title: Thymic stromal-cell abnormalities and dysregulated T-cell development in IL-2-deficient mice.
abstract: The role that interleukin-2 (IL-2) plays in T-cell development is not known. To address this issue, we have investigated the nature of the abnormal thymic development and autoimmune disorders that occurs in IL-2-deficient (IL-2-/-) mice. After 4 to 5 weeks of birth, IL-2-/- mice progressively develop a thymic disorder resulting in the disruption of thymocyte maturation. This disorder is characterized by a dramatic reduction in cellularity, the selective loss of immature CD4-8- (double negative; DN) and CD4+8+ (double positive; DP) thymocytes and defects in the thymic stromal-cell compartment. Immunohistochemical staining of sections of thymuses from specific pathogen-free and germ-free IL-2-/- mice of various ages showed a progressive loss of cortical epithelial cells, MHC class II-expressing cells, monocytes, and macrophages. Reduced numbers of macrophages were apparent as early as 1 week after birth. Since IL-2-/- thymocyte progenitor populations could mature normally on transfer into a normal thymus, the thymic defect in IL-2-/- mice appears to be due to abnormalities among thymic stromal cells. These results underscore the role of IL-2 in maintaining functional microenvironments that are necessary to support thymocyte growth, development, and selection.
authors.affiliation: Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
authors.forename: T
authors.initials: T
authors.lastname: Reya
authors.forename: H
authors.initials: H
authors.lastname: Bassiri
authors.forename: R
authors.initials: R
authors.lastname: Biancaniello
authors.forename: S R
authors.initials: SR
authors.lastname: Carding
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000276:immunology*; D002454:Cell Differentiation; D017690:Cell Transplantation; D005856:Germ-Free Life; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D007376:Interleukin-2 / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D010641:Phenotype; D017154:Stromal Cells / Q000473:pathology / Q000637:transplantation; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology* / Q000473:pathology
chemical_list: D007376:Interleukin-2