ABSTRACT
We have used the continuously growing FRTL-5 rat thyroid cell line to examine the regulation of major histocompatibility complex (MHC) class II (or la) antigen expression. Of the various stimuli investigated, only the supernatant from activated T cells or recombinant γ-interferon induced Ia expression. All Ia-inducing activity was removed from the T cell supernatant by acid dialysis, suggesting that γ-interferon is the single critical mediator for class II antigen expression. Its action was not TSH dependent but expression of class II antigens increased from the G0-G1 to the S and G2 phases of the cell cycle, so that TSH enhanced Ia expression by its action on cell division. Other agents including lectins, hormones, epidermal growth factor, a calcium ionophore and a phorbol ester did not induce Ia expression. Substances known to inhibit murine macrophage Ia expression (cortisol, prostaglandin E2 and 5-hydroxytryptamine) had no effect on FRTL-5 Ia expression. The use of this thyroid cell line has permitted direct examination of modulators in the absence of any possible effects from contaminating non-thyroid cells present in primary cultures and the results suggest that, of the agents tested, only γ-interferon has significance in the context of Ia antigen expression by the thyroid.
J. Endocr. (1987) 115, 481–487
Immunohistochemical changes in the jejunum in first degree relatives of patients with coeliac disease and the coeliac disease marker DQ genes. HLA class II antigen expression, interleukin-2 receptor positive cells and dividing crypt cells.