title: Interferon gamma and interleukin 6 modulate the susceptibility of macrophages to human immunodeficiency virus type 1 infection.
abstract: The effect of interferon gamma (IFN-gamma) and interleukin 6 (IL-6) on infection of macrophages with human immunodeficiency virus type 1 (HIV-1) was investigated. By using a polymerase chain reaction-based viral entry assay and viral infectivity assay, it was demonstrated that IL-6 and IFN-gamma augmented susceptibility of monocyte-derived macrophages (MDMs) to infection with T-cell tropic CXCR4-utilizing (X4) HIV-1 strains. Consistent with this finding, IFN-gamma and IL-6 augmented fusion of MDMs with T-tropic envelope-expressing cells. The enhanced fusion of cytokine-treated MDMs with T-tropic envelopes was inhibited by the CXCR4 ligand, SDF-1, and by T22 peptide. IFN-gamma and IL-6 did not affect expression of surface CXCR4 or SDF-1-induced Ca(++) flux in MDMs. In contrast to the effect of IFN-gamma on the infection of MDMs with X4 strains, IFN-gamma inhibited viral entry and productive infection of MDMs with macrophage-tropic (M-tropic) HIV-1. Consistent with this finding, IFN-gamma induced a decrease in fusion with M-tropic envelopes that correlated with a modest reduction in surface CCR5 and CD4 on MDMs. It was further demonstrated that macrophage inflammatory protein (MIP)-1alpha and MIP-beta secreted by cytokine-treated MDMs augmented their fusion with T-tropic-expressing cells and inhibited their fusion with M-tropic envelope-expressing cells. These data indicate that proinflammatory cytokines, which are produced during opportunistic infections or sexually transmitted diseases, may predispose macrophages to infection with X4 strains that, in turn, could accelerate disease progression.
authors.affiliation: Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA. zaitseva@cber.fda.gov
authors.forename: M
authors.initials: M
authors.lastname: Zaitseva
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: C
authors.initials: C
authors.lastname: Lapham
authors.forename: R
authors.initials: R
authors.lastname: Taffs
authors.forename: L
authors.initials: L
authors.lastname: King
authors.forename: T
authors.initials: T
authors.lastname: Romantseva
authors.forename: J
authors.initials: J
authors.lastname: Manischewitz
authors.forename: H
authors.initials: H
authors.lastname: Golding
mesh_terms: D002118:Calcium / Q000502:physiology; D002454:Cell Differentiation; D002459:Cell Fusion; D002478:Cells, Cultured; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000032:analysis; D019742:Chemokines, CC / Q000032:analysis; D015497:HIV-1 / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015850:Interleukin-6 / Q000494:pharmacology*; D019402:Macrophage Inflammatory Proteins / Q000032:analysis / Q000276:immunology / Q000502:physiology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000821:virology*; D009000:Monocytes / Q000166:cytology; D019718:Receptors, CXCR4 / Q000502:physiology
chemical_list: D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D019742:Chemokines, CC; D015850:Interleukin-6; D019402:Macrophage Inflammatory Proteins; D019718:Receptors, CXCR4; D007371:Interferon-gamma; D002118:Calcium