Spatiotemporal proteomics uncovers cathepsin-dependent macrophage cell death during Salmonella infection.

Abstract

The interplay between host and pathogen relies heavily on rapid protein synthesis and accurate protein targeting to ensure pathogen destruction. To gain insight into this dynamic interface, we combined Click chemistry with pulsed stable isotope labelling of amino acids in cell culture to quantify the host proteome response during macrophage infection with the intracellular bacterial pathogen Salmonella enterica Typhimurium. We monitored newly synthesized proteins across different host cell compartments and infection stages. Within this rich resource, we detected aberrant trafficking of lysosomal proteases to the extracellular space and the nucleus. We verified that active cathepsins re-traffic to the nucleus and that these are linked to cell death. Pharmacological cathepsin inhibition and nuclear targeting of a cellular cathepsin inhibitor (stefin B) suppressed S. enterica Typhimurium-induced cell death. We demonstrate that cathepsin activity is required for pyroptotic cell death via the non-canonical inflammasome, and that lipopolysaccharide transfection into the host cytoplasm is sufficient to trigger active cathepsin accumulation in the host nucleus and cathepsin-dependent cell death. Finally, cathepsin inhibition reduced gasdermin D expression, thus revealing an unexpected role for cathepsin activity in non-canonical inflammasome regulation. Overall, our study illustrates how resolution of host proteome dynamics during infection can drive the discovery of biological mechanisms at the host-microbe interface.

• Authors: Joel Selkrig, Nan Li, Annika Hausmann, Matthew S J Mangan, Matylda Zietek, André Mateus, Jacob Bobonis, Anna Sueki, Haruna Imamura, Bachir El Debs, Gianluca Sigismondo, Bogdan I Florea, Herman S Overkleeft, Nataša Kopitar-Jerala, Boris Turk, Pedro Beltrao, Mikhail M Savitski, Eicke Latz, Wolf-Dietrich Hardt, Jeroen Krijgsveld, Athanasios Typas
• Journal: Nature microbiology (Nat Microbiol) Vol. 5 Issue 9 Pg. 1119-1133 (09 2020) ISSN: 2058-5276 [Electronic] England
• PMID: 32514074 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Gsdmd protein, mouse
• Inflammasomes
• Intracellular Signaling Peptides and Proteins
• Lipopolysaccharides
• Phosphate-Binding Proteins
• Proteome
• Cystatin B
• Cathepsins
• Peptide Hydrolases

Topics

• Animals
• Cathepsins (drug effects, metabolism)
• Cell Death (drug effects, physiology)
• Cystatin B (antagonists & inhibitors)
• Inflammasomes (metabolism)
• Intracellular Signaling Peptides and Proteins (metabolism)
• Lipopolysaccharides (metabolism)
• Lysosomes (metabolism)
• Macrophages (metabolism, microbiology)
• Mice
• Peptide Hydrolases (metabolism)
• Phosphate-Binding Proteins (metabolism)
• Proteome
• Proteomics
• RAW 264.7 Cells
• Salmonella Infections (metabolism, microbiology)
• Salmonella typhimurium (metabolism)