Dockrell, D. H., Lee, M., Lynch, D. H. et al. (1 more author) (2001) Immune-mediated phagocytosis and killing of Streptococcus pneumoniae are associated with direct and bystander macrophage apoptosis. The Journal of infectious diseases, 184 (6). pp. 713-722. ISSN 0022-1899
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.
|Institution:||The University of Sheffield|
|Academic Units:||The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Medicine (Sheffield)|
|Depositing User:||Miss Anthea Tucker|
|Date Deposited:||29 Mar 2012 09:43|
|Last Modified:||29 Mar 2012 09:43|
|Publisher:||Oxford University Press|