Improved detection of melanoma antigen-specific T cells expressing low or high levels of CD8 by HLA-A2 tetramers presenting a Melan-A/Mart-1 peptide analogue.
MHC class I tetramers containing peptide epitopes are sensitive tools for detecting antigen-specific CD8(+) T-cell responses. We demonstrate here that binding of HLA-A2 tetramers to CD8(+) T cells specific for the melanoma-associated antigen Melan-A/MART-1 can be fine-tuned by altering either the bound peptide epitope or residues in the alpha 3 domain of HLA-A2, which is important for CD8 binding. Antigen-specific T cells expressing high levels of CD8 could be detected using HLA-A2 tetramers containing the peptide AAGIGILTV, an epitope which is naturally processed and presented from Melan-A/MART-1. In contrast, low CD8-expressing, antigen-specific T cells could be detected efficiently only by using a mutated HLA-A2 tetramer with an altered CD8 binding site or, less efficiently, using the wild-type HLA-A2 tetramer loaded with the peptide analogue ELAGIGILTV, which is superior in stimulating antigen-specific T-cell responses. Our results suggest ways to optimize the identification and expansion of antigen-specific T cells with different requirements for the costimulatory CD8 molecule in facilitating T-cell receptor binding to peptide variants.
Maeurer
Markus J
MJ
Department of Medical Microbiology, University of Mainz, Mainz, Germany. maeurer@mail.uni-mainz.de
Necker
Antje
A
Salter
Russell D
RD
Castelli
Chiara
C
Höhn
Hanni
H
Karbach
Julia
J
Freitag
Kirsten
K
Neukirch
Claudia
C
Knuth
Alexander
A
Jäger
Elke
E
D000951:Antigens, Neoplasm / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D005434:Flow Cytometry; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D058965:MART-1 Antigen; D008545:Melanoma / Q000276:immunology*; D009363:Neoplasm Proteins / Q000276:immunology*; D009367:Neoplasm Staging; D011485:Protein Binding / Q000187:drug effects / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D016207:Cytokines; D000939:Epitopes; D015789:HLA-A2 Antigen; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins; D011948:Receptors, Antigen, T-Cell