title: Cellular processing of a multibranched lysine core with tumor antigen peptides and presentation of peptide epitopes recognized by cytotoxic T lymphocytes on antigen-presenting cells.
abstract: We showed that pRL1a multiple antigen peptide (MAP)-sensitized dendritic cell (DC) and P815 cell lysis by pRL1a-specific B-24 CTL was blocked by incubating target cells at 4 degrees C during sensitization. The finding suggested that pRL1a MAP was mostly internalized in DC and P815 cells and produced pRL1a peptide epitopes for presentation with H-2L(d). Furthermore, we showed that sensitization with pRL1a MAP was inhibited by the addition of chloroquine, cycloheximide, and brefeldin A to the culture, but not by the addition of inhibitors for lysosomal proteases or proteasome. Inhibition of sensitization by the addition of chloroquine to the culture suggested the requirement of acidification of the endosomal compartment for pRL1a MAP processing. Inhibition of sensitization by the addition of cycloheximide and brefeldin A to the culture indicated the requirement of newly generated MHC class I antigen molecules and the involvement of transport of the peptide MHC class I complex from the endoplasmic reticulum to the Golgi. The findings suggested that pRL1a MAP in the endosomal compartment leaked to the cytosol, and degraded, and the pRL1a peptide produced was presented by the MHC class I pathway.
authors.affiliation: Department of Immunology, Okayama University Graduate School of Medicine and Dentistry, Okayama 700-8558, Japan.
authors.forename: Seisuke
authors.initials: S
authors.lastname: Ota
authors.forename: Toshiro
authors.initials: T
authors.lastname: Ono
authors.forename: Akimichi
authors.initials: A
authors.lastname: Morita
authors.forename: Akiko
authors.initials: A
authors.lastname: Uenaka
authors.forename: Mine
authors.initials: M
authors.lastname: Harada
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000502:physiology*; D000951:Antigens, Neoplasm / Q000276:immunology / Q000378:metabolism*; D020126:Brefeldin A / Q000494:pharmacology; D002738:Chloroquine / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D018984:Epitopes, T-Lymphocyte; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D018613:Microscopy, Confocal; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D018984:Epitopes, T-Lymphocyte; D020126:Brefeldin A; D002738:Chloroquine; D003513:Cycloheximide