title: Decreased CD4-CD8- TCR-alpha beta + cells in lpr/lpr mice lacking beta 2-microglobulin.
abstract: The CD4-CD8- T cells that accumulate in lpr/lpr mice have previously expressed CD8, on the basis of studies of CD8 alpha gene demethylation. The actual requirement for CD8 interaction with class I MHC molecules to promote the appearance of CD4-CD8- T cells in lpr/lpr mice has also been suggested. To examine this point in more detail, the lpr mutation was bred onto a beta 2-microglobulin-deficient background (beta 2-m-/-). C57BL/6 (B6) mice homozygous for both the lpr mutation of the fas gene and inactivation of the beta 2-m gene (beta 2-m-/- lpr/lpr) develop less alpha beta T cell lymphadenopathy than the parental B6 lpr/lpr strain. This is caused by the near absence of CD8+ T cells and a considerable reduction in CD4-CD8- T cells, revealing an important role for positive selection on class I MHC molecules during the ontogeny of lpr CD4-CD8- T cells. Although absolute numbers of peripheral T cells are decreased in beta 2-m-/- lpr/lpr mice, they manifest a B cell lymphadenopathy with age. beta 2-m-/- lpr/lpr mice display only subtle indications of autoimmune disease with age, compared with parental B6 (beta 2-m+/+)lpr/lpr mice. These include limited histopathologic stages of kidney disease and lack of proteinuria, despite the presence of serum anti-DNA Abs. Thus, absence of class I MHC-positive selection of CD8+ and CD4-CD8- TCR-alpha beta + cells limits the autoimmune diathesis observed in beta 2-m+/+ lpr/lpr mice.
authors.affiliation: Department of Medicine, University of Vermont College of Medicine, Burlington 05405.
authors.forename: P F
authors.initials: PF
authors.lastname: Mixter
authors.forename: J Q
authors.initials: JQ
authors.lastname: Russell
authors.forename: F H
authors.initials: FH
authors.lastname: Durie
authors.forename: R C
authors.initials: RC
authors.lastname: Budd
mesh_terms: D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood; D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology; D001483:Base Sequence; D015704:CD4 Antigens / Q000378:metabolism*; D016827:CD8 Antigens / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004251:DNA Transposable Elements; D007674:Kidney Diseases / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008206:Lymphatic Diseases / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009857:Oncogenes; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism*; D001613:beta 2-Microglobulin / Q000172:deficiency* / Q000235:genetics
chemical_list: D000974:Antibodies, Antinuclear; D015704:CD4 Antigens; D016827:CD8 Antigens; D017931:DNA Primers; D004251:DNA Transposable Elements; D016693:Receptors, Antigen, T-Cell, alpha-beta; D001613:beta 2-Microglobulin