Linked Life Data

9794381

Source:http://linkedlifedata.com/resource/pubmed/id/9794381

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1998-11-18
pubmed:abstractText
The addition of Ags to mononuclear leukocyte cultures typically elicits modest Ab responses, implying that cosignals beyond those provided by T cells and macrophages may be needed. Recently, we reported that Ab responses could be dramatically enhanced (10-1000-fold) by the addition of follicular dendritic cells (FDC), suggesting that FDC may provide an important costimulatory signal. This result prompted a study of molecules involved in FDC-mediated enhancement of Ab responses stimulated by specific Ag with memory T and B cells or nonspecifically by the addition of LPS. In this study, we report evidence supporting the concept that FDC bear a ligand that engages complement receptor II (CR2 or CD21) on B cells and provides a critical cosignal for both Ag-specific and polyclonal responses. A blockade of the CR2 ligand on FDC by the use of soluble CR2 or a blockade of CR2 on B cells by use of CR2 knockout mice (or B cells with CR2 blocked) reduced Ab responses from the microg/ml to the ng/ml range (10-1000-fold reductions). FDC from C3 knockout mice, which cannot generate the CR2-binding fragments (iC3b, C3d, and C3dg), were unable to provide costimulatory activity, suggesting the CR2 ligand on FDC consists of C3 fragments. FDC trap complement-activating Ag-Ab complexes, and it appears that FDC present B cells with both specific Ag to engage B cell receptors and a CR2 ligand to engage B cell-CR2. In short, optimal induction of specific Ab responses appears to require the combination of specific Ag and costimulatory molecules from both T cells and FDC.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
161
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4549-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Evidence for an important interaction between a complement-derived CD21 ligand on follicular dendritic cells and CD21 on B cells in the initiation of IgG responses.
pubmed:affiliation
Department of Microbiology and Immunology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.