Thyroglobulin-induced murine thyroiditis assessed by intrathyroidal T cell receptor sequencing

Thyroid glands from CBA/J (H-2(k)) mice, with human thyroglobulin (Tg)- induced thyroiditis, were removed and total cellular RNA was prepared and reverse transcribed as target cDNA for PCRs to detect 17 murine T cell receptor (mTCR) Vβ families. Southern analysis of the resulting PCR fragments showed a marked bias in the intrathyroidal expression of mTCR Vβ gene families with only 10 detectable Vβ gene families of the 17 tested. Four Tg-specific CBA/J T cell lines also showed a biased use of mTCR Vβ gene families with only 7 Vβ gene families detected of the 17 tested. Sequence analysis showed evidence of oligoclonal expansion of the intrathyroidal T cell populations, and some of the CDR3 sequences found in the thyroid infiltrates were identical, or similar, to examples of the patterns of CDR3 sequences seen in the Tg-specific lines. Overall, however, there was marked N-D-N sequence variation in both the lines and thyroid infiltrates. These data indicated that 1) mTCR V gene analysis of intact thyroid tissue reflected the thyroid Ag-specific T cells infiltrating the thyroid gland; 2) confirmed the phenomenon of oligoclonal expansion in early thyroiditis; 3) showed that certain Vβ gene families may be overemployed in the T cell recognition of Tg in the context of H-2(k); and 4) revealed, by the varied patterns of the CDR3 sequences, that the V gene itself may be more important in thyroid Ag recognition than N-D-N region motifs.