Ali, F., Lee, M. E., Iannelli, F., Pozzi, G., Mitchell, T. J., Read, R. C. and Dockrell, D. H. (2003) Streptococcus pneumoniae-associated human macrophage apoptosis after bacterial internalization via complement and Fcgamma receptors correlates with intracellular bacterial load. The Journal of infectious diseases, 188 (8). pp. 1119-1131. ISSN 0022-1899
Opsonization enhances Streptococcus pneumoniae-induced human monocyte-derived macrophage (MDM) apoptosis. Both depletion of complement and immunoglobulin from opsonizing serum and blockade of the macrophages CR1, CR3, FcgammaRII, and FcgammaRIII partially decreased MDM apoptosis after S. pneumoniae phagocytosis, and these effects correlated with reduced numbers of internalized bacteria. Chloramphenicol inhibition of protein synthesis by opsonized S. pneumoniae down-regulated subsequent MDM apoptosis. Phagocytosis of an unencapsulated mutant of S. pneumoniae resulted in increased MDM apoptosis, in association with enhanced internalization. Caspase inhibition was associated with decreased killing of bacteria. Enhanced induction of apoptosis by opsonized S. pneumoniae is the result of increased intracellular burden of bacteria, rather than of a specific pattern of engagement of complement receptor or FcgammaR. A dynamic interaction between live intracellular bacteria and the host cell is necessary for induction of apoptosis in MDMs, and induction of apoptosis contributes to the host defense 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 09:45|
|Last Modified:||01 Jul 2014 14:26|
|Publisher:||Oxford University Press|