title: T-cell receptor repertoire analysis in monozygotic twins concordant and discordant for type 1 diabetes.
abstract: Several data suggest that stochastic rearrangements of the TCR could play a pathogenic role in both disease predisposition and protection in type 1 diabetes (T1D). As twin sets offer an enormous potential in evaluating the role of genetic and environmental factors in susceptibility to disease, the main goal of this study was to assess whether the degree of sharing of the expressed TCR repertoire of twin pairs discordant for T1D differs from that of disease concordant pairs. We performed our analysis in 5 pairs of monozygotic twins, 3 of which were concordant and 2 discordant for T1D, by combining flow cytometry and CDR3 spectratyping on both CD4+ and CD8+ T-cells. Our data show that TCR repertoires show increased level of concordance within each twin pair, especially in CD8+ cells, in terms of mean BV expression levels on flow cytometry as well as of CDR3 patterns and frequencies of skewed or oligoclonal BV subfamilies on spectratyping. It is worth noting that the degree of similarity among twins seems to be independent of concordance or discordance for T1D. Our findings seem to suggest that in monozygotic twins with T1D the TCR repertoire is influenced by genetic factors more than by the presence of the autoimmune disorder itself.
authors.affiliation: Istituto di ematologia, Università di Sassari, Sassari, Italy. cfozza@uniss.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Fozza
authors.forename: Salvatore
authors.initials: S
authors.lastname: Contini
authors.forename: Giovanna
authors.initials: G
authors.lastname: Corda
authors.forename: Patrizia
authors.initials: P
authors.lastname: Virdis
authors.forename: Antonio
authors.initials: A
authors.lastname: Galleu
authors.forename: Silvana
authors.initials: S
authors.lastname: Bonfigli
authors.forename: Adolfo
authors.initials: A
authors.lastname: Pacifico
authors.forename: Mario
authors.initials: M
authors.lastname: Maioli
authors.forename: Francesco
authors.initials: F
authors.lastname: Mastinu
authors.forename: Maristella
authors.initials: M
authors.lastname: Pitzalis
authors.forename: Francesco
authors.initials: F
authors.lastname: Cucca
authors.forename: Maurizio
authors.initials: M
authors.lastname: Longinotti
mesh_terms: D000293:Adolescent; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D014430:Twins, Monozygotic; D055815:Young Adult
chemical_list: D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta