title: CDR3β sequence motifs regulate autoreactivity of human invariant NKT cell receptors.
abstract: Invariant natural killer T (iNKT) cells are a subset of T lymphocytes that recognize lipid ligands presented by monomorphic CD1d. Human iNKT T cell receptor (TCR) is largely composed of invariant Vα24 (Vα24i) TCRα chain and semi-variant Vβ11 TCRβ chain, where complementarity-determining region (CDR)3β is the sole variable region. One of the characteristic features of iNKT cells is that they retain autoreactivity even after the thymic selection. However, the molecular features of human iNKT TCR CDR3β sequences that regulate autoreactivity remain unknown. Since the numbers of iNKT cells with detectable autoreactivity in peripheral blood is limited, we introduced the Vα24i gene into peripheral T cells and generated a de novo human iNKT TCR repertoire. By stimulating the transfected T cells with artificial antigen presenting cells (aAPCs) presenting self-ligands, we enriched strongly autoreactive iNKT TCRs and isolated a large panel of human iNKT TCRs with a broad range autoreactivity. From this panel of unique iNKT TCRs, we deciphered three CDR3β sequence motifs frequently encoded by strongly-autoreactive iNKT TCRs: a VD region with 2 or more acidic amino acids, usage of the Jβ2-5 allele, and a CDR3β region of 13 amino acids in length. iNKT TCRs encoding 2 or 3 sequence motifs also exhibit higher autoreactivity than those encoding 0 or 1 motifs. These data facilitate our understanding of the molecular basis for human iNKT cell autoreactivity involved in immune responses associated with human disease.
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada.
authors.forename: Kenji
authors.initials: K
authors.lastname: Chamoto
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada; Department of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
authors.forename: Tingxi
authors.initials: T
authors.lastname: Guo
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
authors.forename: Osamu
authors.initials: O
authors.lastname: Imataki
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
authors.forename: Makito
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada.
authors.forename: Munehide
authors.initials: M
authors.lastname: Nakatsugawa
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Ochi
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, 460-0001, Japan.
authors.forename: Akiko M
authors.initials: AM
authors.lastname: Saito
authors.affiliation: Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, 460-0001, Japan.
authors.forename: Toshiki I
authors.initials: TI
authors.lastname: Saito
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada; Department of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada; Department of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
authors.forename: Marcus O
authors.initials: MO
authors.lastname: Butler
authors.affiliation: Tumor Immunotherapy Program, Campbell Family Institute for Breast Cancer Research, Campbell Family Cancer Research Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 2M9, Canada; Department of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada. Electronic address: naoto.hirano@utoronto.ca.
authors.forename: Naoto
authors.initials: N
authors.lastname: Hirano
mesh_terms: D020816:Amino Acid Motifs; D017951:Antigen Presentation / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D055610:Antigens, CD1d / Q000276:immunology / Q000378:metabolism; D015551:Autoimmunity; D002460:Cell Line; D022801:Complementarity Determining Regions / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D016130:Immunophenotyping; D010641:Phenotype; D055503:Protein Multimerization; D055607:Receptors, Natural Killer Cell / Q000276:immunology* / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism
chemical_list: D055610:Antigens, CD1d; D022801:Complementarity Determining Regions; D055607:Receptors, Natural Killer Cell
keywords: Autoreactivity; CDR3β; TCR; iNKT