Document Detail


A cardinal role for cathepsin d in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci.
MedLine Citation:
PMID:  21298030     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D(-/-) hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function.
Authors:
Martin A Bewley; Helen M Marriott; Calogero Tulone; Sheila E Francis; Timothy J Mitchell; Robert C Read; Benny Chain; Guido Kroemer; Moira K B Whyte; David H Dockrell
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2011-01-27
Journal Detail:
Title:  PLoS pathogens     Volume:  7     ISSN:  1553-7374     ISO Abbreviation:  PLoS Pathog.     Publication Date:  2011  
Date Detail:
Created Date:  2011-02-07     Completed Date:  2011-05-05     Revised Date:  2011-07-25    
Medline Journal Info:
Nlm Unique ID:  101238921     Medline TA:  PLoS Pathog     Country:  United States    
Other Details:
Languages:  eng     Pagination:  e1001262     Citation Subset:  IM    
Affiliation:
Medical School, University of Sheffield, Sheffield, United Kingdom.
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MeSH Terms
Descriptor/Qualifier:
Animals
Apoptosis*
Bone Marrow Cells
Bone Marrow Transplantation
Cathepsin D / deficiency,  genetics,  metabolism*
Cell Line, Tumor
Cytosol / enzymology,  microbiology
Female
Host-Pathogen Interactions
Humans
Intracellular Membranes / enzymology,  microbiology
Macrophages / enzymology*,  immunology,  microbiology
Mice
Mice, Inbred C57BL
Mice, Knockout
Phagosomes / enzymology,  microbiology
Streptococcus pneumoniae / pathogenicity,  physiology*
Grant Support
ID/Acronym/Agency:
076945//Wellcome Trust; BB/D005469/1//Biotechnology and Biological Sciences Research Council; //Medical Research Council
Chemical
Reg. No./Substance:
EC 3.4.23.5/Cathepsin D
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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