scholarly journals N-Glycosylation Modification of Plant-Derived Virus-Like Particles: An Application in Vaccines

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hyun-Soon Kim ◽  
Jae-Heung Jeon ◽  
Kyung Jin Lee ◽  
Kisung Ko

Plants have been developed as an alternative system to mammalian cells for production of recombinant prophylactic or therapeutic proteins for human and animal use. Effective plant expression systems for recombinant proteins have been established with the optimal combination of gene expression regulatory elements and control of posttranslational processing of recombinant glycoproteins. In plant, virus-like particles (VLPs), viral “empty shells” which maintain the same structural characteristics of virions but are genome-free, are considered extremely promising as vaccine platforms and therapeutic delivery systems. Unlike microbial fermentation, plants are capable of carrying outN-glycosylation as a posttranslational modification of glycoproteins. Recent advances in the glycoengineering in plant allow human-like glycomodification and optimization of desired glycan structures for enhancing safety and functionality of recombinant pharmaceutical glycoproteins. In this review, the current plant-derived VLP approaches are focused, andN-glycosylation and its in planta modifications are discussed.

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 996
Author(s):  
Inge Pietersen ◽  
Albertha van Zyl ◽  
Edward Rybicki ◽  
Inga Hitzeroth

Vaccine efficacy requires the production of neutralising antibodies which offer protection against the native virus. The current gold standard for determining the presence of neutralising antibodies is the pseudovirion-based neutralisation assay (PBNA). PBNAs utilise pseudovirions (PsVs), structures which mimic native virus capsids, but contain non-viral nucleic material. PsVs are currently produced in expensive cell culture systems, which limits their production, yet plant expression systems may offer cheaper, safer alternatives. Our aim was to determine whether plants could be used for the production of functional PsVs of bovine papillomavirus 1 (BPV1), an important causative agent of economically damaging bovine papillomas in cattle and equine sarcoids in horses and wild equids. BPV1 capsid proteins, L1 and L2, and a self-replicating reporter plasmid were transiently expressed in Nicotiana benthamiana to produce virus-like particles (VLPs) and PsVs. Strategies to enhance particle yields were investigated and optimised protocols were established. The PsVs’ ability to infect mammalian cells and express their encapsidated reporter genes in vitro was confirmed, and their functionality as reagents in PBNAs was demonstrated through their neutralisation by several different antibodies. This is the first report of BPV PsVs expressed in plants and demonstrates the potential for the development of therapeutic veterinary vaccines in planta.


Author(s):  
Zhihui Dou ◽  
Dapeng Zhao ◽  
Xiaohua Chen ◽  
Caipeng Xu ◽  
Xiaodong Jin ◽  
...  

AbstractBcl-x pre-mRNA splicing serves as a typical example to study the impact of alternative splicing in the modulation of cell death. Dysregulation of Bcl-x apoptotic isoforms caused by precarious equilibrium splicing is implicated in genesis and development of multiple human diseases, especially cancers. Exploring the mechanism of Bcl-x splicing and regulation has provided insight into the development of drugs that could contribute to sensitivity of cancer cells to death. On this basis, we review the multiple splicing patterns and structural characteristics of Bcl-x. Additionally, we outline the cis-regulatory elements, trans-acting factors as well as epigenetic modifications involved in the splicing regulation of Bcl-x. Furthermore, this review highlights aberrant splicing of Bcl-x involved in apoptosis evade, autophagy, metastasis, and therapy resistance of various cancer cells. Last, emphasis is given to the clinical role of targeting Bcl-x splicing correction in human cancer based on the splice-switching oligonucleotides, small molecular modulators and BH3 mimetics. Thus, it is highlighting significance of aberrant splicing isoforms of Bcl-x as targets for cancer therapy.


2021 ◽  
Vol 22 (5) ◽  
pp. 2643
Author(s):  
Mohamed F. Hassan ◽  
Abdelrahman M. Qutb ◽  
Wubei Dong

Antimicrobial peptides (AMPs) are small molecules consisting of less than fifty residues of amino acids. Plant AMPs establish the first barrier of defense in the innate immune system in response to invading pathogens. The purpose of this study was to isolate new AMPs from the Zea mays L. inbred line B73 and investigate their antimicrobial activities and mechanisms against certain essential plant pathogenic bacteria. In silico, the Collection of Anti-Microbial Peptides (CAMPR3), a computational AMP prediction server, was used to screen a cDNA library for AMPs. A ZM-804 peptide, isolated from the Z. mays L. inbred line B73 cDNA library, was predicted as a new cationic AMP with high prediction values. ZM-804 was tested against eleven pathogens of Gram-negative and Gram-positive bacteria and exhibited high antimicrobial activities as determined by the minimal inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs). A confocal laser scanning microscope observation showed that the ZM-804 AMP targets bacterial cell membranes. SEM and TEM images revealed the disruption and damage of the cell membrane morphology of Clavibacter michiganensis subsp. michiganensis and Pseudomonas syringae pv. tomato (Pst) DC3000 caused by ZM-804. In planta, ZM-804 demonstrated antimicrobial activity and prevented the infection of tomato plants by Pst DC3000. Moreover, four virulent phytopathogenic bacteria were prevented from inducing hypersensitive response (HR) in tobacco leaves in response to low ZM-804 concentrations. ZM-804 exhibits low hemolytic activity against mouse red blood cells (RBCs) and is relatively safe for mammalian cells. In conclusion, the ZM-804 peptide has a strong antibacterial activity and provides an alternative tool for plant disease control. Additionally, the ZM-804 peptide is considered a promising candidate for human and animal drug development.


2001 ◽  
Vol 356 (3) ◽  
pp. 867-873 ◽  
Author(s):  
Kay STUBENRAUCH ◽  
Stefan GLEITER ◽  
Ulrich BRINKMANN ◽  
Rainer RUDOLPH ◽  
Hauke LILIE

The development of cell-type-specific delivery systems is highly desirable for gene-therapeutic applications. Current virus-based vector systems show broad cell specificity, which results in the need to restrict the natural tropism of these viral systems. Here we demonstrate that tumour-cell-specific virus-like particles can be functionally assembled in vitro from recombinant viral coat protein expressed in Escherichia coli. The insertion of a negatively charged peptide in the HI loop of polyoma VP1 interferes with the binding of VP1 to the natural recognition site on mammalian cells and also serves as an adapter for the coupling of antibody fragments that contain complementary charged fusion peptides. A recombinant antibody fragment of the tumour-specific anti-(Lewis Y) antibody B3 could be coupled to the mutant VP1 by engineered polyionic peptides and an additional disulphide bond. With this system an entirely recombinant cell-specific delivery system assembled in vitro could be generated that transfers genes preferentially to cells presenting the tumour-specific antigen on the cell surface.


2001 ◽  
Vol 21 (1) ◽  
pp. 298-309 ◽  
Author(s):  
Yong-Qing Feng ◽  
Matthew C. Lorincz ◽  
Steve Fiering ◽  
John M. Greally ◽  
Eric E. Bouhassira

ABSTRACT We have inserted two expression cassettes at tagged reference chromosomal sites by using recombinase-mediated cassette exchange in mammalian cells. The three sites of integration displayed either stable or silencing position effects that were dominant over the different enhancers present in the cassettes. These position effects were strongly dependent on the orientation of the construct within the locus, with one orientation being permissive for expression and the other being nonpermissive. Orientation-specific silencing, which was observed at two of the three site tested, was associated with hypermethylation but not with changes in chromatin structure, as judged by DNase I hypersensitivity assays. Using CRE recombinase, we were able to switch in vivo the orientation of the transgenes from the permissive to the nonpermissive orientation and vice versa. Switching from the permissive to the nonpermissive orientation led to silencing, but switching from the nonpermissive to the permissive orientation did not lead to reactivation of the transgene. Instead, transgene expression occurred dynamically by transcriptional oscillations, with 10 to 20% of the cells expressing at any given time. This result suggested that the cassette had been imprinted (epigenetically tagged) while it was in the nonpermissive orientation. Methylation analysis revealed that the methylation state of the inverted cassettes resembled that of silenced cassettes except that the enhancer had selectively lost some of its methylation. Sorting of the expressing and nonexpressing cell populations provided evidence that the transcriptional oscillations of the epigenetically tagged cassette are associated with changes in the methylation status of regulatory elements in the transgene. This suggests that transgene methylation is more dynamic than was previously assumed.


2009 ◽  
Vol 84 (5) ◽  
pp. 2294-2303 ◽  
Author(s):  
Yuliang Liu ◽  
Luis Cocka ◽  
Atsushi Okumura ◽  
Yong-An Zhang ◽  
J. Oriol Sunyer ◽  
...  

ABSTRACT The filovirus VP40 protein is capable of budding from mammalian cells in the form of virus-like particles (VLPs) that are morphologically indistinguishable from infectious virions. Ebola virus VP40 (eVP40) contains well-characterized overlapping L domains, which play a key role in mediating efficient virus egress. L domains represent only one component required for efficient budding and, therefore, there is a need to identify and characterize additional domains important for VP40 function. We demonstrate here that the 96LPLGVA101 sequence of eVP40 and the corresponding 84LPLGIM89 sequence of Marburg virus VP40 (mVP40) are critical for efficient release of VP40 VLPs. Indeed, deletion of these motifs essentially abolished the ability of eVP40 and mVP40 to bud as VLPs. To address the mechanism by which the 96LPLGVA101 motif of eVP40 contributes to egress, a series of point mutations were introduced into this motif. These mutants were then compared to the eVP40 wild type in a VLP budding assay to assess budding competency. Confocal microscopy and gel filtration analyses were performed to assess their pattern of intracellular localization and ability to oligomerize, respectively. Our results show that mutations disrupting the 96LPLGVA101 motif resulted in both altered patterns of intracellular localization and self-assembly compared to wild-type controls. Interestingly, coexpression of either Ebola virus GP-WT or mVP40-WT with eVP40-ΔLPLGVA failed to rescue the budding defective eVP40-ΔLPLGVA mutant into VLPs; however, coexpression of eVP40-WT with mVP40-ΔLPLGIM successfully rescued budding of mVP40-ΔLPLGIM into VLPs at mVP40-WT levels. In sum, our findings implicate the LPLGVA and LPLGIM motifs of eVP40 and mVP40, respectively, as being important for VP40 structure/stability and budding.


2019 ◽  
Author(s):  
Federico Comoglio ◽  
Marta Simonatto ◽  
Sara Polletti ◽  
Xin Liu ◽  
Stephen T. Smale ◽  
...  

ABSTRACTAccessibility of the genomic regulatory information is largely controlled by the nucleosome-organizing activity of transcription factors (TFs). Whereas stimulus-induced TFs bind to genomic regions that are maintained accessible by lineage-determining TFs, they also increase accessibility of thousands of cis-regulatory elements. Nucleosome remodeling events underlying such changes and their interplay with basal positioning are unknown. Here, we devised a novel quantitative framework discriminating different types of nucleosome remodeling events in micrococcal nuclease ChIP-seq datasets and used it to analyze nucleosome dynamics at stimulus-regulated cis-regulatory elements. At enhancers, remodeling preferentially affected poorly positioned nucleosomes while sparing well-positioned nucleosomes flanking the enhancer core, indicating that inducible TFs do not suffice to overrule basal nucleosomal organization maintained by lineage-determining TFs. Remodeling events appeared to be combinatorially driven by multiple TFs, with distinct TFs showing however different remodeling efficiencies. Overall, these data provide a systematic view of the impact of stimulation on nucleosome organization and genome accessibility in mammalian cells.


1999 ◽  
Vol 17 (1) ◽  
pp. 273-304
Author(s):  
Jane Williams-Hogan

In this paper, the author examines the issue of charisma and prophecy in secularized societies. In traditional society the charismatic personality or the prophet brought a universalizing and rationalizing message which simultaneously expanded and penetrated the sphere of external order in the world, giving people the ability to manipulate and control the natural world. The disenchanted world is the end product of this process, when no more mysterious forces come into play, and when one can in principle master all things through rational calculation. The gift of rationality almost randomly bestowed in the ancient world becomes, for Weber, the rightful inheritance of the modern individual. Clarity brought by charisma in a dark and foreboding world loses its brilliance and its ability to beckon when the world is filled with light. In investigating charisma in only traditional societies, Weber saw charisma as one dimensional, solely as the force of rationality. So envisioned, charisma dissipates in the very act of realizing itself through the transformation of the world. Given Weber's analysis, therefore, one would not expect to find genuinely new religions emerging within our transformed and rational modern society. In the examination of the founding something that is best identified by the sociological term charisma, though obviously in modern guise, is clearly evident. This points to the possibility that charisma is not static but has the dynamic capacity to be responsive to the structural characteristics of the society in which it operates.


Author(s):  
L. M. Kravchenko ◽  
K. V. Kudzin ◽  
U. A. Prakulevich

The porcine reproductive and respiratory syndrome (PRRS) caused the serious economic damage to swine breeding around the world. It is a viral infective disease against which live attenuated and inactivated vaccines are not always successful. Development of new types of drugs such as DNA vaccines is necessary for improving the protection against the virus. DNA vaccines induce the development of both a cellular and humoral immune response. Such vaccines consist of a plasmid or viral vector with genes of potentially immunogenic proteins. The expression of these genes realized in cells of the vaccinated animal. It leads to the synthesis of antigen proteins triggering the immune response. The purpose of this work is to create a genetic construction that can be used as DNA vaccine against PRRS virus. The construction consists of the commercial vector pVAX1 and open reading frame of two structural proteins of PRRS virus, a lysosomal localization signal sequence of the invariant chain gene and regulatory elements necessary for the expression of cloned genes in mammalian cells.


Author(s):  
Ilya Inishev

В статье идёт речь о формах образного, которые во всё возрастающей степени становятся характерными для современной культуры. Центральная характеристика этих форм – распределённость в пространстве и времени, их способность сопровождать нас практически повсеместно, не будучи привязанными к каким-либо организационным формам. Распределённые разновидности образного противопоставляются «традиционным», нераспределённым образам, «репрезентирующим» некоторое идентифицируемое содержание. Одна из базовых черт нераспределенного образного – заключённое в нём нормативное притязание, затрагивающее не только способы его интерпретации, но и телесные практики воспринимающего «субъекта», релевантные для его восприятия. В отличие от репрессивного характера нераспределённого образа, являющегося его структурной характеристикой, связанной с характерным для него режимом восприятия, распределённая образность базируется не на редукции и контроле телесности воспринимающего, но – напротив – на интенсификации (и в этом смысле эмансипации) его эмоционально-телесного самоприсутствия. В диахронической перспективе отношение между нераспределённой и распределённой образностью опосредовано сложной социально-исторической и материально-технологической динамикой развитого и позднего модерна. Реконструкция этой динамики позволяет выстроить генетическую связь (континуальность) между нераспределённой и распределённой образностью. В синхронической перспективе распределённая и нераспределенная разновидности образности генерируют несовместимые типы опыта с взаимоисключающими структурными характеристиками и социально-политическими импликациями (дискретность).Main theme of the article are the types of imagery becoming increasingly characteristic of contemporary culture. The core feature of these types is their being distributed across time and space, their ability to accompany us virtually everywhere, without being tied to any organizational form. Distributed imagery opposes “traditional”, non-distributed images “representing” some identifiable subject-matter. One of the essential traits of non-distributed imagery is its normative claim addressing not only the ways of its interpretation but also bodily practices of the perceiving subject, relevant for experiencing images of this kind. In contrast to the inherent oppressiveness of non-distributed image connected to a perceptual regime characteristic of it, the distributed imagery draws not on reduction and control of body of the perceiving subject but – on the contrary – on intensifying (and in this sense, on emancipating) its bodily emotional self-presence. From a diachronic point of view, the relationship between distributed and non-distributed imageries is mediated by quite a complicated socio-historical and material-technological dynamic of the developed and late modernity. Reconstruction of this dynamic enables us to identify the genetic interrelation (continuity) between non-distributed and distributed imagery. From a synchronic point of view, distributed and non-distributed imagery forms generate incompatible experience types with mutually exclusive structural characteristics and social-political implications (discontinuity).


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