Mycobacterium tuberculosis triggers formation of lymphoid structure in murine lungs

J Infect Dis. 2007 Jan 1;195(1):46-54. doi: 10.1086/508894. Epub 2006 Nov 14.

Abstract

The hallmark of pulmonary tuberculosis is the granuloma, which consists predominantly of lymphocytes and macrophages and promotes immune-cell interaction with the causative pathogen, Mycobacterium tuberculosis. Granuloma formation is a highly organized process, which depends on leukocyte recruitment facilitated by adhesion molecules and chemokines. Thus, during chronic experimental tuberculosis, granulomata display characteristics of lymphoid structures comprising follicular aggregation of B cells, formation of high endothelial venules, presence of follicular dendritic cells, and expression of the homeostatic chemokines CXCL13 and CCL19. CCR7-/- mice, which are deficient in CCL19 and CCL21 signaling, exhibit increased local inflammatory infiltrates but no follicular B-cell aggregation within those lymphoid structures. However, CCR7-deficient mice are fully capable to control pulmonary tuberculosis; at time points later than 6 weeks postinfection, they carry a lower bacterial load in peripheral organs. Our results show that, during chronic pulmonary tuberculosis in mice, the homeostatic chemokine signaling-network contributes to spatial organization of the granulomatous response, which participates in both containment of M. tuberculosis and the latter's dissemination to other organs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Lung / immunology
  • Lung / microbiology*
  • Lung / pathology*
  • Mice
  • Mice, Inbred BALB C
  • Mycobacterium tuberculosis / immunology*
  • Tuberculosis / immunology
  • Tuberculosis / microbiology
  • Tuberculosis / pathology*