Interleukin (IL)-12-driven primary hypothyroidism: the contrasting roles of two Th1 cytokines (IL-12 and interferon-gamma).
IL-12, a prototypic T helper 1 cytokine, has been implicated in the pathogenesis of organ-specific autoimmune diseases, such as Hashimoto's thyroiditis, but reported to give conflicting results in murine models of lymphocytic thyroiditis. To determine the effects of chronic, local production of IL-12 within the thyroid gland, we created transgenic mice that express IL-12 p70 under the transcriptional control of the thyroglobulin promoter. Transgenics developed growth retardation, moderate primary hypothyroidism, and mild lymphocytic infiltration of the thyroid gland. The hypothyroidism was associated with increased mRNA levels of the sodium-iodide symporter, an increase partly due to a direct effect of IL-12 on the thyrocyte. Upon immunization with a suboptimal dose of mouse thyroglobulin, IL-12 transgenic mice developed a lymphocytic thyroiditis that was more frequent and severe than that observed in wild-type littermates. The disease-promoting effect of IL-12 was independent of interferon-gamma, as shown by the similar interferon-gamma levels in transgenics and controls. These findings highlight the contrasting roles of two T helper 1 cytokines and report a novel role of IL-12 on thyroid hormonogenesis.
Kimura
Hiroaki
H
Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
Tzou
Shey-Cherng
SC
Rocchi
Roberto
R
Kimura
Miho
M
Suzuki
Koichi
K
Parlow
Albert F
AF
Rose
Noel R
NR
Caturegli
Patrizio
P
D000818:Animals; D030801:Animals, Genetically Modified; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D007037:Hypothyroidism / Q000276:immunology*; D007371:Interferon-gamma / Q000235:genetics / Q000502:physiology*; D018664:Interleukin-12 / Q000235:genetics / Q000502:physiology*; D008297:Male; D051381:Rats; D018417:Th1 Cells / Q000276:immunology*
D018664:Interleukin-12; D007371:Interferon-gamma