Extension of HLA-A*0201-restricted minimal epitope by N epsilon-palmitoyl-lysine increases the life span of functional presentation to cytotoxic T cells.
The delineation of the minimal requirements for efficient delivery of functional cytotoxic epitopes into APC could be a step toward the definition of "minimal length" lipopeptides for the modulation of CTL activity. Several analogues of the HLA-A*0201-restricted HIV-1 polymerase (pol476-484) minimal cytotoxic epitope were obtained by modifying P0, P1, or P10 positions by a single N epsilon-palmitoyl-lysine residue. The use of fluorescent derivatives confirmed the cell-permeating activities and suggested that a P0- and a P1-modified lipopeptide possessing ionizable extremities fulfills the structural requirements for MHC loading. The expressions of HLA-peptide complexes at the surface of TAP-deficient cells incubated with the parent epitope or lipopeptide derivatives were compared, in terms of intensity and stability. Both lipopeptides induced a considerably prolonged expression of conformationally correct complexes, which were dependent on the integrity of the exocytosis pathway, suggesting a dynamic mechanism of formation or reloading of the complexes from an intracellular pool. The agonistic activities of the different HLA-peptide complexes were evaluated using two independent T cell lines from HIV-infected donors. We report that a lipodecapeptide obtained by N-terminal addition of a N epsilon-palmitoyl-lysine to the pol476-484 epitope was able to increase the life span of functional presentation to cytotoxic T cells specific for the parent peptide.
Loing
E
E
Unité Mixte de Recherche 8525, Centre National de la Recherche Scientifique-Lille II University and Institut Pasteur de Lille, Lille, France. Estelle.Loing@pasteur-lille.fr
Andrieu
M
M
Thiam
K
K
Schörner
D
D
Wiesmüller
K H
KH
Hosmalin
A
A
Jung
G
G
Gras-Masse
H
H
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D019943:Amino Acid Substitution; D017951:Antigen Presentation; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D015234:HLA-A Antigens / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006822:Hybrid Cells; D007700:Kinetics; D008074:Lipoproteins / Q000276:immunology / Q000378:metabolism; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism; D046911:Macromolecular Substances; D010455:Peptides / Q000276:immunology / Q000378:metabolism; D012235:Rhodamines / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D018984:Epitopes, T-Lymphocyte; D005456:Fluorescent Dyes; D015234:HLA-A Antigens; D008074:Lipoproteins; D046911:Macromolecular Substances; C104968:N(epsilon)-palmitoyllysine; D010455:Peptides; D012235:Rhodamines; C073119:TAP1 protein, human; D008239:Lysine