H-2Ld class I molecule protects an HIV N-extended epitope from in vitro trimming by endoplasmic reticulum aminopeptidase associated with antigen processing.
In the classical MHC class I Ag presentation pathway, antigenic peptides derived from viral proteins by multiple proteolytic cleavages are transported to the endoplasmic reticulum lumen and are then exposed to ami-nopeptidase activity. In the current study, a long MHC class I natural ligand recognized by cytotoxic T lymphocytes was used to study the kinetics of degradation by aminopeptidase. The in vitro data indicate that this N-extended peptide is efficiently trimmed to a 9-mer, unless its binding to the MHC molecules protects the full-length peptide.
Infantes
Susana
S
Unidad de Proteómica, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid, Madrid, Spain.
Samino
Yolanda
Y
Lorente
Elena
E
Jiménez
Mercedes
M
García
Ruth
R
Del Val
Margarita
M
López
Daniel
D
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D002478:Cells, Cultured; D004721:Endoplasmic Reticulum / Q000276:immunology / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000276:immunology / Q000378:metabolism*; D006183:H-2 Antigens / Q000276:immunology / Q000378:metabolism*; D015699:HIV Envelope Protein gp120 / Q000276:immunology / Q000378:metabolism*; D064532:Histocompatibility Antigen H-2D; D006801:Humans; D007931:Leucyl Aminopeptidase / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D018984:Epitopes, T-Lymphocyte; D006183:H-2 Antigens; D015699:HIV Envelope Protein gp120; D064532:Histocompatibility Antigen H-2D; D011994:Recombinant Proteins; D007931:Leucyl Aminopeptidase; C456799:puromycin-insensitive leucyl-specific aminopeptidase