Subcellular proteomic analysis of host-pathogen interactions using human monocytes exposed toYersinia pestis andYersinia pseudotuberculosis

Abstract

Yersinia pestis, the etiological agent of plague, is of concern to human health both from an infectious disease and a biodefense perspective. While Y. pestis and Yersinia pseudotuberculosis share more than 90% DNA homology, they have significantly different clinical manifestations. Plague is often fatal if untreated, yet Y. pseudotuberculosis causes severe intestinal distress but is rarely fatal. A better understanding of host response to these closely related pathogens may help explain the different mechanisms of virulence and pathogenesis that result in such different clinical outcomes. The aim of this study was to characterize host protein expression changes in human monocyte U937 cells after exposure to Y. pestis and Y. pseudotuberculosis. In order to gain global proteomic coverage of host response, proteins from cytoplasmic, nuclear and membrane fractions of host cells were studied by two-dimensional differential gel electrophoresis and relative protein expression differences were quantitated. Differentially expressed proteins, with at least 1.5-fold expression changes and p values of 0.01 or less, were identified by mass spectrometry including matrix-assisted laser desorption/ionization-MS or liquid chromatography tandem mass spectrometry. With these criteria, differential expression was detected in 16 human proteins after Y. pestis exposure and 13 human proteins after Y. pseudotuberculosis exposure, of which only two of the differentially expressed proteins identified were shared between the two exposures. Proteins identified in this study are reported to be involved in a wide spectrum of cellular functions and host defense mechanisms including apoptosis, cytoskeletal rearrangement, protein synthesis and degradation, DNA replication and transcription, metabolism, protein folding, and cell signaling. Notably, the differential expression patterns observed can distinguish the two pathogen exposures from each other and from unexposed host cells. The functions of the differentially expressed proteins identified provide insight on the different virulence and pathogenic mechanisms of Y. pestis and Y. pseudotuberculosis.

An in vivo proteomic study of the interaction between Salmonella Typhimurium and porcine ileum mucosa

“…the intracellular SERPINB1 protein occurs in vitro after Yersinia pestis and Y. pseudotuberculosis exposure [65]. These and our results would support the up-regulation of SERPINB1 as a common strategy of Yersinia and Salmonella to evade host immune defense.…”

Proteomic Characterization ofYersinia pestisVirulence

“…Upon interaction with the host, the TTSS enables virulence factors to enter the host cell through a specialized apparatus, the injectisome (15). Once inside the host cell, Yops affect a variety of host pathways, with detectable expression changes in the pathogen as well as the host (14,52,82).…”

“…Upon interaction with the host, the TTSS enables virulence factors to enter the host cell through a specialized apparatus, the injectisome (15). Once inside the host cell, Yops affect a variety of host pathways, with detectable expression changes in the pathogen as well as the host (14,52,82).The Y. pestis proteome was previously examined using twodimensional electrophoresis (57,60,71,72). These studies demonstrated that virulence factors were not induced at 26°C or 37°C in the presence of calcium concentrations similar to that found in mammalian plasma (2.5 mM) (71).…”

Omics strategies for revealing Yersinia pestis virulence

“…Several differentially expressed host proteins involved in protein synthesis, cytoskeletal interactions, immune responses, and apoptosis were identified, suggesting that a specific host protein response profile may be useful for diagnosis of disease without any information of possible pathogens. The same group also quantitatively reveals the protein expression differences from cytoplasmic, nuclear, and membrane fractions of host cells U937 by 2DE DIGE between Y. pestis and Y. pseudotuberculosis challenges (Zhang et al, 2005b). The functions of the differentially expressed proteins can provide insight into the different virulence and pathogenic mechanisms of these two genetically related pathogens.…”