Linked Life Data

19265139

Source:http://linkedlifedata.com/resource/pubmed/id/19265139

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2009-3-6
pubmed:abstractText
To present virus and tumor Ags, HLA class I molecules undergo a complex multistep assembly involving discrete but transient folding intermediates. The most extensive folding abnormalities occur in cells lacking the class I L chain subunit, called beta(2)-microglobulin (beta(2)m). Herein, this issue was investigated taking advantage of eight conformational murine mAbs (including the prototypic W6/32 mAb) to mapped H chain epitopes of class I molecules, four human mAbs to class I alloantigens, as well as radioimmunoprecipitation, in vitro assembly, pulse-chase, flow cytometry, and peptide-pulse/ELISPOT experiments. We show that endogenous (HLA-A1, -A66, and -B58) as well as transfected (HLA-A2) heavy chains in beta(2)m-defective Burkitt lymphoma Daudi cells are capable of being expressed on the cell surface, although at low levels, and exclusively as immature glycoforms. In addition, HLA-A2 is: 1) partially folded at crucial interfaces with beta(2)m, peptide Ag, and CD8; 2) receptive to exogenous peptide; and 3) capable of presenting exogenous peptide epitopes (from virus and tumor Ags) to cytotoxic T lymphocytes (bulk populations as well as clones) educated in a beta(2)m-positive environment. These experiments demonstrate a precursor-product relationship between novel HLA class I folding intermediates, and define a stepwise mechanism whereby distinct interfaces of the class I H chain undergo successive, ligand-induced folding adjustments in vitro as well as in vivo. Due to this unprecedented class I plasticity, Daudi is the first human cell line in which folding and function of class I HLA molecules are observed in the absence of beta(2)m. These findings bear potential implications for tumor immunotherapy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1550-6606
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
182
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3609-17
pubmed:dateRevised
2009-12-8
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Class I HLA folding and antigen presentation in beta 2-microglobulin-defective Daudi cells.
pubmed:affiliation
Laboratory of Immunology, Regina Elena Cancer Institute Centro della Ricerca Sperimentale, Rome, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't