The Effect of Cyclosporin a on Spontaneous Autoimmune Thyroiditis in Obese Strain (OS) Chickens

Abstract

For the last twelve years data were accumulated by several groups that spontaneous autoimmune thyroiditis (SAT) which develops in the Obese strain (OS) of chickens depends on the presence of an intact B-dependent portion of the immune system (for review see refs. 1,2). Four types of effector mechanisms can be conceived as initiators of this disease and have been studied in detail: (a) complement binding thyroglobulin autoantibodies (Tg-AAb) either transferred from the mother hen via the egg yolk into the embryo and newly hatched chick or produced by the chick itself; (b) noncomplement binding IgG Tg-AAb triggering antibody-dependent cellular cytotoxicity (ADCC) by K-cells; (c) the occurrence of B-cells or mature plasma cells within the thyroid epithelial cell lining, a process called “periopolesis,” where formation of Tg-AAb has been demonstrated in situ which can again either bind complement or not and lead to a destruction or neighboring thyroid epithelial cells by mechanisms (a) or (b); (d) cytotoxic T-cells (T_c).