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Charles TP, Shellito JE. Human Immunodeficiency Virus Infection and Host Defense in the Lungs. Semin Respir Crit Care Med 2016; 37:147-56. [PMID: 26974294 DOI: 10.1055/s-0036-1572553] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Immunosuppression associated with human immunodeficiency virus (HIV) infection impacts all components of host defense against pulmonary infection. Cells within the lung have altered immune function and are important reservoirs for HIV infection. The host immune response to infected lung cells further compromises responses to a secondary pathogenic insult. In the upper respiratory tract, mucociliary function is impaired and there are decreased levels of salivary immunoglobulin A. Host defenses in the lower respiratory tract are controlled by alveolar macrophages, lymphocytes, and polymorphonuclear leukocytes. As HIV infection progresses, lung CD4 T cells are reduced in number causing a lack of activation signals from CD4 T cells and impaired defense by macrophages. CD8 T cells, on the other hand, are increased in number and cause lymphocytic alveolitis. Specific antibody responses by B-lymphocytes are decreased and opsonization of microorganisms is impaired. These observed defects in host defense of the respiratory tract explain the susceptibility of HIV-infected persons for oropharyngeal candidiasis, bacterial pneumonia, Pneumocystis pneumonia, and other opportunistic infections.
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Affiliation(s)
- Tysheena P Charles
- Section of Pulmonary/Critical Care & Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Judd E Shellito
- Section of Pulmonary/Critical Care & Allergy/Immunology, Department of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
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Glass JJ, Kent SJ, De Rose R. Enhancing dendritic cell activation and HIV vaccine effectiveness through nanoparticle vaccination. Expert Rev Vaccines 2016; 15:719-29. [PMID: 26783186 DOI: 10.1586/14760584.2016.1141054] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Novel vaccination approaches are needed to prevent and control human immunodeficiency virus (HIV) infection. A growing body of literature demonstrates the potential of nanotechnology to modulate the human immune system and generate targeted, controlled immune responses. In this Review, we summarize important advances in how 'nanovaccinology' can be used to develop safe and effective vaccines for HIV. We highlight the central role of dendritic cells in the immune response to vaccination and describe how nanotechnology can be used to enhance delivery to and activation of these important antigen-presenting cells. Strategies employed to improve biodistribution are discussed, including improved lymph node delivery and mucosal penetration concepts, before detailing methods to enhance the humoral and/or cellular immune response to vaccines. We conclude with a commentary on the current state of nanovaccinology.
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Affiliation(s)
- Joshua J Glass
- a ARC Centre of Excellence in Convergent Bio-Nano Science and Technology , The University of Melbourne , Melbourne , Australia.,b Department of Microbiology and Immunology , Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne , Australia
| | - Stephen J Kent
- a ARC Centre of Excellence in Convergent Bio-Nano Science and Technology , The University of Melbourne , Melbourne , Australia.,b Department of Microbiology and Immunology , Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne , Australia.,c Melbourne Sexual Health Centre and Department of Infectious Diseases , Alfred Health, Central Clinical School, Monash University , Melbourne , Australia
| | - Robert De Rose
- a ARC Centre of Excellence in Convergent Bio-Nano Science and Technology , The University of Melbourne , Melbourne , Australia.,b Department of Microbiology and Immunology , Peter Doherty Institute for Infection and Immunity, The University of Melbourne , Melbourne , Australia
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Abstract
Plasmacytoid dendritic cells (pDCs) are a unique DC subset that specializes in the production of type I interferons (IFNs). pDCs promote antiviral immune responses and have been implicated in the pathogenesis of autoimmune diseases that are characterized by a type I IFN signature. However, pDCs can also induce tolerogenic immune responses. In this Review, we summarize recent progress in the field of pDC biology, focusing on the molecular mechanisms that regulate the development and functions of pDCs, the pathways involved in their sensing of pathogens and endogenous nucleic acids, their functions at mucosal sites, and their roles in infection, autoimmunity and cancer.
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Masotti A, Donninelli G, Da Sacco L, Varano B, Del Cornò M, Gessani S. HIV-1 gp120 influences the expression of microRNAs in human monocyte-derived dendritic cells via STAT3 activation. BMC Genomics 2015; 16:480. [PMID: 26116514 PMCID: PMC4483217 DOI: 10.1186/s12864-015-1673-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/29/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND MicroRNAs (miRs) are an abundant class of small non-coding RNAs (~22 nt) that reprogram gene expression by targeting mRNA degradation and translational disruption. An emerging concept implicates miR coupling with transcription factors in myeloid cell development and function, thus contributing to host defense and inflammation. The important role that these molecules play in the pathogenesis of HIV-1 is only now emerging. RESULTS We provide evidence that exposure of monocyte-derived dendritic cells (MDDCs) to recombinant HIV-1 R5 gp120, but not to CCR5 natural ligand CCL4, influences the expression of a panel of miRs (i.e., miR-21, miR-155 and miR-181b) regulated by STAT3 and potentially targeting genes belonging to the STAT3 signaling pathway. The blockage of gp120-induced STAT3 activation impairs gp120 capacity to modulate the expression level of above mentioned miRs. Predictive analysis of miR putative targets emphasizes that these miRs share common target genes. Furthermore, gene ontology and pathway enrichment analysis outline that these genes mainly belong to biological processes related to regulation of transcription, in a complex network of interactions involving pathways relevant to HIV-DC interaction. CONCLUSIONS Overall, these results point to gp120-triggered modulation of miR expression via STAT3 activation as a novel molecular mechanism exploited by HIV-1 to affect DC biology and thus modulate the immune response through complex regulatory loops involving, at the same time, miRs and transcription factors.
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Affiliation(s)
- Andrea Masotti
- Bambino Gesù Children's Hospital-IRCCS, Viale di San Paolo 15, 00146, Rome, Italy.
| | - Gloria Donninelli
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
| | - Letizia Da Sacco
- Bambino Gesù Children's Hospital-IRCCS, Viale di San Paolo 15, 00146, Rome, Italy.
| | - Barbara Varano
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
| | - Manuela Del Cornò
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
| | - Sandra Gessani
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy.
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de Repentigny L, Goupil M, Jolicoeur P. Oropharyngeal Candidiasis in HIV Infection: Analysis of Impaired Mucosal Immune Response to Candida albicans in Mice Expressing the HIV-1 Transgene. Pathogens 2015; 4:406-21. [PMID: 26110288 PMCID: PMC4493482 DOI: 10.3390/pathogens4020406] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 06/13/2015] [Accepted: 06/16/2015] [Indexed: 01/07/2023] Open
Abstract
IL-17-producing Th17 cells are of critical importance in host defense against oropharyngeal candidiasis (OPC). Speculation about defective Th17 responses to oral C. albicans infection in the context of HIV infection prompted an investigation of innate and adaptive immune responses to Candida albicans in transgenic mice expressing the genome of HIV-1 in immune cells and displaying an AIDS-like disease. Defective IL-17 and IL-22-dependent mucosal responses to C. albicans were found to determine susceptibility to OPC in these transgenic mice. Innate phagocytes were quantitatively and functionally intact, and individually dispensable for control of OPC and to prevent systemic dissemination of Candida to deep organs. CD8+ T-cells recruited to the oral mucosa of the transgenic mice limited the proliferation of C. albicans in these conditions of CD4+ T-cell deficiency. Therefore, the immunopathogenesis of OPC in the context of HIV infection involves defective T-cell-mediated immunity, failure of crosstalk with innate mucosal immune effector mechanisms, and compensatory cell responses, which limit Candida infection to the oral mucosa and prevent systemic dissemination.
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Affiliation(s)
- Louis de Repentigny
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, University of Montreal, C.P. 6128, succursale Centre-Ville, Montreal, PQ H3C 3J7, Canada.
| | - Mathieu Goupil
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, University of Montreal, C.P. 6128, succursale Centre-Ville, Montreal, PQ H3C 3J7, Canada.
| | - Paul Jolicoeur
- Laboratory of Molecular Biology, Clinical Research Institute of Montreal, 110, avenue des Pins Ouest, Montreal, PQ H2W 1R7, Canada.
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Coccia EM, Battistini A. Early IFN type I response: Learning from microbial evasion strategies. Semin Immunol 2015; 27:85-101. [PMID: 25869307 PMCID: PMC7129383 DOI: 10.1016/j.smim.2015.03.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/10/2015] [Indexed: 12/12/2022]
Abstract
Type I interferon (IFN) comprises a class of cytokines first discovered more than 50 years ago and initially characterized for their ability to interfere with viral replication and restrict locally viral propagation. As such, their induction downstream of germ-line encoded pattern recognition receptors (PRRs) upon recognition of pathogen-associated molecular patterns (PAMPs) is a hallmark of the host antiviral response. The acknowledgment that several PAMPs, not just of viral origin, may induce IFN, pinpoints at these molecules as a first line of host defense against a number of invading pathogens. Acting in both autocrine and paracrine manner, IFN interferes with viral replication by inducing hundreds of different IFN-stimulated genes with both direct anti-pathogenic as well as immunomodulatory activities, therefore functioning as a bridge between innate and adaptive immunity. On the other hand an inverse interference to escape the IFN system is largely exploited by pathogens through a number of tactics and tricks aimed at evading, inhibiting or manipulating the IFN pathway, that result in progression of infection or establishment of chronic disease. In this review we discuss the interplay between the IFN system and some selected clinically important and challenging viruses and bacteria, highlighting the wide array of pathogen-triggered molecular mechanisms involved in evasion strategies.
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Affiliation(s)
- Eliana M Coccia
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy
| | - Angela Battistini
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy.
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Abstract
PURPOSE OF REVIEW The purpose of this study is to describe the alterations that HIV-1 induces in antigen-presenting cells (APCs), in vitro, ex vivo and in vivo. RECENT FINDINGS HIV-1 disarms several arms of the immune system including APCs. We summarize here recent findings on the impact of the virus on APC. SUMMARY HIV-1 can invade APC and overall reduce their capacity to present antigens effectively, mostly by reducing their numbers and inducing permanent hyperactivation. This occurs via a combination of alterations; however, the host can counteract, at least in part, some of these defects via restriction factors, autophagy, the production of type I interferon, antiviral cytokines, among others. However, these specific mechanisms of viral evasion from APCs' control lead to a chronic hyperactivation of the immune system implicated in AIDS-related and non-AIDS related pathogenesis. Unfortunately, the current regimens of antiretroviral therapy are unable to dampen sufficiently APC-driven viral-induced immune hyperactivation. Understanding how HIV alters APC will help to tune appropriately both intrinsic immunity and innate immunity, as well as achieve efficient antigen presentation to the adaptive immune system, without inducing a detrimental pervasive hyperactivation of the immune system.
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Bruchfeld J, Correia-Neves M, Källenius G. Tuberculosis and HIV Coinfection. Cold Spring Harb Perspect Med 2015; 5:a017871. [PMID: 25722472 DOI: 10.1101/cshperspect.a017871] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Tuberculosis (TB) and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) constitute the main burden of infectious disease in resource-limited countries. In the individual host, the two pathogens, Mycobacterium tuberculosis and HIV, potentiate one another, accelerating the deterioration of immunological functions. In high-burden settings, HIV coinfection is the most important risk factor for developing active TB, which increases the susceptibility to primary infection or reinfection and also the risk of TB reactivation for patients with latent TB. M. tuberculosis infection also has a negative impact on the immune response to HIV, accelerating the progression from HIV infection to AIDS. The clinical management of HIV-associated TB includes the integration of effective anti-TB treatment, use of concurrent antiretroviral therapy (ART), prevention of HIV-related comorbidities, management of drug cytotoxicity, and prevention/treatment of immune reconstitution inflammatory syndrome (IRIS).
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Affiliation(s)
- Judith Bruchfeld
- Unit of Infectious Diseases, Institution of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm SE-171 77, Sweden
| | - Margarida Correia-Neves
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga 4710-057, Portugal ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Gunilla Källenius
- Karolinska Institutet, Department of Clinical Science and Education, Stockholm SE-118 83, Sweden
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60
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Costiniuk CT, Jenabian MA. HIV reservoir dynamics in the face of highly active antiretroviral therapy. AIDS Patient Care STDS 2015; 29:55-68. [PMID: 25412339 DOI: 10.1089/apc.2014.0173] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Upon discontinuation of highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV)-infected individuals experience a brisk rebound in blood plasma viremia due to the exodus of HIV from various body reservoirs. Assessment of HIV dynamics during HAART and following treatment discontinuation is essential to better understand HIV persistence. Here we will first provide a brief overview of the molecular mechanisms involved in HIV reservoir formation and persistence. After a summary of HAART-mediated HIV decay within peripheral blood, we discuss findings from clinical studies examining the effects of HAART initiation and interruption on HIV reservoir dynamics in major anatomical compartments, including lymph nodes and spleen, gut associated lymphoid tissue, reproductive organs, the central nervous system, and the lungs. Features contributing to these reservoirs as distinct compartments, including anatomical features, the presence of drug transporters, and the effect of co-infection, are also discussed.
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Affiliation(s)
- Cecilia T. Costiniuk
- Department of Medicine, Divisions of Infectious Diseases/Chronic Viral Illness Service and Lachine Hospital, McGill University Health Centre, Montreal, Quebec, Canada
| | - Mohammad-Ali Jenabian
- Département des Sciences Biologiques et Centre de recherche BioMed, Université du Québec à Montréal (UQAM), Montreal, Quebec, Canada
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61
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Percario ZA, Ali M, Mangino G, Affabris E. Nef, the shuttling molecular adaptor of HIV, influences the cytokine network. Cytokine Growth Factor Rev 2014; 26:159-73. [PMID: 25529283 DOI: 10.1016/j.cytogfr.2014.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 11/05/2014] [Indexed: 12/17/2022]
Abstract
Several viruses manipulate host innate immune responses to avoid immune recognition and improve viral replication and spreading. The viral protein Nef of Human Immunodeficiency Virus is mainly involved in this "hijacking" activity and is a well established virulence factor. In the last few years there have been remarkable advances in outlining a defined framework of its functions. In particular Nef appears to be a shuttling molecular adaptor able to exert its effects both on infected and non infected bystander cell. In addition it is emerging fact that it has an important impact on the chemo-cytokine network. Nef protein represents an interesting new target to develop therapeutic drugs for treatment of seropositive patients. In this review we have tried to provide a unifying view of the multiple functions of this viral protein on the basis of recently available experimental data.
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Affiliation(s)
| | - Muhammad Ali
- Department of Sciences, University Roma Tre, Rome, Italy
| | - Giorgio Mangino
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Italy
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62
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The role of human dendritic cells in HIV-1 infection. J Invest Dermatol 2014; 135:1225-1233. [PMID: 25407434 DOI: 10.1038/jid.2014.490] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 08/25/2014] [Accepted: 09/27/2014] [Indexed: 12/24/2022]
Abstract
Dendritic cells (DCs) and their subsets have multifaceted roles in the early stages of HIV-1 transmission and infection. DC studies have led to remarkable discoveries, including identification of restriction factors, cellular structures promoting viral transmission including the infectious synapse or the interplay of the C-type lectins, Langerin on Langerhans cells (LCs), and dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin on other DC subsets, limiting or facilitating HIV transmission to CD4(+) T cells, respectively. LCs/DCs are also exposed to encountering HIV-1 and other sexually transmitted infections (herpes simplex virus-2, bacteria, fungi), which reprogram HIV-1 interaction with these cells. This review will summarize advances in the role of DCs during HIV-1 infection and discuss their potential involvement in the development of preventive strategies against HIV-1 and other sexually transmitted infections.
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63
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Dinkins C, Pilli M, Kehrl JH. Roles of autophagy in HIV infection. Immunol Cell Biol 2014; 93:11-7. [PMID: 25385065 DOI: 10.1038/icb.2014.88] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 08/28/2014] [Accepted: 08/29/2014] [Indexed: 02/07/2023]
Abstract
Autophagy is a major cellular pathway, which at basal levels regulates and maintains the cytoplasmic environment through the capture, isolation and digestion of intracellular materials in a specialized structure called an autophagosome. The unique ability of autophagy to degrade large targets, such as damaged and surplus organelles, intracellular microbes and protein aggregates, has made it a prime focus in inflammation and microbial research. Indeed, autophagy has been shown to be involved in a number of infectious and inflammatory pathologies, by which it may confer protection against intracellular microbes, be targeted by microbes for evasion or be hijacked for microbe biogenesis. In addition, autophagy helps regulate the intracellular and global immune response to both extracellular and intracellular pathogens. Here we review the current literature on the interactions between autophagy and HIV among different immune cells and discuss new research that re-emphasizes the role of inflammation in HIV-mediated CD4(+) T cell death.
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Affiliation(s)
- Christina Dinkins
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Manohar Pilli
- Center for Advanced Sensor Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - John H Kehrl
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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Acchioni C, Marsili G, Perrotti E, Remoli AL, Sgarbanti M, Battistini A. Type I IFN--a blunt spear in fighting HIV-1 infection. Cytokine Growth Factor Rev 2014; 26:143-58. [PMID: 25466629 DOI: 10.1016/j.cytogfr.2014.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 10/22/2014] [Indexed: 02/07/2023]
Abstract
For more than 50 years, Type I Interferon (IFN) has been recognized as critical in controlling viral infections. IFN is produced downstream germ-line encoded pattern recognition receptors (PRRs) upon engagement by pathogen-associated molecular patterns (PAMPs). As a result, hundreds of different interferon-stimulated genes (ISGs) are rapidly induced, acting in both autocrine and paracrine manner to build a barrier against viral replication and spread. ISGs encode proteins with direct antiviral and immunomodulatory activities affecting both innate and adaptive immune responses. During infection with viruses, as HIV-1, that can establish a persistent infection, IFN although produced, is not able to block the initial infection and a chronic IFN-mediated immune activation/inflammation becomes a pathogenic mechanism of disease progression. This review will briefly summarize when and how IFN is produced during HIV-1 infection and the way this innate immune response is manipulated by the virus to its own advantage to drive chronic immune activation and progression to AIDS.
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Affiliation(s)
- Chiara Acchioni
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy
| | - Giulia Marsili
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy
| | - Edvige Perrotti
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy
| | - Anna Lisa Remoli
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy
| | - Marco Sgarbanti
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy
| | - Angela Battistini
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome 00161, Italy.
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HIV infection of monocytes-derived dendritic cells inhibits Vγ9Vδ2 T cells functions. PLoS One 2014; 9:e111095. [PMID: 25340508 PMCID: PMC4207784 DOI: 10.1371/journal.pone.0111095] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/26/2014] [Indexed: 12/05/2022] Open
Abstract
DCs act as sentinel cells against incoming pathogens and represent the most potent antigen presenting cells, having the unique capability to prime naïve T cells. In addition to their role in induction of adaptive immune responses, DC are also able to activate innate cells as γδ T cells; in particular, a reciprocal crosstalk between DC and γδ T cells was demonstrated. However, whether HIV infection may alter DC-Vγ9Vδ2 T cells cross-talk was not yet described. To clarify this issue, we cultured activated Vγ9Vδ2 T cells with HIV infected monocyte derived DC (MoDC). After 5 days we evaluated MoDC phenotype, and Vγ9Vδ2 T cells activation and proliferation. In our model, Vγ9Vδ2 T cells were not able to proliferate in response to HIV-infected MoDC, although an up-regulation of CD69 was observed. Upon phosphoantigens stimulation, Vγ9Vδ2 T cells proliferation and cytokine production were inhibited when cultured with HIV-infected MoDC in a cell-contact dependent way. Moreover, HIV-infected MoDC are not able to up-regulate CD86 molecules when cultured with activated Vγ9Vδ2 T cells, compared with uninfected MoDC. Further, activated Vγ9Vδ2 T cells are not able to induce HLA DR up-regulation and CCR5 down-regulation on HIV-infected MoDC. These data indicate that HIV-infected DC alter the capacity of Vγ9Vδ2 T cells to respond to their antigens, pointing out a new mechanisms of induction of Vγ9Vδ2 T cells anergy carried out by HIV, that could contribute to immune evasion.
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HIV-1 gp120 activates the STAT3/interleukin-6 axis in primary human monocyte-derived dendritic cells. J Virol 2014; 88:11045-55. [PMID: 25008924 DOI: 10.1128/jvi.00307-14] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Dendritic cells (DCs) are fundamental for the initiation of immune responses and are important players in AIDS immunopathogenesis. The modulation of DC functional activities represents a strategic mechanism for HIV-1 to evade immune surveillance. Impairment of DC function may result from bystander effects of HIV-1 envelope proteins independently of direct HIV-1 infection. In this study, we report that exposure of immature monocyte-derived DCs (MDDCs) to HIV-1 R5 gp120 resulted in the CCR5-dependent production of interleukin-6 (IL-6) via mitogen-activated protein kinase (MAPK)/NF-κB pathways. IL-6 in turn activated STAT3 by an autocrine loop. Concomitantly, gp120 promoted an early activation of STAT3 that further contributed to IL-6 induction. This activation paralleled a concomitant upregulation of the STAT3 inhibitor PIAS3. Notably, STAT3/IL-6 pathway activation was not affected by the CCR5-specific ligand CCL4. These results identify STAT3 as a key signaling intermediate activated by gp120 in MDDCs and highlight the existence of a virus-induced dysregulation of the IL-6/STAT3 axis. HIV-1 gp120 signaling through STAT3 may provide an explanation for the impairment of DC function observed upon HIV exposure. IMPORTANCE This study provides new evidence for the molecular mechanisms and signaling pathways triggered by HIV-1 gp120 in human DCs in the absence of productive infection, emphasizing a role of aberrant signaling in early virus-host interaction, contributing to viral pathogenesis. We identified STAT3 as a key component in the gp120-mediated signaling cascade involving MAPK and NF-κB components and ultimately leading to IL-6 secretion. STAT3 now is recognized as a key regulator of DC functions. Thus, the identification of this transcription factor as a signaling molecule mediating some of gp120's biological effects unveils a new mechanism by which HIV-1 may deregulate DC functions and contribute to AIDS pathogenesis.
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Hasan M, Yan N. Safeguard against DNA sensing: the role of TREX1 in HIV-1 infection and autoimmune diseases. Front Microbiol 2014; 5:193. [PMID: 24817865 PMCID: PMC4012220 DOI: 10.3389/fmicb.2014.00193] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/11/2014] [Indexed: 12/14/2022] Open
Abstract
Innate immune recognition is crucial for host responses against viral infections, including infection by human immunodeficiency virus 1 (HIV-1). Human cells detect such invading pathogens with a collection of pattern recognition receptors that activate the production of antiviral proteins, such as the cytokine interferon-type I, to initiate antiviral responses immediately as well as the adaptive immune response for long-term protection. To establish infection in the host, many viruses have thus evolved strategies for subversion of these mechanisms of innate immunity. For example, acute infection by HIV-1 and other retroviruses have long been thought to be non-immunogenic, signifying suppression of host defenses by these pathogens. Studies in the past few years have begun to uncover a multifaceted scheme of how HIV-1 evades innate immune detection, especially of its DNA, by exploiting host proteins. This review will discuss the host mechanisms of HIV-1 DNA sensing and viral immune evasion, with a particular focus on TREX1, three prime repair exonuclease 1, a host 3′ exonuclease (also known as DNase III).
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Affiliation(s)
- Maroof Hasan
- Department of Internal Medicine, University of Texas Southwestern Medical Center Dallas, TX, USA ; DDepartment of Microbiology, University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Nan Yan
- Department of Internal Medicine, University of Texas Southwestern Medical Center Dallas, TX, USA ; DDepartment of Microbiology, University of Texas Southwestern Medical Center Dallas, TX, USA
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