Dominant Infiltration of TH 1-type CD4+T Cells at the Retrobulbar Space of Patients with Thyroid-Associated Ophthalmopathy

Lymphocyte infiltration in the retrobulbar space is a prominent histological feature of thyroid-associated ophthalmopathy (TAO). We have characterized phenotypic and functional features of T cells derived from retrobulbar infiltrates of 3 TAO patients to better understand their roles in the disease. One hundred four T-cell clones (TCC) were directly established from cells of retrobulbar tissues using a highly efficient cloning procedure. Phenotypic analysis of TCC showed approximately 70% to 80% were CD3+ CD4+ CD8- T cells, and approximately 20% to 30% were CD3+ CD8+ CD4- T cells. None of the TCC were CD3+ CD4- CD8- T cells. Analysis of the cytokine profile of TCC, as documented by the ability to express interferon-γ, interleukin (IL)-2, IL-4, and IL-10 demonstrated that the majority of TCC expressed T helper (TH)l-like profile in both the mRNA and protein levels. A few TCC showed TH0-like profile, but no TCC showed Tn2-like profile. These results suggest that THl-type CD4+ T cells play important roles in the pathogenesis of TAO.