Apoptotic neutrophils augment caspase-1 activation in Mtb-stimulated hMDMs.

<p>hMDMs were stimulated with γ-irr Mtb for one hour with or without subsequent stimulation with PMNapo or Jurkatapo at a ratio of 2∶1 for one hour where after non-ingested prey were removed and the hMDMs were cultured for 3 h. hMDMs were extensively washed and lysed in Laemmli sample buffer. (A) Representative SDS-PAGE immunoblots of hMDM cell lysates probed with anti-caspase-1 antibodies, detecting both unprocessed inactive caspase-1 (p45) and cleaved activated caspase-1 (p20). Membranes were then stripped and re-probed for β-actin as a control for equal loading. (B) Caspase-1 activity shown as the ratio between caspase-1 p20/caspase-1 p45 and data expressed as mean + SEM (n = 4-5). Differences between groups were calculated using paired sample Student t-test, and significant differences are shown as * (p<0.05); ns, not significant.