Hla-dr gene expression in a proliferating human thyroid cell clone (12s)

We have used a retroviral vector carrying the adenovirus ElA oncogene and the neomycin phosphotransferase gene to establish a human thyroid-derived cell line that exhibits TSH-mediated cAMP generation as well as the differential expression of HLA class II antigens in response to recombinant γ-interferon. Twenty-two-week gestation, histologically confirmed, human fetal thyroid was collagenase digested, cultured as a monolayer, and infected directly with 12S or 13S ElA-containing retrovirus constructs. Infected clones (n = 30) were selected in a hormone-supplemented medium containing bovine TSH (bTSH; 1 mU/ml), 10% fetal bovine serum, and 0.5 mg/ml G418 antibiotic. A rapidly growing clone (designated 12S) was chosen for detailed analysis over 18 months of continuous culture. The 12S clone was sensitive to less than 10 μU/ml bTSH when assessed by extracellular accumulation of cAMP, but TSH had no influence on 72-h incorporation of [³H]thymidine. Clone 12S responded to recombinant human 7-interferon (1–10⁴ U/ml) by induction of HLA DR α-chain-specific mRNA and the surface expression of HLA-DR antigen detected by fluorescein isothiocyanate- labeled monoclonal antibody to nonpolymorphic HLADR regions using flow cytometry. These studies indicate the potential for immortalizing human thyroid cells for use as targets of anti-TSH receptor immune responses and for long term studies of human thyrocyte HLA gene regulation.