Dormancy phenotype displayed by extracellular Mycobacterium tuberculosis within artificial granulomas in mice

Petros C. Karakousis, Tetsuyuki Yoshimatsu, Gyanu Lamichhane, Samuel C. Woolwine, Eric L. Nuermberger, Jacques Grosset, William R. Bishai

Research output: Contribution to journalArticlepeer-review

Abstract

Mycobacterium tuberculosis residing within pulmonary granulomas and cavities represents an important reservoir of persistent organisms during human latent tuberculosis infection. We present a novel in vivo model of tuberculosis involving the encapsulation of bacilli in semidiffusible hollow fibers that are implanted subcutaneously into mice. Granulomatous lesions develop around these hollow fibers, and in this microenvironment, the organisms demonstrate an altered physiologic state characterized by stationary-state colony-forming unit counts and decreased metabolic activity. Moreover, these organisms show an antimicrobial susceptibility pattern similar to persistent bacilli in current models of tuberculosis chemotherapy in that they are more susceptible to the sterilizing drug, rifampin, than to the bactericidal drug isoniazid. We used this model of extracellular persistence within host granulomas to study both gene expression patterns and mutant survival patterns. Our results demonstrate induction of dosR (Rv3133c) and 20 other members of the DosR regulon believed to mediate the transition into dormancy, and that relMtb is required for Mycobacterium tuberculosis survival during extracellular persistence within host granulomas. Interestingly, the dormancy phenotype of extracellular M. tuberculosis within host granulomas appears to be immune mediated and interferon-γ dependent.

Original languageEnglish (US)
Pages (from-to)647-657
Number of pages11
JournalJournal of Experimental Medicine
Volume200
Issue number5
DOIs
StatePublished - Sep 6 2004

Keywords

  • Antibiotics
  • Gene expression
  • Latency
  • Microarrays
  • Persistence

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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