9,15–18 Further studies are needed to increase our understanding of the roles of eosinophils and IL-5 in inflammatory responses and other diseases in which hypereosinophilia occurs. The differential migration of eosinophils versus neutrophils to thyroids of IFN-γ−/− and WT mice during the development of G-EAT offers a unique opportunity to examine the role of eosinophil trafficking to sites of inflammation and to investigate the potential role of these

cells in the induction and resolution of inflammation. Neutralization of IL-5 markedly inhibited migration of eosinophils to thyroids of IFN-γ−/− mice during development of G-EAT. However, IL-5 neutralization had no effect on the severity or rate of resolution of inflammation in G-EAT, suggesting that eosinophil migration has no apparent pathogenic role in G-EAT. WT and IFN-γ−/− DBA/1 mice were produced Metabolism inhibitor in our animal facilities at the University of Missouri as previously described.6–8 Both male and female mice (6–10 weeks old) were used. G-EAT was induced as previously described.1,5 Briefly, mice were injected intravenously

(i.v.) twice at 10-day intervals with 150 μg of MTg3 and 15 μg of lipopolysaccharide (LPS) (Escherichia coli 011:B4; Sigma Chemical Co., St Louis, MO). Seven days later, donor spleen cells were re-stimulated in vitro MLN8237 purchase with 25 μg/ml MTg and 5 ng/ml IL-12.1 Cells were harvested after 72 hr and washed twice, and 3·5 × 107 cells were transferred i.v. to 500-Rad irradiated

syngeneic recipients. Anti-IL-5 was purified from culture supernatants of the anti-IL-5-producing hybridoma TRFK-5 (provided by Dr Robert Coffman, DNAX Research Institute, Palo Alto, CA, USA) using protein G. IFN-γ−/− recipients of IFN-γ−/− donor cells were given 300 μg of anti-IL-5 intraperitoneally (i.p.) or rat immunoglobulin G (control IgG) every 4 days beginning on the Calpain day of cell transfer until euthanasia. WT recipients of WT donor cells were used for comparison. Thyroids were removed from groups of five or six recipient mice 20 days (peak of disease) or 40–50 days (fibrosis versus resolution) after cell transfer.1–6 Thyroids were fixed in formalin, sectioned and stained with haematoxylin and eosin (H&E), and scored quantitatively for G-EAT severity (the extent of inflammatory cell infiltration and thyroid follicle destruction) using a scale of 1+ to 5+, as described previously.6 1+ thyroiditis is defined as an infiltrate of at least 125 cells in one or several foci; 2+ is 10–20 foci of cellular infiltration involving up to 25% of the gland; 3+ indicates that 25–50% of the gland is infiltrated; 4+ indicates that > 50% of the gland is destroyed by infiltrating inflammatory cells; and 5+ indicates virtually complete destruction of the thyroid with few or no remaining follicles. Thyroid lesions were also evaluated qualitatively.