iTRAQ quantitative analysis of Francisella tularensis ssp. holarctica live vaccine strain and Francisella tularensis ssp. tularensis SCHU S4 response to different temperatures and stationary phases of growth

Abstract

Proteomics has been shown to significantly contribute to the investigation of the pathogenicity of the extremely infectious bacteria Francisella tularensis. In this study, the authors employed iTRAQ quantitative proteomic analysis in order to monitor alterations in proteomes of F. tularensis ssp. holarctica live vaccine strain and F. tularensis ssp. tularensis SCHU S4 associated with the cultivation at different temperatures or in the stationary phase. Correlated production of the identified proteins studied by the exploratory statistical analysis revealed novel candidates for virulence factors that were regulated in a similar manner to the genes encoded in the Francisella Pathogenicity Island. Moreover, the assessment of the adaptation of live vaccine strain and SCHU S4 strain to the examined stimuli uncovered differences in their physiological responses to the stationary phase of growth.

Identification of a Putative Chaperone Involved in Stress Resistance and Virulence in Francisella tularensis

“…Only 16 proteins presented a ⌬FTL_0200/LVS ratio different from 1, and this was statistically significant in at least three out of four comparative analyses ( Table 2). As observed previously, differences in protein abundance were rather small (17), confirming that the values recorded by the iTRAQ technique can only be used for a relative quantitative evaluation of protein abundance.…”

“…However, several other quantitative methods have recently been developed, including iTRAQ, a powerful non-gel-based technology that allows simultaneous quantification of up to four (or even eight) different samples in one analysis (25). Very recently, iTRAQ has been successfully applied to study the heat response of F. tularensis strains LVS and Schu S4 (17). iTRAQ analysis of the LVS ⌬FTL_0200 mutant indicated that only three proteins were found at lower levels in the LVS ⌬FTL_0200 mutant strain than in wild-type LVS, suggesting that they required MoxR for expression and/or stability.…”

Effects of temperature and salt concentration on Francisella noatunensis subsp. orientalis infections in Nile tilapia Oreochromis niloticus

“…orientalis, upon culture and incubation under different conditions, should elucidate the expression of different virulence factors and immunogens that may play a pathogenic role. Proteomic analysis of the mammalian pathogen F. tularensis grown at different temperatures confirmed the significantly decreased expression of virulent factors, like the pathogenicity determinant protein C (PdpC) and the intracellular growth proteins C and D (IglC and IglD), at 25°C as compared with 37°C (Lenco et al 2009), indicating that in this particular case, the expression of virulence factors by the pathogen is favored at normal mammal body temperature.…”

“…orientalis, upon culture and incubation under different conditions, should elucidate the expression of different virulence factors and immunogens that may play a pathogenic role. Proteomic analysis of the mammalian pathogen F. tularensis grown at different temperatures confirmed the significantly decreased expression of virulent factors, like the pathogenicity determinant protein C (PdpC) and the intracellular growth proteins C and D (IglC and IglD), at 25°C as compared with 37°C (Lenco et al 2009), indicating that in this particular case, the expression of virulence factors by the pathogen is favored at normal mammal body temperature.A better understanding of the tilapia innate and adaptive immune responses could benefit the development of environmentally friendly prophylactic and therapeutic practices, thereby reducing the chemical and antimicrobial residues generated by the aquaculture industry. Progress in this area will benefit not only wild fish populations but other aquatic animals, and possibly terrestrial animals, including humans.…”

CysTRAQ — A combination of iTRAQ and enrichment of cysteinyl peptides for uncovering and quantifying hidden proteomes

“…BSA-based pilot experiments were performed using LC-MALDI-MS/MS approach (4800 MALDI-TOF/TOF Analyzer (AB SCIEX)) as described previously [23]. Amniotic fluid nanoLC peptide separation was performed on an Eksigent nanoLC Ultra and cHiPLC-nanoflex (Eksigent, Dublin, CA) in Trap Elute configuration.…”