Structure of extrachromosomal circular DNAs excised from T-cell antigen receptor alpha and delta-chain loci.

Small polydisperse circular (spc) DNA was isolated from mouse thymocytes, fragmented by HindIII digestion and cloned into the vector. Sixty DNA clones were randomly selected from the 10,400 phage library. The average size of insert was one-fifth of the original circular molecule. Twenty spc-DNA clones were homologous to DNA probes derived from T-cell antigen receptor (TCR) alpha-chain loci. We have characterized nine clones by DNA sequencing; they contain new germline sequences of the TCR alpha-chain variable (V alpha) and joining (J alpha) gene segments and the products out of the recombination of a V alpha with a J alpha gene segment. An additional four spc-DNA clones carried a new rearranging gene of the TCR delta-chain that is located between V alpha and J alpha genes. At least nine of 60 DNA clones carried the recombination junction of a heptamer-heptamer head-to-head structure expected from an excised product of V-J joining. This shows that most extrachromosomal circular DNAs in the thymus are formed by a sequence-dependent recombination mechanism. We suggest that a functional T-cell receptor V alpha gene can be constructed by somatic random rearrangements through successive looping-out, excision and deletion.

[1]  S. Tonegawa,et al.  A third rearranged and expressed gene in a clone of cytotoxic T lymphocytes , 1984, Nature.

[2]  L. Hood,et al.  Direct evidence for chromosomal inversion during T-cell receptor β-gene rearrangements , 1986, Nature.

[3]  P. Doherty,et al.  Diversity, rearrangement, and expression of murine T cell gamma genes , 1986, Cell.

[4]  Hitoshi Sakano,et al.  T cell receptor β gene sequences in the circular DNA of thymocyte nuclei: Direct evidence for intramolecular DNA deletion in V-D-J joining , 1987, Cell.

[5]  Hitoshi Sakano,et al.  Two types of somatic recombination are necessary for the generation of complete immunoglobulin heavy-chain genes , 1980, Nature.

[6]  T. Honjo,et al.  Expression and rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor in cloned murine large granular lymphocyte lines. No correlation with the cytotoxic spectrum , 1986, The Journal of experimental medicine.

[7]  J. Freed,et al.  Peptide sequences of T-cell receptor δ and γ chains are identical to predicted X and γ proteins , 1987, Nature.

[8]  J. Bluestone,et al.  Characterization of murine thymocytes with CDS-associated T-cell receptor structures , 1987, Nature.

[9]  F. Sanger,et al.  Cloning in single-stranded bacteriophage as an aid to rapid DNA sequencing. , 1980, Journal of molecular biology.

[10]  H. Yamagishi,et al.  Isolation of an excision product of T-cell receptor α-chain gene rearrangments , 1987, Nature.

[11]  L. Hood,et al.  An immunoglobulin heavy chain variable region gene is generated from three segments of DNA: VH, D and JH , 1980, Cell.

[12]  E. Southern,et al.  Removal of repeated sequences from hybridisation probes. , 1985, Nucleic acids research.

[13]  M. Reth,et al.  A novel VH to VHDJH joining mechanism in heavy-chain-negative (null) pre-B cells results in heavy-chain production , 1986, Nature.

[14]  C. Yanisch-Perron,et al.  Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors. , 1985, Gene.

[15]  D. Baltimore,et al.  Joining of VK to JK gene segments in a retroviral vector introduced into lymphoid cells , 1984, Nature.

[16]  L. Hood,et al.  The molecular genetics of the T-cell antigen receptor and T-cell antigen recognition. , 1986, Annual review of immunology.

[17]  J. Dangl,et al.  Recombination between an expressed immunoglobulin heavy-chain gene and a germline variable gene segment in a Ly 1+ B-cell lymphoma , 1986, Nature.

[18]  J. Seidman,et al.  Identification of a putative second T-cell receptor , 1986, Nature.

[19]  L. Hood,et al.  Diversity and structure of genes of the α family of mouse T-cell antigen receptor , 1985, Nature.

[20]  E. Reinherz,et al.  Clonotypic structures involved in antigen-specific human T cell function. Relationship to the T3 molecular complex , 1983, The Journal of experimental medicine.

[21]  Mark M. Davis,et al.  Variability and repertoire size of T-cell receptor Vα gene segments , 1985, Nature.

[22]  Yamagishi Hideo,et al.  Purification of small polydisperse circular DNA of eukaryotic cells by use of ATP-dependent deoxyribonuclease , 1983 .

[23]  T. Kunisada,et al.  Sequence organization of repetitive sequences enriched in small polydisperse circular DNAs from HeLa cells. , 1987, Journal of molecular biology.

[24]  F. Alt,et al.  Continuing kappa-gene rearrangement in a cell line transformed by Abelson murine leukemia virus , 1982, Cell.

[25]  D. Baltimore,et al.  DNA elements are asymmetrically joined during the site-specific recombination of kappa immunoglobulin genes. , 1985, Science.

[26]  Mark M. Davis,et al.  A new T-cell receptor gene located within the alpha locus and expressed early in T-cell differentiation , 1987, Nature.

[27]  J. Coligan,et al.  Differential expression of two distinct T-cell receptors during thymocyte development , 1987, Nature.

[28]  S. Cory,et al.  Deletions are associated with somatic rearrangement of immunoglobulin heavy chain genes , 1980, Cell.

[29]  P. Marrack,et al.  The major histocompatibility complex-restricted antigen receptor on T cells. I. Isolation with a monoclonal antibody , 1983, The Journal of experimental medicine.

[30]  Sergey M. Deev,et al.  Reciprocal recombination products of VK-JK joining reactions in human lymphoid cell lines , 1987, Nucleic Acids Res..

[31]  J. Coligan,et al.  Characterization of T cell receptor gamma chain expression in a subset of murine thymocytes. , 1986, Science.

[32]  T. Kunisada,et al.  Small circular DNA complexes in eucaryotic cells. , 1982, Plasmid.

[33]  J. Allison,et al.  Delta is the C x-gene product in the γ/δ antigen receptor of dendritic epidermal cells , 1987, Nature.

[34]  J. Allison,et al.  Tumor-specific antigen of murine T-lymphoma defined with monoclonal antibody. , 1982, Journal of immunology.

[35]  H. Zachau,et al.  A rearranged DNA sequence possibly related to the translocation of immunoglobulin gene segments. , 1980, Nucleic acids research.

[36]  Hitoshi Sakano,et al.  Sequences at the somatic recombination sites of immunoglobulin light-chain genes , 1979, Nature.

[37]  S. Tonegawa,et al.  Unusual organization and diversity of T-cell receptor a-chain genes , 1985, Nature.

[38]  L. Hood,et al.  Genomic organization of the genes encoding mouse T-cell receptor α-chain , 1985, Nature.