IMMUNOGENETIC ASPECTS OF HUMAN THYROGLOBULIN‐REACTIVE T CELL LINES AND HYBRIDOMAS

The in vitro proliferative response of T cells primed with human thyroglobulin (Tg) was compared in 11 independent haplotypes on B10 background. B10.K and B10.S mice were the most responsive, whereas, with the exception of B10.PL (H‐2u, all other B10 congenics were intermediate responders. The two best responders to in vitro challenge with human Tg, of the k and s haplotype, are the same as those showing H‐2‐linked susceptibility to induction of experimental autoimmune thyroiditis (EAT) with mouse Tg. Since shared epitopes on human and mouse Tgs have been shown to be thyroiditogenic by adoptive transfer studies in CBA (H‐2k) mice, the findings indicate that shared epitopes may be studied in appropriate (i.e. EAT‐susceptible) strains of mice. Therefore, we proceeded to develop methods to produce T‐cell lines and hybridomas to human Tg in B10.K and B10.S mice, test their cross‐reactivity to heterologous Tgs and their Ia restriction patterns. By using antigen‐presenting cells from recombinant strains, we identified restriction elements encoded by the I‐A subregion alone and a combinatorial molecule from the I‐AI/I‐E subregions.