Caspase-1 independent IL-1beta production is critical for host resistance to mycobacterium tuberculosis and does not require TLR signaling in vivo

J Immunol. 2010 Apr 1;184(7):3326-30. doi: 10.4049/jimmunol.0904189. Epub 2010 Mar 3.

Abstract

To investigate the respective contributions of TLR versus IL-1R mediated signals in MyD88 dependent control of Mycobacterium tuberculosis, we compared the outcome of M. tuberculosis infection in MyD88, TRIF/MyD88, IL-1R1, and IL-1beta-deficient mice. All four strains displayed acute mortality with highly increased pulmonary bacterial burden suggesting a major role for IL-1beta signaling in determining the MyD88 dependent phenotype. Unexpectedly, the infected MyD88 and TRIF/MyD88-deficient mice, rather than being defective in IL-1beta expression, displayed increased cytokine levels relative to wild-type animals. Similarly, infected mice deficient in caspase-1 and ASC, which have critical functions in inflammasome-mediated IL-1beta maturation, showed unimpaired IL-1beta production and importantly, were considerably less susceptible to infection than IL-1beta deficient mice. Together our findings reveal a major role for IL-1beta in host resistance to M. tuberculosis and indicate that during this infection the cytokine can be generated by a mechanism that does not require TLR signaling or caspase-1.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport
  • Animals
  • Blotting, Western
  • Caspase 1 / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Interleukin-1beta / biosynthesis*
  • Interleukin-1beta / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mycobacterium tuberculosis / immunology
  • Myeloid Differentiation Factor 88 / immunology
  • Receptors, Interleukin-1 / immunology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / immunology*
  • Toll-Like Receptors / immunology*
  • Tuberculosis, Pulmonary / immunology*

Substances

  • Adaptor Proteins, Vesicular Transport
  • Interleukin-1beta
  • Myeloid Differentiation Factor 88
  • Receptors, Interleukin-1
  • TICAM-1 protein, mouse
  • Toll-Like Receptors
  • Caspase 1