title: Carrier-mediated uptake and presentation of a major histocompatibility complex class I-restricted peptide.
abstract: Antigenic peptides derived from endogenous or viral proteins can associate with class I or class II major histocompatibility complex (MHC) molecules, while exogenous antigens are endocytosed, processed intracellularly and presented on MHC class II molecules. Here we describe a method that allows the presentation of an MHC class I-restricted antigenic peptide on MHC class I molecules, although it was taken up from the outside. The HLA-A2-restricted influenza virus matrix protein-derived peptide (flu, 57-68) was used either in soluble form or coupled via an S-S bridge to transferrin (Tf-flu). Target cells were incubated with flu or Tf-flu and the effective antigen presentation was detected in a cytotoxicity assay using flu peptide-specific, HLA-A2-restricted CD8+ cytotoxic T lymphocytes. Sensitization of target cells with Tf-flu required 5 to 10 times higher molar concentrations of peptide compared to sensitization with soluble free peptide. The Tf-flu construct was taken up by the cells via the Tf receptor (CD71) as the binding of Tf-flu was blocked by an excess of Tf. In contrast to the flu peptide, cytotoxicity elicited by Tf-flu was blocked by brefeldin A but not by chloroquine nor inhibitors of intracellular reducing steps, like 1-buthionine-(s,r)-sulfoximine or n-ethylmaleimide. Presentation of the flu peptide derived from Tf-flu construct is not hindered in the mutant T2 cell line, which lacks genes coding for transporter proteins for antigenic peptides (TAP1/TAP2) and proteasomes subunits, suggesting that the processing pathway described in this report may involve TAP-independent steps.
authors.affiliation: Institute of Clinical Immunology, Inselspital, Bern, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Brander
authors.forename: T
authors.initials: T
authors.lastname: Wyss-Coray
authors.forename: D
authors.initials: D
authors.lastname: Mauri
authors.forename: F
authors.initials: F
authors.lastname: Bettens
authors.forename: W J
authors.initials: WJ
authors.lastname: Pichler
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D017951:Antigen Presentation; D002352:Carrier Proteins / Q000502:physiology; D002461:Cell Line, Transformed; D015789:HLA-A2 Antigen / Q000032:analysis / Q000502:physiology*; D000949:Histocompatibility Antigens Class II / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*; D011990:Receptors, Transferrin / Q000502:physiology; D014168:Transferrin / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000378:metabolism*
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D015789:HLA-A2 Antigen; D000949:Histocompatibility Antigens Class II; C031540:M-protein, influenza virus; D010446:Peptide Fragments; D011990:Receptors, Transferrin; C073119:TAP1 protein, human; D014168:Transferrin; D014763:Viral Matrix Proteins; C071692:TAP2 protein, human