Linked Life Data

14971035

Source:http://linkedlifedata.com/resource/pubmed/id/14971035

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-2-18
pubmed:abstractText
Immune complexes (IC) initiate immunoreceptor tyrosine-based inhibition motif (ITIM) signaling and inhibit B cell activation by coligating B cell receptor for antigen (BCR) and FcgammaRII. Nevertheless, IC on follicular dendritic cells (FDC) stimulate rapid germinal center (GC) B cell proliferation suggesting that interactions between IC and FDC render IC capable of B cell activation. To understand this, we studied the kinetics of FDC FcgammaRII and complement receptors 1 and 2 (CR1&2) expressions during the GC reaction and determined whether FDC FcgammaRII could bind Fc in IC and block ITIM signaling. Mice were immunized with sheep red blood cells (SRBC), and CR1&2 and FcgammaRII levels in FDC reticula were monitored. The role of FDC FcgammaRII was studied using anti-BCR-stimulated A20 cells. Levels of FDC FcgammaRII in spleens of SRBC-injected mice increased within 24 h and were dramatically increased (approximately 50-fold) on days 3 and 5. In contrast, CR1&2 levels increased less than twofold. Addition of normal FDC, but not FDC lacking FcgammaRII, reduced and reversed anti-BCR-induced SH2 domain-containing inositol phosphatase (SHIP)-1 phosphorylation in A20 cells. FDC were able to induce normal recall responses even after overnight incubation of the lymphocytes with IC to stimulate ITIM signaling. Engagement of Ig Fc with numerous FcgammaRII on FDC appears to minimize IC-induced ITIM signaling. Thus, rapid up-regulation of FDC FcgammaRII may explain why poorly immunogenic IC are rendered highly immunogenic when presented by FDC in GC.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
98-107
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
FcgammaRII expression on follicular dendritic cells and immunoreceptor tyrosine-based inhibition motif signaling in B cells.
pubmed:affiliation
Department of Microbiology and Immunology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.