title: Monozygotic twins display differences in their allospecific cytotoxic T-cell repertoire.
abstract: The antigen-specific repertoire of peripheral blood T lymphocytes is generated by selection in the thymus followed by peripheral immunological events. While thymic selection is predominantly under genetic control, i.e. self-HLA molecules + self-peptides, confrontation with foreign antigens will lead to expansion of given T-cells, thus modifying the T-cell repertoire. To evaluate the relative importance of such modifying events the precursor frequencies (pf) of cytotoxic T lymphocytes (CTL) against given allogeneic HLA molecules were compared in six pairs of monozygotic twins. Using limiting dilution analyses, experiments with several different allogeneic stimulator/target cell donors were performed for each twin pair. In 12 out of 17 experiments, when the twins were tested against the same stimulator/ target cell donor, the CTL pf differed and the 95% confidence intervals were non-overlapping. This suggests that modifying effects by confrontation with foreign antigens play an important role in shaping the allospecific T-cell repertoire.
authors.affiliation: Institute of Transplantation Immunology, Rikshospitalet, National Hospital, Oslo, Norway.
authors.forename: A V
authors.initials: AV
authors.lastname: Reisaeter
authors.forename: J E
authors.initials: JE
authors.lastname: Brinchmann
authors.forename: K E
authors.initials: KE
authors.lastname: Lundin
authors.forename: E
authors.initials: E
authors.lastname: Thorsby
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells; D006801:Humans; D008875:Middle Aged; D015203:Reproducibility of Results; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014430:Twins, Monozygotic