 30 min (red histograms) or left untreated (black histograms), followed by incubation with Bb914, at the following m.o.i.: RAW264.7 and CHO-CR3/CD14, 25; BMMs, 10. The cells were analyzed by flow cytometry. The grey histogram represents the control performed at 4 ºC. The experiments shown are representative of at least 3 performed.