title: Evidence for the existence of two parallel differentiation pathways in the thymus of MRL lpr/lpr mice.
abstract: MRL mice homozygous for the lpr/lpr gene develop a massive lymphadenopathy caused by the accumulation of CD4-CD8-, Thy-1-positive T cells that express B220. This phenotypically unusual T cell population coexists with normal, B220- T cells in lpr/lpr animals. To investigate the origin and differentiation pathway of B220+ T cells, the expression of a panel of developmentally regulated cell surface markers including TCR, CD4, CD8, Thy-1, and B220 was examined. Thymocytes and peripheral T lymphocytes from lpr/lpr mice were analyzed by four-color flow cytometry. The results showed that both B220+ and B220- thymocytes contained all of CD4-CD8-, CD4+CD8+, and CD4 or CD8 single positive T cell subpopulation in the lpr thymus. Expression of the V beta 11 TCR, measured by flow cytometry and reverse polymerase chain reaction, was demonstrated in lpr thymus. However, the number of T cells expressing V beta 11 was greatly reduced in both the B220+ and B220- T cell populations in lymph node, spleen, and liver. Taken together, the data provide evidence for maturation and selection of a distinct population of B220+ T cells in the thymus of MRL lpr/lpr mice.
authors.affiliation: Laboratory of Molecular Regulation of Aging, Institute of Physical and Chemical Research (RIKEN), Tsukuba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuzaki
authors.forename: C
authors.initials: C
authors.lastname: Pannetien
authors.forename: O
authors.initials: O
authors.lastname: Kanagawa
authors.forename: G
authors.initials: G
authors.lastname: Gachelin
authors.forename: H
authors.initials: H
authors.lastname: Nakauchi
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000473:pathology; D016827:CD8 Antigens / Q000032:analysis; D002454:Cell Differentiation; D005434:Flow Cytometry; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D017493:Leukocyte Common Antigens; D008099:Liver / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D008817:Mice, Mutant Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D013154:Spleen / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000473:pathology*; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000473:pathology*
chemical_list: D000954:Antigens, Surface; D016827:CD8 Antigens; D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018800:Thy-1 Antigens; D017493:Leukocyte Common Antigens