2.50
Hdl Handle:
http://hdl.handle.net/2336/10597
Title:
Evidence for extrathymic T cell maturation after thymectomy in infancy
Authors:
Torfadottir, H; Freysdottir, J; Skaftadottir, I; Haraldsson, A; Sigfusson, G; Ogmundsdottir, H M
Citation:
Clin. Exp. Immunol. 2006, 145(3):407-12
Issue Date:
1-Sep-2006
Abstract:
Our previous study showed that children who had been partially or completely thymectomized during heart surgery as infants had lower proportions and numbers of total lymphocytes and reduced proportions of T cells (CD3(+)), helper T cells (CD4(+)) and naive T cells (CD3(+) CD4(+) CD45RA(+)), but normal proportion of cytotoxic T cells (CD8(+)). In this study T lymphocytes from a selected group of eight of these children and age- and gender-matched controls were characterized further using flow cytometry to determine phenotypes of T cells and T cell subsets related to T cell regulation and phenotypes suggestive of extrathymic maturation. Immune function was assessed by measuring autoantibodies and antibodies against vaccines. The study group had significantly lower numbers of all the main subsets of T lymphocytes and the composition was different. Thus, the proportions of lymphocytes with the following phenotypes: CD3(+), CD2(+), CD7(+), CD4(+), CD62L(+), CD4(+) CD62L(+) and CD4(+) CD69(-) were significantly reduced in the study group compared with the control group, but significantly higher proportions were seen of lymphocytes expressing CD8alpha(+) CD8beta(-) and TCRgammadelta(+) CD8alpha(+) CD8beta(-). The absolute number and proportion of CD4(+) CD25(+) cells were reduced but the proportions of the subgroup of naive regulatory T cells (CD4(+) CD25(+) CD62L(+)) and non-activated regulatory T cells (CD4(+) CD25(+) CD69(-)) were not reduced in the thymectomized children. We conclude that the phenotypic characteristics of T lymphocytes of children who have lost their thymus in infancy are indicative of extrathymic maturation. T regulatory cells appear to be less affected than other subsets by the general reduction in T cell numbers.
Description:
To access publisher full text version of this article. Please click on the hyperlink in Additional Links field
Additional Links:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2249.2006.03139.x

Full metadata record

DC FieldValue Language
dc.contributor.authorTorfadottir, H-
dc.contributor.authorFreysdottir, J-
dc.contributor.authorSkaftadottir, I-
dc.contributor.authorHaraldsson, A-
dc.contributor.authorSigfusson, G-
dc.contributor.authorOgmundsdottir, H M-
dc.date.accessioned2007-03-12T14:01:09Z-
dc.date.available2007-03-12T14:01:09Z-
dc.date.issued2006-09-01-
dc.date.submitted2007-03-12-
dc.identifier.citationClin. Exp. Immunol. 2006, 145(3):407-12en
dc.identifier.issn0009-9104-
dc.identifier.pmid16907907-
dc.identifier.doi10.1111/j.1365-2249.2006.03139.x-
dc.identifier.otherAAA12-
dc.identifier.otherPED12-
dc.identifier.otherRHE12-
dc.identifier.urihttp://hdl.handle.net/2336/10597-
dc.descriptionTo access publisher full text version of this article. Please click on the hyperlink in Additional Links fielden
dc.description.abstractOur previous study showed that children who had been partially or completely thymectomized during heart surgery as infants had lower proportions and numbers of total lymphocytes and reduced proportions of T cells (CD3(+)), helper T cells (CD4(+)) and naive T cells (CD3(+) CD4(+) CD45RA(+)), but normal proportion of cytotoxic T cells (CD8(+)). In this study T lymphocytes from a selected group of eight of these children and age- and gender-matched controls were characterized further using flow cytometry to determine phenotypes of T cells and T cell subsets related to T cell regulation and phenotypes suggestive of extrathymic maturation. Immune function was assessed by measuring autoantibodies and antibodies against vaccines. The study group had significantly lower numbers of all the main subsets of T lymphocytes and the composition was different. Thus, the proportions of lymphocytes with the following phenotypes: CD3(+), CD2(+), CD7(+), CD4(+), CD62L(+), CD4(+) CD62L(+) and CD4(+) CD69(-) were significantly reduced in the study group compared with the control group, but significantly higher proportions were seen of lymphocytes expressing CD8alpha(+) CD8beta(-) and TCRgammadelta(+) CD8alpha(+) CD8beta(-). The absolute number and proportion of CD4(+) CD25(+) cells were reduced but the proportions of the subgroup of naive regulatory T cells (CD4(+) CD25(+) CD62L(+)) and non-activated regulatory T cells (CD4(+) CD25(+) CD69(-)) were not reduced in the thymectomized children. We conclude that the phenotypic characteristics of T lymphocytes of children who have lost their thymus in infancy are indicative of extrathymic maturation. T regulatory cells appear to be less affected than other subsets by the general reduction in T cell numbers.en
dc.language.isoenen
dc.publisherBlackwell Scientific Publicationsen
dc.relation.urlhttp://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2249.2006.03139.xen
dc.subject.meshAdolescenten
dc.subject.meshAntibodiesen
dc.subject.meshAntigens, CDen
dc.subject.meshAutoantibodiesen
dc.subject.meshBiological Markersen
dc.subject.meshCase-Control Studiesen
dc.subject.meshCell Differentiationen
dc.subject.meshChilden
dc.subject.meshFlow Cytometryen
dc.subject.meshHeart Septal Defects, Ventricularen
dc.subject.meshImmunoglobulin Gen
dc.subject.meshImmunophenotypingen
dc.subject.meshInfanten
dc.subject.meshLymphocyte Counten
dc.subject.meshMeasles virusen
dc.subject.meshMumps virusen
dc.subject.meshT-Lymphocyte Subsetsen
dc.subject.meshT-Lymphocytes, Regulatoryen
dc.subject.meshTetanus Toxoiden
dc.subject.meshThymectomyen
dc.titleEvidence for extrathymic T cell maturation after thymectomy in infancyen
dc.typeArticleen
dc.format.digYES-

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