Ljj. Beijleveld et al., X-IRRADIATION OF THE THYMUS IS NOT REQUIRED FOR THE INDUCTION OF CYCLOSPORINE-INDUCED AUTOIMMUNITY, Transplantation, 59(11), 1995, pp. 1601-1605
The thymus-dependent model of cyclosporine-induced autoimmunity (CsA-A
I) in the Lewis rat requires a lethal total body X-irradiation and res
cue with syngeneic or autologous bone marrow and cyclosporine (CsA) ad
ministration for at least 4 weeks; two to three weeks after cessation
of CsA, the animals develop a graft-versus-host-like disease. The obli
gatory role of the thymus in the etiology of CsA-AI has been establish
ed unequivocally, but the way in which disease is thymus dependent is
a topic of debate. In the present study we demonstrate that the model
of CsA-AI requires the presence of a thymus for at least 2 weeks after
total body irradiation and CsA administration, but that X-irradiation
of the thymus itself is not necessary to bring about disease. Transpl
antation of neonatal thymus shows in addition that in the absence of X
-irradiation of the thymus, CsA therapy is required to generate autore
active cells, but that disease occurs only if peripheral autoregulator
y cells are eliminated by X-irradiation.