Format

Send to

Choose Destination
J Infect Dis. 2001 Sep 15;184(6):713-22. Epub 2001 Aug 24.

Immune-mediated phagocytosis and killing of Streptococcus pneumoniae are associated with direct and bystander macrophage apoptosis.

Author information

1
Division of Genomic Medicine, University of Sheffield Medical School, Sheffield S10 2RX, United Kingdom. d.h.dockrell@shef.ac.uk

Abstract

Apoptosis of macrophages may be a pathogen-directed mechanism of immune escape or may represent appropriate host response to infection. Human monocyte-derived macrophages (MDMs) from healthy donors (C-MDMs) exhibited low-level constitutive apoptosis, but culture of MDMs with opsonized serotype I Streptococcus pneumoniae (I-MDMs) for 20 h resulted in significantly increased apoptosis. I-MDM apoptosis was associated with phagocytosis of bacteria and intracellular killing that was blocked by the caspase inhibitor z-VAD-fmk but not by Fas-blocking antibody. Paraformaldehyde-fixed I-MDMs induced apoptosis in uninfected syngeneic monocytes at levels greater than those in monocytes incubated alone or incubated with fixed C-MDMs. Apoptosis of syngeneic monocytes was blocked by anti-Fas antibody. The immune response of macrophages to S. pneumoniae includes a novel form of apoptosis that is associated with successful phagocytosis and bacterial killing. This response in vivo may regulate the inflammatory response to infection during a successful host response against S. pneumoniae.

PMID:
11517432
DOI:
10.1086/323084
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center