Abstract
Priming of CD8(+) T cells requires presentation of short peptides bound to MHC class I molecules of professional APCs. Cross-presentation is a mechanism whereby professional APC present on their own MHC class I molecules peptides derived from degradation of Ags synthesized by other Ag "donor cells." The mechanism of cross-presentation is poorly understood, and the nature of the transferred Ag is unknown. In this report, we demonstrate that the bulk of a cross-presented Ag transferred from donor cells recently infected with vaccinia virus are proteasomal products that are susceptible to peptidases within the donor cell cytosol and not full-length proteins or mature epitopes either free or bound to chaperones.
Publication types
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Animals
-
Antigen Presentation / immunology*
-
Antigen-Presenting Cells / immunology*
-
Antigen-Presenting Cells / metabolism*
-
Antigen-Presenting Cells / virology
-
Antigens / metabolism*
-
Cell Line
-
Chickens
-
Cysteine Endopeptidases / metabolism*
-
Cytosol / immunology
-
Cytosol / metabolism
-
Egg Proteins / immunology
-
Egg Proteins / metabolism
-
Endoplasmic Reticulum / immunology
-
Endoplasmic Reticulum / metabolism
-
H-2 Antigens / immunology
-
H-2 Antigens / metabolism*
-
HeLa Cells
-
Humans
-
Hybridomas
-
Immunodominant Epitopes / immunology
-
Immunodominant Epitopes / metabolism
-
Mice
-
Molecular Chaperones / metabolism
-
Multienzyme Complexes / metabolism*
-
Ovalbumin / immunology
-
Ovalbumin / metabolism
-
Peptide Fragments
-
Proteasome Endopeptidase Complex
-
Protein Binding / immunology
-
Protein Transport / immunology
-
Vaccinia virus / immunology*
Substances
-
Antigens
-
Egg Proteins
-
H-2 Antigens
-
Immunodominant Epitopes
-
Molecular Chaperones
-
Multienzyme Complexes
-
OVA-8
-
Peptide Fragments
-
Ovalbumin
-
Cysteine Endopeptidases
-
Proteasome Endopeptidase Complex