Abnormal stem cells in autoimmune-prone mice are responsible for premature thymic involution.
Autoimmune-prone mice show premature thymic involution, including morphological and functional abnormalities. To determine why the thymic abnormalities develop in autoimmune-prone mice, transplantation of the thymus and/or bone marrow was performed. When thymuses of newborn MRL/1 (H-2k) mice were grafted into C3H/HeN nu/nu(H-2k) mice, the engrafted thymuses did not show the abnormalities which characterize the thymus in the autoimmune-prone MRL/1 mice. By contrast, when thymuses of newborn C3H/HeN or MRL/n mice were grafted into MRL/1 mice, the engrafted thymuses developed after an interval of 3 months the same morphological abnormalities as were seen in MRL/1 mice. Thus, we can conclude that premature involution of the thymus in autoimmune-prone mice may not be a genetically determined abnormality intrinsic to the thymus, but rather an abnormality secondary to other events occurring in these mice. When bone marrow of young C3H/HeN nu/nu mice was transplanted into irradiated (850 rad) MRL/1 mice, neither thymic abnormalities nor autoimmune diseases developed. Therefore, it seem likely that abnormal stem cells in autoimmune-prone mice induce thymic abnormalities, and these, in turn, are associated with the development of autoimmune diseases.
D000818:Animals; D000936:Antigen-Antibody Complex; D001327:Autoimmune Diseases / Q000276:immunology / Q000473:pathology*; D001853:Bone Marrow / Q000473:pathology; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D008180:Lupus Erythematosus, Systemic / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude / Q000502:physiology*; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology* / Q000637:transplantation
D000936:Antigen-Antibody Complex