title: Detection and regulation of rat thyroid MHC class II (RT1.D) transcripts.
abstract: We have reexamined 1B-6 cells, a cloned line of FRTL-5 rat thyroid cells in order to determine whether such cells demonstrate constitutive MHC class II gene expression. A new homologous cDNA probe for the RT1.D alpha-chain region was developed and proved significantly more sensitive at detecting specific mRNA levels in 1B-6 cells than a human class II alpha-chain specific probe used in previous studies. Recombinant rat gamma-interferon induced MHC class II (RT1.D) antigen at concentrations as low as 1 U/ml (in the presence of bovine TSH), as detected by both alpha-chain specific mRNA transcripts and surface antigen expression. There was no evidence for constitutive expression of MHC class II transcripts in proliferating 1B-6 cells in the absence of gamma-interferon, even when bovine TSH was present. These studies add further evidence to our hypothesis that MHC class II antigen expression in thyroid cells is secondary to external stimulating factors.
mesh_terms: D000818:Animals; D002460:Cell Line; D002999:Clone Cells; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D006649:Histocompatibility Antigens / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D013961:Thyroid Gland / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D006649:Histocompatibility Antigens; D012333:RNA, Messenger; D011994:Recombinant Proteins; D007371:Interferon-gamma; D013972:Thyrotropin; D004247:DNA