IL-27 Inhibits HIV-1 Infection in Human Macrophages by Down-regulating Host Factor SPTBN1 during Monocyte to Macrophage Differentiation
ABSTRACT: 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:IL-27 treated DCs were shown to be highly potent inhibitors of cis HIV-1, particularly of CCR5 tropic strains. Microarray studies of IL-27 treated DCs showed no up-regulation of Type I (IFN) gene expression. Neutralization of the Type-I IFN receptor had no impact on the HIV inhibition. Lastly, IL-27 mediated inhibition was shown to act post-viral entry and prior to completion of reverse transcription. These results show for the first time that IL-27 is a potent inhibitor of cis HIV-1 infection in DCs by a Type I IFN independent mechanism. Gene expression microarrays from 3 samples of immature dendritic cells (iDCs) were compared with 3 samples of iDCs treated with IL-27
Project description:In this study, we hypothesized that IL-27 could induce the expression of novel miRNAs in macrophages which may have functional relevance in terms of anti-viral activity. In this study, primary monocytes were differentiated into macrophages using M-CSF (M-Mac) or with a combination of M-CSF and IL-27 (I-Mac) for seven days. Following this, total RNA was extracted from these cells and deep sequencing was performed, in parallel with gene expression microarrays. Using the novel miRNA discovery software, miRDeep, seven novel miRNAs were discovered in the macrophages, four of which were expressed higher in I-Mac (miRNAs 2.1, 8.1, 9.1 and 14.2) whilst three were detected in both M-Mac and I-Mac (miRNAs 9.3, 13.6 and 15.8). The expression of six of the seven novel miRNAs was highly correlated with qRT-PCR using specific primer/probes designed for the novel miRNAs. Gene expression microarray further demonstrated that a number of genes were potentially targeted by these differentially expressed novel miRNAs. Gene expression microarrays from 3 samples of microphage treated with M-CSF (M-MAC) were compared with 3 samples of micropahge treated with M-CSF + IL-27 (I-MAC)
Project description:Macrophages play a key role in both innate and adaptive immunity, but our knowledge on the changes in transcription regulation that occurs during their differentiation from monocytes is still limited. In this study, we used a meta-analysis followed by a systems biology approach for the identification of differentially expressed genes between monocytes and macrophages and possible regulators of these changes in transcription. Based on the pattern of gene expression change, transcription regulator analysis predicted a decrease in Enhancer of Zeste homolog 2 (EZH2), a histone 3 lysine 27 methyl transferase, activity after differentiation of monocytes into macrophages. This inhibition was validated by a significant decrease in trimethylated H3K27 during differentiation of both human primary monocytes into macrophages and the THP-1 cell line into macrophage-like cells. Overexpressing EZH2 during differentiation of monocytes and THP-1 cells obstructs cellular adhesion, thus preventing the first step in differentiation. Another facet of macrophage differentiation is the cessation of proliferation, and inhibition of EZH2 by the small molecule inhibitor GSK126 in THP-1 cells indeed impedes proliferation. This study shows an important part for epigenetic changes during monocyte differentiation. It highlights the role of EZH2 activity behind the changes needed in adhesion and proliferation mechanisms for macrophage formation. Monocytes isolated from human peripherial mononuclear cells were differentiated in monocyte derived macrophages by M-CSF stimulation
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:In this study, we hypothesized that IL-27 could induce the expression of novel miRNAs in macrophages which may have functional relevance in terms of anti-viral activity. In this study, primary monocytes were differentiated into macrophages using M-CSF (M-Mac) or with a combination of M-CSF and IL-27 (I-Mac) for seven days. Following this, total RNA was extracted from these cells and deep sequencing was performed, in parallel with gene expression microarrays. Using the novel miRNA discovery software, miRDeep, seven novel miRNAs were discovered in the macrophages, four of which were expressed higher in I-Mac (miRNAs 2.1, 8.1, 9.1 and 14.2) whilst three were detected in both M-Mac and I-Mac (miRNAs 9.3, 13.6 and 15.8). The expression of six of the seven novel miRNAs was highly correlated with qRT-PCR using specific primer/probes designed for the novel miRNAs. Gene expression microarray further demonstrated that a number of genes were potentially targeted by these differentially expressed novel miRNAs. screening novel and known miRNAs which may have antiviral properties in 2 different treatments in 2 donors.
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:To study effects of IFNalpha treatment on monocyte-derived macrophages which may influence susceptibility or resistance to HIV. Experiment Overall Design: Human monocyte-derived macrophages were stimulated with IFNalpha and analyzed for global gene expression.
Project description:The effect of human immunodeficiency virus (HIV) infection and high-level HIV replication on the function of monocytes was investigated. HIV-positive patients had elevated levels of spontaneous production of some or all of the monocyte proinflammatory cytokines measured (interleukin-1beta [IL-1beta], IL-6, and tumor necrosis factor alpha [TNF-alpha]) compared to uninfected controls. In patients on therapy with high frequencies of monocytes producing proinflammatory cytokines, this frequency was diminished in the context of viremia during an interruption of therapy. Diminished production of proinflammatory cytokines during viremia was restored by culture with autologous CD4(+) T cells or monocytes from an on-therapy time point or lipopolysaccharide (LPS). Microarray analysis demonstrated that diminished monocyte production of proinflammatory cytokines was correlated with elevated type I interferon-stimulated gene transcripts. The addition of exogenous alpha 2A interferon diminished the spontaneous production of IL-1beta, IL-6, and TNF-alpha but did not affect responses to LPS, recapitulating the changes observed for HIV-viremic patients. These results suggest that monocyte function is diminished during high-level HIV viremia and that this effect is mediated by chronic stimulation by type I interferons. This effect on monocytes during viremia may play a role in diminished innate or adaptive immune system functions in HIV-infected patients. In addition, the restoration of these functions may also play a role in some immune reconstitution syndromes observed during initiation of therapy.
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).