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1.
Int J Mol Sci ; 25(13)2024 Jun 29.
Article in English | MEDLINE | ID: mdl-39000316

ABSTRACT

We aimed to produce a mouse model of spinocerebellar ataxia type 3 (SCA3) using the mouse blood-brain barrier (BBB)-penetrating adeno-associated virus (AAV)-PHP.B. Four-to-five-week-old C57BL/6 mice received injections of high-dose (2.0 × 1011 vg/mouse) or low-dose (5.0 × 1010 vg/mouse) AAV-PHP.B encoding a SCA3 causative gene containing abnormally long 89 CAG repeats [ATXN3(Q89)] under the control of the ubiquitous chicken ß-actin hybrid (CBh) promoter. Control mice received high doses of AAV-PHP.B encoding ATXN3 with non-pathogenic 15 CAG repeats [ATXN3(Q15)] or phosphate-buffered saline (PBS) alone. More than half of the mice injected with high doses of AAV-PHP.B encoding ATXN3(Q89) died within 4 weeks after the injection. No mice in other groups died during the 12-week observation period. Mice injected with low doses of AAV-PHP.B encoding ATXN3(Q89) exhibited progressive motor uncoordination starting 4 weeks and a shorter stride in footprint analysis performed at 12 weeks post-AAV injection. Immunohistochemistry showed thinning of the molecular layer and the formation of nuclear inclusions in Purkinje cells from mice injected with low doses of AAV-PHP.B encoding ATXN3(Q89). Moreover, ATXN3(Q89) expression significantly reduced the number of large projection neurons in the cerebellar nuclei to one third of that observed in mice expressing ATXN3(Q15). This AAV-based approach is superior to conventional methods in that the required number of model mice can be created simply by injecting AAV, and the expression levels of the responsible gene can be adjusted by changing the amount of AAV injected. Moreover, this method may be applied to produce SCA3 models in non-human primates.


Subject(s)
Ataxin-3 , Dependovirus , Disease Models, Animal , Genetic Vectors , Machado-Joseph Disease , Mice, Inbred C57BL , Animals , Dependovirus/genetics , Machado-Joseph Disease/genetics , Machado-Joseph Disease/therapy , Machado-Joseph Disease/metabolism , Machado-Joseph Disease/pathology , Mice , Genetic Vectors/administration & dosage , Genetic Vectors/genetics , Ataxin-3/genetics , Ataxin-3/metabolism , Injections, Intravenous , Blood-Brain Barrier/metabolism , Promoter Regions, Genetic
2.
Article in English | MEDLINE | ID: mdl-38863240

ABSTRACT

The initial assumption that viewed inclusion bodies as a hindrance to the efficient production of protein is no longer held due to the emergence of catalytically active inclusion bodies (CatIBs). Recent studies revealed their potential to be used in free form or immobilized as biocatalysts. The curiosity to acquire suitable catalysts has remained the measure of concern for researchers and industrialists. Numerous processes and production in various sectors of food industries, petroleum, pharmaceutical, cosmetics, and many others are still searching for a robust catalyst with outstanding features such as recyclability, resistance to pH, as well as temperature. CatIBs are forms of inclusion bodies that possess catalytic activity, which can improve catalysis efficiency, stability, and recyclability. One of the advantages of CatIBs is their potential to be used as catalysts for numerous bioprocesses when generated by an enzyme. These aggregates can efficiently be used as a replacement for traditional enzyme immobilization. This review tends to focus on the possibility of its application in various processes. The novelty of this review is that it considered the production of CatIBs both from artificial and natural perspectives, as well as how to improve it. Inclusion bodies' immobilization may provide an efficient alternative in the area of biocatalysis, and hence it will improve industrial sectors and substantially provide a means of achieving excellent performance in the near future.

3.
Prep Biochem Biotechnol ; : 1-13, 2024 Jun 02.
Article in English | MEDLINE | ID: mdl-38824503

ABSTRACT

Interleukin-2 has emerged as a potent protein-based drug to treat various cancers, AIDS, and autoimmune diseases. Despite its immense requirement, the production procedures are inefficient to meet the demand. Therefore, efficient production procedures must be adopted to improve protein yield and decrease procedural loss. This study analyzed cytoplasmic and periplasmic IL-2 expression for increased protein yield and significant biological activity. The study is focused on cloning IL-2 into a pET-SUMO and pET-28a vector that expresses IL-2 in soluble form and inclusion bodies, respectively. Both constructs were expressed into different E. coli expression strains, but the periplasmic and cytoplasmic expression of IL-2 was highest in overnight culture in Rosetta 2 (DE3). Therefore, E. coli Rosetta 2 (DE3) was selected for large-scale production and purification. Purified IL-2 was characterized by SDS-PAGE and western blotting, while its biological activity was determined using MTT bioassay. The results depict that the periplasmic and cytoplasmic IL-2 achieved adequate purification, yielding 0.86 and 0.51 mg/mL, respectively, with significant cytotoxic activity of periplasmic and cytoplasmic IL-2. Periplasmic IL-2 has shown better yield and significant biological activity in vitro which describes its attainment of native protein structure and function.

4.
Prep Biochem Biotechnol ; : 1-12, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38701182

ABSTRACT

The effect of gradients of elevated glucose and low dissolved oxygen in the addition zone of fed-batch E. coli thermoinduced recombinant high cell density cultures can be evaluated through two-compartment scale-down models. Here, glucose was fed in the inlet of a plug flow bioreactor (PFB) connected to a stirred tank bioreactor (STB). E. coli cells diminished growth from 48.2 ± 2.2 g/L in the stage of RP production if compared to control (STB) with STB-PFB experiments, when residence time inside the PFB was 25 s (34.1 ± 3.5 g/L) and 40 s (25.6 ± 5.1 g/L), respectively. The recombinant granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) production decreased from 34 ± 7% of RP in inclusion bodies (IB) in control cultures to 21 ± 8%, and 7 ± 4% during the thermoinduction production phase when increasing residence time inside the PFB to 25 s and 40 s, respectively. This, along with the accumulation of acetic and formic acid (up to 4 g/L), indicates metabolic redirection of central carbon routes through metabolic flow and mixed acid fermentation. Special care must be taken when producing a recombinant protein in heat-induced E. coli, because the yield and productivity of the protein decreases as the size of the bioreactors increases, especially if they are carried at high cell density.


Thermoinduced recombinant E. coli grew less in a two-compartment scale-down model.Heat-inducible E. coli cultures at a large scale significantly decrease recombinant protein production.The accumulation of acetic and formic acid increases when E. coli is exposed to glucose and oxygen gradients.The axial flow pattern inside the PFB mimics glucose and dissolved oxygen gradients at the industrial scale.

5.
Methods Mol Biol ; 2808: 129-140, 2024.
Article in English | MEDLINE | ID: mdl-38743367

ABSTRACT

Many negative-sense single-stranded RNA viruses within the order Mononegavirales harm humans. A common feature shared among cells infected by these viruses is the formation of subcellular membraneless structures called biomolecular condensates, also known as inclusion bodies (IBs), that form through a process called liquid-liquid phase separation (LLPS). Like many other membraneless organelles, viral IBs enrich a specific subset of viral and host proteins involved in the formation of viral particles. Elucidation of the properties and regulation of these IBs as they mature throughout the viral replication process are important for our understanding of viral replication, which may also lead to the development of alternative antiviral treatments. The protocol outlined in this chapter aims to characterize the intrinsic properties of LLPS within the measles virus (MeV, a member of Mononegavirales) IBs by using an imaging approach that fluorescently tags an IB-associated host protein. This method uses common laboratory techniques and is generalizable to any host factors as well as other viral systems.


Subject(s)
Fluorescence Recovery After Photobleaching , Inclusion Bodies, Viral , Measles virus , Humans , Inclusion Bodies, Viral/metabolism , Fluorescence Recovery After Photobleaching/methods , Measles virus/physiology , Measles virus/metabolism , Virus Replication , Inclusion Bodies/metabolism , Animals , Host-Pathogen Interactions , Phase Separation
6.
Autophagy ; : 1-13, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38762760

ABSTRACT

Severe fever with thrombocytopenia syndrome virus (SFTSV) nonstructural protein (NSs) is an important viral virulence factor that sequesters multiple antiviral proteins into inclusion bodies to escape the antiviral innate immune response. However, the mechanism of the NSs restricting host innate immunity remains largely elusive. Here, we found that the NSs induced complete macroautophagy/autophagy by interacting with the CCD domain of BECN1, thereby promoting the formation of a BECN1-dependent autophagy initiation complex. Importantly, our data showed that the NSs sequestered antiviral proteins such as TBK1 into autophagic vesicles, and therefore promoted the degradation of TBK1 and other antiviral proteins. In addition, the 8A mutant of NSs reduced the induction of BECN1-dependent autophagy flux and degradation of antiviral immune proteins. In conclusion, our results indicated that SFTSV NSs sequesters antiviral proteins into autophagic vesicles for degradation and to escape antiviral immune responses.

7.
J Biol Chem ; 300(6): 107398, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38777145

ABSTRACT

The unfolded protein response pathways (UPR), autophagy, and compartmentalization of misfolded proteins into inclusion bodies are critical components of the protein quality control network. Among inclusion bodies, aggresomes are particularly intriguing due to their association with cellular survival, drug resistance, and aggresive cancer behavior. Aggresomes are molecular condensates formed when collapsed vimentin cages encircle misfolded proteins before final removal by autophagy. Yet significant gaps persist in the mechanisms governing aggresome formation and elimination in cancer cells. Understanding these mechanisms is crucial, especially considering the involvement of LC3A, a member of the MAP1LC3 family, which plays a unique role in autophagy regulation and has been reported to be epigenetically silenced in many cancers. Herein, we utilized the tetracycline-inducible expression of LC3A to investigate its role in choroid plexus carcinoma cells, which inherently exhibit the presence of aggresomes. Live cell imaging was employed to demonstrate the effect of LC3A expression on aggresome-positive cells, while SILAC-based proteomics identified LC3A-induced protein and pathway alterations. Our findings demonstrated that extended expression of LC3A is associated with cellular senescence. However, the obstruction of lysosomal degradation in this context has a deleterious effect on cellular viability. In response to LC3A-induced autophagy, we observed significant alterations in mitochondrial morphology, reflected by mitochondrial dysfunction and increased ROS production. Furthermore, LC3A expression elicited the activation of the PERK-eIF2α-ATF4 axis of the UPR, underscoring a significant change in the protein quality control network. In conclusion, our results elucidate that LC3A-mediated autophagy alters the protein quality control network, exposing a vulnerability in aggresome-positive cancer cells.


Subject(s)
Activating Transcription Factor 4 , Autophagy , Eukaryotic Initiation Factor-2 , Microtubule-Associated Proteins , Mitochondria , eIF-2 Kinase , Humans , Activating Transcription Factor 4/metabolism , Activating Transcription Factor 4/genetics , eIF-2 Kinase/metabolism , eIF-2 Kinase/genetics , Mitochondria/metabolism , Mitochondria/pathology , Microtubule-Associated Proteins/metabolism , Microtubule-Associated Proteins/genetics , Eukaryotic Initiation Factor-2/metabolism , Eukaryotic Initiation Factor-2/genetics , Cell Line, Tumor , Unfolded Protein Response , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/genetics
8.
Life Sci ; 344: 122562, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38492921

ABSTRACT

Polyglutamine/poly(Q) diseases are a group nine hereditary neurodegenerative disorders caused due to abnormally expanded stretches of CAG trinucleotide in functionally distinct genes. All human poly(Q) diseases are characterized by the formation of microscopically discernable poly(Q) positive aggregates, the inclusion bodies. These toxic inclusion bodies are responsible for the impairment of several cellular pathways such as autophagy, transcription, cell death, etc., that culminate in disease manifestation. Although, these diseases remain largely without treatment, extensive research has generated mounting evidences that various events of poly(Q) pathogenesis can be developed as potential drug targets. The present review article briefly discusses the key events of disease pathogenesis, model system-based investigations that support the development of effective therapeutic interventions against pathogenesis of human poly(Q) disorders, and a comprehensive list of pharmacological and bioactive compounds that have been experimentally shown to alleviate poly(Q)-mediated neurotoxicity. Interestingly, due to the common cause of pathogenesis, all poly(Q) diseases share etiology, thus, findings from one disease can be potentially extrapolated to other poly(Q) diseases as well.


Subject(s)
Neurotoxicity Syndromes , Peptides , Humans , Cell Death/genetics , Neurotoxicity Syndromes/metabolism
9.
J Cell Sci ; 137(7)2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38477372

ABSTRACT

Biogenesis of inclusion bodies (IBs) facilitates protein quality control (PQC). Canonical aggresomes execute degradation of misfolded proteins while non-degradable amyloids sequester into insoluble protein deposits. Lewy bodies (LBs) are filamentous amyloid inclusions of α-synuclein, but PQC benefits and drawbacks associated with LB-like IBs remain underexplored. Here, we report that crosstalk between filamentous LB-like IBs and aggresome-like IBs of α-synuclein (Syn-aggresomes) buffer the load, aggregation state, and turnover of the amyloidogenic protein in mouse primary neurons and HEK293T cells. Filamentous LB-like IBs possess unorthodox PQC capacities of self-quarantining α-synuclein amyloids and being degradable upon receding fresh amyloidogenesis. Syn-aggresomes equilibrate biogenesis of filamentous LB-like IBs by facilitating spontaneous degradation of α-synuclein and conditional turnover of disintegrated α-synuclein amyloids. Thus, both types of IB primarily contribute to PQC. Incidentally, the overgrown perinuclear LB-like IBs become degenerative once these are misidentified by BICD2, a cargo-adapter for the cytosolic motor-protein dynein. Microscopy indicates that microtubules surrounding the perinuclear filamentous inclusions are also distorted, misbalancing the cytoskeleton-nucleoskeleton tension leading to widespread lamina injuries. Together, nucleocytoplasmic mixing, DNA damage, and deregulated transcription of stress chaperones defeat the proteostatic purposes of the filamentous amyloids of α-synuclein.


Subject(s)
Nuclear Lamina , alpha-Synuclein , Animals , Humans , Mice , alpha-Synuclein/metabolism , Amyloid/metabolism , Amyloidogenic Proteins/metabolism , HEK293 Cells , Inclusion Bodies/metabolism , Nuclear Lamina/metabolism , Nuclear Lamina/pathology
10.
Front Bioeng Biotechnol ; 12: 1392514, 2024.
Article in English | MEDLINE | ID: mdl-38532877

ABSTRACT

[This corrects the article DOI: 10.3389/fbioe.2023.1249196.].

11.
Methods Mol Biol ; 2778: 31-41, 2024.
Article in English | MEDLINE | ID: mdl-38478269

ABSTRACT

Transmembrane ß-barrel proteins reside in the outer membrane of Gram-negative bacteria and are thus in direct contact with the environment. Because of that, they are involved in many key processes stretching from cellular survival to virulence. Hence, they are an attractive target for the development of novel antimicrobials, in addition to being of fundamental biological interest. To study this class of proteins, they are often required to be expressed in Escherichia coli. Recombinant expression of ß-barrel proteins can be achieved using two fundamentally different strategies. The first alternative uses a complete coding sequence that includes a signal peptide for targeting the protein to its native cellular location, the bacterial outer membrane. The second alternative omits the signal peptide in the gene, leading to mislocalization and aggregation of the protein in the bacterial cytoplasm. These aggregates, called inclusion bodies, can be solubilized and the protein can be folded into its native form in vitro. In this chapter, we present example protocols for both strategies and discuss their advantages and disadvantages.


Subject(s)
Escherichia coli Proteins , Protein Folding , Bacterial Outer Membrane Proteins/metabolism , Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Protein Sorting Signals/genetics
12.
Animals (Basel) ; 14(6)2024 Mar 09.
Article in English | MEDLINE | ID: mdl-38539943

ABSTRACT

Recent studies have demonstrated that immune-related recombinant proteins can enhance immune function, increasing host survival against infectious diseases in salmonids. This research evaluated inclusion bodies (IBs) of antimicrobial peptides (CAMPIB and HAMPIB) and a cytokine (IL1ßIB and TNFαIB) as potential immunostimulants in farmed salmonids. For this purpose, we produced five IBs (including iRFPIB as a control), and we evaluated their ability to modulate immune marker gene expression of three IBs in the RTS11 cell line by RT-qPCR. Additionally, we characterized the scale-up of IBs production by comparing two different scale systems. The results showed that CAMPIB can increase the upregulation of tnfα, il1ß, il8, and il10, HAMPIB significantly increases the upregulation of tnfα, inos, and il10, and IL1ßIB significantly upregulated the expression of tnfα, il1ß, and cox2. A comparison of IL1ßIB production showed that the yield was greater in shake flasks than in bioreactors (39 ± 1.15 mg/L and 14.5 ± 4.08 mg/L), and larger nanoparticles were produced in shake flasks (540 ± 129 nm and 427 ± 134 nm, p < 0.0001, respectively). However, compared with its shake flask counterpart, the IL1ßIB produced in a bioreactor has an increased immunomodulatory ability. Further studies are needed to understand the immune response pathways activated by IBs and the optimal production conditions in bioreactors, such as a defined medium, fed-batch production, and mechanical bacterial lysis, to increase yield.

13.
Microb Cell Fact ; 23(1): 67, 2024 Feb 24.
Article in English | MEDLINE | ID: mdl-38402403

ABSTRACT

BACKGROUND: In recent years, the production of inclusion bodies that retain substantial catalytic activity was demonstrated. These catalytically active inclusion bodies (CatIBs) are formed by genetic fusion of an aggregation-inducing tag to a gene of interest via short linker polypeptides. The resulting CatIBs are known for their easy and cost-efficient production, recyclability as well as their improved stability. Recent studies have outlined the cooperative effects of linker and aggregation-inducing tag on CatIB activities. However, no a priori prediction is possible so far to indicate the best combination thereof. Consequently, extensive screening is required to find the best performing CatIB variant. RESULTS: In this work, a semi-automated cloning workflow was implemented and used for fast generation of 63 CatIB variants with glucose dehydrogenase of Bacillus subtilis (BsGDH). Furthermore, the variant BsGDH-PT-CBDCell was used to develop, optimize and validate an automated CatIB screening workflow, enhancing the analysis of many CatIB candidates in parallel. Compared to previous studies with CatIBs, important optimization steps include the exclusion of plate position effects in the BioLector by changing the cultivation temperature. For the overall workflow including strain construction, the manual workload could be reduced from 59 to 7 h for 48 variants (88%). After demonstration of high reproducibility with 1.9% relative standard deviation across 42 biological replicates, the workflow was performed in combination with a Bayesian process model and Thompson sampling. While the process model is crucial to derive key performance indicators of CatIBs, Thompson sampling serves as a strategy to balance exploitation and exploration in screening procedures. Our methodology allowed analysis of 63 BsGDH-CatIB variants within only three batch experiments. Because of the high likelihood of TDoT-PT-BsGDH being the best CatIB performer, it was selected in 50 biological replicates during the three screening rounds, much more than other, low-performing variants. CONCLUSIONS: At the current state of knowledge, every new enzyme requires screening for different linker/aggregation-inducing tag combinations. For this purpose, the presented CatIB toolbox facilitates fast and simplified construction and screening procedures. The methodology thus assists in finding the best CatIB producer from large libraries in short time, rendering possible automated Design-Build-Test-Learn cycles to generate structure/function learnings.


Subject(s)
Automation, Laboratory , High-Throughput Screening Assays , Reproducibility of Results , Bayes Theorem , Inclusion Bodies , Automation
14.
J Virol ; 98(3): e0015324, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38421168

ABSTRACT

Orthopneumoviruses characteristically form membrane-less cytoplasmic inclusion bodies (IBs) wherein RNA replication and transcription occur. Here, we report a strategy whereby the orthopneumoviruses sequester various components of the translational preinitiation complex machinery into viral inclusion bodies to facilitate translation of their own mRNAs-PIC-pocketing. Electron microscopy of respiratory syncytial virus (RSV)-infected cells revealed bi-phasic organization of IBs, specifically, spherical "droplets" nested within the larger inclusion. Using correlative light and electron microscopy, combined with fluorescence in situ hybridization, we showed that the observed bi-phasic morphology represents functional compartmentalization of the inclusion body and that these domains are synonymous with the previously reported inclusion body-associated granules (IBAGs). Detailed analysis demonstrated that IBAGs concentrate nascent viral mRNA, the viral M2-1 protein as well as components of eukaryotic translation initiation factors (eIF), eIF4F and eIF3, and 40S complexes involved in translation initiation. Interestingly, although ribopuromycylation-based imaging indicates that the majority of viral mRNA translation occurs in the cytoplasm, there was some evidence for intra-IBAG translation, consistent with the likely presence of ribosomes in a subset of IBAGs imaged by electron microscopy. Mass spectrometry analysis of sub-cellular fractions from RSV-infected cells identified significant modification of the cellular translation machinery; however, interestingly, ribopuromycylation assays showed no changes to global levels of translation. The mechanistic basis for this pathway was subsequently determined to involve the viral M2-1 protein interacting with eIF4G, likely to facilitate its transport between the cytoplasm and the separate phases of the viral inclusion body. In summary, our data show that these viral organelles function to spatially regulate early steps in viral translation within a highly selective bi-phasic biomolecular condensate. IMPORTANCE: Respiratory syncytial viruses (RSVs) of cows and humans are a significant cause of morbidity and mortality in their respective populations. These RNA viruses replicate in the infected cells by compartmentalizing the cell's cytoplasm into distinct viral microdomains called inclusion bodies (IBs). In this paper, we show that these IBs are further compartmentalized into smaller structures that have significantly different density, as observed by electron microscopy. Within smaller intra-IB structures, we observed ribosomal components and evidence for active translation. These findings highlight that RSV may additionally compartmentalize translation to favor its own replication in the cell. These data contribute to our understanding of how RNA viruses hijack the cell to favor replication of their own genomes and may provide new targets for antiviral therapeutics in vivo.


Subject(s)
Biomolecular Condensates , Respiratory Syncytial Virus, Human , Humans , Animals , Cattle , Cell Line , In Situ Hybridization, Fluorescence , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/metabolism , Viral Proteins/genetics , Viral Proteins/metabolism , Ribosomes/metabolism , Virus Replication
15.
J Biomed Sci ; 31(1): 11, 2024 Jan 20.
Article in English | MEDLINE | ID: mdl-38245749

ABSTRACT

Liquid-liquid phase separation (LLPS) in biology describes a process by which proteins form membraneless condensates within a cellular compartment when conditions are met, including the concentration and posttranslational modifications of the protein components, the condition of the aqueous solution (pH, ionic strength, pressure, and temperature), and the existence of assisting factors (such as RNAs or other proteins). In these supramolecular liquid droplet-like inclusion bodies, molecules are held together through weak intermolecular and/or intramolecular interactions. With the aid of LLPS, cells can assemble functional sub-units within a given cellular compartment by enriching or excluding specific factors, modulating cellular function, and rapidly responding to environmental or physiological cues. Hence, LLPS is emerging as an important means to regulate biology and physiology. Yet, excessive inclusion body formation by, for instance, higher-than-normal concentrations or mutant forms of the protein components could result in the conversion from dynamic liquid condensates into more rigid gel- or solid-like aggregates, leading to the disruption of the organelle's function followed by the development of human disorders like neurodegenerative diseases. In summary, well-controlled formation and de-formation of LLPS is critical for normal biology and physiology from single cells to individual organisms, whereas abnormal LLPS is involved in the pathophysiology of human diseases. In turn, targeting these aggregates or their formation represents a promising approach in treating diseases driven by abnormal LLPS including those neurodegenerative diseases that lack effective therapies.


Subject(s)
Neurodegenerative Diseases , Phase Separation , Humans , Proteins
16.
Elife ; 122024 Jan 29.
Article in English | MEDLINE | ID: mdl-38285487

ABSTRACT

Viral inclusion bodies (IBs) commonly form during the replication of Ebola virus (EBOV) in infected cells, but their role in viral immune evasion has rarely been explored. Here, we found that interferon regulatory factor 3 (IRF3), but not TANK-binding kinase 1 (TBK1) or IκB kinase epsilon (IKKε), was recruited and sequestered in viral IBs when the cells were infected by EBOV transcription- and replication-competent virus-like particles (trVLPs). Nucleoprotein/virion protein 35 (VP35)-induced IBs formation was critical for IRF3 recruitment and sequestration, probably through interaction with STING. Consequently, the association of TBK1 and IRF3, which plays a vital role in type I interferon (IFN-I) induction, was blocked by EBOV trVLPs infection. Additionally, IRF3 phosphorylation and nuclear translocation induced by Sendai virus or poly(I:C) stimulation were suppressed by EBOV trVLPs. Furthermore, downregulation of STING significantly attenuated VP35-induced IRF3 accumulation in IBs. Coexpression of the viral proteins by which IB-like structures formed was much more potent in antagonizing IFN-I than expression of the IFN-I antagonist VP35 alone. These results suggested a novel immune evasion mechanism by which EBOV evades host innate immunity.


Subject(s)
Hemorrhagic Fever, Ebola , Immune Evasion , Inclusion Bodies, Viral , Interferon Regulatory Factor-3 , Interferon Type I , Humans , Ebolavirus , Hemorrhagic Fever, Ebola/immunology
17.
BMC Neurol ; 24(1): 9, 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38166833

ABSTRACT

BACKGROUND: Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is a rare genetic disorder characterized by progressive cognitive decline and myoclonic epilepsy, caused by pathogenic variants of SERPINI1. We reported a case of genetically confirmed FENIB with de novo H338R mutation in the SERPINI1, in which frontal deficits including inattention and disinhibition, and relevant atrophy in the vmPFC on brain MRI were observed in the early stage of the disease. CASE PRESENTATION: A 23-year-old Japanese man presented with progressive inattention and disinhibition over 4 years followed by myoclonic epilepsy. The whole-genome sequencing and filtering analysis showed de novo heterozygous H338R mutation in the SERPINI1, confirming the diagnosis of FENIB. Single-case voxel-based morphometry using brain magnetic resonance imaging obtained at the initial visit revealed focal gray matter volume loss in the ventromedial prefrontal cortices, which is presumed to be associated with inattention and disinhibition. CONCLUSION: Frontal deficits including inattention and disinhibition can be the presenting symptoms of patients with FENIB. Single-case voxel-based morphometry may be useful for detecting regional atrophy of the frontal lobe in FENIB. Detecting these abnormalities in the early stage of disease may be key findings for differentiating FENIB from other causes of progressive myoclonic epilepsy.


Subject(s)
Epilepsies, Myoclonic , Serpins , Male , Humans , Young Adult , Adult , Neuroserpin , Epilepsies, Myoclonic/diagnostic imaging , Epilepsies, Myoclonic/genetics , Epilepsies, Myoclonic/pathology , Inclusion Bodies/pathology , Magnetic Resonance Imaging/methods
18.
Biotechnol Bioeng ; 121(2): 535-550, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37927002

ABSTRACT

A new platform has been developed to facilitate the production of biologically active proteins and peptides in Escherichia coli. The platform includes an N-terminal self-associating L6 KD peptide fused to the SUMO protein (small ubiquitin-like protein modifier) from the yeast Saccharomyces cerevisiae, which is known for its chaperone activity. The target proteins are fused at the C termini of the L6 KD-SUMO fusions, and the resulting three-component fusion proteins are synthesized and self-assembled in E. coli into so-called active inclusion bodies (AIBs). In vivo, the L6 KD-SUMO platform facilitates the correct folding of the target proteins and directs them into AIBs, greatly simplifying their purification. In vitro, the platform facilitates the effective separation of AIBs by centrifugation and subsequent target protein release using SUMO-specific protease. The properties of the AIBs were determined using five proteins with different sizes, folding efficiencies, quaternary structure, and disulfide modifications. Electron microscopy shows that AIBs are synthesized in the form of complex fibrillar structures resembling "loofah sponges" with unusually thick filaments. The obtained results indicate that the new platform has promising features and could be developed to facilitate the synthesis and purification of target proteins and protein complexes without the use of renaturation.


Subject(s)
Escherichia coli , Peptides , Escherichia coli/genetics , Escherichia coli/metabolism , Peptides/metabolism , Protein Folding , Endopeptidases/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Inclusion Bodies/genetics , Inclusion Bodies/metabolism , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism
19.
Arq. neuropsiquiatr ; 82(3): s00441779692, 2024. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1557127

ABSTRACT

Abstract In 1912, Friedrich Lewy described the inclusion bodies present in Parkinson disease and in Lewy body dementia. Throughout his life, Lewy fought in two wars - on opposite sides. He was born in Berlin in a Jewish family, and served in the German Army in World War I. In the following years, on many occasions he had to change his line of research due to Nazi persecution. Lewy became a naturalized American, changed his name to Frederic Henry Lewey, and served in the US Army as a lieutenant colonel. Lewy died in 1950 and never used the famous eponym in his papers.


Resumo Em 1912, Friedrich Lewy descreveu os corpos de inclusão presentes na doença de Parkinson e na demência com corpos de Lewy. Ao longo sua vida, Lewy lutou em duas guerras, em lados opostos. Ele nasceu em Berlin em uma família de origem judaica e serviu no Exército alemão na Primeira Guerra Mundial. Nos anos seguintes, passou muitas vezes teve de mudar sua linha de pesquisa devido à perseguição Nazista. Lewy naturalizou-se americano, mudou seu nome para Frederic Henry Lewey, e serviu no Exército americano como tenente-coronel. Lewy morreu em 1950 e nunca usou o famoso epônimo em seus artigos.

20.
Virol Sin ; 2023 Dec 09.
Article in English | MEDLINE | ID: mdl-38072230

ABSTRACT

Inclusion bodies (IBs) of respiratory syncytial virus (RSV) are formed by liquid-liquid phase separation (LLPS) and contain internal structures termed "IB-associated granules" (IBAGs), where anti-termination factor M2-1 and viral mRNAs are concentrated. However, the mechanism of IBAG formation and the physiological function of IBAGs are unclear. Here, we found that the internal structures of RSV IBs are actual M2-1-free viral messenger ribonucleoprotein (mRNP) condensates formed by secondary LLPS. Mechanistically, the RSV nucleoprotein (N) and M2-1 interact with and recruit PABP to IBs, promoting PABP to bind viral mRNAs transcribed in IBs by RNA-recognition motif and drive secondary phase separation. Furthermore, PABP-eIF4G1 interaction regulates viral mRNP condensate composition, thereby recruiting specific translation initiation factors (eIF4G1, eIF4E, eIF4A, eIF4B and eIF4H) into the secondary condensed phase to activate viral mRNAs for ribosomal recruitment. Our study proposes a novel LLPS-regulated translation mechanism during viral infection and a novel antiviral strategy via targeting on secondary condensed phase.

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