Biological properties and structure of the lipopolysaccharide of a vaccine strain of Francisella tularensis generated by inactivation of a quorum sensing system gene qseC

Мокриевич, А. Н.; Kondakova, Anna N.; Valade, Eric; Platonov, M. E.; Vakhrameeva, G. M.; Shaikhutdinova, Rima Z.; Mironova, R. I.; Blaha, Didier; Бахтеева, И. В.; Титарева, Г. М.; Kravchenko, T. B.; Комбарова, Т. И.; Vidal, Dominique; Павлов, В. М.; Lindner, Buko; Dyatlov, I. A.; Knirel, Yu. A.

doi:10.1134/s0006297910040073

Cited by 17 publications

(14 citation statements)

References 22 publications

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“…QseC has been previously reported to be an activator of virulence. It has been shown to positively regulate motility in EHEC O157, Salmonella, and UPEC (3,4,10,21,37,49,72), invasion in Salmonella (49), and overall virulence in many other pathogens (47,57,59,79). Here, we have shown that deletion of qseC significantly decreases formation of A/E lesions on HeLa cells and that the qseC mutant's ability to form these lesions is unaffected by epinephrine (Fig.…”

Section: Discussionmentioning

confidence: 51%

Enterohemorrhagic Escherichia coli Virulence Regulation by Two Bacterial Adrenergic Kinases, QseC and QseE

Njoroge

Sperandio

2012

Infect Immun

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The human pathogen enterohemorrhagic Escherichia coli (EHEC) O157:H7 has two histidine sensor kinases, QseC and QseE, which respond to the mammalian adrenergic hormones epinephrine and norepinephrine by increasing their autophosphorylation. Although QseC and QseE are present in nonpathogenic strains of E. coli, EHEC exploits these kinases for virulence regulation. To further investigate the full extent of epinephrine and its sensors' impact on EHEC virulence, we performed transcriptomic and phenotypic analyses of single and double deletions of qseC and qseE genes in the absence or presence of epinephrine. We showed that in EHEC, epinephrine sensing seems to occur primarily through QseC and QseE. We also observed that QseC and QseE regulate expression of the locus of enterocyte effacement (LEE) genes positively and negatively, respectively. LEE activation, which is required for the formation of the characteristic attaching and effacing (A/E) lesions by EHEC on epithelial cells, is epinephrine dependent. Regulation of the LEE and the non-LEE-contained virulence factor gene nleA by QseE is indirect, through transcription inhibition of the RcsB response regulator. Finally, we show that coincubation of HeLa cells with epinephrine increases EHEC infectivity in a QseC-and QseE-dependent manner. These results genetically and phenotypically map the contributions of the two adrenergic sensors QseC and QseE to EHEC pathogenesis.

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Section: Discussionmentioning

confidence: 51%

Enterohemorrhagic Escherichia coli Virulence Regulation by Two Bacterial Adrenergic Kinases, QseC and QseE

Njoroge

Sperandio

2012

Infect Immun

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“…The bacterial strains used in these studies, E. coli O130 ( 26 ), Francisella tularensis 15 ( 27 ), A. baumannii 1053 ( 28 ), P. aeruginosa 2192 (a clinical isolate from a cystic fibrosis patient) ( 29 ), and B. mallei C-5 ( 30 ), were grown as previously described.…”

Section: Methodsmentioning

confidence: 99%

Structural Relationship of the Lipid A Acyl Groups to Activation of Murine Toll-Like Receptor 4 by Lipopolysaccharides from Pathogenic Strains of Burkholderia mallei, Acinetobacter baumannii, and Pseudomonas aeruginosa

et al. 2015

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Toll-like receptor 4 (TLR4) is required for activation of innate immunity upon recognition of lipopolysaccharide (LPS) of Gram-negative bacteria. The ability of TLR4 to respond to a particular LPS species is important since insufficient activation may not prevent bacterial growth while excessive immune reaction may lead to immunopathology associated with sepsis. Here, we investigated the biological activity of LPS from Burkholderia mallei that causes glanders, and from the two well-known opportunistic pathogens Acinetobacter baumannii and Pseudomonas aeruginosa (causative agents of nosocomial infections). For each bacterial strain, R-form LPS preparations were purified by hydrophobic chromatography and the chemical structure of lipid A, an LPS structural component, was elucidated by HR-MALDI-TOF mass spectrometry. The biological activity of LPS samples was evaluated by their ability to induce production of proinflammatory cytokines, such as IL-6 and TNF, by bone marrow-derived macrophages. Our results demonstrate direct correlation between the biological activity of LPS from these pathogenic bacteria and the extent of their lipid A acylation.

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“…The distinctions in protective activity of the preparations and their ability to increase functional activity of white mice lymphocytes determined during the examination can be possibly caused by nucleotide polymorphism of the genes coding outer membrane proteins [8], and variability of LPS structure [9,10] in F. tularensis subspecies that undoubtedly affects on the bacteria virulence.…”

Section: Discussionmentioning

confidence: 99%

Cell Envelopes of Francisella tularensis: Immunogenic Activity and Toxicity

Sv¹

2017

CBCM

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At present, development of effective vaccines of new generation is an actual problem, in particular concerning the tularemia causative agent. It determines the need to search antigen determinants with high immunogenic activity. Some authors demonstrate that outer membrane proteins of Francisella tularensis possess immunological activity. This fact gave occasion to isolation and comprehensive study of Francisella tularensis cellular envelopes as a perspective component in vaccine engineering. Toxicity and immunogenic activity of Cell Envelopes (CE) of Francisella tularensis different subspecies is complex studied. It is shown that these preparations in doses 6.3; 19.0; 57.0 and 100 µg fail to possess toxicity. The immunizing dose (95 µg) of CE Francisella tularensis subsp. holarctica 306, Francisella tularensis subsp. mediasiatica А-61 and Francisella tularensis subsp. tularensis B-399 A-Cole protecting white mice against experimental tularemia infection was determined. It is experimentally demonstrated that 83 % animals survive only after using CE Francisella tularensis subsp. mediasiatica А-61. It is shown that F. tularensis CE preparations influence on activation of T and B lympho-cytes of white mice blood cells. New data concerning the possibility of F. tularensis antigen preparation application for increase of experimental animal resistance to F. tularensis are obtained. On the basis of the findings there is need for the further detailed investigation of immunogenic properties of CE F. tularensis subsp. holarctica 306, F. tularensis subsp. mediasiatica А-61 and F. tularensis subsp. tularensis B-399 A-Cole as perspective components in development of tularemia vaccines.

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Biological properties and structure of the lipopolysaccharide of a vaccine strain of Francisella tularensis generated by inactivation of a quorum sensing system gene qseC

Cited by 17 publications

References 22 publications

Enterohemorrhagic Escherichia coli Virulence Regulation by Two Bacterial Adrenergic Kinases, QseC and QseE

Enterohemorrhagic Escherichia coli Virulence Regulation by Two Bacterial Adrenergic Kinases, QseC and QseE

Structural Relationship of the Lipid A Acyl Groups to Activation of Murine Toll-Like Receptor 4 by Lipopolysaccharides from Pathogenic Strains of Burkholderia mallei, Acinetobacter baumannii, and Pseudomonas aeruginosa

Cell Envelopes of Francisella tularensis: Immunogenic Activity and Toxicity

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