Generation of thyroglobulin-specific T-cell clones derived from F₁ Fisher rats

We established T-cell clones from 'poor-responder' Fisher rats specific for thyroglobulin (Tg) with a view to examining Tg presentation by cloned Fisher rat thyroid (FRTL) cells. From the screening of 60 T-cell clones, three high-responding Tg-specific clones (B21.01, B21.04 and B21.05) were isolated from the lymph nodes of F₁ generation (Fisher x 'high-repsonder' Buffalo) female rats immunized with murine Tg in complete Freund's adjuvant (CFA). Three T-cell clones expressed a W3/25⁺, Ox-8^- phenotype and responded specifically to murine and rat Tg in T-cell proliferation assays with Fisher rat antigen-presenting cells and secreted IL-2 as measured using a murine cytotoxic T-lymphocyte line (CTLL-2). Both B21.04 and B21.05 T-cell clones were capable of providing helper T-cell function for rat Tg anitbody production in syngeneic reconstituation cultures in vitro. In contrast, clone B21.01 inhibited Tg antibody secretion. These data demonstrate that 'poor-responder' Fisher rats are capable of mounting significant T-cell responders to Tg in an F₁ generation. Such Tg-specific T-cell clones will allow us to analyse their interaction with cloned Fisher rat thyroid cells and determine the role, if any, of thyroid cell antigen self-presentation to the immune system.