Linked Life Data

21063021

Source:http://linkedlifedata.com/resource/pubmed/id/21063021

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2011-1-28
pubmed:abstractText
Complement alternative pathway plays an important, but not clearly understood, role in neutrophil-mediated diseases. We here show that neutrophils themselves activate complement when stimulated by cytokines or coagulation-derived factors. In whole blood, tumor necrosis factor/formyl-methionyl-leucyl-phenylalanine or phorbol myristate acetate resulted in C3 fragments binding on neutrophils and monocytes, but not on T cells. Neutrophils, stimulated by tumor necrosis factor, triggered the alternative pathway on their surface in normal and C2-depleted, but not in factor B-depleted serum and on incubation with purified C3, factors B and D. This occurred independently of neutrophil proteases, oxidants, or apoptosis. Neutrophil-secreted properdin was detected on the cell surface and could focus "in situ" the alternative pathway activation. Importantly, complement, in turn, led to further activation of neutrophils, with enhanced CD11b expression and oxidative burst. Complement-induced neutrophil activation involved mostly C5a and possibly C5b-9 complexes, detected on tumor necrosis factor- and serum-activated neutrophils. In conclusion, neutrophil stimulation by cytokines results in an unusual activation of autologous complement by healthy cells. This triggers a new amplification loop in physiologic innate immunity: Neutrophils activate the alternative complement pathway and release C5 fragments, which further amplify neutrophil proinflammatory responses. This mechanism, possibly required for effective host defense, may be relevant to complement involvement in neutrophil-mediated diseases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1528-0020
pubmed:author
pubmed:issnType
Electronic
pubmed:day
27
pubmed:volume
117
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1340-9
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Complement alternative pathway acts as a positive feedback amplification of neutrophil activation.
pubmed:affiliation
INSERM U845, Université René Descartes, Hôpital Necker, 161 rue de Sèvres, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't