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
Blood. 2008 Nov 15;112(10):4117-27. doi: 10.1182/blood-2007-12-129767. Epub 2008 Sep 8.

Resolution-phase macrophages possess a unique inflammatory phenotype that is controlled by cAMP.

Author information

  • 1Centre for Clinical Pharmacology and Therapeutics, Division of Medicine, University College London, London, United Kingdom.

Abstract

Neutralizing injurious stimuli, proinflammatory mediator catabolism, and polymorphonuclear leukocyte (PMN) clearance are determinants of inflammatory resolution. To this, we recently added innate-type lymphocyte repopulation as being central for restoring postinflammation tissue homeostasis with a role in controlling innate immune-mediated responses to secondary infection. However, although macrophages dominate resolution, their phenotype and role in restoring tissue physiology once inflammation abates are unknown. Therefore, we isolated macrophages from the resolving phase of acute inflammation and found that compared with classically activated proinflammatory M1 cells, resolution-phase macrophages (rMs) possess weaker bactericidal properties and express an alternatively activated phenotype but with elevated markers of M1 cells including inducible cyclooxygenase (COX 2) and nitric oxide synthase (iNOS). This phenotype is controlled by cAMP, which, when inhibited, transforms rM to M1 cells. Conversely, elevating cAMP in M1 cells transforms them to rMs, with implications for cAMP in the resolution of systemic inflammation. It transpires that although rMs are dispensable for clearing PMNs during self-limiting inflammation, they are essential for signaling postresolution lymphocyte repopulation via COX 2 lipids. Thus, rM macrophages are neither classically nor alternatively activated but a hybrid of both, with a role in mediating postresolution innate-lymphocyte repopulation and restoring tissue homeostasis.

PMID:
18779392
[PubMed - indexed for MEDLINE]
PMCID:
PMC2581990
Free PMC Article

Images from this publication.See all images (6)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
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