Interleukin 23 Produced by Myeloid Dendritic Cells Contributes to T-Cell Dysfunction in HIV Type 1 Infection by Inducing SOCS1 Expression (original) (raw)
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IL-23 and IL-12p70 production by monocytes and dendritic cells in primary HIV-1 infection
Journal of Leukocyte Biology, 2010
IL-12 enhances protective responses against HIV replication. Its production after in vitro stimulation is defective in chronic HIV infection, but higher responses can be found. IL-23 shares the p40 chain and some properties with IL-12 and enhances Th17 responses, but its role in HIV infection is unknown. The production of IL-12 and IL-23 and the respective contribution of monocytes and myeloid conventional DC (cDCs) during primary HIV infection were determined. Sixteen patients included in the French PRIMO-ANRS Cohort without antiretroviral treatment were followed prospectively and compared with uninfected donors. Intracellular p40 expression by monocytes and cDCs, analyzed by flow cytometry, was transiently increased in monocytes and cDCs in response to LPS and more consistently, in monocytes in response to LPS ϩ IFN-␥. IL-23 production, measured by ELISA after PBMC stimulation, was induced by LPS in strong correlation with VLs. IL-12p70 production required the addition of IFN-␥ and was transiently increased in patients compared with controls in correlation with VLs, whereas IL-23 was increased sustainedly. Therefore, an apparent domination of IL-23 over IL-12 responses occurred throughout primary HIV infection, and a potential restoration of IL-12 responses might be expected from a treatment mimicking activated T cell signals.
PloS one, 2015
Severely immunocompromised state during advanced stage of HIV-1 infection has been linked to functionally defective antigen presentation by dendritic cells (DCs). The molecular mechanisms behind DC impairment are still obscure. We investigated changes in DC function and association of key regulators of cytokine signaling during different stages of HIV-1 infection and following antiretroviral therapy (ART). Phenotypic and functional characteristics of circulating myeloid DCs (mDCs) in 56 ART-naive patients (23 in early and 33 in advanced stage of disease), 36 on ART and 24 healthy controls were evaluated. Sixteen patients were studied longitudinally prior-to and 6 months after the start of ART. For functional studies, monocyte-derived DCs (Mo-DCs) were evaluated for endocytosis, allo-stimulation and cytokine secretion. The expression of suppressor of cytokine signaling (SOCS)-1 and other regulators of cytokine signaling was evaluated by real-time RT-PCR. The ability to respond to an ...
Cellular Immunology, 2007
We compared TLR responsiveness in PBMC from HIV-1-infected and uninfected individuals using the TLR agonists: TLR7 (3M-001), TLR8 (3M-002) and TLR7/8 (3M-011). Activation and maturation of plasmacytoid dendritic cells (pDC)were measured by evaluating CD86, CD40 and CD83 expression and myeloid dendritic cell (mDC) activation was measured by evaluating CD40 expression. All agonists tested induced activation and maturation of pDC in PBMC cultures of cells from HIV+ and HIV− individuals. The TLR7 agonist induced significantly less pDC maturation in cells from HIV+ individuals. Quantitative assessment of secreted IFN-α and pro-inflammatory cytokines at the single cell level showed that pDC from HIV+ individuals stimulated with TLR7 and TLR7/8 induced IFN-α. TLR8 and TLR7/8 agonists induced IL-12 and COX-2 expression in mDC from HIV+ and HIV− individuals. Understanding pDC and mDC activation and maturation in HIV-1 infection could lead to more rational development of immunotherapeutic strategies to stimulate the adaptive immune response to HIV-1.
Journal of Virology, 2004
In this study, we analyzed the phenotypic and physiological consequences of the interaction of plasmacytoid dendritic cells (pDCs) with human immunodeficiency virus type 1 (HIV-1). pDCs are one cellular target of HIV-1 and respond to the virus by producing alpha/beta interferon (IFN-␣/) and chemokines. The outcome of this interaction, notably on the function of bystander myeloid DC (CD11c ؉ DCs), remains unclear. We therefore evaluated the effects of HIV-1 exposure on these two DC subsets under various conditions. Bloodpurified pDCs and CD11c ؉ DCs were exposed in vitro to HIV-1, after which maturation markers, cytokine production, migratory capacity, and CD4 T-cell stimulatory capacity were analyzed. pDCs exposed to different strains of infectious or even chemically inactivated, nonreplicating HIV-1 strongly upregulated the expression of maturation markers, such as CD83 and functional CCR7, analogous to exposure to R-848, a synthetic agonist of toll-like receptor-7 and -8. In addition, HIV-1-activated pDCs produced cytokines (IFN-␣ and tumor necrosis factor alpha), migrated in response to CCL19 and, in coculture, matured CD11c ؉ DCs, which are not directly activated by HIV. pDCs also acquired the ability to stimulate naïve CD4 ؉ T cells, albeit less efficiently than CD11c ؉ DCs. This HIV-1-induced maturation of both DC subsets may explain their disappearance from the blood of patients with high viral loads and may have important consequences on HIV-1 cellular transmission and HIV-1-specific T-cell responses.
Clinical and Experimental Immunology, 2003
Use of interleukin-2 (IL-2) in the immunotherapy of human immunodeficiency virus (HIV) has frequently resulted in the restoration of CD4 lymphocyte counts but not of virus-specific responses. We reasoned that the absence of reconstituted functional immune parameters could be related to the inability of IL-2 to correct HIV-induced dysfunctions in antigen-presenting cells. In this study, we used in vitro-differentiated monocyte-derived macrophages (MDMs) and mature dendritic cells (MDDCs), acutely infected with primary HIV-1 isolates, to analyse the effects of IL-2 on virus replication, coreceptor expression, and cytokine or chemokine release. Stimulation of MDMs with IL-2 had no measurable effect on HIV-1 replication, on cytokine secretion, or on CD4 and CXCR4 gene expression. Moreover, although a significant down-regulation of CCR5 mRNA expression could be repeatedly detected in MDMs, this IL-2-mediated effect was not of substantial magnitude to affect virus replication. On the other hand, IL-2 stimulation of MDDCs dramatically increased HIV-1 replication and this effect was highly evident on low-replicating, CXCR4-dependent isolates. Nevertheless, the HIVenhancing activity of IL-2 in MDDCs was not accompanied by any measurable change in cytokine or chemokine release, in virus receptor and co-receptor mRNA accumulation, or in the surface expression of a battery of receptors implicated in virus entry, cell activation or costimulatory function. Taken together, these findings point to a role for IL-2 in inducing virus purging from dendritic cell reservoirs but indicate no relevant potential of the cytokine in restoring defective elements of innate immunity in HIV infection.
Clinical and Developmental Immunology, 2012
A variety of immune-based therapies has been developed in order to boost or induce protective CD8 + T cell responses in order to control HIV replication. Since dendritic cells (DCs) are professional antigen-presenting cells (APCs) with the unique capability to stimulate naïve T cells into effector T cells, their use for the induction of HIV-specific immune responses has been studied intensively. In the present study we investigated whether modulation of the activation state of DCs electroporated with consensus codon-optimized HxB2 gag mRNA enhances their capacity to induce HIV gag-specific T cell responses. To this end, mature DCs were (i) co-electroporated with mRNA encoding interleukin (IL)-12p70 mRNA, or (ii) activated with a cytokine cocktail consisting of R848 and interferon (IFN)-γ. Our results confirm the ability of HxB2 gag-expressing DCs to expand functional HIV-specific CD8 + T cells. However, although most of the patients had detectable gag-specific CD8 + T cell responses, no significant differences in the level of expansion of functional CD8 + T cells could be demonstrated when comparing conventional or immune-modulated DCs expressing IL-12p70. This result which goes against expectation may lead to a re-evaluation of the need for IL-12 expression by DCs in order to improve T-cell responses in HIV-1-infected individuals.
Plasmacytoid dendritic cells (pDCs) sense viral and bacterial products through Toll-like receptor (TLR)-7 and -9 and translate this sensing in Interferon-α (IFN-α) production and T cell polarization. These cells are considered a link between innate and adaptive immunity, inducing and maintaining antigen-specific T cell responses and contributing to the control and eventually to the chronic immune activation and disease progression in HIV-1 infection scenario. The understanding of the mechanisms involved in pDCs stimulation may contribute to immunotherapeutic strategies aiming to decrease HIV-1 reservoir. The objective of the present study was to characterize the immunomodulatory effects of TLR agonist stimulations through a pDC/T cell coculture in different HIV-1 disease progression phenotypes and healthy donors (HD). pDCs were previously stimulated with AT-2-HIV-1, CpGA, CpGC and GS9620. After coculture with autologous CD4 or CD8 T cells we observed an increase of pDCs activation m...
Viral Immunology, 2017
Plasmacytoid dendritic cells (pDCs) play an important role in innate immune response against viruses, mainly through interferon-a (IFN-a) secretion. Impaired IFN-a secretion has been observed in patients with acute human immunodeficiency virus type 1 (HIV-1) infection and the reasons for this impairment are still obscure. To know the grounds behind this situation, HIV-1 viral copy numbers similar to those found in primary HIV-1 infection were used to stimulate peripheral blood mononuclear cells (PBMCs) and pDCs in this study. Intracellular IFN-a production was seen as early as 2 h in pDCs with TLR-7 agonist (imiquimod) stimulation, but HIV-1 required 48 h to induce secretion of IFN-a in supernatants and it was 10 times less compared to imiquimod. Thus, it shows that HIV-1 delays and impairs IFN-a production from pDCs. Furthermore, the IFN-a inhibitory activity of HIV-1 was checked by stimulating PBMCs and pDCs with imiquimod either simultaneously with HIV-1 or after 2 h pre-exposure to HIV-1. Pre-exposure to HIV-1 resulted in significant reduction in IFN-a secretion by pDCs and PBMCs when compared to imiquimod alone. In addition, simultaneous stimulation of these populations with HIV-1 and imiquimod resulted in significant impairment in IFN-a production in pDCs but not in PBMCs. HIV-1 not only fails to induce IFN-a in adequate quantities but also inhibits IFN-a secretary capacity of pDCs. HIV-1 particles were found to bind CD303 receptor on pDC surface probably blocking initiation of cascade leading to IFN-a impairment. The understanding of the pathways that lead to this suppression may help in devising the HIV control strategies.
2015
II Acknowledgements IV Table of contents V List of figures X List of abbreviation XIII Chapter 1: Introduction 1 Human immunodeficiency virus infection: 1 Transmission of HIV and Reverse transcription: 2 HIV structure and genome organization: 6 HIV-Tat and its function: 7 Role of HIV-Tat in HIV pathogenesis 8 HIV-Tat and immune dysfunction 10 Structure of HIV-Tat 11 HIV infection in Macrophages 16 HIV entry into macrophages 16 HIV infection and cytokines production: 17 IL-12 family of cytokines and their role in HIV infection 18 Interleukin-23 20 The role of IL-23 in HIV infection 22 Interleukin-27: 24 The role of IL-27 in HIV infection: 25 Toll-Like Receptor Signalling: 28