English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Francisella tularensis  subsp.  tularensis  is a highly virulent pathogen for humans especially if inhaled. Consequently, it is considered to be a potential biothreat agent. An experimental vaccine,  F. tularensis  live vaccine strain, derived from the less virulent subsp.  holarctica , was developed more than 50 years ago, but remains unlicensed. Previously, we developed a novel live vaccine strain, by deleting the chaperonin  clpB  gene from  F. tularensis  subsp.  tularensis  strain, SCHU S4. SCHU S4 ΔclpB  was less virulent for mice than LVS and a more effective vaccine against respiratory challenge with wild type SCHU S4. In the current study, we were interested to determine whether a similar mutant on the less virulent subsp.  holarctica  background would also outperform LVS in terms of safety and efficacy. To this end,  clpB  was deleted from clinical  holarctica  strain, FSC200. FSC 200ΔclpB  had a significantly higher intranasal LD 50  than LVS for BALB/c mice, but replicated to higher numbers at foci of infection after dermal inoculation. Moreover, FSC 200ΔclpB  killed SCID mice more rapidly than LVS. However, dermal vaccination of BALB/c mice with the former versus the latter induced greater protection against respiratory challenge with SCHU S4. This increased efficacy was associated with enhanced production of pulmonary IL-17 after SCHU S4 challenge.

plos one

A ΔclpB Mutant of Francisella tularensis Subspecies holarctica Strain, FSC200, Is a More Effective Live Vaccine than F. tularensis LVS in a Mouse Respiratory Challenge Model of Tularemia