Editor: Willem van Eden
Peptidase N encoded by Salmonella enterica serovar Typhimurium modulates systemic infection in mice
Article first published online: 18 SEP 2007
FEMS Immunology & Medical Microbiology
Volume 51, Issue 2, pages 431–442, November 2007
How to Cite
Patil, V., Kumar, A., Kuruppath, S. and Nandi, D. (2007), Peptidase N encoded by Salmonella enterica serovar Typhimurium modulates systemic infection in mice. FEMS Immunology & Medical Microbiology, 51: 431–442. doi: 10.1111/j.1574-695X.2007.00323.x
- Issue published online: 18 SEP 2007
- Article first published online: 18 SEP 2007
- Received 29 December 2006; revised 17 July 2007; accepted 23 July 2007.First published online October 2007.
- cytosolic protein degradation;
- Salmonella typhimurium
The cytosolic protein degradation pathway, involving ATP-dependent proteases and ATP-independent peptidases, is important for modulating several cellular responses. The involvement of pathogen-encoded ATP-dependent proteases is well established during infection. However, the roles of ATP-independent peptidases in this process are not well studied. The functional role of Peptidase N (PepN), an ATP-independent enzyme belonging to the M1 family, during systemic infection of mice by Salmonella enterica serovar Typhimurium (Salmonella typhimurium) was investigated. In a systemic model of infection, the number of CFU of S. typhimurium containing a targeted deletion in peptidase N (ΔpepN), compared with wild type, was significantly higher in the lymph node and spleen. In addition, S. typhimurium replicated in the thymus and greatly reduced the number of immature CD4+CD8+ thymocytes in a dose- and time-dependent manner. Strains lacking or overexpressing pepN were used to show that the reduction in the number of thymocytes, but not lymph node cells, depends on a critical number of CFU. These findings establish a role for PepN in reducing the in vivo CFU of S. typhimurium during systemic infection. The implications of these results, in the context of the roles of proteases and peptidases, during host–pathogen interactions are discussed.