Infection rate and tissue localization of murine IL-12p40-producing monocyte-derived CD103(+) lung dendritic cells during pulmonary tuberculosis

PLoS One. 2013 Jul 8;8(7):e69287. doi: 10.1371/journal.pone.0069287. Print 2013.

Abstract

Non-hematopoietic cells, including lung epithelial cells, influence host immune responses. By co-culturing primary alveolar epithelial cells and monocytes from naïve donor mice, we show that alveolar epithelial cells support monocyte survival and differentiation in vitro, suggesting a role for non-hematopoietic cells in monocyte differentiation during the steady state in vivo. CD103(+) dendritic cells (αE-DC) are present at mucosal surfaces. Using a murine primary monocyte adoptive transfer model, we demonstrate that αE-DC in the lungs and pulmonary lymph nodes are monocyte-derived during pulmonary tuberculosis. The tissue localization may influence the functional potential of αE-DC that accumulate in Mycobacterium tuberculosis-infected lungs. Here, we confirm the localization of αE-DC in uninfected mice beneath the bronchial epithelial cell layer and near the vascular wall, and show that αE-DC have a similar distribution in the lungs during pulmonary tuberculosis and are detected in the bronchoalveolar lavage fluid from infected mice. Lung DC can be targeted by M. tuberculosis in vivo and play a role in bacterial dissemination to the draining lymph node. In contrast to other DC subsets, only a fraction of lung αE-DC are infected with the bacterium. We also show that virulent M. tuberculosis does not significantly alter cell surface expression levels of MHC class II on infected cells in vivo and that αE-DC contain the highest frequency of IL-12p40(+) cells among the myeloid cell subsets in infected lungs. Our results support a model in which inflammatory monocytes are recruited into the M. tuberculosis-infected lung tissue and, depending on which non-hematopoietic cells they interact with, differentiate along different paths to give rise to multiple monocyte-derived cells, including DC with a distinctive αE-DC phenotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alveolar Epithelial Cells / microbiology
  • Alveolar Epithelial Cells / pathology
  • Animals
  • Antigens, CD / metabolism*
  • Bronchi / microbiology
  • Bronchi / pathology
  • Cell Count
  • Cell Differentiation
  • Cell Survival
  • Cells, Cultured
  • Dendritic Cells / immunology
  • Dendritic Cells / pathology*
  • Down-Regulation
  • Female
  • Histocompatibility Antigens Class II / metabolism
  • Inflammation / pathology
  • Integrin alpha Chains / metabolism*
  • Interleukin-12 Subunit p40 / biosynthesis*
  • Lung / immunology
  • Lung / microbiology
  • Lung / pathology*
  • Lymph Nodes / pathology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Monocytes / pathology*
  • Mycobacterium tuberculosis / physiology
  • Tuberculosis, Pulmonary / immunology*
  • Tuberculosis, Pulmonary / microbiology
  • Tuberculosis, Pulmonary / pathology*

Substances

  • Antigens, CD
  • Histocompatibility Antigens Class II
  • Integrin alpha Chains
  • Interleukin-12 Subunit p40
  • alpha E integrins

Grants and funding

This work was supported by grants from The Swedish Research Council (grant no. K2007-57X-20360-01-4, www.vr.se), The Swedish Heart-Lung Foundation and Konung Oscar II:s jubileumsfond (www.hjart-lungfonden.se), Stiftelsen Clas Groschinskys Minnesfond (www.groschinsky.org) and Karolinska Institutet (ki.se) to MS. CL was supported by a scholarship from the Royal Thai Government and a grant from Stiftelsen Sigurd och Elsa Goljes Minne. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.