A polyclonal T cell repertoire of V-alpha and V-beta T cell receptor gene families in intrathyroidal T lymphocytes of Graves' disease patients.

Abstract

We have examined for the presence or absence of T cell receptor V-alpha (VA) and V-beta (VB) gene expression in infiltrating T lymphocytes (ITL) isolated from Graves' thyroid glands in comparison to paired peripheral blood lymphocyte (PBL) samples using a qualitative based polymerase chain reaction (PCR) assay. Sequence specific oligonucleotides for VA and VB T cell receptor gene (TCR) families that had previously been validated in other studies, were used for the PCR analysis, followed by Southern blot hybridization with a labelled, internal C-region primer. A total of seven Graves' disease patients who had been treated with carbimazole were studied. T cell receptor VA and VB gene usage was examined in freshly isolated, unstimulated ITLs from five patients. A widespread usage of VA and VB gene families with 12 to 18 families being used was apparent. Use of oligo-dT or C-region priming of the mRNA prior to reverse transcription of the mRNA did not have any significant affect on the results nor did the use of whole Graves' thyroid mRNA as the starting material (n = 2) or perfusion of one gland with saline to remove as much of the contaminating blood from the gland. Our results contrast with those of Davies and colleagues who have previously shown a restricted repertoire of VA gene families in ITLs in comparison to autologous PBLs, and are much more in line with other recent reports indicating a diverse VA repertoire of the infiltrating T cells in Graves' thyroid glands derived from patients treated with anti-thyroid drugs.