Molecular characterization of dendritic cells operating at the interface of innate or acquired immunity.
Dendritic Cells (DC) are natural adjuvants able to elicit specific cellular interactions and priming of naive T cells at a mature stage of their differentiation. Recent genomic approaches helped defining DC or Langherans Cells (LC) in more molecular terms. DC-SIGN, the DC specific ICAM-3 grabbing non integrin is a C-type lectin, absent on LC but expressed on dermal, lymph node and tonsils DC. DC-SIGN is defined as an ICAM-3 receptor supporting DC mediated-T cell proliferation. Moreover, DC-SIGN plays an important role in binding and presentation of HIV virions, because DC-SIGN specifically binds the gp120 coat protein of HIV.DC-SIGN also plays a part in DC trafficking since it not only binds ICAM-3 but also ICAM-2 expressed by many endothelial cells, supporting tethering and rolling of DC on endothelium and chemokine induced-transmigration of DC across both resting and activated endothelium in vitro. ALCAM (Activated Leukocyte Cell Adhesion Molecule) is another cell surface protein expressed by DC upon differentiation from monocytes. ALCAM appears to be expressed on activated leukocytes and might be involved in inflammatory processes. ALCAM belongs to the IgG superfamily of proteins and mediate heterotypic (T cell antigen ligand CD6) or homotypic interactions. ALCAM is linked to the cytoskeleton and might play a role in DC migration. Measurements of cell/cell contacts at single molecular levels using optical traps is a useful tool to investigate intercellular interactions.
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Department of Immunology, Nijmegen Center for Molecular Life Sciences, NCMLS/187 Til University Medical Center Postbox 9101, 6500 HB The, Nijmegen, Netherlands. c.figdor@mailbox.kun.nl <c.figdor@mailbox.kun.nl>
D020410:Activated-Leukocyte Cell Adhesion Molecule / Q000502:physiology*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism / Q000502:physiology*; D002465:Cell Movement; D003713:Dendritic Cells / Q000737:chemistry / Q000145:classification / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D007801:Langerhans Cells / Q000166:cytology / Q000276:immunology; D037102:Lectins; D037181:Lectins, C-Type / Q000502:physiology*; D008213:Lymphocyte Activation; D011956:Receptors, Cell Surface / Q000502:physiology*; D011971:Receptors, Immunologic / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
D020410:Activated-Leukocyte Cell Adhesion Molecule; D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D015699:HIV Envelope Protein gp120; D037102:Lectins; D037181:Lectins, C-Type; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C065289:ICAM2 protein, human