The TSH-receptor (TSH-R) and thyroid peroxidase (TPO) are targets of autoantibody production in the autoimmune thyroid disease, Graves' disease, and are also likely to be the target of T-cell responses. To facilitate the analysis of T-cell responses we have investigated a system that allows expression of these autoantigens as recombinant proteins in autologous cells. Human B-lymphoblastoid cell lines (B-LCL), which are known to present antigen to autologous T cells, were transfected with constructs directing the expression of human TSH-R and TPO. The constructs utilized an expression vector replicating under the control of EBV-derived sequences that is maintained episomally in transfected cells. Both proteins were shown to be expressed by transfected B-LCL and present on the cell surface. Such transfected B-LCL could be used for the derivation, screening and characterization of autologous T-cell clones against thyroid autoantigens.