title: Predominant role of T cell receptor (TCR)-alpha chain in forming preimmune TCR repertoire revealed by clonal TCR reconstitution system.
abstract: The CDR3 regions of T cell receptor (TCR)-alpha and -beta chains play central roles in the recognition of antigen (Ag)-MHC complex. TCR repertoire is created on the basis of Ag recognition specificity by CDR3s. To analyze the potential spectrum of TCR-alpha and -beta to exhibit Ag specificity and generate TCR repertoire, we established hundreds of TCR transfectants bearing a single TCR-alpha or -beta chain derived from a cytotoxic T cell (CTL) clone, RT-1, specific for HIVgp160 peptide, and randomly picked up TCR-beta or -alpha chains. Surprisingly, one-third of such TCR-beta containing random CDR3 beta from naive T cells of normal mice could reconstitute the antigen-reactive TCR coupling with RT-1 TCR-alpha. A similar dominant function of TCR-alpha in forming Ag-specific TCR, though low-frequency, was obtained for lymphocytic choriomeningitis virus-specific TCR. Subsequently, we generated TCR-alpha and/or -beta transgenic (Tg) mice specific for HIVgp160 peptide, and analyzed the TCR repertoire of Ag-specific CTLs. Similar to the results from TCR reconstitution, TCR-alpha Tg generated CTLs with heterogeneous TCR-beta, whereas TCR-beta Tg-induced CTLs bearing a single TCR-alpha. These findings of Ag recognition with minimum involvement of CDR3 beta expand our understanding regarding the flexibility of the spectrum of TCR and suggest a predominant role of TCR-alpha chain in determining the preimmune repertoire of Ag-specific TCR.
authors.affiliation: Department of Molecular Genetics, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yokosuka
authors.forename: Kan
authors.initials: K
authors.lastname: Takase
authors.forename: Misao
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yohko
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Taki
authors.forename: Hidemi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Takehiko
authors.initials: T
authors.lastname: Fujisawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Arase
authors.forename: Takashi
authors.initials: T
authors.lastname: Saito
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D001483:Base Sequence; D018076:DNA, Complementary; D019302:HIV Envelope Protein gp160 / Q000276:immunology; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology*
chemical_list: D018076:DNA, Complementary; D019302:HIV Envelope Protein gp160; D016693:Receptors, Antigen, T-Cell, alpha-beta