title: Subset of DC-SIGN(+) dendritic cells in human blood transmits HIV-1 to T lymphocytes.
abstract: The dendritic cell (DC)-specific molecule DC-SIGN is a receptor for the HIV-1 envelope glycoprotein gp120 and is essential for the dissemination of HIV-1. DC-SIGN is expressed by DCs, both monocyte-derived DCs and DCs in several tissues, including mucosa and lymph nodes. To identify a DC-SIGN(+) DC in blood that may be involved in HIV-1 infection through blood, we have analyzed the expression of DC-SIGN in human blood cells. Here we describe the characterization of a subset of DCs in human blood, isolated from T-/NK-/B-cell-depleted peripheral blood mononuclear cells (PBMCs) on the basis of expression of DC-SIGN. This subset coexpresses CD14, CD16, and CD33 and is thus of myeloid origin. In contrast to CD14(+) monocytes, DC-SIGN(+) blood cells display a DC-like morphology and express markers of antigen-presenting cells, including CD1c, CD11b, CD11c, CD86, and high levels of major histocompatibility complex (MHC) class I and II molecules. This DC population differs from other described CD14(-) blood DC subsets. Functionally, DC-SIGN(+) blood DCs are able to stimulate proliferation of allogeneic T cells and can produce tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) upon activation with lipopolysaccharide (LPS). When they encounter HIV-1, low amounts of these blood DC-SIGN(+) DCs enhance infection of T lymphocytes in trans, whereas blood monocytes and CD14(-) blood DCs are not capable of transmitting HIV-1. Therefore DC-SIGN(+) blood DCs can be the first target for HIV-1 upon transmission via blood; they can capture minute amounts of HIV-1 through DC-SIGN and transfer HIV-1 to infect target T cells in trans.
authors.affiliation: Department of Molecular Cell Biology, Vrÿe Universiteit Medical Center, Amsterdam, The Netherlands.
authors.forename: Anneke
authors.initials: A
authors.lastname: Engering
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Van Vliet
authors.forename: Teunis B H
authors.initials: TB
authors.lastname: Geijtenbeek
authors.forename: Yvette
authors.initials: Y
authors.lastname: Van Kooyk
mesh_terms: D015815:Cell Adhesion Molecules; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D037102:Lectins / Q000276:immunology*; D037181:Lectins, C-Type; D011956:Receptors, Cell Surface / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D014764:Viral Proteins / Q000276:immunology; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D015815:Cell Adhesion Molecules; D037102:Lectins; D037181:Lectins, C-Type; D011956:Receptors, Cell Surface; D014764:Viral Proteins; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin