Linked Life Data

11532976

Source:http://linkedlifedata.com/resource/pubmed/id/11532976

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2001-9-4
pubmed:abstractText
Dendritic cells (DCs) are specialized antigen-presenting cells characterized by their ability to migrate into target sites, process antigens, and activate naive T cells. In this study, we analyzed the biological activity and intracellular signaling of adenosine by using reverse transcriptase-polymerase chain reaction assays to investigate mRNA expression of A(1), A(2a) and A(3) adenosine receptors in immature and mature human DCs. Functional experiments on adenosine stimulation showed chemotaxis, intracellular calcium transients, and actin polymerization, but no activation of adenylate cyclase in immature DCs. Experiments with receptor isotype-selective agonists and antagonists as well as pertussis toxin revealed that chemotaxis, calcium transients, and actin polymerization were mediated via G(i-) or G(0-)protein-coupled A(1) and A(3) receptors. Maturation of DCs induced by lipopolysaccharide (LPS) resulted in down-regulation of A(1) and A(3) receptor mRNAs, although A(2a) receptor mRNA was still expressed. However, in LPS-differentiated DCs, adenosine and an A(2a) receptor agonist stimulated adenylate cyclase activity, enhanced intracellular cAMP levels, and inhibited interleukin 12 (IL-12) production. These effects could be completely prevented by pretreatment with A(2) receptor antagonist. These findings strongly suggest that adenosine has important but distinct biological effects in DCs activity as a chemotaxin for immature DCs and as a modulator of IL-12 production in mature DCs. These effects can be explained by differential expression of adenosine receptor subtypes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0892-6638
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1963-70
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Expression and function of adenosine receptors in human dendritic cells.
pubmed:affiliation
Department of Experimental Dermatology, University of Freiburg, Hauptstrasse 7, D-79104 Freiburg i.Br., Germany.
pubmed:publicationType
Journal Article