TLR2-dependent mast cell activation contributes to the control of Mycobacterium tuberculosis infection

Microbes Infect. Jul-Aug 2009;11(8-9):770-8. doi: 10.1016/j.micinf.2009.04.025. Epub 2009 May 13.


Mast Cells (MCs) express toll-like receptor 2 (TLR2), a receptor known to be triggered by several major mycobacterial ligands and involved in resistance against Mycobacterium tuberculosis (MTB) infection. This study investigated whether adoptive transfer of TLR2 positive MCs (TLR2(+/+)) corrects the increased susceptibility of TLR2(-/-) mice to MTB infection. TLR2(-/-) mice displayed increased mycobacterial burden, diminished myeloid cell recruitment and proinflammatory cytokine production accompanied by defective granuloma formation. The reconstitution of these mice with TLR2(+/+) MCs, but not TLR2(-/-), confers better control of the infection, promotes the normalization of myeloid cell recruitment associated with reestablishment of the granuloma formation. In addition, adoptive transfer of TLR2(+/+) MC to TLR2(-/-) mice resulted in regulation of the pulmonary levels of IL-beta, IL-6, TNF-alpha, enhanced Th1 response and activated CD8(+) T cell homing to the lungs. Our results suggest that activation of MCs via TLR2 is required to compensate the defect in protective immunity and inability of TLR2(-/-) mice to control MTB infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adoptive Transfer
  • Animals
  • CD8-Positive T-Lymphocytes / immunology
  • Cell Movement
  • Cells, Cultured
  • Cytokines / metabolism
  • Granuloma / immunology
  • Granuloma / pathology
  • Mast Cells / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mycobacterium tuberculosis*
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 2 / metabolism*
  • Tuberculosis, Pulmonary / immunology*
  • Tuberculosis, Pulmonary / prevention & control


  • Cytokines
  • Tlr2 protein, mouse
  • Toll-Like Receptor 2