Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-1-12
pubmed:abstractText
Video-intensification fluorescence microscopy has been used to study the cell surface distribution of the complement receptor (CR) for C3bi (CR3) on human neutrophils. Fluorescein- or rhodamine-labeled monoclonal IgG or Fab fragments of antireceptor antibody were used as probes of receptor localization. C3bi receptors are uniformly distributed on untreated cells. Glass coverslips were coated with lipopolysaccharide (LPS) and serum was added; the serum deposits complement components, including C3bi, on the surface. When neutrophils were adherent to these coverslips, receptors were found in large clusters, and a fraction of the fluorescence remained uniform. Double-labeling studies were conducted by first labeling with anti-CR3 followed by attachment to LPS/serum-treated slides. This, in turn, was followed by labeling with the antibody conjugated to a second fluorophore. These studies revealed that the CR3 clusters were predominantly new antigenic sites exposed after attachment to the LPS/serum-treated slides. To determine the contribution of granule-associated CR3, we have studied neutrophils defective in receptor up-regulation, neutrophil cytoplasts, and a stimulator of granule release, A23187. Neutrophils from a patient with specific granule deficiency were found to be defective in granular CR3 and did not form clusters on C3-modified surfaces. The patient's neutrophils were defective in CR3 up-regulation and enzyme release as shown by fluorescence flow cytometry and gelatinase release, respectively. Cytoplasts also failed to show CR3 clusters on LPS/serum-treated coverslips. Furthermore, neutrophils treated with A23187 demonstrated numerous CR3 clusters. We suggest that formation of CR3 membrane domains during immune recognition requires the participation of intracellular granules. We speculate that these domains are formed by fusion of CR3-bearing granules at local sites of adhesion.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
133
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
235-42, 256
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Neutrophil C3bi receptors: formation of membrane clusters during cell triggering requires intracellular granules.
pubmed:affiliation
Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't