Linked Life Data

18393378

Source:http://linkedlifedata.com/resource/pubmed/id/18393378

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2008-4-16
pubmed:abstractText
MHC class II-mediated antigen presentation by B lymphocytes or dendritic cells (DC) initiates CD4+ T lymphocyte activation. In B lymphocytes, MHC class II peptide presentation has been characterised by recruitment of MHC class II, F-actin and lipid rafts to the B cell-T cell immunological synapse. We now show that MHC class II engagement in B lymphocytes induced lipid raft-independent Rho and Rac activation and that inhibition of either Rho-GTPase activation or actin polymerisation in the B cell abrogated T cell activation without altering B cell-T cell conjugate formation. Short-hairpin RNA studies excluded a role for the Cdc42 effector Wiskott-Aldrich syndrome protein. In contrast, antigen presentation by DC was Rho-GTPase-independent although actin was recruited to the DC-T cell interaction site. Moreover, actin depolymerisation in the DC significantly increased T cell activation without altering the number of DC-T cell conjugates. Finally we show that stable recruitment of HLA-DR to the site of the immunological synapse is not a uniform observation in DC and demonstrate reduced HLA-DR expression at the site of microtubule organising centre polarization. Therefore although actin accumulates in DC and B lymphocytes at the immunological synapse with antigen-specific T lymphocytes, this does not reflect comparable functional roles of their actin cytoskeletons in antigen presentation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1096-105
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Contrasting cytoskeletal regulation of MHC class II peptide presentation by human B cells or dendritic cells.
pubmed:affiliation
INSERM Unité 662 Paris, Institut Universitaire d'Hématologie, Université Paris-Diderot, Faculté de Médecine, Hôpital Saint-Louis, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't