[PDF][PDF] Caspase-1 cleavage of the TLR adaptor TRIF inhibits autophagy and β-interferon production during Pseudomonas aeruginosa infection

MS Jabir, ND Ritchie, D Li, HK Bayes, P Tourlomousis… - Cell host & …, 2014 - cell.com
MS Jabir, ND Ritchie, D Li, HK Bayes, P Tourlomousis, D Puleston, A Lupton, L Hopkins…
Cell host & microbe, 2014cell.com
Bacterial infection can trigger autophagy and inflammasome activation, but the effects of
inflammasome activation on autophagy are unknown. We examined this in the context of
Pseudomonas aeruginosa macrophage infection, which triggers NLRC4 inflammasome
activation. P. aeruginosa induced autophagy via TLR4 and its adaptor TRIF. NLRC4 and
caspase-1 activation following infection attenuated autophagy. Caspase-1 directly cleaved
TRIF to diminish TRIF-mediated signaling, resulting in inhibition of autophagy and in …
Summary
Bacterial infection can trigger autophagy and inflammasome activation, but the effects of inflammasome activation on autophagy are unknown. We examined this in the context of Pseudomonas aeruginosa macrophage infection, which triggers NLRC4 inflammasome activation. P. aeruginosa induced autophagy via TLR4 and its adaptor TRIF. NLRC4 and caspase-1 activation following infection attenuated autophagy. Caspase-1 directly cleaved TRIF to diminish TRIF-mediated signaling, resulting in inhibition of autophagy and in reduced type I interferon production. Expression of a caspase-1 resistant TRIF mutant enhanced autophagy and type I interferon production following infection. Preventing TRIF cleavage by caspase-1 in an in vivo model of P. aeruginosa infection resulted in enhanced bacterial autophagy, attenuated IL-1β production, and increased bacterial clearance. Additionally, TRIF cleavage by caspase-1 diminished NLRP3 inflammasome activation. Thus, caspase-1 mediated TRIF cleavage is a key event in controlling autophagy, type I interferon production, and inflammasome activation with important functional consequences.
cell.com