title: Large and dissimilar repertoire of Melan-A/MART-1-specific CTL in metastatic lesions and blood of a melanoma patient.
abstract: It is widely accepted that the repertoire of Melan-A-specific T cells naturally selected in melanoma patients is diverse and mostly nonoverlapping among different individuals. To date, however, no studies have addressed the TCR profile in different tumor sites and the peripheral blood from the same patient. We compared the TCR usage of Melan-A-specific T cells from different compartments of a single melanoma patient to evaluate possible clonotype expansion or preferential homing over a 4-mo follow-up period. Using HLA-A2 peptide tetramers, CD8(+) T cells recognizing the modified Melan-A immunodominant ELAGIGILTV peptide were isolated from four metastatic lesions resected from a single melanoma patient, and their TCR repertoire was studied. A panel of T cell clones was generated by cell cloning of tetramer-positive cells. Analysis of the TCR beta-chain V segment and the complementarity-determining region 3 (CDR3) length and sequence revealed a large diversity in the TCR repertoire, with only some of the clones showing a partial conservation in the CDR3. A similar degree of diversity was found by analyzing a number of T cell clones obtained after sorting a Melan-A-specific population derived from PBLs of the same patient after in vitro culture with the immunodominant epitope. Moreover, clonotypes found at one site were not present in another, suggesting the lack of expansion and circulation of one or more clonotypes. Taken together, these results buttress the notion that the CTLs recognizing the immunodominant Ag of Melan-A comprise a high number of different clonotypic TCR, of which only some exhibit common features in the CDR3.
authors.affiliation: Department of Oncology, University of Padova, Padova, Italy. susanna.mandruzzato@unipd.it
authors.forename: Susanna
authors.initials: S
authors.lastname: Mandruzzato
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Rossi
authors.forename: Fabiola
authors.initials: F
authors.lastname: Bernardi
authors.forename: Valeria
authors.initials: V
authors.lastname: Tosello
authors.forename: Beatrice
authors.initials: B
authors.lastname: Macino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Basso
authors.forename: Vanna
authors.initials: V
authors.lastname: Chiarion-Sileni
authors.forename: Carlo Riccardo
authors.initials: CR
authors.lastname: Rossi
authors.forename: Cristina
authors.initials: C
authors.lastname: Montesco
authors.forename: Paola
authors.initials: P
authors.lastname: Zanovello
mesh_terms: D000595:Amino Acid Sequence; D000951:Antigens, Neoplasm; D001483:Base Sequence; D002999:Clone Cells; D018984:Epitopes, T-Lymphocyte / Q000032:analysis* / Q000097:blood; D005434:Flow Cytometry; D019674:Genes, T-Cell Receptor beta; D015789:HLA-A2 Antigen / Q000032:analysis; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics; D016246:Lymphocytes, Tumor-Infiltrating / Q000737:chemistry / Q000276:immunology / Q000473:pathology; D058965:MART-1 Antigen; D008545:Melanoma / Q000737:chemistry / Q000276:immunology* / Q000473:pathology / Q000556:secondary*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000097:blood; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D007135:Immunoglobulin Variable Region; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta