Project description:The susceptibility of macrophages to HIV-1 infection is modulated during monocyte differentiation. IL-27 is an anti-HIV cytokine that also modulates monocyte activation. Here, we present new evidence that IL-27 promotes monocyte differentiation into macrophages that are non-permissive for HIV-1 infection. While IL-27 treatment does not affect expression of macrophage differentiation markers or macrophage biological functions, it confers HIV resistance by down-regulating spectrin beta non-erythrocyte 1 (SPTBN1), a required host factor for HIV-1 infection. IL-27 down-regulates SPTBN1 through a TAK-1-mediated MAPK signaling pathway. Knockdown of SPTBN1 strongly inhibits HIV-1 infection of macrophages; conversely, overexpression of SPTBN1 markedly increases HIV susceptibility of IL-27 treated macrophages. Moreover, we demonstrate that SPTBN1 associates with HIV-1 gag proteins. Collectively, our results underscore the ability of IL-27 to protect macrophages from HIV-1 infection by down-regulating SPTBN1, thus indicating that SPTBN1 is an important host target to reduce HIV-1 replication in one major element of the viral reservoir. 2 samples with different treatments were analyzed. Genes with absolute fold change >= 5 were selected.
Project description:The susceptibility of macrophages to HIV-1 infection is modulated during monocyte differentiation. IL-27 is an anti-HIV cytokine that also modulates monocyte activation. Here, we present new evidence that IL-27 promotes monocyte differentiation into macrophages that are non-permissive for HIV-1 infection. While IL-27 treatment does not affect expression of macrophage differentiation markers or macrophage biological functions, it confers HIV resistance by down-regulating spectrin beta non-erythrocyte 1 (SPTBN1), a required host factor for HIV-1 infection. IL-27 down-regulates SPTBN1 through a TAK-1-mediated MAPK signaling pathway. Knockdown of SPTBN1 strongly inhibits HIV-1 infection of macrophages; conversely, overexpression of SPTBN1 markedly increases HIV susceptibility of IL-27 treated macrophages. Moreover, we demonstrate that SPTBN1 associates with HIV-1 gag proteins. Collectively, our results underscore the ability of IL-27 to protect macrophages from HIV-1 infection by down-regulating SPTBN1, thus indicating that SPTBN1 is an important host target to reduce HIV-1 replication in one major element of the viral reservoir.
Project description:HIV-1 infection of monocytes/macrophages is modulated by several host factors. For instance, although HIV-1 successfully enters monocytes, antiviral restriction factors inhibit HIV-1 productive infection in these cells. We recently identified two microRNAs, miR-221 and miR-222, which limit HIV-1 entry during infection of monocyte-derived macrophages (MDM) by down-regulating CD4 expression. Interestingly, CD4 is also down regulated during the differentiation of monocytes into macrophages. In this study, we compared microRNA expression in monocytes and macrophages by RNAseq and found that miR-221/miR-222 are enhanced in macrophages.Taken together, these results show that both miR-221 and miR-222 act as modulators of CD4 mRNA expression throughout the monocyte/macrophage lineage, having roles in their differentiation, activation processes and modulating macrophage resistance to HIV-1.
Project description:Macrophages provide an interface between innate and adaptive immunity and are important long-lived reservoirs for Human Immunodeficiency Virus Type-1 (HIV-1). Multiple genetic networks involved in regulating signal transduction cascades and immune responses in macrophages are coordinately modulated by HIV-1 infection. To evaluate complex interrelated processes and to assemble an integrated view of activated signaling networks, a systems biology strategy was applied to genomic and proteomic responses by primary human macrophages over the course of HIV-1 infection. Macrophage responses, including cell cycle, calcium, apoptosis, mitogen-activated protein kinases (MAPK), and cytokines/chemokines, to HIV-1 were temporally regulated, in the absence of cell proliferation. In contrast, Toll-like receptor (TLR) pathways remained unaltered by HIV-1, although TLRs 3, 4, 7, and 8 were expressed and responded to ligand stimulation in macrophages. HIV-1 failed to activate phosphorylation of IRAK-1 or IRF-3, modulate intracellular protein levels of Mx1, an interferon-stimulated gene, or stimulate secretion of TNF, IL-1b, or IL-6. Activation of pathways other than TLR was inadequate to stimulate, via cross-talk mechanisms through molecular hubs, the production of proinflammatory cytokines typical of a TLR response. HIV-1 sensitized macrophage responses to TLR ligands, and the magnitude of viral priming was related to virus replication. HIV-1 induced a primed, proinflammatory state, M1HIV, which increased the responsiveness of macrophages to TLR ligands. HIV-1 might passively evade pattern recognition, actively inhibit or suppress recognition and signaling, or require dynamic interactions between macrophages and other cells, such as lymphocytes or endothelial cells. HIV-1 evasion of TLR recognition and simultaneous priming of macrophages may represent a strategy for viral survival, contribute to immune pathogenesis, and provide important targets for therapeutic approaches. Affymetrix arrays were used to identify genomic macrophage response to HIV during viral spread in culture. Experiment Overall Design: An HIV-1 spreading infection was established in primary human macrophages. RNA was extracted from both viral- and mock-infected macrophages cultures over 7 days and hybridized to Affymetrix HG-U95Av2 GeneChips for analysis.
Project description:M2 macrophages can be polarized into M2a, M2b, M2c, and M2d by various stimuli, and Interleukin (IL)-27-treated M2 macrophages (27-Mac) resists HIV infection. Since IL-27 is a member of IL-6 family of cytokines, and IL-6 polarizes M2 macrophages into M2d, 27-Mac was considered an M2d-like cells. In the current study, we compared 27-Mac and M2d and characterized 27-Mac. Monocytes derived from health donors were differentiated to M2 using M-CSF, and then the resulting M2 were polarized into subtypes using IL-6, IL-27, or BAY60-658 (an adenosine analog which polarizes M2 into M2d). Although IL-6 and IL-27 share gp130 to induce STAT3 signaling pathway, only 27-Mac resisted HIV infection and enhanced the generation of reactive oxygen species (ROS). In contrast, BAY60-6583-polarized M2 macrophages (BAY-M2d) resisted HIV infection without affecting ROS production. The cytokine-producing profile of 27-Mac did not resemble those of the two subtypes. The analysis of the gene expression profiles using single-cell RNA sequencing indicated that 27-Mac clustered differed from other cell types and significantly expressed CD38 and secreted CXCL9 in culture supernatants. These data indicate that 27-Mac is distinct from traditional M2d and provide a new insight into the function of IL-27 and the polarized M2 macrophages.
Project description:HIV-1 infection of monocyte-derived macrophages does not elicit a detectable type I IFN response in vitro, however, previously published data has shown that blocking STAT1 and STAT3 inhibits HIV-1 replication. Here we test to see if low levels of IFN inducible genes are detectable in human monocyte-derived macrophages that have been infected with HIV-1 in vitro.
Project description:Mechanisms that may allow circulating monocytes to persist as CD4 T cells diminish in HIV-1 infection have not been investigated. We have characterized steady-state gene expression signatures in circulating monocytes from HIV-infected subjects and have identified a stable anti-apoptosis gene signature comprised of 38 genes associated with p53, CD40L, TNF and MAPKinase signaling networks. The significance of this gene signature is indicated by our demonstration of cadmium chloride- or Fas ligand-induced apoptosis resistance in circulating monocytes in contrast to increasing apoptosis in CD4 T cells from the same infected subjects. As potential mechanisms in vivo, we show that monocyte CCR5 binding by HIV-1 virus or agonist chemokines serve as independent viral and host modulators resulting in increased monocyte apoptosis resistance in vitro. We also show evidence for concordance between circulating monocyte apoptosis-related gene expression in HIV-1 infection in vivo and available datasets following viral infection or envelope exposure in monocyte derived macrophages in vitro. The identification of in vivo gene expression associated with monocyte resistance to apoptosis is of relevance to AIDS pathogenesis since it would contribute to: (1) maintaining viability of infection targets and long-term reservoirs of HIV-1 infection in the monocyte/macrophage populations, and (2) protecting a cell subset critical to host survival in spite of sustained high viral replication. Keywords: two group study design 33 samples hybridized, including 13 HIV-1 Patients, 12 Healthy Controls and 4 HIV-1 Patients and 4 Controls followed 6 months later
Project description:Macrophages are important effector cells of the immune system and play an important role in mounting inflammatory responses. Macrophages can be activated by different stimuli in the tissue, either by cytokines produced by T helper cells (M1 or M2 polarization) or by the pathogens they encounter. Macrophages are also important target cells of HIV-1 and are preferentially infected by CCR5-using viruses. In this study, we investigated the ability of HIV-1 to induce changes in gene expression in unpolarized macrophages as well as in M1 or M2 polarized cells. We observed that CCR5-using HIV-1 regulates the expression of genes that are also regulated by IL-4 in macrophages. Genes regulated by HIV-1 infection and IL-4 polarization are involved in dampening pro-inflammatory responses in macrophages, which may facilitate HIV-1 to escape from detection by other immune cells. We also observed that changes in macrophage gene expression triggered by CCR5-using HIV-1 differed from those regulated by a CXCR4-using virus. This indicates that CCR5-using HIV-1 may be able to modulate macrophage gene expression to achieve successful replication. Our results provide insight in the complex interplay between HIV-1 and cells of the immune system. Polarized macrophages were obtained by stimulation of primary human monocytes with IFN-gamma (250 U/ml) in combination with TNF-alpha (12.5 ng/ml) (M1), IL-4 (50 ng/ml) (M2a), IL-10 (50 ng/ml) (M2c) for 5 days. Cells were inoculated for 24 hours with one of two HIV-1 strains (CCR5 or CXCR4 using HIV1) or their non replicating counterparts (heat inactivated virus). Macrophages that were not stimulated wiht cyokines or inoculates with HIV-1 were used as control. A total of 16 treatment conditions were tested in triplicate, for a total of 48 samples analysed.
Project description:Macrophages provide an interface between innate and adaptive immunity and are important long-lived reservoirs for Human Immunodeficiency Virus Type-1 (HIV-1). Multiple genetic networks involved in regulating signal transduction cascades and immune responses in macrophages are coordinately modulated by HIV-1 infection. To evaluate complex interrelated processes and to assemble an integrated view of activated signaling networks, a systems biology strategy was applied to genomic and proteomic responses by primary human macrophages over the course of HIV-1 infection. Macrophage responses, including cell cycle, calcium, apoptosis, mitogen-activated protein kinases (MAPK), and cytokines/chemokines, to HIV-1 were temporally regulated, in the absence of cell proliferation. In contrast, Toll-like receptor (TLR) pathways remained unaltered by HIV-1, although TLRs 3, 4, 7, and 8 were expressed and responded to ligand stimulation in macrophages. HIV-1 failed to activate phosphorylation of IRAK-1 or IRF-3, modulate intracellular protein levels of Mx1, an interferon-stimulated gene, or stimulate secretion of TNF, IL-1b, or IL-6. Activation of pathways other than TLR was inadequate to stimulate, via cross-talk mechanisms through molecular hubs, the production of proinflammatory cytokines typical of a TLR response. HIV-1 sensitized macrophage responses to TLR ligands, and the magnitude of viral priming was related to virus replication. HIV-1 induced a primed, proinflammatory state, M1HIV, which increased the responsiveness of macrophages to TLR ligands. HIV-1 might passively evade pattern recognition, actively inhibit or suppress recognition and signaling, or require dynamic interactions between macrophages and other cells, such as lymphocytes or endothelial cells. HIV-1 evasion of TLR recognition and simultaneous priming of macrophages may represent a strategy for viral survival, contribute to immune pathogenesis, and provide important targets for therapeutic approaches. Affymetrix arrays were used to identify genomic macrophage response to HIV during viral spread in culture. Keywords: time course
Project description:Atherosclerosis is a chronic inflammatory disease. Lesion progression is primarily mediated by cells of the monocyte/macrophage lineage. Interleukin-17A is a pro-inflammatory cytokine, which modulates immune cell trafficking and is involved inflammation in (auto)immune and infectious diseases. But the role of IL-17A still remains controversial. In the current study we investigated effects of IL-17A on advanced murine and human atherosclerosis, the common disease phenotype in clinical care. 26-weeks old apolipoprotein E-deficient (Apoe-/-) mice were fed a standard chow diet and treated either with IL-17A mAb (n=15) or irrelevant immunoglobulin (n=10) for 16 weeks. Furthermore, essential mechanisms of IL-17A in atherogenesis were studied in vitro. Inhibition of IL-17A markedly prevented atherosclerotic lesion progression (P=0.001) by reducing inflammatory burden and cellular infiltration (P=0.01) and improved lesion stability (P=0.01). In vitro experiments showed that IL-17A plays a role in chemoattractance, monocyte adhesion, sensitization of antigen-presenting cells toward pathogen-derived TLR4 ligands. Also, IL-17A induced a unique transcriptome pattern in monocyte-derived macrophages distinct from known macrophage types. Stimulation of human carotid plaque tissue ex vivo with IL-17A induced a pro-inflammatory milieu and up-regulation of molecules expressed by the IL-17A-induced macrophage subtype. We here show for the first time that functional blockade of IL-17A prevents atherosclerotic lesion progression and induces plaque stabilization in advanced lesions in Apoe-/- mice. The underlying mechanisms involve reduced inflammation and distinct effects of IL-17A on monocyte / macrophage lineage. In addition, translational experiments underline the relevance for the human system. Effects of IL-17A on human monocyte-derived macrophages were assessed (n=2 per group).