Figure 2.

Mechanism underlying the beneficial role of pre-existing thyroiditis on PTC growth and progression in a double transgenic mouse model NOD.H2^h4_TPO-CRE-ER_BRAF^v600E. (A) autoimmune thyroiditis and PTC induction. Autoimmune thyroiditis was induced by administration of sodium iodide (NaI) in the drinking water for 12 consecutive weeks. PTC is induced by five consecutive daily injections of Tamoxifen (100 mg/Kg i.p.). The two diseases can then be established with various combinations: Thyroiditis first and then PTC; Thyroiditis and PTC induced at the same time; PTC only (positive control); Thyroiditis only (negative control). (B) Pre-existing iodine-induced thyroiditis as a primary event in PTC development has a beneficial effect leading to small PTC foci and higher lymphocytic infiltration characterized by CD8 effector memory T cells and CD19+ B cells.