Involvement of T cell immunity in the transient thyroid inflammation induced by iodide in goitrous BALB/C and nude mice.
To evaluate the involvement of T cell immunity in the thyroiditis induced in goitrous mice by iodide administration, we analyzed the immunological changes happening in the thyroid glands and lymph nodes during goiter involution in balb/c and athymic nude mice of similar background. In both balb/c and nude mice, goiter involution was characterized by thyroid cell necrosis and inflammation. In balb/c mice, the inflammatory infiltrate was made of numerous Ia+ cells. Their number was unchanged during goiter development, but was significantly increased after 2 days of involution and remained high after 8 days. CD4+ and CD8+ T cells were also observed, some of which were clearly activated since they expressed the receptor for Interleukin-2 (IL-2R). The numbers of CD4+, CD8+ and IL-2R+ T cells were increased during goiter as compared to control mice, and they reached a maximum at day 1 of involution. In nude mice, unexpectedly, CD4+ and CD8+ T cells were also found in the thyroid. Their numbers, as well as the number of Ia+ cells, were significantly increased at the onset of involution, but they remained systematically lower than in the corresponding groups of balb/c mice. Iodide treatment of goitrous mice also induced modifications of the lymph nodes draining the thyroid: enlargement of the paracortical T zone, presence of germinal centers in cortical follicles, and increase of the density of IL-2R+ cells. Mesenteric lymph nodes taken as controls were unchanged. Thus, three observations suggest the involvement of T cell immunity in iodine-induced thyroid inflammation: 1. Infiltration of Ia+, CD4+, CD8+ and IL-2R+ cells. 2. Signs of stimulation in thyroid lymph nodes, 3. Significant differences between balb/c and nude mice, in which the inflammatory reaction is weaker.
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Laboratory of Histology, Catholic University of Louvain, Medical School, Brussels, Belgium.
Rebai
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T
Denef
J F
JF
Many
M C
MC
D000818:Animals; D005260:Female; D006042:Goiter / Q000276:immunology* / Q000473:pathology*; D007124:Immunoenzyme Techniques; D008198:Lymph Nodes / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D012974:Sodium Iodide / Q000633:toxicity*; D013601:T-Lymphocytes / Q000276:immunology*; D013966:Thyroiditis / Q000139:chemically induced* / Q000276:immunology* / Q000473:pathology
D012974:Sodium Iodide