35 research outputs found
IRG and GBP host resistance factors target aberrant, ââNon-selfââ vacuoles characterized by the missing of ââSelfââ IRGM proteins
Interferon-inducible GTPases of the Immunity Related GTPase (IRG) and Guanylate Binding Protein (GBP) families provide resistance to intracellular pathogenic microbes. IRGs and GBPs stably associate with pathogen-containing vacuoles (PVs) and elicit immune pathways directed at the targeted vacuoles. Targeting of Interferon-inducible GTPases to PVs requires the formation of higher-order protein oligomers, a process negatively regulated by a subclass of IRG proteins called IRGMs. We found that the paralogous IRGM proteins Irgm1 and Irgm3 fail to robustly associate with âânon-selfââ PVs containing either the bacterial pathogen Chlamydia trachomatis or the protozoan pathogen Toxoplasma gondii. Instead, Irgm1 and Irgm3 reside on ââselfââ organelles including lipid droplets (LDs). Whereas IRGM-positive LDs are guarded against the stable association with other IRGs and GBPs, we demonstrate that IRGM-stripped LDs become high affinity binding substrates for IRG and GBP proteins. These data reveal that intracellular immune recognition of organelle-like structures by IRG and GBP proteins is partly dictated by the missing of ââselfââ IRGM proteins from these structures.Fil: Haldar, Arun K.. University Of Duke; Estados UnidosFil: Saka, Hector Alex. University Of Duke; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂmica ClĂnica e InmunologĂa; ArgentinaFil: Piro, Anthony S.. University Of Duke; Estados UnidosFil: Dunn, Joe Dan. University Of Duke; Estados UnidosFil: Henry, Stanley C.. University Of Duke; Estados Unidos. Veteran Affairs Medical Center; Estados UnidosFil: Taylor, Gregory A.. University Of Duke; Estados Unidos. Veteran Affairs Medical Center; Estados UnidosFil: Frickel, Eva M.. National Institute for Medical Research; Reino UnidoFil: Valdivia, Raphael H.. University Of Duke; Estados UnidosFil: Coers, Jörn. University Of Duke; Estados Unido
Recommended from our members
Detection of Cytosolic Shigella flexneri via a C-Terminal Triple-Arginine Motif of GBP1 Inhibits Actin-Based Motility
ABSTRACT Dynamin-like guanylate binding proteins (GBPs) are gamma interferon (IFN-Îł)-inducible host defense proteins that can associate with cytosol-invading bacterial pathogens. Mouse GBPs promote the lytic destruction of targeted bacteria in the host cell cytosol, but the antimicrobial function of human GBPs and the mechanism by which these proteins associate with cytosolic bacteria are poorly understood. Here, we demonstrate that human GBP1 is unique among the seven human GBP paralogs in its ability to associate with at least two cytosolic Gram-negative bacteria, Burkholderia thailandensis and Shigella flexneri. Rough lipopolysaccharide (LPS) mutants of S. flexneri colocalize with GBP1 less frequently than wild-type S. flexneri does, suggesting that host recognition of O antigen promotes GBP1 targeting to Gram-negative bacteria. The targeting of GBP1 to cytosolic bacteria, via a unique triple-arginine motif present in its C terminus, promotes the corecruitment of four additional GBP paralogs (GBP2, GBP3, GBP4, and GBP6). GBP1-decorated Shigella organisms replicate but fail to form actin tails, leading to their intracellular aggregation. Consequentially, the wild type but not the triple-arginine GBP1 mutant restricts S. flexneri cell-to-cell spread. Furthermore, human-adapted S. flexneri, through the action of one its secreted effectors, IpaH9.8, is more resistant to GBP1 targeting than the non-human-adapted bacillus B. thailandensis. These studies reveal that human GBP1 uniquely functions as an intracellular âglue trap,â inhibiting the cytosolic movement of normally actin-propelled Gram-negative bacteria. In response to this powerful human defense program, S. flexneri has evolved an effective counterdefense to restrict GBP1 recruitment
CSF1R inhibitor JNJ-40346527 attenuates microglial proliferation and neurodegeneration in P301S mice
Neuroinflammation and microglial activation are significant processes in Alzheimerâs disease pathology. Recent genome-wide association studies have highlighted multiple immune-related genes in association with Alzheimerâs disease, and experimental data have demonstrated microglial proliferation as a significant component of the neuropathology. In this study, we tested the efficacy of the selective CSF1R inhibitor JNJ-40346527 (JNJ-527) in the P301S mouse tauopathy model. We first demonstrated the anti-proliferative effects of JNJ-527 on microglia in the ME7 prion model, and its impact on the inflammatory profile, and provided potential CNS biomarkers for clinical investigation with the compound, including pharmacokinetic/pharmacodynamics and efficacy assessment by TSPO autoradiography and CSF proteomics. Then, we showed for the first time that blockade of microglial proliferation and modification of microglial phenotype leads to an attenuation of tau-induced neurodegeneration and results in functional improvement in P301S mice. Overall, this work strongly supports the potential for inhibition of CSF1R as a target for the treatment of Alzheimerâs disease and other tau-mediated neurodegenerative diseases
A systematic review of human coronaviruses survival on environmental surfaces
The current pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led people to implement preventive measures, including surface disinfection and use of alcohol-based hand gel, in order to avoid viral transmission via fomites. However, the role of surface transmission is still debated. The present systematic review aims to summarize all the evidence on surface survival of coronaviruses infecting humans. The analysis of 18 studies showed the longest coronavirus survival time is 28 days at room temperature (RT) on different surfaces: polymer banknotes, vinyl, steel, glass, and paper banknotes. Concerning SARS-CoV-2 human infection from contaminated surfaces, dangerous viral load on surfaces for up to 21 days was determined on polymer banknotes, steel, glass and paper banknotes. For viruses other than SARS-CoV-2, the longest period of survival was 14 days, recorded on glass. Environmental conditions can affect virus survival, and indeed, low temperatures and low humidity support prolonged survival of viruses on contaminated surfaces independently of surface type. Furthermore, it has been shown that exposure to sunlight significantly reduces the risk of surface transmission. Although studies are increasingly investigating the topic of coronavirus survival, it is difficult to compare them, given the methodology differences. For this reason, it is advisable to define a reference working protocol for virus survival trials, but, as an immediate measure, there is also a need for further investigations of coronavirus survival on surfaces
Clinical Markers of Need for Surgery in Orbital Complication of Acute Rhinosinusitis in Children: Overview and Systematic Review
Background: Although they can occur at all ages, orbital (OC) and periorbital cellulitis (POC) prevail in the pediatric population. Acute rhinosinusitis (ARS) is the most frequent predisposing factor of OC. Recent literature has suggested a medical management approach for OC and POC, with surgery reserved only for more severe cases. However, there is still a lack of consensus on the clinical markers of a need for surgery. The aim of this systematic review was to identify clinical markers of a need for surgery in children with OC. Our systematic review, in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) process, yielded 1289 articles finally screened. This resulted in 31 full texts that were included in a qualitative analysis. The results of this review suggest that in children aged over 9 years, large subperiosteal orbital abscesses (SPOAs), impaired vision, ophthalmoplegia, proptosis, elevated C-reactive protein (CRP) and absolute neutrophil counts (ANC), hemodynamic compromise, no clinical improvement after 48/72 h of antibiotic therapy, and a Chandler III score or higher are clinical markers of the need for surgery. However, most of the studies are observational and retrospective, and further studies are needed to identify reliable and repeatable clinical markers of the need for surgery
Clinical Markers of Need for Surgery in Orbital Complication of Acute Rhinosinusitis in Children: Overview and Systematic Review
Background: Although they can occur at all ages, orbital (OC) and periorbital cellulitis (POC) prevail in the pediatric population. Acute rhinosinusitis (ARS) is the most frequent predisposing factor of OC. Recent literature has suggested a medical management approach for OC and POC, with surgery reserved only for more severe cases. However, there is still a lack of consensus on the clinical markers of a need for surgery. The aim of this systematic review was to identify clinical markers of a need for surgery in children with OC. Our systematic review, in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) process, yielded 1289 articles finally screened. This resulted in 31 full texts that were included in a qualitative analysis. The results of this review suggest that in children aged over 9 years, large subperiosteal orbital abscesses (SPOAs), impaired vision, ophthalmoplegia, proptosis, elevated C-reactive protein (CRP) and absolute neutrophil counts (ANC), hemodynamic compromise, no clinical improvement after 48/72 h of antibiotic therapy, and a Chandler III score or higher are clinical markers of the need for surgery. However, most of the studies are observational and retrospective, and further studies are needed to identify reliable and repeatable clinical markers of the need for surgery
Prevalence of SARS-CoV-2 RNA on inanimate surfaces: a systematic review and meta-analysis
Coronavirus disease (COVID-19) is a respiratory disease affecting many people and able to be transmitted through direct and perhaps indirect contact. Direct contact transmission, mediated by aerosols or droplets, is widely demonstrated, whereas indirect transmission is only supported by collateral evidence such as virus persistence on inanimate surfaces and data from other similar viruses. The present systematic review aims to estimate SARS-CoV-2 prevalence on inanimate surfaces, identifying risk levels according to surface characteristics. Data were obtained from studies in published papers collected from two databases (PubMed and Embase) with the last search on 1 September 2020. Included studies had to be papers in English, had to deal with coronavirus and had to consider inanimate surfaces in real settings. Studies were coded according to our assessment of the risk that the investigated surfaces could be contaminated by SARS-CoV-2. A meta-analysis and a metaregression were carried out to quantify virus RNA prevalence and to identify important factors driving differences among studies. Thirty-nine out of forty retrieved paper reported studies carried out in healthcare settings on the prevalence of virus RNA, five studies carry out also analyses through cell culture and six tested the viability of isolated viruses. Overall prevalences of SARS-CoV-2 RNA on high-, medium- and low-risk surfaces were 0.22 (CI95 [0.152-0.296]), 0.04 (CI95 [0.007-0.090]), and 0.00 (CI95 [0.00-0.019]), respectively. The duration surfaces were exposed to virus sources (patients) was the main factor explaining differences in prevalence
A new way to enrich museum experience through X-ray tomography the diagnostic study of a wax anatomical model of the 18th century made by Anna Morandi Manzolini
The result of Computed Tomography (CT) investigation consists in a 3D volume of the object able to show its inner parts, revealing hidden structures
and materials used in a completely non-invasive way. Its application, in Cultural Heritage field, is an important resource to enhance the knowledge
of execution the construction technique and the state of conservation. This work was triggered by a need of diagnostic investigation before the restoration
of anatomical wax model of the 18th century made by Anna Morandi Manzolini, kept at the Palazzo Poggi Museum in Bologna, but the peculiarity
of the application and its results has yielded new purposes to the diagnostic investigation related to scientific communication and museum fruition. CT analysis
was carried out using an experimental CT system specifically designed for the analysis of Cultural Heritage materials, developed by the X-ray imaging research
group at the Physics and Astronomy Department of the University of Bologna. The results of the investigation were shown then at the Anatomical Wax Museum
"Luigi Cattaneo" in Bologna, during the "Festival of Medical Science. Long Life", from 7 to 10 May 2015, through a 3D virtual projection
A new way to enrich museum experience through X-ray tomography the diagnostic study of a wax anatomical model of the 18th century made by Anna Morandi Manzolini
The result of Computed Tomography (CT) investigation consists in a 3D volume of the object able to show its inner parts, revealing hidden structures
and materials used in a completely non-invasive way. Its application, in Cultural Heritage field, is an important resource to enhance the knowledge
of execution the construction technique and the state of conservation. This work was triggered by a need of diagnostic investigation before the restoration
of anatomical wax model of the 18th century made by Anna Morandi Manzolini, kept at the Palazzo Poggi Museum in Bologna, but the peculiarity
of the application and its results has yielded new purposes to the diagnostic investigation related to scientific communication and museum fruition. CT analysis
was carried out using an experimental CT system specifically designed for the analysis of Cultural Heritage materials, developed by the X-ray imaging research
group at the Physics and Astronomy Department of the University of Bologna. The results of the investigation were shown then at the Anatomical Wax Museum
"Luigi Cattaneo" in Bologna, during the "Festival of Medical Science. Long Life", from 7 to 10 May 2015, through a 3D virtual projection