title: A conserved enhancer element differentially regulates developmental expression of CD5 in B and T cells.
abstract: We previously identified an enhancer element upstream of the mouse cd5 gene that was required in reporter assays for the induction of cd5 promoter activity by BCR cross-linking. This element is highly conserved in placental mammals. To determine its physiological role, we have now generated mice with a targeted deletion of the enhancer. The result is the loss of CD5 expression in peritoneal and splenic B-1a cells of adult mice and an inability to induce CD5 by cross-linking of the BCR on splenic B-2 cells. Surprisingly, CD5 expression on B-1a cells of neonatal mice was only minimally compromised. Cd5 enhancer deletion also had only a modest effect on CD5 expression in the T lineage. Thus, this enhancer provides age- and tissue-specific regulation of CD5 expression and is an example of the utilization of different modes of regulation of expression in T and B cells.
authors.affiliation: Department of Pathology, Tufts University School of Medicine, Boston, MA 02111, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Berland
authors.forename: Steven
authors.initials: S
authors.lastname: Fiering
authors.forename: Henry H
authors.initials: HH
authors.lastname: Wortis
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018956:CD5 Antigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D004742:Enhancer Elements, Genetic / Q000502:physiology*; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology*; D007152:Immunologic Capping; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009928:Organ Specificity / Q000502:physiology; D010529:Peritoneal Cavity / Q000166:cytology; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D018956:CD5 Antigens; C526836:Cd5 protein, mouse; D011947:Receptors, Antigen, B-Cell