Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
J Exp Med. 2004 Jul 19;200(2):267-72.

The scavenger receptor MARCO is required for lung defense against pneumococcal pneumonia and inhaled particles.

Author information

  • 1Physiology Program, Harvard School of Public Health, 665 Huntington Ave., SPH-II, Rm. 221, Boston, MA 02115, USA.

Abstract

Alveolar macrophages (AMs) express the class A scavenger receptor macrophage receptor with collagenous structure (MARCO), but its role in vivo in lung defense against bacteria and environmental particles has not been studied. We used MARCO-deficient mice to directly test the in vivo role of AM MARCO in innate defense against pneumococcal infection and environmental particles. In a murine model of pneumococcal pneumonia, MARCO(-/-) mice displayed an impaired ability to clear bacteria from the lungs, increased pulmonary inflammation and cytokine release, and diminished survival. In vitro binding of Streptococcus pneumoniae and in vivo uptake of unopsonized particles by MARCO(-/-) AMs were dramatically impaired. MARCO(-/-) mice treated with the "inert" environmental particle TiO(2) showed enhanced inflammation and chemokine expression, indicating that MARCO-mediated clearance of inert particles by AMs prevents inflammatory responses otherwise initiated by other lung cells. Our findings point to an important role of MARCO in mounting an efficient and appropriately regulated innate immune response against inhaled particles and airborne pathogens.

PMID:
15263032
[PubMed - indexed for MEDLINE]
PMCID:
PMC2212010
Free PMC Article

Images from this publication.See all images (4)Free text

Figure 1.
Figure 2.
Figure 3.
Figure 4.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk