title: Most IL-4-producing gamma delta thymocytes of adult mice originate from fetal precursors.
abstract: Thy-1(dull) gammadelta T cells constitute a distinct adult gammadelta T cell subset characterized by the expression of a TCR composed of Vgamma1Cgamma4 and Vdelta6Cdelta chains with limited junctional sequence diversity. However, several features of the expressed Thy-1(dull) TCR-gammadelta genes, in particular the absence or minimal presence of N region diversity and the almost invariable Ddelta2-Jdelta1 junction, are typical of rearrangements often found in the fetal thymus. In this study, we have investigated the origin of these cells. Few Thy-1(dull) gammadelta thymocytes developed in syngeneic radiation adult chimeras, regardless of whether the recipient mice were given adult bone marrow or fetal liver cells as a source of hemopoietic precursors. In contrast, normal numbers of Thy-1(dull) gammadelta T cells developed in fetal thymi grafted into adult syngeneic recipients. Interestingly, the majority of Thy-1(dull) gammadelta thymocytes present in the grafts were of graft origin, even when most conventional gammadelta and alphabeta thymocytes in the grafted thymi originated from T cell precursors of recipient origin. Single-cell PCR analyses of the nonselected TCR-gamma rearrangements present in adult Thy-1(dull) gammadelta thymocytes revealed that more than one-half of these cells represent the progenies of a limited number of clones that greatly expanded possibly during the first weeks of life. Finally, the second TCR-delta allele of a large number of Thy-1(dull) gammadelta T cells contained incomplete TCR-delta rearrangements, thus providing an explanation for the adult-type rearrangements previously found among nonfunctional V(D)J rearrangements present in Thy-1(dull) gammadelta thymocytes.
authors.affiliation: Unité du Développement des Lymphocytes, Centre National de la Recherche Scientifique Unité de Recherche Associée 1961, Institut Pasteur, 25 Rue du Dr. Roux, 75724 Paris Cedex 15, France.
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Grigoriadou
authors.forename: Laurent
authors.initials: L
authors.lastname: Boucontet
authors.forename: Pablo
authors.initials: P
authors.lastname: Pereira
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology; D000483:Alleles; D000818:Animals; D001483:Base Sequence; D016026:Bone Marrow Transplantation / Q000276:immunology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D002478:Cells, Cultured; D002999:Clone Cells; D005260:Female; D016332:Fetal Tissue Transplantation / Q000276:immunology / Q000473:pathology; D005333:Fetus; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D015847:Interleukin-4 / Q000096:biosynthesis*; D016031:Liver Transplantation / Q000276:immunology / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D011828:Radiation Chimera; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis* / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D018800:Thy-1 Antigens / Q000096:biosynthesis; D013950:Thymus Gland / Q000166:cytology / Q000254:growth & development* / Q000276:immunology* / Q000378:metabolism; D014185:Transplantation, Isogeneic
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; D018800:Thy-1 Antigens; D015847:Interleukin-4