Persistence of Mycobacterium tuberculosis in macrophages and mice requires the glyoxylate shunt enzyme isocitrate lyase. Academic Article uri icon


  • Mycobacterium tuberculosis claims more human lives each year than any other bacterial pathogen. Infection is maintained in spite of acquired immunity and resists eradication by antimicrobials. Despite an urgent need for new therapies targeting persistent bacteria, our knowledge of bacterial metabolism throughout the course of infection remains rudimentary. Here we report that persistence of M. tuberculosis in mice is facilitated by isocitrate lyase (ICL), an enzyme essential for the metabolism of fatty acids. Disruption of the icl gene attenuated bacterial persistence and virulence in immune-competent mice without affecting bacterial growth during the acute phase of infection. A link between the requirement for ICL and the immune status of the host was established by the restored virulence of delta icl bacteria in interferon-gamma knockout mice. This link was apparent at the level of the infected macrophage: Activation of infected macrophages increased expression of ICL, and the delta icl mutant was markedly attenuated for survival in activated but not resting macrophages. These data suggest that the metabolism of M. tuberculosis in vivo is profoundly influenced by the host response to infection, an observation with important implications for the treatment of chronic tuberculosis.

published proceedings

  • Nature

altmetric score

  • 15.25

author list (cited authors)

  • McKinney, J. D., Hner zu Bentrup, K., Muoz-Elas, E. J., Miczak, A., Chen, B., Chan, W. T., ... Russell, D. G.

citation count

  • 1103

complete list of authors

  • McKinney, JD||Höner zu Bentrup, K||Muñoz-Elías, EJ||Miczak, A||Chen, B||Chan, WT||Swenson, D||Sacchettini, JC||Jacobs, WR||Russell, DG

publication date

  • August 2000

published in