Linked Life Data

10570297

Source:http://linkedlifedata.com/resource/pubmed/id/10570297

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1999-12-20
pubmed:abstractText
Several intracellular pathogens exploit macrophages as a niche for survival and replication. The success of this strategy requires the subversion or the avoidance of microbicidal functions of macrophages. Coxiella burnetii, the agent of Q fever, is a strictly intracellular bacterium that multiplies in myeloid cells. The survival of C. burnetii may depend on the selective use of macrophage receptors. Virulent C. burnetii organisms were poorly internalized but survived successfully in human monocytes, whereas avirulent variants were efficiently phagocytosed but were also rapidly eliminated. The uptake of avirulent organisms was mediated by leukocyte response integrin (alphavbeta3 integrin) and CR3 (alphaMbeta2 integrin), as demonstrated by using specific Abs and RGD sequence-containing peptides. The phagocytic efficiency of CR3 depends on its activation via alphavbeta3 integrin and integrin-associated protein. Indeed, CR3-mediated phagocytosis of avirulent C. burnetii was abrogated in macrophages from integrin-associated protein-/- mice. In contrast, the internalization of virulent C. burnetii organisms involved the engagement of alphavbeta3 integrin but not that of CR3. The pretreatment of monocytes with virulent C. burnetii organisms prevented the CR3-mediated phagocytosis of zymosan particles and CR3 activation assessed by the expression of the 24 neo-epitope. We conclude that the virulence of C. burnetii is associated with the engagement of alphavbeta3 integrin and the impairment of CR3 activity, which probably results from uncoupling alphavbeta3 integrin from integrin-associated protein. This study describes a strategy not previously reported of phagocytosis modulation by intracellular pathogens.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
163
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6078-85
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Subversion of monocyte functions by coxiella burnetii: impairment of the cross-talk between alphavbeta3 integrin and CR3.
pubmed:affiliation
Université de la Méditerranée, Unité des Rickettsies, Centre National de la Recherche Scientifique, Unité Propre de Recherche de l'Enseignement Supérieur Associée 6020, Faculté de Médecine, Marseille, France.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't