Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1998-10-6
pubmed:abstractText
In this study, we elucidate the Fc epsilon RI-mediated Ag uptake and presentation mechanisms of dendritic cells (DC). We found that Fc epsilon RI-bound IgE, after polyvalent but not after monovalent ligation, is efficiently internalized into acidic, proteolytic compartments, degraded, and delivered into organelles containing MHC class II, HLA-DM, and lysosomal proteins. To follow the fate of the fragmented ligand, we sought to interfere with invariant chain (Ii) degradation, a process critical for peptide loading of nascent MHC class II molecules. We found DC to express cathepsin (Cat) S, a cysteine protease involved in Ii processing by B cells. Exposure of DC to a specific, active-site inhibitor of Cat S resulted in the loss of anti-Cat S immunoreactivity, led to the appearance of an N-terminal Ii remnant, and decreased the export of newly synthesized MHC class II to the DC surface. Furthermore, inactivation of Cat S as well as blockade of protein neosynthesis by cycloheximide strongly reduced IgE/Fc epsilon RI-mediated Ag presentation by DC. Thus, multimeric ligands of Fc epsilon RI, instead of being delivered into a recycling MHC class H pathway, are channeled efficiently into MIIC (MHC class II compartment)-like organelles of DC, in which Cat S-dependent Ii processing and peptide loading of newly synthesized MHC class II molecules occur. This IgE/Fc epsilon RI-dependent signaling pathway in DC may be a particularly effective route for immunization and a promising target for interfering with the early steps of allergen presentation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
161
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2731-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Fc epsilon receptor I on dendritic cells delivers IgE-bound multivalent antigens into a cathepsin S-dependent pathway of MHC class II presentation.
pubmed:affiliation
Division of Immunology, Allergy and Infectious Diseases, University of Vienna Medical School, Austria. Dieter.Maurer@akh-wien.ac.at
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't