Genetic Manipulation of Francisella Tularensis

Zogaj, Xhavit; Klose, Karl E.

doi:10.3389/fmicb.2010.00142

Cited by 12 publications

(12 citation statements)

References 74 publications

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“…Third, the defined iglD mutation prevents intracellular replication in permissive host cells and virulence in permissive animal models, resulting in a highly attenuated and inherently safer strain. Finally, Fn is more amenable to genetic manipulations than Ftt or Fth [34] , which facilitates the further development of this vaccine platform to enhance efficacy and provide protection against heterologous antigens.…”

Section: Discussionmentioning

confidence: 99%

Live Attenuated Francisella novicida Vaccine Protects against Francisella tularensis Pulmonary Challenge in Rats and Non-human Primates

Chu

Cunningham

et al. 2014

PLoS Pathog

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Francisella tularensis causes the disease tularemia. Human pulmonary exposure to the most virulent form, F. tularensis subsp. tularensis (Ftt), leads to high morbidity and mortality, resulting in this bacterium being classified as a potential biothreat agent. However, a closely-related species, F. novicida, is avirulent in healthy humans. No tularemia vaccine is currently approved for human use. We demonstrate that a single dose vaccine of a live attenuated F. novicida strain (Fn iglD) protects against subsequent pulmonary challenge with Ftt using two different animal models, Fischer 344 rats and cynomolgus macaques (NHP). The Fn iglD vaccine showed protective efficacy in rats, as did a Ftt iglD vaccine, suggesting no disadvantage to utilizing the low human virulent Francisella species to induce protective immunity. Comparison of specific antibody profiles in vaccinated rat and NHP sera by proteome array identified a core set of immunodominant antigens in vaccinated animals. This is the first report of a defined live attenuated vaccine that demonstrates efficacy against pulmonary tularemia in a NHP, and indicates that the low human virulence F. novicida functions as an effective tularemia vaccine platform.

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Section: Discussionmentioning

confidence: 99%

Live Attenuated Francisella novicida Vaccine Protects against Francisella tularensis Pulmonary Challenge in Rats and Non-human Primates

Chu

Cunningham

et al. 2014

PLoS Pathog

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“…The same applies for molecular microbiology and genetic manipulation techniques, such as the development of random insertional mutants for B. pseudomallei , 12 the allelic exchange in F. tularensis , 13 and the genome-wide screens for B. anthracis 14 . Finally, the reproducibility and regulatory compliance for relevant animal models is debatable, as it is reflected from comparative studies in F. tularensis and Burkholderia sp 15 .…”

Section: Key Bacterial Biological Warfare Agents (Bwas)mentioning

confidence: 99%

Biodefense

Tegos

2013

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“…Despite the efforts in recent years, complementation from plasmid remains difficult in Francisella . Non-native expression levels (Santic et al, 2007 ; Zogaj and Klose, 2010 ) and spontaneous deletions in pFNL200 (Pomerantsev et al, 2001b ) and pFNLTP (Maier et al, 2004 ) were reported. Another problem is the relatively low electroporation efficiency in Francisella and especially in F. novicida for plasmids isolated from E. coli .…”

Section: Introductionmentioning

confidence: 99%

Mobilizable Plasmids for Tunable Gene Expression in Francisella novicida

Brodmann

Heilig

Brož

et al. 2018

Front. Cell. Infect. Microbiol.

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Francisella tularensis is the causative agent of the life-threatening disease tularemia. However, the molecular tools to study Francisella are limited. Especially, expression plasmids are sparse and difficult to use, as they are unstable and prone to spontaneous loss. Most Francisella expression plasmids lack inducible promoters making it difficult to control gene expression levels. In addition, available expression plasmids are mainly designed for F. tularensis, however, genetic differences including restriction-modification systems impede the use of these plasmids in F. novicida, which is often used as a model organism to study Francisella pathogenesis. Here we report construction and characterization of two mobilizable plasmids (pFNMB1 and pFNMB2) designed for regulated gene expression in F. novicida. pFNMB plasmids contain a tetracycline inducible promoter to control gene expression levels and oriT for RP4 mediated mobilization. We show that both plasmids are stably maintained in bacteria for more than 40 generations over 4 days of culturing in the absence of selection against plasmid loss. Expression levels are dependent on anhydrotetracycline concentration and homogeneous in a bacterial population. pFNMB1 and pFNMB2 plasmids differ in the sequence between promoter and translation start site and thus allow to reach different maximum levels of protein expression. We used pFNMB1 and pFNMB2 for complementation of Francisella Pathogenicity Island mutants ΔiglF, ΔiglI, and ΔiglC in-vitro and pFNMB1 to complement ΔiglI mutant in bone marrow derived macrophages.

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Genetic Manipulation of Francisella Tularensis

Cited by 12 publications

References 74 publications

Live Attenuated Francisella novicida Vaccine Protects against Francisella tularensis Pulmonary Challenge in Rats and Non-human Primates

Live Attenuated Francisella novicida Vaccine Protects against Francisella tularensis Pulmonary Challenge in Rats and Non-human Primates

Biodefense

Mobilizable Plasmids for Tunable Gene Expression in Francisella novicida

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