       Document 0561
 DOCN  M9650561
 TI    Circulating human dendritic cells differentially express high levels of
       a 55-kd actin-bundling protein.
 DT    9605
 AU    Mosialos G; Birkenbach M; Ayehunie S; Matsumura F; Pinkus GS; Kieff E;
       Langhoff E; Department of Microbiology and Molecular Genetics and
       Medicine,; Harvard Medical School, Boston, Massachusetts, USA.
 SO    Am J Pathol. 1996 Feb;148(2):593-600. Unique Identifier : AIDSLINE
       MED/96163293
 AB    This study was initiated to examine the differential expression of an
       evolutionary conserved human 55-kd actin-bundling (p55) protein that is
       induced in B lymphocytes by Epstein-Barr virus infection. Our study
       demonstrates that p55 is specifically expressed at constitutively high
       levels in human peripheral blood dendritic cells and lymph node
       (interdigitating) dendritic cells. Blood dendritic cells constitute a
       minority (< 2%) of all blood leukocytes but are a distinct population of
       potent antigen-presenting cells. Immunofluorescence microscopy with a
       monoclonal antibody specific for p55 showed that 87% of peripheral blood
       dendritic cells stained brightly in the cytoplasm and in the veiled
       cytoplasmic extensions. In contrast, monocytes, granulocytes, T cells,
       and B lymphocytes showed no expression of the p55 protein. Western blot
       analysis confirmed that only the dendritic cell component of peripheral
       blood expressed high levels of p55. Staining of human lymph node
       sections demonstrated selective expression of the p55 antigen by
       dendritic cells in the T-cell-dependent areas but not in the B cell
       follicles. p55 is likely to be involved in the organization of a
       specialized microfilament cytoskeleton in the dendritic cells, and the
       anti-p55 antibody should be useful for further characterization of this
       important population of antigen-presenting cells in clinical
       transplantation, HIV-1 pathogenesis, and autoimmune diseases.
 DE    Actins/METABOLISM  B-Lymphocytes/CHEMISTRY  Blotting, Western  Carrier
       Proteins/ANALYSIS/*BIOSYNTHESIS  Cell Separation  Cells, Cultured
       Dendritic Cells/*METABOLISM/PHYSIOLOGY  Fluorescein-5-isothiocyanate
       Granulocytes/CHEMISTRY  Human  Lymph Nodes/CHEMISTRY/CYTOLOGY
       Lymphocyte Culture Test, Mixed  Microfilament
       Proteins/ANALYSIS/*BIOSYNTHESIS  Monocytes/CHEMISTRY  Support, U.S.
       Gov't, P.H.S.  T-Lymphocytes/CHEMISTRY  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

