Linked Life Data

21123174

Source:http://linkedlifedata.com/resource/pubmed/id/21123174

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2011-1-31
pubmed:abstractText
Human neutrophils constitutively express a unique combination of Fc?Rs, namely Fc?RIIa and Fc?RIIIb. Numerous lines of evidence support the concept that these Fc?Rs generate only partially characterized intracellular signals. However, despite the fact that both receptors are likely to be engaged simultaneously in a physiological setting, no recent publications have investigated the distinct, although partially convergent, results of their joint activation in IgG-dependent responses. To examine the significance of the co-expression of Fc?RIIa and Fc?RIIIb on human neutrophils, we analyzed the neutrophil responses to stimuli that engage these Fc?Rs, namely the phagocytosis of human IgG-opsonized zymosan and the responses to heat-aggregated IgGs. Blocking antibodies to either Fc?R significantly decreased the phagocytic index and the stimulated production of superoxide anions. Both receptors are required for optimal IgG-dependent responses by human neutrophils. On the other hand, only blocking antibodies to Fc?RIIIb, but not to Fc?RIIa, inhibited the mobilization of calcium in response to heat-aggregated IgGs. Furthermore, phagocytosis of IgG-opsonized zymosan by human neutrophils required an extracellular influx of calcium that was blocked only by antibodies against Fc?RIIIb. We also observed that this calcium influx as well as the IgG-dependent phagocytosis were dependent on the integrity of the plasma membrane detergent-resistant microdomains to which both isoforms were recruited following stimulation by heat-aggregated IgGs. These data clarify the mechanisms that regulate the Fc?Rs constitutively expressed on human neutrophils, describe a specific contribution of Fc?RIIIb at the level of the mobilization of calcium, and provide evidence for a crucial role of detergent-resistant microdomains in this process.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
286
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3509-19
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Fc gammaRIIIb triggers raft-dependent calcium influx in IgG-mediated responses in human neutrophils.
pubmed:affiliation
Centre de Recherche du Centre Hospitalier Universitaire de Québec, Department of Microbiology-Infectiology and Immunology, Faculty of Medicine, Laval University, Québec City, Québec G1V 4G2, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't