scholarly journals The Novel Omega-6 Fatty Acid Docosapentaenoic Acid Positively Modulates Brain Innate Immune Response for Resolving Neuroinflammation at Early and Late Stages of Humanized APOE-Based Alzheimer's Disease Models

2020 ◽  
Vol 11 ◽  
Author(s):  
Qiu-Lan Ma ◽  
Cansheng Zhu ◽  
Marco Morselli ◽  
Trent Su ◽  
Matteo Pelligrini ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Immune Response ◽  
Fatty Acid ◽  
Innate Immune Response ◽  
Docosapentaenoic Acid ◽  
Innate Immune ◽  
Disease Models ◽  
The Novel ◽  
Omega 6 ◽  
Late Stages

scholarly journals Mammalian Orthoreovirus Factories Modulate Stress Granule Protein Localization by Interaction with G3BP1

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Promisree Choudhury ◽  
Luke D. Bussiere ◽  
Cathy L. Miller
Keyword(s):  
Immune Response ◽  
Virus Infection ◽  
Innate Immune Response ◽  
Nonstructural Protein ◽  
Innate Immune ◽  
Common Mechanism ◽  
Effector Protein ◽  
Associated Proteins ◽  
Mammalian Orthoreovirus ◽  
Late Stages

ABSTRACT Mammalian orthoreovirus (MRV) infection induces phosphorylation of translation initiation factor eIF2α, which promotes the formation of discrete cytoplasmic inclusions, termed stress granules (SGs). SGs are emerging as a component of the innate immune response to virus infection, and modulation of SG assembly is a common mechanism employed by viruses to counter this antiviral response. We previously showed that MRV infection induces SGs early and then interferes with SG formation as infection proceeds. In this work, we found that SG-associated proteins localized to the periphery of virus-encoded cytoplasmic structures, termed virus factories (VFs), where viral transcription, translation, and replication occur. The localization of SG proteins to VFs was dependent on polysome dissociation and occurred via association of the SG effector protein, Ras-GAP SH3-binding protein 1 (G3BP1), with the MRV nonstructural protein σNS, which localizes to VFs via association with VF nucleating protein, μNS. Deletion analysis of the σNS RNA binding domain and G3BP1 RNA (RRM) and ribosomal (RGG) binding domains showed that σNS association and VF localization phenotypes of G3BP1 do not occur solely through RNA or ribosomal binding but require both the RRM and RGG domains of G3BP1 for maximal viral-factory-like structure (VFL) localization and σNS association. Coexpression of σNS and μNS resulted in disruption of normal SG puncta, and in cells lacking G3BP1, MRV replication was enhanced in a manner correlating with strain-dependent induction of host translation shutoff. These results suggest that σNS association with G3BP1 and relocalization of G3BP1 to the VF periphery play roles in SG disruption to facilitate MRV replication in the host translational shutoff environment. IMPORTANCE SGs and SG effector proteins have emerged as important, yet poorly understood, players in the host's innate immune response to virus infection. MRV infection induces SGs early during infection that are dispersed and/or prevented from forming during late stages of infection despite continued activation of the eIF2α signaling pathway. Cellular and viral components involved in disruption of SGs during late stages of MRV infection remain to be elucidated. This work provides evidence that MRV disruption of SGs may be facilitated by association of the MRV nonstructural protein σNS with the major SG effector protein G3BP1 and subsequent localization of G3BP1 and other SG-associated proteins around the peripheries of virus-encoded factories, interrupting the normal formation of SGs. Our findings also reveal the importance of G3BP1 as an inhibitor of MRV replication during infection for the first time.

scholarly journals IL-33 ameliorates Alzheimer’s disease-like pathology and cognitive decline

2016 ◽  
Vol 113 (19) ◽  
pp. E2705-E2713 ◽  
Author(s):  
Amy K. Y. Fu ◽  
Kwok-Wang Hung ◽  
Michael Y. F. Yuen ◽  
Xiaopu Zhou ◽  
Deejay S. Y. Mak ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Immune Response ◽  
Innate Immune Response ◽  
Memory Loss ◽  
Neuronal Loss ◽  
Innate Immune ◽  
Therapeutic Role ◽  
Potential Therapeutic Role ◽  
The Brain

Alzheimer’s disease (AD) is a devastating condition with no known effective treatment. AD is characterized by memory loss as well as impaired locomotor ability, reasoning, and judgment. Emerging evidence suggests that the innate immune response plays a major role in the pathogenesis of AD. In AD, the accumulation of β-amyloid (Aβ) in the brain perturbs physiological functions of the brain, including synaptic and neuronal dysfunction, microglial activation, and neuronal loss. Serum levels of soluble ST2 (sST2), a decoy receptor for interleukin (IL)-33, increase in patients with mild cognitive impairment, suggesting that impaired IL-33/ST2 signaling may contribute to the pathogenesis of AD. Therefore, we investigated the potential therapeutic role of IL-33 in AD, using transgenic mouse models. Here we report that IL-33 administration reverses synaptic plasticity impairment and memory deficits in APP/PS1 mice. IL-33 administration reduces soluble Aβ levels and amyloid plaque deposition by promoting the recruitment and Aβ phagocytic activity of microglia; this is mediated by ST2/p38 signaling activation. Furthermore, IL-33 injection modulates the innate immune response by polarizing microglia/macrophages toward an antiinflammatory phenotype and reducing the expression of proinflammatory genes, including IL-1β, IL-6, and NLRP3, in the cortices of APP/PS1 mice. Collectively, our results demonstrate a potential therapeutic role for IL-33 in AD.

scholarly journals A newly established in vitro culture using transgenic Drosophila reveals functional coupling between the phospholipase A2-generated fatty acid cascade and lipopolysaccharide-dependent activation of the immune deficiency (imd) pathway in insect immunity

2003 ◽  
Vol 371 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Masashi YAJIMA ◽  
Masatoshi TAKADA ◽  
Nahoko TAKAHASHI ◽  
Haruhisa KIKUCHI ◽  
Shunji NATORI ◽  
...  
Keyword(s):  
Immune Deficiency ◽  
Immune Response ◽  
Innate Immunity ◽  
Arachidonic Acid ◽  
Fatty Acid ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Insect Immunity ◽  
Imd Pathway

Innate immunity is the first line of defence against infectious micro-organisms, and the basic mechanisms of pathogen recognition and response activation are evolutionarily conserved. In mammals, the innate immune response in combination with antigen-specific recognition is required for the activation of adaptive immunity. Therefore, innate immunity is a pharmaceutical target for the development of immune regulators. Here, for the purpose of pharmaceutical screening, we established an in vitro culture based on the innate immune response of Drosophila. The in vitro system is capable of measuring lipopolysaccharide (LPS)-dependent activation of the immune deficiency (imd) pathway, which is similar to the tumour necrosis factor signalling pathway in mammals. Screening revealed that well-known inhibitors of phospholipase A2 (PLA2), dexamethasone (Dex) and p-bromophenacyl bromide (BPB) inhibit LPS-dependent activation of the imd pathway. The inhibitory effects of Dex and BPB were suppressed by the addition of an excess of three (arachidonic acid, eicosapentaenoic acid and γ-linolenic acid) of the fatty acids so far tested. Arachidonic acid, however, did not activate the imd pathway when used as the sole agonist. These findings indicate that PLA2 participates in LPS-dependent activation of the imd pathway via the generation of arachidonic acid and other mediators, but requires additional signalling from LPS stimulation. Moreover, PLA2 was activated in response to bacterial infection in Sarcophaga. These results suggest a functional link between the PLA2-generated fatty acid cascade and the LPS-stimulated imd pathway in insect immunity.

scholarly journals SARS-CoV-2 infection and the antiviral innate immune response

2020 ◽  
Author(s):  
Hui Yang ◽  
Yingying Lyu ◽  
Fajian Hou
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Clinical Manifestations ◽  
Innate Immune ◽  
World Health ◽  
The Novel ◽  
Global Public Health ◽  
Replication Process ◽  
Novel Coronavirus ◽  
Health Organization

Abstract The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak began in December 2019, causing the illness known as the novel coronavirus disease 2019 (COVID-19). The virus spread rapidly worldwide to become a global public health emergency. As of 15 November 2020, more than 53 million confirmed cases and over one million deaths worldwide have been reported (World Health Organization, 2020). The SARS-CoV-2 genome was sequenced and studies are ongoing to further understand the epidemiology, clinical manifestations, etiological structure, cellular receptor angiotensin II converting enzyme (ACE2), and intracellular replication process of the virus. Currently, thousands of clinical trials related to SARS-CoV-2 are underway (https://clinicaltrials.gov/). However, no vaccines or drugs have yet been approved, until very recently, for direct treatment or prevention of COVID-19 and only supportive treatment has been applied clinically. This review will discuss the possible mechanism of the innate immune response to SARS-CoV-2 infection and provide insight into the development of related therapeutics.

scholarly journals iPSC-Derived Microglia for Modeling Human-Specific DAMP and PAMP Responses in the Context of Alzheimer’s Disease

2020 ◽  
Vol 21 (24) ◽  
pp. 9668
Author(s):  
Ivanna Ihnatovych ◽  
Barbara Birkaya ◽  
Emily Notari ◽  
Kinga Szigeti
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Immune Response ◽  
Inflammatory Response ◽  
Innate Immune Response ◽  
Fusion Gene ◽  
Innate Immune ◽  
Negative Regulator ◽  
Α7 Nachr ◽  
Human Specific

Neuroinflammation in Alzheimer’s disease (AD) has been the focus for identifying targetable pathways for drug development. The role of amyloid beta (Aβ), a prototype of damage-associated molecular patterns (DAMPs), has been implicated in triggering an inflammatory response. As alpha7 nicotinic acetylcholine receptor (α7 nAChR) binds Aβ with high affinity, α7 nAChR may play a role in Aβ-induced neuroinflammation. The conundrum of how α7 nAChR as the mediator of the cholinergic anti-inflammatory response may trigger an inflammatory response has not been resolved. CHRFAM7A, the uniquely human fusion gene between ULK4 and CHRNA7, is a negative regulator of α7 nAChR ionotropic function. To provide the human context, isogenic induced pluripotent stem cell (iPSC) lines were developed from CHRFAM7A null and carrier individuals by genome-editing the null line using TALENs to knock-in CHRFAM7A. In iPSC-derived microglia-like cells, CHRFAM7A mitigated Aβ uptake through the α7 nAChR. Despite the lower Aβ uptake, the presence of CHRFAM7A was associated with an innate immune response that was characterized by NF-κB activation and NF-κB target transcription (TNFA, IL6, and IL1B). LPS, a prototype PAMP, induced a heightened immune response in CHRFAM7A carriers. CHRFAM7A modified the dynamics of NF-κB translocation by prolonging its nuclear presence. CHRFAM7A modified the α7 nAChR metabotropic function, resulting in a human-specific innate immune response. This iPSC model provided an opportunity to elucidate the mechanism and establish high throughput screens.

scholarly journals Apolipoprotein E isoforms and regulation of the innate immune response in brain of patients with Alzheimer's disease

2011 ◽  
Vol 21 (6) ◽  
pp. 920-928 ◽  
Author(s):  
C Dirk Keene ◽  
Eiron Cudaback ◽  
Xianwu Li ◽  
Kathleen S Montine ◽  
Thomas J Montine
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Immune Response ◽  
Apolipoprotein E ◽  
Innate Immune Response ◽  
Innate Immune

scholarly journals Mammalian Orthoreovirus Factories Modulate Stress Granule Protein Localization by Interaction with G3BP1

2017 ◽  
Author(s):  
Promisree Choudhury ◽  
Luke Bussiere ◽  
Cathy L. Miller
Keyword(s):  
Immune Response ◽  
Virus Infection ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Effector Protein ◽  
Structural Protein ◽  
Binding Domains ◽  
Associated Proteins ◽  
Mammalian Orthoreovirus ◽  
Late Stages

ABSTRACTMammalian orthoreovirus (MRV) infection induces phosphorylation of translation initiation factor eIF2α which promotes formation of discrete cytoplasmic inclusions, termed stress granules (SGs). SGs are emerging as a component of the innate immune response to virus infection, and modulation of SG assembly is a common mechanism employed by viruses to counter this antiviral response. We previously showed that MRV infection induces SGs early, then interferes with SG formation as infection proceeds. In this work, we found that SG associated proteins localized to the periphery of virus-encoded cytoplasmic structures, termed virus factories (VFs), where viral transcription, translation, and replication occur. The localization of SG proteins to VFs was dependent on polysome dissociation and occurred via association of SG effector protein, G3BP1, with MRV non-structural protein σNS, which localizes to VFs via association with VF nucleating protein, μNS. Deletion analysis of the σNS RNA binding domain and G3BP1 RNA (RRM) and ribosomal (RGG) binding domains showed that the association and VF localization of G3BP1 is not occurring solely through RNA or ribosomal binding, but requires both RNA and ribosomal binding domains of G3BP1 for maximal VFL localization and σNS association. Co-expression of σNS and μNS resulted in disruption of normal SG puncta, and in cells lacking G3BP1, MRV replication was enhanced in a manner correlating with strain-dependent induction of host translation shutoff. These results suggest that σNS association with and relocalization of G3BP1 to the VF periphery plays a role in SG disruption to facilitate MRV replication in the host translational shutoff environment.IMPORTANCESGs and SG effector proteins have emerged as important, yet poorly understood, players in the host’s innate immune response to virus infection. MRV infection induces SGs early during infection that are dispersed and/or prevented from forming during late stages of infection despite continued activation of the eIF2α signaling pathway. Cellular and viral components involved in disruption of SGs during late stages of MRV infection remain to be elucidated. This work provides evidence that MRV disruption of SGs may be facilitated by association of MRV non-structural protein σNS with major SG effector protein G3BP1 and subsequent localization of G3BP1 and other SG associated proteins around the periphery of virus encoded factories, interrupting the normal formation of SGs. Our findings also reveal the importance of G3BP1 as an inhibitor of MRV replication during infection for the first time.

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