Life and death in the granuloma: immunopathology of tuberculosis

Immunol Cell Biol. 2007 Feb-Mar;85(2):103-11. doi: 10.1038/sj.icb.7100027. Epub 2007 Jan 9.

Abstract

During tuberculosis (TB) infection, the granuloma provides the microenvironment in which antigen-specific T cells colocate with and activate infected macrophages to inhibit the growth of Mycobacterium tuberculosis. Although the granuloma is the site for mycobacterial killing, virulent mycobacteria have developed a variety of mechanisms to resist this macrophage-mediated killing. These surviving mycobacteria become dormant, however, if host cellular immunity or the signals maintaining granuloma structure wane, or if mycobacteria resume replication, leading to reactivation of TB. This balance of life and death applies not only to the mycobacterium but also to the host macrophages that may undergo apoptosis or necrosis, leading to the characteristic caseous necrosis within the granuloma, and the potential spread of TB infection. The immunological factors controlling the development and maintenance of the granuloma will be reviewed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adaptation, Biological / immunology
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • Chemokines / physiology*
  • Granuloma / immunology*
  • Humans
  • Immunity, Cellular / physiology
  • Inflammation / immunology
  • Microbial Viability / immunology*
  • Models, Biological
  • Mycobacterium tuberculosis / immunology*
  • Species Specificity
  • Tuberculosis, Pulmonary / immunology*
  • Tumor Necrosis Factor-alpha / physiology*
  • Virus Latency

Substances

  • Chemokines
  • Tumor Necrosis Factor-alpha