Disturbed immune-endocrine communication in autoimmune disease. Lack of corticosterone response to immune signals in obese strain chickens with spontaneous autoimmune thyroiditis.

Abstract

Antigenic challenge as well as injection of lymphokine-containing media lead to a transient increase of serum glucocorticoids, a phenomenon that has been implicated in the regulation of the specificity of immune responses. In the present study we examined the dialogue between the immune and the neuroendocrine systems in Obese strain (OS) chickens, an animal model for human Hashimoto thyroiditis. The following results were obtained: A) OS and normal White Leghorn (NWL) chickens, 5-mo-old, were immunized with sheep red blood cells followed by daily monitoring of corticosterone (CN) serum levels. Whereas in NWL animals CN serum levels markedly increase 3 to 4 days after immunization, OS animals did not respond with CN elevation. B) A single i.v. injection of conditioned medium (CM) from concanavalin A-stimulated spleen cells also led to a transient, dose-dependent peak in plasma CN (maximum after 30 min). This CN response to a given CM preparation was significantly lower in OS than in NWL animals. C) CM, whether obtained from OS or NWL splenocytes, were equally effective to stimulate CN production. D) A single i.v. injection of CM leads--concomitantly to the CN peak--to a decrease of the concanavalin A-mediated proliferative response of peripheral blood lymphocytes in both OS and NWL chickens. This suppression, however, was significantly more pronounced in NWL chickens. In summary, these data suggest a disturbance of the immune-neuroendocrine communication in OS chickens with spontaneous thyroid autoimmunity. The possible implications for the generation of "forbidden" autoimmune responses are discussed.