Rearrangements of the human TCRD-deleting elements

• Published in: Immunogenetics (New York) 1994-01, Vol.40 (1), p.70-75
• Main Authors: BREIT, T. M, WOLVERS-TETTERO, I. L. M, BOGERS, A. J. J. C, DE KRIJGER, R. R, WLADIMIROFF, J. W, VAN DONGEN, J. J. M
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aging - immunology; Base Sequence; Biological and medical sciences; Blood - immunology; Child, Preschool; Fetal Blood - immunology; Fetus - immunology; Fundamental and applied biological sciences. Psychology; Gene Rearrangement, delta-Chain T-Cell Antigen Receptor; Genes. Genome; Humans; Infant; Infant, Newborn; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Receptors, Antigen, T-Cell, gamma-delta - genetics; Sequence Deletion; Sequence Homology, Nucleic Acid; Thymus Gland - embryology; Thymus Gland - immunology
• ISSN: 0093-7711; 1432-1211
• DOI: 10.1007/BF00163967

There are two types of T-cell receptors (TCR) present on human peripheral blood (PB) T lymphocytes: TCR- alpha beta and TCR- gamma delta . Although little is known about the mechanisms that commit a T cell to the alpha beta - or gamma delta lineage, it is generally assumed that the TCRD gene plays a pivotal role in the divergence of the two lineages. This assumption is based on two features of the TCRD gene. Firstly, the TCRD gene is located in the middle of the TCRA gene and is therefore deleted during V alpha -J alpha rearrangement, which in principle excludes co-expression of TCRD and TCRA chains. Secondly, in normal polyclonal thymocytes a predominant rearrangement is observed, which represents the rearranged delta REC and psi J alpha gene segments. These two gene segments flank the major part of the TCRD gene and are called TCRD deleting elements, because their non-productive rearrangement deletes the intermediate germline and/or rearranged TCRD gene sequences. Therefore, a model is postulated in which a germline or a rearranged TCRD gene is deleted by the delta REC- psi J alpha rearrangement, which in turn can be replaced by a V alpha -J alpha gene rearrangement. Because new genetic nomenclature concerning TCR gene segments has recently been introduced, we propose renaming the formerly designated delta REC and psi J alpha gene segments according to this new nomenclature as defined by the WHO-IUIS Nomenclature Subcommittee on TCR Designation (WHO Bulletin 1993). The delta REC gene segment could be renamed TCRDREC1, homologous to the delta REC1 to delta REC3 gene segments defined in the mouse. The psi J alpha gene segment could be renamed TCRAJ61P, as it is the most upstream-located gene segment of the 61 human J alpha gene segments. We designate the delta REC- psi J alpha rearrangement TCRDREC1AJ61P. Hereafter, we will use the WHO nomenclature for all TCR genes and rearrangements, with the abbreviations DREC1 ( delta REC), AJ61P ( psi J alpha ), and DREC1.AJ61P ( delta REC- psi J alpha ).