Linked Life Data

21918193

Source:http://linkedlifedata.com/resource/pubmed/id/21918193

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2011-10-4
pubmed:abstractText
Epithelial linings serve as physical barriers and produce antimicrobial peptides (AMPs) to maintain host integrity. Examples are the bactericidal proteins midkine (MK) and BRAK/CXCL14 that are constitutively produced in the skin epidermal layer, where the anaerobic Gram-positive coccoid commensal Finegoldia magna resides. Consequently, this bacterium is likely to encounter both MK and BRAK/CXCL14, making these molecules possible threats to its habitat. In this study, we show that MK expression is upregulated during inflammation, concomitant with a strong downregulation of BRAK/CXCL14, resulting in changed antibacterial conditions. MK, BRAK/CXCL14, and the inflammation-dependent antimicrobial ?-defensins human ?-defensin (hBD)-2 and hBD-3 all showed bactericidal activity against both F. magna and the virulent pathogen Streptococcus pyogenes at similar concentrations. SufA, a released protease of F. magna, degraded MK and BRAK/CXCL14 but not hBD-2 nor hBD-3. Cleavage was seen at lysine and arginine residues, amino acids characteristic of AMPs. Intermediate SufA-degraded fragments of MK and BRAK/CXCL14 showed stronger bactericidal activity against S. pyogenes than F. magna, thus promoting survival of the latter. In contrast, the cysteine-protease SpeB of S. pyogenes rapidly degraded all AMPs investigated. The proteins FAF and SIC, released by F. magna and S. pyogenes, respectively, neutralized the antibacterial activity of MK and BRAK/CXCL14, protein FAF being the most efficient. Quantitation and colocalization by immunoelectron microscopy demonstrated significant levels and interactions of the molecules in in vivo and ex vivo samples. The findings reflect strategies used by a permanently residing commensal and a virulent pathogen, the latter operating during the limited time course of invasive disease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1550-6606
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
187
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4300-9
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Constitutive and inflammation-dependent antimicrobial peptides produced by epithelium are differentially processed and inactivated by the commensal Finegoldia magna and the pathogen Streptococcus pyogenes.
pubmed:affiliation
Section for Infection Medicine, Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-221 85 Lund, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't