title: Macrophage-tropic HIV induces and exploits dendritic cell chemotaxis.
abstract: Immature dendritic cells (iDCs) express the CC chemokine receptor (CCR)5, which promotes chemotaxis toward the CC chemokines regulated on activation, normal T cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta. By contrast, mature DCs downregulate CCR5 but upregulate CXC chemokine receptor (CXCR)4, and as a result exhibit enhanced chemotaxis toward stromal cell-derived factor (SDF)-1alpha. CCR5 and CXCR4 also function as coreceptors for macrophage-tropic (M-tropic) and T cell-tropic (T-tropic) human immunodeficiency virus (HIV)-1, respectively. Here, we demonstrate chemotaxis of iDCs toward M-tropic (R5) but not T-tropic (X4) HIV-1. Furthermore, preexposure to M-tropic HIV-1 or its recombinant envelope protein prevents migration toward CCR5 ligands. The migration of iDCs toward M-tropic HIV-1 may enhance formation of DC-T cell syncytia, thus promoting viral production and destruction of both DC and T helper lymphocytes. Therefore, disturbance of DC chemotaxis by HIV-1 is likely to contribute to immunosuppression in primary infection and AIDS. In addition, migration of iDCs toward HIV-1 may aid the capture of R5 HIV-1 virions by the abundant DC cell surface protein DC-specific intercellular adhesion molecule (ICAM)3-grabbing nonintegrin (DC-SIGN). HIV-1 bound to DC cell-specific DC-SIGN retains the ability to infect replication-permissive T cells in trans for several days. Consequently, recruitment of DC by HIV-1 could combine with the ability of DC-SIGN to capture and transmit the virus to T cells, and so facilitate dissemination of virus within an infected individual.
authors.affiliation: Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
authors.forename: C L
authors.initials: CL
authors.lastname: Lin
authors.forename: A K
authors.initials: AK
authors.lastname: Sewell
authors.forename: G F
authors.initials: GF
authors.lastname: Gao
authors.forename: K T
authors.initials: KT
authors.lastname: Whelan
authors.forename: R E
authors.initials: RE
authors.lastname: Phillips
authors.forename: J M
authors.initials: JM
authors.lastname: Austyn
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000378:metabolism; D015815:Cell Adhesion Molecules; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000378:metabolism; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000378:metabolism; D002633:Chemotaxis; D003713:Dendritic Cells / Q000378:metabolism / Q000502:physiology*; D015483:HIV Antibodies / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000378:metabolism; D015497:HIV-1 / Q000276:immunology / Q000502:physiology*; D006801:Humans; D037102:Lectins / Q000378:metabolism; D037181:Lectins, C-Type; D019402:Macrophage Inflammatory Proteins / Q000378:metabolism; D008264:Macrophages / Q000821:virology*; D011233:Precipitin Tests; D019713:Receptors, CCR5 / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000821:virology*; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D015704:CD4 Antigens; D015815:Cell Adhesion Molecules; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D037102:Lectins; D037181:Lectins, C-Type; D019402:Macrophage Inflammatory Proteins; D019713:Receptors, CCR5; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C515255:CXCL12 protein, human