Microdissection of the cytokine milieu of pulmonary granulomas from tuberculous guinea pigs

Cell Microbiol. 2007 May;9(5):1127-36. doi: 10.1111/j.1462-5822.2006.00854.x. Epub 2007 Jan 9.

Abstract

Levels of IL-12p40, TNFalpha, TGFbeta, IFNgamma and IL-10 mRNA were assessed by laser capture microdissection followed by quantitative real-time PCR in the pulmonary granulomas of unimmunized and BCG-vaccinated guinea pigs infected by aerosol with virulent Mycobacterium tuberculosis. Lesions microdissected from unimmunized guinea pigs were overwhelmed by the pro-inflammatory TNFalpha mRNA at both 3 and 6 weeks post infection, indicating the struggle to control the mounting infection. The cytokine profile of granulomas from vaccinated guinea pigs shifted from type 1 cytokine mRNA (IFNgamma and IL-12p40) at 3 weeks to a predominantly anti-inflammatory environment (TGFbeta mRNA) at 6 weeks. The relative proportions of cytokine mRNA transcripts in the periphery of the granuloma were different from the centre, reflecting differences in cell composition and architecture. Moreover, analysis of the individual lung lobes at 6 weeks post infection suggests that heterogeneity exists in the cytokine profile between the lobes of the lung.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • BCG Vaccine / immunology
  • Cytokines / genetics*
  • Gene Expression Profiling
  • Granuloma / genetics
  • Granuloma / immunology*
  • Granuloma / microbiology
  • Guinea Pigs
  • Interferon-gamma / genetics
  • Interleukin-10 / genetics
  • Interleukin-12 / genetics
  • Interleukin-12 Subunit p40 / genetics
  • Lung / metabolism
  • Lung / microbiology
  • Lung / pathology
  • Microdissection / methods
  • Mycobacterium tuberculosis / immunology
  • Mycobacterium tuberculosis / pathogenicity*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Time Factors
  • Transforming Growth Factor alpha / genetics
  • Transforming Growth Factor beta / genetics
  • Tuberculosis, Pulmonary / genetics
  • Tuberculosis, Pulmonary / immunology*
  • Tuberculosis, Pulmonary / microbiology
  • Virulence

Substances

  • BCG Vaccine
  • Cytokines
  • Interleukin-12 Subunit p40
  • RNA, Messenger
  • Transforming Growth Factor alpha
  • Transforming Growth Factor beta
  • Interleukin-10
  • Interleukin-12
  • Interferon-gamma