Cytokine profiles of in vivo activated thyroid-infiltrating T cells cloned in the presence or absence of interleukin 4

We compared Th1 and Th2 cytokines secreted by randomly selected, intrathyroidal CD4+ T cell clones isolated from a patient with Graves' disease using IL-4 + IL-2 versus IL-2 alone. Prior to T cell isolation, PCR of cDNA from the intact thyroid tissue generated IL-4 and IL-10, but not IFN-γ, products. As controls, IL-4, IFN-γ and IL-10 cDNA was amplified from stimulated, but not unstimulated, PBMC. All 21 of the nine IL-2 clones and twelve IL-2 + IL-4 clones isolated from the thyroid tissue were CD4+. With the exception of one clone in the IL-2 group, all clones produced IL-10 on stimulation with anti-CD3 and phorbol-12-myristate 13-acetate (PMA) with similar mean values for both groups. The majority of clones in both groups also produced IFN-y and IL-4 after stimulation. However, the IL-4: IFN-γ ratios were significantly higher in clones isolated using IL-2 + IL-4 than in those isolated with IL-2 alone. Furthermore, the distribution of Thl, ThO and Th2 type clones, defined by their IL-4: IFN-γ ratios, was...