Clonal analysis of T lymphocytes infiltrating the thyroid gland in Hashimoto's thyroiditis.
T cells isolated from thyroid tissue and peripheral blood of 2 patients with Hashimoto's thyroiditis were studied by a high cloning efficiency microculture technique. Clonal efficiencies of 37 and 24% were obtained from thyroid-derived T cell cultures, while 40 and 90% efficiencies resulted from peripheral-blood-derived cultures. A prevalence of T4-/T8+ T cell clones were found in thyroid infiltrates. The functional analysis of the clones demonstrated significantly higher proportions of clones with cytolytic activity in a lectin-dependent assay in thyroid-derived microcultures, as compared to peripheral blood-derived ones. The proportion of clones displaying natural-killer-like activity was increased in 1 patient only. Cytolytic activity was displayed not only by all T4-/T8+, but also by several T4+/T8- intrathyroid clones. Remarkable proportions of cytolytic clones were also able to release interleukin-2 upon phytohemagglutinin stimulation. Finally, the proportion of T cell clones able to release gamma-interferon following mitogen stimulation was significantly higher in thyroid- vs. peripheral-blood-derived microcultures. These results provide further data about the possible pathogenetical role of both regulatory and effector T lymphocytes in human autoimmune thyroiditis.
D000328:Adult; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D008875:Middle Aged; D010641:Phenotype; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology*; D013961:Thyroid Gland / Q000166:cytology*; D013967:Thyroiditis, Autoimmune / Q000209:etiology / Q000473:pathology*
D007376:Interleukin-2; D007371:Interferon-gamma