Soluble Factors Mediating Innate Immune Responses to HIV Infection

Soluble Factors Mediating Innate Immune Responses to HIV Infection PDF Author: Massimo Alfano
Publisher: Bentham Science Publishers
ISBN: 1608050068
Category : Medical
Languages : en
Pages : 168

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Book Description
"Human Immunodeficiency Virus (HIV) infection represents one of the biggest challenges of current years. However, scientists and physicians still do not have an efficient therapy for preventing or eradicating the virus. The selection of drug-resistant stra"

Soluble Factors Mediating Innate Immune Responses to HIV Infection

Soluble Factors Mediating Innate Immune Responses to HIV Infection PDF Author: Massimo Alfano
Publisher: Bentham Science Publishers
ISBN: 1608050068
Category : Medical
Languages : en
Pages : 168

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Book Description
"Human Immunodeficiency Virus (HIV) infection represents one of the biggest challenges of current years. However, scientists and physicians still do not have an efficient therapy for preventing or eradicating the virus. The selection of drug-resistant stra"

Molecular Biology of the Cell

Molecular Biology of the Cell PDF Author:
Publisher:
ISBN: 9780815332183
Category : Cells
Languages : en
Pages : 0

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Book Description


Effects of Complement Opsonization of HIV on Dendritic Cells

Effects of Complement Opsonization of HIV on Dendritic Cells PDF Author: Rada Ellegård
Publisher: Linköping University Electronic Press
ISBN: 9176852210
Category :
Languages : en
Pages : 65

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Book Description
Dendritic cells are key players during HIV pathogenesis, and shape both the immediate immune response at the site of infection as well as directing the adaptive immune response against the virus. HIV has developed a plethora of immune evasion mechanisms that hijack dendritic cell functions, suppressing their ability to mount an accurate immune response and exploiting them for efficient viral transfer to target T cells. To achieve successful replication within dendritic cells without triggering danger signaling, HIV accomplishes a delicate balance where only a low level of transcription can be sustained without triggering antiviral responses that would harm the virus. Here, we describe how the presence of HSV2 coinfection, which is very common in geographic areas with a high HIV prevalence and almost triples the risk of HIV acquisition, alters dendritic cell state to support much higher levels of HIV infection. We found this effect to be mediated by the STING pathway, which is involved in the sensing of DNA in the cell cytosol. STING activation led to an upregulation of factors such as IRF3 and NFkB that can be used for HIV transcription and a degradation of factors that restrict HIV replication. In addition, we describe how HIV exploits the human complement system, a group of proteins that usually help the human body to identify dangerous pathogens while avoiding reaction towards self. HIV can coat itself, i.e. become opsonized, in complement fragments that are typically only present on the body’s own cells, allowing it to activate signaling pathways that are associated with tolerance. Dendritic cells that come into contact with complement opsonized HIV do not mount danger responses, despite the fact that HIV-derived single stranded RNA triggers the pathogen recognition receptor TLR8. The suppression of danger responses is mediated by activation of complement receptor 3, and leads to an increased infection of the dendritic cell and affects its interactions with other immune cells. There is a lack of recruitment of NK cells to the site of infection, and an inhibition of NK cell killing, which plays an important role in the destruction of HIV-infected cells in vivo. T cells primed by dendritic cells exposed to complement opsonized HIV have a lower ability to develop towards effector phenotype, and have an increased expression of the markers PD1, TIM3 and LAG3 which are associated with T cell dysfunction and exhaustion. In addition, T cells primed by these dendritic cells in the presence of NK cells upregulate markers CD38, CXCR3 and CCR4, which have been linked to an increased susceptibility to HIV infection. In summary, we add to the current knowledge on HIV immune evasion mechanisms that allow the virus to establish infection, as well as describing mechanisms that govern whether dendritic cells mount danger signaling and an immune response or not.

HIV Interactions with Dendritic Cells

HIV Interactions with Dendritic Cells PDF Author: Li Wu
Publisher: Springer Science & Business Media
ISBN: 1461444330
Category : Medical
Languages : en
Pages : 303

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Book Description
Given rapid research progress and advance of the techniques in studying HIV interactions with host cells and factors, there is a critical need for a book on HIV interactions with DCs. The proposed book will aim for a broad readership to facilitate HIV/AIDS research and provide a practical tool for HIV researchers to continuously address novel questions. Specifically, the editors will summarize the literature in this field and provide critical analysis and future directions. International researchers will be invited as contributors of the book, highlighting authors who have contributed significantly to the field from different angles and aspects of virology, cell biology and immunology, etc.

Handbook on Immunosenescence

Handbook on Immunosenescence PDF Author: Tamas Fulop
Publisher: Springer Science & Business Media
ISBN: 1402090633
Category : Medical
Languages : en
Pages : 1693

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Book Description
This authoritative handbook covers all aspects of immunosenescence, with contributions from experts in the research and clinical areas. It examines methods and models for studying immunosenescence; genetics; mechanisms including receptors and signal transduction; clinical relevance in disease states including infections, autoimmunity, cancer, metabolic syndrome, neurodegenerative diseases, frailty and osteoporosis; and much more.

HIV-Host Interactions

HIV-Host Interactions PDF Author: Theresa Li-Yun Chang
Publisher: IntechOpen
ISBN: 9789533074429
Category : Medical
Languages : en
Pages : 378

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Book Description
HIV remains the major global health threat, and neither vaccine nor cure is available. Increasing our knowledge on HIV infection will help overcome the challenge of HIV/AIDS. This book covers several aspects of HIV-host interactions in vitro and in vivo. The first section covers the interaction between cellular components and HIV proteins, Integrase, Tat, and Nef. It also discusses the clinical relevance of HIV superinfection. The next two chapters focus on the role of innate immunity including dendritic cells and defensins in HIV infection followed by the section on the impact of host factors on HIV pathogenesis. The section of co-infection includes the impact of Human herpesvirus 6 and Trichomonas vaginalis on HIV infection. The final section focuses on generation of HIV molecular clones that can be used in macaques and the potential use of cotton rats for HIV studies.

HIV-1 Latency

HIV-1 Latency PDF Author: Guido Silvestri
Publisher: Springer
ISBN: 303002816X
Category : Medical
Languages : en
Pages : 253

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Book Description
This volume summarizes recent advances in understanding the mechanisms of HIV-1 latency, in characterizing residual viral reservoirs, and in developing targeted interventions to reduce HIV-1 persistence during antiretroviral therapy. Specific chapters address the molecular mechanisms that govern and regulate HIV-1 transcription and latency; assays and technical approaches to quantify viral reservoirs in humans and animal models; the complex interchange between viral reservoirs and the host immune system; computational strategies to model viral reservoir dynamics; and the development of therapeutic approaches that target viral reservoir cells. With contributions from an interdisciplinary group of investigators that cover a broad spectrum of subjects, from molecular virology to proof-of-principle clinical trials, this book is a valuable resource for basic scientists, translational investigators, infectious-disease physicians, individuals living with HIV/AIDS and the general public.

Encyclopedia of AIDS

Encyclopedia of AIDS PDF Author: Thomas J. Hope
Publisher:
ISBN: 9781461496106
Category : AIDS (Disease)
Languages : en
Pages :

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Book Description


Control of Innate Antiviral Immunity by HIV-1

Control of Innate Antiviral Immunity by HIV-1 PDF Author: Arjun Rustagi
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

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Book Description
Human immunodeficiency virus 1 (HIV-1) infection continues to be a major public health problem, with 34 million people infected worldwide. Cell-intrinsic innate immune defenses are essential for the control of HIV-1 infection but are subverted by the virus to establish successful infection. Interferon regulatory factor 3 (IRF3) is a central transcription factor of innate immune signaling that is activated by cellular pattern recognition receptors in response to the presence of non-self molecules (e.g. viral RNA or DNA). Activation of IRF3 induces the expression of antiviral and immunomodulatory genes whose products can suppress HIV-1 infection within target cells and regulate the adaptive immune response to infection. We have found that during acute infection HIV-1 evades innate antiviral immunity through the actions of HIV-1 viral protein u (Vpu), which interacts with IRF3 and inhibits its activity. While HIV infection eventually results in proteolytic destruction of IRF3 at later time points of acute infection, we found that inhibition of IRF3-dependent IFN-[Beta] transcription by Vpu occurs at early time points. In addition, Vpu blocked both IRF3- and NF[kappa]B-dependent activities at the IFN-[Beta] promoter. These findings led us to hypothesize that Vpu blocks IRF3 activation to prevent IRF3 from carrying out the necessary biochemical steps to drive antiviral gene expression. We investigated the process of Vpu regulation of IRF3, and found that IRF3 and Vpu form a stable complex during infection of CD4+ T cells with HIV-1. Using truncation and deletion mutants of recombinant IRF3, we mapped the binding epitope for Vpu on IRF3 to a region of IRF3 protein called the IRF association domain. This domain is the site necessary for homodimerization of IRF3 molecules after activation and interaction with transcriptional cofactors. Thus, we hypothesized that Vpu alters IRF3 dimerization and cofactor interaction. Indeed, when we examined the IRF3 activation pathway in the presence of Vpu to identify the site of the Vpu-induced block in IRF3 activity, we found that Vpu inhibited IRF3 dimerization and CBP binding. We predict that Vpu antagonism of IRF3-directed innate immunity is a key step in HIV-1 pathogenesis during acute infection. Further, IRF3 depletion and control of innate antiviral immunity by HIV-1 may correlate with disease progression in HIV-infected patients. To test these predictions, we have developed two novel monoclonal antibodies to human IRF3 to support the study of IRF3 activation and HIV-mediated IRF3 depletion among patient samples in a high-throughput manner. One of these antibodies, AR-1, is specific for activated IRF3. The other, AR-2, detects total IRF3 levels in a flow cytometric assay of blood leukocytes. Use of these new antibodies to study IRF-3 levels during HIV infection could reveal an innate immune correlate of HIV-1 disease progression, while studies to fully define the interaction between Vpu and IRF3 may reveal novel targets for the development of drugs that preserve IRF3 activity during HIV-1 infection.

Human Cytomegalovirus

Human Cytomegalovirus PDF Author: Thomas E. Shenk
Publisher: Springer Science & Business Media
ISBN: 3540773495
Category : Medical
Languages : en
Pages : 477

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Book Description
This volume has gathered some of the experts in the field to review aspects of our understanding of CMV and to offer perspectives of the current problems associated with CMV. The editors and authors hope that the chapters will lead to a better understanding of the virus that will assist in the development of new and unique antivirals, a protective vaccine, and a full understanding of CMV's involvement in human disease.