Murine FLIP transgene expressed on thyroid epithelial cells promotes resolution of granulomatous experimental autoimmune thyroiditis in DBA/1 mice.
Granulomatous experimental autoimmune thyroiditis (G-EAT) is induced by mouse thyroglobulin-sensitized splenocytes activated in vitro with mouse thyroglobulin and interleukin-12. In wild-type (WT) DBA/1 recipients of WT donor splenocytes, thyroid lesions reach maximal severity at day 20, with ongoing inflammation and extensive fibrosis at day 60. Our previous studies indicated the site of expression of FLIP and Fas ligand [thyroid epithelial cells (TECs) versus inflammatory cells] differed in mice when lesions would resolve or progress to fibrosis. To test the hypothesis that expression of FLIP by TECs would promote earlier G-EAT resolution in DBA/1 mice, transgenic (Tg) DBA/1 mice expressing FLIP on TECs were generated. In FLIP Tg(+) and Tg(-) littermate recipients of WT donor splenocytes, G-EAT severity was comparable at day 20, but fibrosis was decreased, and many lesions resolved by day 60 in Tg(+) but not Tg(-) recipients. FLIP and Fas ligand were primarily expressed by TECs in Tg(+) recipients and by inflammatory cells in Tg(-) recipients at day 60. Apoptosis of inflammatory cells was greater, and expression of proinflammatory cytokines was decreased in thyroids of Tg(+) compared with Tg(-) recipients. These results are consistent with the hypothesis that transgenic expression of FLIP on thyroid epithelial cells promotes earlier resolution of granulomatous experimental autoimmune thyroiditis.
Fang
Yujiang
Y
Department of Internal Medicine, University of Missouri School of Medicine, and Veterans Affairs Research Service, Columbia, Missouri 65212, USA.
Wei
Yongzhong
Y
Demarco
Vincent
V
Chen
Kemin
K
Sharp
Gordon C
GC
Braley-Mullen
Helen
H
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000276:immunology / Q000378:metabolism*; D016207:Cytokines / Q000096:biosynthesis; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D053222:Fas Ligand Protein / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D006099:Granuloma / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D008811:Mice, Inbred DBA; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013961:Thyroid Gland / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D013967:Thyroiditis, Autoimmune / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D019076:Transgenes
D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D016207:Cytokines; D053222:Fas Ligand Protein; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D012333:RNA, Messenger