An improved vaccine for prevention of respiratory tularemia caused by Francisella tularensis SchuS4 strain

Chandra Shekhar Bakshi, Meenakshi Malik, Manish Mahawar, Girish S. Kirimanjeswara, Karsten R.O. Hazlett, Lance E. Palmer, Martha B. Furie, Rajendra Singh, J. Andres Melendez, Timothy J. Sellati, Dennis W. Metzger

Research output: Contribution to journalArticlepeer-review

67 Scopus citations


Vaccination of mice with Francisella tularensis live vaccine strain (LVS) mutants described so far have failed to induce protection in C57BL/6 mice against challenge with the virulent strain F. tularensis SchuS4. We have previously reported that a mutant of F. tularensis LVS deficient in iron superoxide dismutase (sodBFt) is hypersensitive to oxidative stress and attenuated for virulence in mice. Herein, we evaluated the efficacy of this mutant as a vaccine candidate against respiratory tularemia caused by F. tularensis SchuS4. C57BL/6 mice were vaccinated intranasally (i.n.) with the sodBFt mutant and challenged i.n. with lethal doses of F. tularensis SchuS4. The level of protection against SchuS4 challenge was higher in sodBFt vaccinated group as compared to the LVS vaccinated mice. sodBFt vaccinated mice following SchuS4 challenge exhibited significantly reduced bacterial burden in lungs, liver and spleen, regulated production of pro-inflammatory cytokines and less severe histopathological lesions compared to the LVS vaccinated mice. The sodBFt vaccination induced a potent humoral immune response and protection against SchuS4 required both CD4 and CD8 T cells in the vaccinated mice. sodBFt mutants revealed upregulated levels of chaperonine proteins DnaK, GroEL and Bfr that have been shown to be important for generation of a potent immune response against Francisella infection. Collectively, this study describes an improved live vaccine candidate against respiratory tularemia that has an attenuated virulence and enhanced protective efficacy than the LVS.

Original languageEnglish (US)
Pages (from-to)5276-5288
Number of pages13
Issue number41
StatePublished - Sep 26 2008

All Science Journal Classification (ASJC) codes

  • Molecular Medicine
  • General Immunology and Microbiology
  • General Veterinary
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases


Dive into the research topics of 'An improved vaccine for prevention of respiratory tularemia caused by Francisella tularensis SchuS4 strain'. Together they form a unique fingerprint.

Cite this