title: Specific roles of each TCR hemichain in generating functional chain-centric TCR.
abstract: TCRα- and β-chains cooperatively recognize peptide-MHC complexes. It has been shown that a "chain-centric" TCR hemichain can, by itself, dictate MHC-restricted Ag specificity without requiring major contributions from the paired TCR counterchain. Little is known, however, regarding the relative contributions and roles of chain-centric and its counter, non-chain-centric, hemichains in determining T cell avidity. We comprehensively analyzed a thymically unselected T cell repertoire generated by transducing the α-chain-centric HLA-A*02:01(A2)/MART127-35 TCRα, clone SIG35α, into A2-matched and unmatched postthymic T cells. Regardless of their HLA-A2 positivity, a substantial subset of peripheral T cells transduced with SIG35α gained reactivity for A2/MART127-35. Although the generated A2/MART127-35-specific T cells used various TRBV genes, TRBV27 predominated with >10(2) highly diverse and unique clonotypic CDR3β sequences. T cells individually reconstituted with various A2/MART127-35 TRBV27 TCRβ genes along with SIG35α possessed a wide range (>2 log orders) of avidity. Approximately half possessed avidity higher than T cells expressing clone DMF5, a naturally occurring A2/MART127-35 TCR with one of the highest affinities. Importantly, similar findings were recapitulated with other self-Ags. Our results indicate that, although a chain-centric TCR hemichain determines Ag specificity, the paired counterchain can regulate avidity over a broad range (>2 log orders) without compromising Ag specificity. TCR chain centricity can be exploited to generate a thymically unselected Ag-specific T cell repertoire, which can be used to isolate high-avidity antitumor T cells and their uniquely encoded TCRs rarely found in the periphery because of tolerance.
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada;
authors.forename: Munehide
authors.initials: M
authors.lastname: Nakatsugawa
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada;
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada;
authors.forename: Toshiki
authors.initials: T
authors.lastname: Ochi
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Takara Bio, Inc., Otsu, Shiga 520-2193, Japan;
authors.forename: Shinya
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada;
authors.forename: Kenji
authors.initials: K
authors.lastname: Chamoto
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; and.
authors.forename: Tingxi
authors.initials: T
authors.lastname: Guo
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Department of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
authors.forename: Marcus O
authors.initials: MO
authors.lastname: Butler
authors.affiliation: Immune Therapy Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada; Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; and naoto.hirano@utoronto.ca.
authors.forename: Naoto
authors.initials: N
authors.lastname: Hirano
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D045744:Cell Line, Tumor; D022801:Complementarity Determining Regions / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D015789:HLA-A2 Antigen / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D058965:MART-1 Antigen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D014161:Transduction, Genetic
chemical_list: D022801:Complementarity Determining Regions; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D058965:MART-1 Antigen; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011993:Recombinant Fusion Proteins