title: A novel CD45RA+CD4+ transient thymic subpopulation in MRL-lpr/lpr mice: its relation to non-proliferating CD4-CD8-CD45RA+ tumor cells.
abstract: MRL-lpr/lpr mice have hypertrophied lymph nodes comprising CD4-CD8- T cells. In addition, they contain CD4+CD8- T cells co-expressing the CD45RA marker. The correlation between these two subpopulations has been difficult to assess. We analyzed the expression of CD45RA (with the RA3-2C2 antibody) in various thymic and peripheral T cell subsets, using three-color immunofluorescence. We showed that in lpr mice (i) a transient CD4+CD8- thymic subset co-expresses CD45RA during the course of the disease, and (ii) thymic as well as peripheral CD4-CD8- and CD4+CD8- T cells brightly express CD45RA; furthermore (iii) in the lymph nodes, during lymphadenopathy, CD4+CD8-CD45RA+ T cells show a broad range of the CD4 fluorescence intensity, and (iv) the increase in MHC class II expression is restricted to CD45RA-T cells of the thymus and lymph nodes of lpr mice. Taken together, these data suggest that the CD4+CD8-CD45RA+ population might generate the CD4-CD8- tumor cells. In addition, using the bromodeoxyuridine labeling technique, we demonstrate that these cells are not the result of increased proliferation.
authors.affiliation: U345 INSERM, CHU Necker-Enfants Malades, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Ezine
authors.forename: B
authors.initials: B
authors.lastname: Lucas
authors.forename: A
authors.initials: A
authors.lastname: Vicari
authors.forename: N
authors.initials: N
authors.lastname: Dautigny
authors.forename: F
authors.initials: F
authors.lastname: Vasseur
authors.forename: C
authors.initials: C
authors.lastname: Penit
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000096:biosynthesis; D015704:CD4 Antigens / Q000096:biosynthesis*; D016827:CD8 Antigens / Q000096:biosynthesis; D004247:DNA / Q000096:biosynthesis; D005434:Flow Cytometry; D015870:Gene Expression; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000096:biosynthesis*; D008198:Lymph Nodes / Q000276:immunology; D008206:Lymphatic Diseases / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D000949:Histocompatibility Antigens Class II; D016693:Receptors, Antigen, T-Cell, alpha-beta; D004247:DNA; D017493:Leukocyte Common Antigens