title: Dissecting cytotoxic T cell responses towards the NY-ESO-1 protein by peptide/MHC-specific antibody fragments.
abstract: NY-ESO-1 is a germ cell antigen aberrantly expressed by different tumor types that elicits strong humoral and cellular immune responses, representing one of the most promising candidates for vaccination of cancer patients. A detailed analysis of CD8(+) T cells generated in vaccine trials using NY-ESO-1-derived peptides (157-165 and 157-167) revealed that the dominant immune response was directed against a cryptic epitope (159-167) diverting the immune response from tumor recognition. Only CTL reactivity to the NY-ESO-1(157-165) peptide appeared to be capable of lysing NY-ESO-1/HLA-A0201-expressing tumor cells. To study the process of NY-ESO-1 peptide presentation by tumor cells in more detail we generated a high-affinity (K(D)=60 nM) antibody fragment that specifically recognizes the NY-ESO-1(157-165) peptide/HLA-A0201 complex. Peptide variants such as the NY-ESO-1(157-167) peptide or the cryptic NY-ESO-1(159-167) peptide were not recognized. The antibody fragment blocked in a dose-dependent fashion the recognition of NY-ESO-1/HLA-A2-positive tumor cells by NY-ESO-1(157-165) peptide-specific CD8(+) T cells. This antibody fragment is a novel reagent that binds with TCR-like specificity to the NY-ESO-1(157-165)/HLA-A2 complex thus distinguishing between CTL responses against immunological meaningful or cryptic NY-ESO-1-derived peptides. It may therefore become a useful monitoring tool for the development of NY-ESO-1-based cancer vaccines.
authors.affiliation: Clinic for Internal Medicine I, Saarland University Medical School, Homburg/Saar, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Held
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Matsuo
authors.forename: Malka
authors.initials: M
authors.lastname: Epel
authors.forename: Sacha
authors.initials: S
authors.lastname: Gnjatic
authors.forename: Gerd
authors.initials: G
authors.lastname: Ritter
authors.forename: Sang Yull
authors.initials: SY
authors.lastname: Lee
authors.forename: Tsin Yee
authors.initials: TY
authors.lastname: Tai
authors.forename: Cyril J
authors.initials: CJ
authors.lastname: Cohen
authors.forename: Lloyd J
authors.initials: LJ
authors.lastname: Old
authors.forename: Michael
authors.initials: M
authors.lastname: Pfreundschuh
authors.forename: Yoram
authors.initials: Y
authors.lastname: Reiter
authors.forename: Hennie R
authors.initials: HR
authors.lastname: Hoogenboom
authors.forename: Christoph
authors.initials: C
authors.lastname: Renner
mesh_terms: D000595:Amino Acid Sequence; D000918:Antibody Specificity / Q000276:immunology*; D017951:Antigen Presentation / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology*; D019496:Cancer Vaccines / Q000276:immunology; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D007140:Immunoglobulin Fab Fragments / Q000276:immunology*; D008285:Major Histocompatibility Complex / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology*; D010455:Peptides / Q000276:immunology*; D011487:Protein Conformation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection
chemical_list: D000951:Antigens, Neoplasm; C104948:CTAG1B protein, human; D019496:Cancer Vaccines; D016056:Immunodominant Epitopes; D007140:Immunoglobulin Fab Fragments; D008565:Membrane Proteins; D010455:Peptides