Mycobacterium tuberculosis Induces an Atypical Cell Death Mode to Escape from Infected Macrophages
Figure 5
Mtb does not kill macrophages by pyroptosis.
(A) Caspase-1 null (Casp 1 KO) and wildtype (WT) macrophages on the same NOD genetic background were infected with Mtb (18 h). Cell death was measured by PI incorporation (*P<0.05). (B) C57BL/6 macrophages were infected with S. typhimurium (Stm) or Mtb, both at MOI 25 for 4 h. Cell death was measured by neutral red dye uptake (*P<0.05 compared with uninfected or Mtb-infected macrophages. (C) TEM image of S. typhimurium-infected macrophage (MOI 25, 2 h) showing evidence of osmotic lysis with preserved nuclear morphology. Bar = 2 µm.