title: Dendritic cells transmit human immunodeficiency virus type 1 to monocytes and monocyte-derived macrophages.
abstract: Previous studies have shown that human immunodeficiency virus type 1 (HIV-1) exploits dendritic cells (DC) to replicate and spread among CD4(+) T cells. To explain the predominance of non-syncytium-inducing (NSI) over syncytium-inducing (SI) strains during the initial viremia of HIV, we investigated the ability of blood monocyte (Mo)-derived DC to transmit HIV-1 to CD4(+) cells of the monocytoid lineage. First, we demonstrate that in our system, DC are able to transmit NSI strains, but not SI strains, of HIV-1 to fresh blood Mo and to Mo-derived macrophages (MDM). To establish a productive infection, a 10-fold-lower amount of virus was necessary for DC-mediated transmission of HIV-1 to Mo than in case of cell-free infection. Second, immature CD83(-) DC (imDC) transmit virus to Mo and MDM with higher efficacy compared to mature CD83(+) DC (maDC); this finding is in contrast to data previously obtained with CD4(+) T cells. Third, maturation from imDC to maDC efficiently silenced expression of beta2-integrins CD11b, CD11c, and CD18 by maDC. Moreover, monoclonal antibody against CD18 inhibited transmission of HIV-1 from imDC to Mo. We propose that the adhesion molecules of the CD11/CD18 family, involved in cell-cell interactions of DC with the microenvironment, may play a major role in imDC-mediated HIV-1 infection of Mo and MDM.
authors.affiliation: Institute for Hygiene, University of Innsbruck, Innsbruck, Austria. Laco.Kacani@uibk.ac.at
authors.forename: L
authors.initials: L
authors.lastname: Kacani
authors.forename: I
authors.initials: I
authors.lastname: Frank
authors.forename: M
authors.initials: M
authors.lastname: Spruth
authors.forename: M G
authors.initials: MG
authors.lastname: Schwendinger
authors.forename: B
authors.initials: B
authors.lastname: Müllauer
authors.forename: G M
authors.initials: GM
authors.lastname: Sprinzl
authors.forename: F
authors.initials: F
authors.lastname: Steindl
authors.forename: M P
authors.initials: MP
authors.lastname: Dierich
mesh_terms: D018920:Coculture Techniques; D003713:Dendritic Cells / Q000502:physiology / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008264:Macrophages / Q000502:physiology / Q000821:virology*; D009000:Monocytes / Q000502:physiology / Q000821:virology*; D013194:Staining and Labeling