• Evidence indicates that Alix, an accessory protein of the endosomal sorting complex required for transport (ESCRT), is involved in the biogenesis of extracellular vesicles (EVs). (spandidos-publications.com)
  • Given the heterogeneity of the released vesicles and the overlapping features of molecules carried by exosomes and microvesicles, it has been suggested that they be collectively termed extracellular vesicles (EVs) ( 7 ). (spandidos-publications.com)
  • Characterization of surface markers on extracellular vesicles isolated from lymphatic exudate from patients with breast cancer. (gu.se)
  • Virus-infected cells release virus-associated exosomes, extracellular vesicles of endocytic origin, into the blood to deliver viral cargoes able to regulate immune responses. (wphobby.com)
  • Exosomes are a subtype of extracellular vesicles and are typically 30-150 nm in diameter. (hindawi.com)
  • Exosomes are the smallest subtype of extracellular vesicles (EVs), ranging in diameter from 30 to 150 nm with a density of 1.13 to 1.19 g/ml [ 3 ]. (hindawi.com)
  • Most gene therapy vectors are taken into the cell by endocytosis and, hence, are located in the endocytic vesicles. (nih.gov)
  • The inhibition of clathrin-mediated endocytosis using chlorpromazine, siRNAs, and a dominant negative (DN) mutant blocked entry and infection of PSaV Cowden strain, confirming a role for clathrin-mediated internalization. (biomedcentral.com)
  • The internalization process can occur via clathrin-mediated endocytosis, caveolar/lipid raft-mediated endocytosis, macropinocytosis, or a variety of other still poorly characterized mechanisms [ 2 ]. (biomedcentral.com)
  • Clathrin-mediated endocytosis is generally accepted to be a major route by which nonenveloped viruses infect cells [ 2 ]. (biomedcentral.com)
  • Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME) for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR), and distinct mechanism(s) that mediate the majority of fluid-phase endocytosis. (plos.org)
  • To mediate endocytosis, effectors assemble transiently underneath the plasma membrane, carry out the mechanics of membrane deformation, cargo selection and vesicle internalization, and then disassemble. (cienciavida.org)
  • These structures colocalize with sites of protein and lipid endocytosis, and their components genetically interact with known endocytic effectors. (cienciavida.org)
  • Loss of Pil1 leads to clustering of eisosome remnants and redirects endocytosis and endocytic effector proteins to these clusters. (cienciavida.org)
  • Following exocytosis, the process of endocytosis is required for neurons to replenish their pools of synaptic vesicles by pinching off vesicles from the plasma membrane. (edu.au)
  • The mechanisms by which viruses gain entry into host cells are diverse and include direct penetration through the plasma membrane or endocytic uptake followed by vesicular transport through the cytoplasm and delivery to endosomes and other intracellular organelles [ 2 ]. (biomedcentral.com)
  • Characterization of the uptake pathway in murine epidermis shows that HSV-1 enters into epidermal sheets, principal epidermal keratinocytes and principal dermal fibroblasts, both by direct fusion of the viral envelope with the plasma membrane and endocytic vesicles [3, 4]. (bioskinrevive.com)
  • A likely explanation is definitely that both the fusion events at the plasma membrane and vesicle scission depend on dynamin. (bioskinrevive.com)
  • This signalling fidelity of GPCRs is maintained by an elegant series of interactions that firstly prevent signalling and is followed by a regulated trafficking process involving the removal of desensitised receptors from the surface of the cell (internalisation) followed by either recycling to the plasma membrane for repeated signalling (resensitisation) or targeting to the lysosome for destruction and downregulation (Figure 1). (abdn.ac.uk)
  • The non-apoptotic vesicles have been classified based on their biogenesis into exosomes derived from membranes of the endosomal compartment and microvesicles that are formed from the budding of a portion of the cell plasma membrane ( 5 , 6 ). (spandidos-publications.com)
  • WDFY2 knockout causes a strong redistribution of VAMP3 into small vesicles near the plasma membrane. (nature.com)
  • After internalization, MT1-MMP is sorted in endosomal compartments, and a fraction is recycled back to the plasma membrane. (nature.com)
  • Here, we have studied the function of WDFY2, a cytosolic protein that has been described to reside on endocytic vesicles close to the plasma membrane 6 . (nature.com)
  • Whereas APPL1- positive vesicles localize close to the plasma membrane, we observed that WDFY2 localized to a pool of vesicles that was further from the plasma membrane and negative for APPL1. (nature.com)
  • Here we describe large immobile protein assemblies at the plasma membrane in the yeast Saccharomyces cerevisiae that mark endocytic sites. (cienciavida.org)
  • Our discoveries have led to a deep understanding of how secretory vesicles interact with the cortical actin network prior to fusing with the plasma membrane to release the neurotransmitter. (edu.au)
  • We have identified a critical role of the phospholipid phosphatidylinositol (4,5) bisphosphate in coordinating the actin-mediated recruitment of secretory vesicles to the plasma membrane. (edu.au)
  • This active mechanism allows secretory vesicles to dock with the plasma membrane prior to fusion and is controlled by the effector cdc42. (edu.au)
  • This novel trafficking/chaperoning pathway underpins neurotransmission, as secretory vesicles rely on the zippering of SNARE proteins such as syntaxin-1 to undergo fusion with the plasma membrane. (edu.au)
  • The method is based on chemical compounds (photosensitisers) that localise specifically in the membranes of endocytic vesicles and, following activation by light, induce the rupture of the vesicular membranes. (nih.gov)
  • We show that viral assembly occurs within single-membrane compartments closely associated with endoplasmic reticulum (ER) membranes, though we failed to elucidate the exact nature of the virus-wrapping membranes. (bvsalud.org)
  • As their name suggests, IFITMs are membrane proteins, allowing them to police the cell surface and endocytic membranes that viruses must cross to invade cells. (life-science-alliance.org)
  • First, endocytic vesicles arise when the cellular membranes invaginate, and they fuse together to create early endosomes. (hindawi.com)
  • However, protein levels of components of cell membranes, vesicles and synapses, RNA modulation, and cellular structures (including tau and tubulin filaments) are markedly altered from the age of 75. (ibecbarcelona.eu)
  • In the poster section, Joanna Shisler (University of Illinois at Urbana-Champaign [UIUC], Urbana) reported that the modified virus, Ankara, activates nuclear factor κB through the mitogen-activated protein kinase, extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, possibly facilitating the host immune response. (cdc.gov)
  • We have previously shown that IBDV hijacks the endocytic pathway to construct viral replication complexes on endosomes linked to the Golgi complex (GC). (bvsalud.org)
  • We previously demonstrated that IBDV hijacks the endocytic pathway for establishing the viral replication complexes on endosomes associated with the Golgi complex (GC). (bvsalud.org)
  • In the poster section, Joanna Shisler (University of Illinois at Urbana-Champaign [UIUC], Urbana) reported that the modified virus, Ankara, activates nuclear factor κB through the mitogen-activated protein kinase, extracellular signal–regulated kinase (MEK)/extracellular signal–regulated kinase (ERK) pathway, possibly facilitating the host immune response. (cdc.gov)
  • To date, the function of WDFY2 in the endocytic pathway is poorly characterized. (nature.com)
  • To define the localization of WDFY2 in the endocytic pathway, we transiently transfected hTERT-RPE1 cells with green flourescent protein (GFP)-WDFY2 and performed structured illumination microscopy (SIM) together with APPL1 and EEA1 visualized with antibodies (Fig. 1a ). (nature.com)
  • However, some protease-sensitive determinants associate with MHC II earlier in the endocytic pathway, thereby avoiding destruction by lysosomal cathepsins. (silverchair.com)
  • In many cases and even within the same family, viruses utilize different endocytic pathways. (biomedcentral.com)
  • Whether both internalization pathways result in productive illness is hard to determine although studies BMS-387032 kinase inhibitor in human being keratinocytes support endocytic uptake as contributing to HSV-1 entry [7]. (bioskinrevive.com)
  • No consensus has been reached about the pathways of MHC internalization. (silverchair.com)
  • At this point TGFβ-1 signaling meets the endolysosomal compartment (hereafter referred to as lysosomes), which represents the site for processing and degradation of proteins delivered by endocytic and autophagic pathways [ 5 , 6 ]. (biomedcentral.com)
  • Internalization of proteins, lipids and other cargo can occur by one of several pathways that have different, but often overlapping, molecular requirements1-5. (cienciavida.org)
  • Untangling the viral replication pathways from host cell functions is challenging because viruses hijack cell machinery upon infection, creating cell conditions more conducive for virus production. (thermofisher.cn)
  • Although viral vectors have developed the means to escape from these vesicles, poor endosomal release is one of the major obstacles for non-viral vectors. (nih.gov)
  • It was further determined that cell entry of PSaV Cowden strain required actin rearrangements for vesicle internalization, endosomal trafficking from early to late endosomes through microtubules, and late endosomal acidification for uncoating. (biomedcentral.com)
  • For successful transgene expression, viruses administered into muscle must undergo a series of processes, including host cell interaction and internalization, intracellular sorting, long-range retrograde axonal transport, endosomal liberation, and nuclear import. (frontiersin.org)
  • On completion of my PhD, I took a postdoctoral position at the University of California, San Francisco, where I continued my training in the laboratory of Prof Mark von Zastrow, a renowned leader in the field of endocytic trafficking in the function of G-protein-coupled receptors, where I investigated the role of Ubiquitin in endosomal trafficking. (abdn.ac.uk)
  • A class of proteins involved in the transport of molecules via TRANSPORT VESICLES. (lookformedical.com)
  • The outer surface of these vesicles are covered with a lattice-like network of coat proteins, such as CLATHRIN, coat protein complex proteins, or CAVEOLINS. (lookformedical.com)
  • A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. (lookformedical.com)
  • Loss of Pcs impairs Rab11 localization on the trans-side of Golgi units and induces the cytoplasmic accumulation of post-Golgi vesicles bearing rhabdomere proteins, as observed in Rab11-deficiency. (sdbonline.org)
  • The present study unravels a new molecular system for vesicle-based axonal transport of proteins in male and female flies (Drosophila melanogaster). (sdbonline.org)
  • Interferon-induced transmembrane proteins (IFITMs) are antiviral factors that act uniquely and early in viral replication cycles to restrict the entry of a diverse range of primarily enveloped viruses into cells ( 1 ). (life-science-alliance.org)
  • Since the genomic sequence of HCV was determined, progress has been made towards understanding the functions of the HCV-encoded proteins and identifying the cellular receptor(s) responsible for adsorption and penetration of the virus particle into the target cells. (biomedcentral.com)
  • Our results demonstrate that SH3 (Src homology 3) domain-PRM (proline-rich motif) interactions involving multivalent linker proteins play central roles in concentrating NPFs at endocytic sites. (elifesciences.org)
  • The virus capsid is assembled by 60 copies of each of four structure proteins (VP1-4) in a stepwise process [ 8 ]. (biomedcentral.com)
  • An accumulation of those proteins and of lysosomal vesicles was further confirmed by independent methods. (biomedcentral.com)
  • Shortly after formation, however, the clathrin coat is removed and the vesicles are referred to as ENDOSOMES. (lookformedical.com)
  • An adaptor protein complex primarily involved in the formation of clathrin-related endocytotic vesicles (ENDOSOMES) at the CELL MEMBRANE. (lookformedical.com)
  • Pcs fused with the EM-tag APEX2 localizes on 150-300 nm vesicles at the trans-side of Golgi units, which are presumably fly recycling endosomes. (sdbonline.org)
  • Of these, IFITM3 potently inhibits viruses that enter cells through acidic endosomes, many of which are zoonotic and emerging viruses with bats (order Chiroptera) as their natural hosts. (life-science-alliance.org)
  • Mutation of this residue in microbat IFITM3 impairs restriction of representatives of four different virus families that enter cells via endosomes. (life-science-alliance.org)
  • Sorting of endocytic cargos occurs at specialized tubular domains of early endosomes. (nature.com)
  • These vesicles can then further mature into early endosomes containing the canonical marker EEA1 9 . (nature.com)
  • We have identified a novel mechanism by which dynamin and actin coordinate a series of membrane events that culminate in the formation of bulk endosomes from which new synaptic vesicles emanate at the neuromuscular junction. (edu.au)
  • Thus, in MDCK cell transformants that express the VSV G protein, cytochalasin blocked the internalization of an anti-G mAb bound to apical G molecules, but did not reduce the uptake of antibody bound to the basolateral surface. (rupress.org)
  • The actin cytoskeleton appears to play a critical role in adsorptive as well as fluid phase apical endocytic events, since treatment with cytochalasin D prevented the apical uptake of cationized ferritin, that occurs after the marker binds to the cell surface, as well as uptake of Lucifer yellow, a fluorescent soluble dye. (rupress.org)
  • On the other hand, it did not inhibit the basolateral uptake of Lucifer yellow, nor did it prevent infection with VSV from the basolateral surface, or with influenza when this virus was applied to monolayers in which the formation of tight junctions had been prevented by depletion of calcium ions. (rupress.org)
  • Quantitative Analysis of Extracellular Vesicle Uptake and Fusion with Recipient Cells. (kyoto-u.ac.jp)
  • A molecular understanding of membrane traffic has broad implications for our understanding of growth control in cancer, receptor trafficking errors in heart disease, regulation of insulin secretion in diabetes and synaptic vesicle biogenesis and transport in neurological disorders. (stanford.edu)
  • We also developed a new technique sdTIM, Subdiffractional tracking of internalised molecules, to be able to visualise small synaptic vesicles in living hippocampal nerve terminals (Joensuu et al. (edu.au)
  • This super-resolution technique was able to capture, and subsequently analyse, the dynamics of thousands of individual synaptic vesicle trajectories, to uncover the dynamics of synaptic vesicle pool mobility. (edu.au)
  • It revealed diffusive and transport states of synaptic vesicles in resting and stimulated conditions. (edu.au)
  • Plays a role in synaptic plasticity by regulating t he trafficking and internalization of AMPA receptors. (univ-amu.fr)
  • One area of particular interest is the role of ubiquitination in directing receptor translocation to intralumenal vesicles and its requirement or otherwise for trafficking to the lysosome. (abdn.ac.uk)
  • These findings indicate that there is a fundamental difference in the process by which endocytic vesicles are formed at the two surfaces of polarized epithelial cells and that the integrity and/or the polymerization of actin filaments are required at the apical surface. (rupress.org)
  • Actin filaments in microvilli may be part of a mechanochemical motor that moves membrane components along the microvillar surface towards intermicrovillar spaces, or provides the force required for converting a membrane invagination or pit into an endocytic vesicle within the cytoplasm. (rupress.org)
  • In yeast, Arp2/3-mediated actin filament assembly drives endocytic membrane invagination and vesicle scission. (elifesciences.org)
  • Here we used genetics and quantitative live-cell imaging to probe the mechanisms that concentrate NPFs at endocytic sites, and to investigate how NPFs regulate actin assembly onset. (elifesciences.org)
  • These studies provide evidence that WASP and WIP play central roles in establishment of a robust multivalent SH3 domain-PRM network in vivo, giving actin assembly onset at endocytic sites a switch-like behavior. (elifesciences.org)
  • We have recently uncovered a new mechanism that allows secretory vesicles to be recruited on the cortical actin network. (edu.au)
  • Exosomes were first described in 1981 as ATPase-containing vesicles exfoliated from cells and were found in various normal cells and tumor cells [ 16 ]. (hindawi.com)
  • Crucially, some viral vectors (i.e., viruses specifically used to deliver genetic material into cells) have the potential to circumvent the blood-brain- (BBB) and blood-spinal cord barriers (BSCB) when intravenously injected. (frontiersin.org)
  • The main structural coat protein of COATED VESICLES which play a key role in the intracellular transport between membranous organelles. (lookformedical.com)
  • They play a role in the intracellular transport of molecules contained within membrane vesicles. (lookformedical.com)
  • Viruses are obligatory intracellular parasites, and so must deliver their genetic material into host cells to initiate infection. (biomedcentral.com)
  • It has been recognized that under physiological and pathological conditions, cells may release vesicles that may be instrumental in intercellular communication as they carry biologically active molecules ( 1 - 4 ). (spandidos-publications.com)
  • Moreover, the drug efficiently blocked infection of the cells with influenza virus, when the viral inoculum was applied to the apical surface. (rupress.org)
  • Administration of gene therapy viruses into skeletal muscle, where distal terminals of motor and sensory neurons reside, has been shown to result in extensive transduction of cells within the spinal cord, brainstem, and sensory ganglia. (frontiersin.org)
  • Aliotta et al ( 15 ) demonstrated that lung-derived vesicles carried RNA to marrow cells and altered the phenotype of these cells both genetically and functionally. (spandidos-publications.com)
  • Vesicles derived from adult human liver stem-like cells (HLSCs) have also been shown to contain ribonucleoproteins and different RNA species involved in hepatic regeneration ( 20 ). (spandidos-publications.com)
  • DEC-205 (CD205), a member of the macrophage mannose receptor protein family, is the prototypic endocytic receptor of dendritic cells, whose ligands include phosphorothioated cytosine-guanosine (CpG) oligonucleotides, a motif often seen in bacterial or viral DNA. (uci.edu)
  • Interorganelle Tethering to Endocytic Organelles Determines Directional Cytokine Transport in CD4+ T Cells. (leica-microsystems.com)
  • This is based on the fact that viruses within this subfamily, such as the Mammalian orthoreovirus, Aquareovirus, Coltivirus, Cypovirus, etc., have the presence of a turreted protein on the inner capsid. (wikipedia.org)
  • The outer surface of these vesicles is covered with a lattice-like network of the protein CLATHRIN. (lookformedical.com)
  • Lipid-specific oligomerization of the Marburg virus matrix protein VP40 is regulated by two distinct interfaces for virion assembly. (uci.edu)
  • affinity acid mechanism in base pollutants transduces with the complex of the many granule( protein) during the active M Calcium and increases in the core cleavage of the other enzyme internalization, a expression solely used triphosphate bike tumor polypeptide. (erik-mill.de)
  • Here, we report that MHC I and MHC II were internalized by separate endocytic carriers that lacked transferrin receptor. (silverchair.com)
  • Marburg virus (MARV) is a lipid-enveloped virus harboring a negative sense RNA genome, which has caused sporadic outbreaks of viral hemorrhagic fever in Sub-Saharan Africa. (uci.edu)
  • We recently developed a generic method for producing polymer-supported lipid bilayers directly from cell-derived native membrane vesicles (NMVs). (lu.se)
  • Infectious bursal disease virus (IBDV), the prototypic family member, is the etiological agent of Gumboro disease, a highly contagious immunosuppressive disease in the poultry industry worldwide. (bvsalud.org)
  • Some diseases that occur as a result of this virus or are associated with this virus include mild upper respiratory illness, and gastrointestinal illness. (wikipedia.org)
  • The attempts to treat virus infections occur even earlier than there was an understanding of the concept of a virus as an independent entity. (medsci.org)
  • In this review article, we outline key characteristics of major gene therapy viruses-adenovirus, adeno-associated virus (AAV), and lentivirus-and summarize the mechanisms regulating important steps in the virus journey from binding at peripheral nerve terminals to nuclear delivery. (frontiersin.org)
  • Extracellular vesicle DNA from human melanoma tissues contains cancer-specific mutations. (gu.se)
  • Because of the importance of Munc18-1 in vesicle fusion, human mutations are linked to epilepsy and other neurological symptoms. (edu.au)
  • This can involve ubiquitin regulated sorting by the ESCRT complex (2), initial ubiquitin-indendent sorting (possibly by GASP) before ubiquitin and ESCRT mediated transfer to Intralumenal vesicles (3) or direct interaction with the ESCRT III component, independent of ubiquitination (4) mediated by ALIX. (abdn.ac.uk)
  • We established an infection style of murine epidermal bed sheets to investigate the contribution of the receptors, and used an experimental environment that allows the virus to enter the basal level of the skin. (bioskinrevive.com)
  • To study the adsorption, penetration and replication of the virus, a major obstacle has been the lack of an efficient and reproducible in vitro infection system. (biomedcentral.com)
  • The immune system could play a crucial role in virus infection. (medsci.org)
  • The successful development and implementation to intervene prevention and treatment of virus infection over the past hundred years have had great advances on human and animal health. (medsci.org)
  • However, to this day, in the fight against virus infection, there is no real winner. (medsci.org)
  • Rab11 often links vesicles to molecular motors, and this study finds that loss of the microtubule motor dynein also leads to defective Neuroglian and Ppk26 degradation. (sdbonline.org)
  • The study of pH stability of FMDV not only contributes to the exploration of molecule and mechanism information for FMDV uncoating, but also enlightens the development of FMDV vaccines, including the traditionally inactivated vaccines and the new VLP (virus-like particle) vaccines. (biomedcentral.com)
  • WDFY2 showed labeling of two vesicle pools, a small pool negative for both APPL1 and EEA1, and one major pool, which is positive for EEA1. (nature.com)
  • This approach will allow us to transfer our know ledge of virus entry mechanisms caused by studies in a variety of cellular lines into a knowledge of how HSV enters its organic target tissues. (bioskinrevive.com)
  • There have been strenuous efforts to reveal the mechanisms that the host defends itself against invasion by this virus. (medsci.org)
  • This study found that Parcas (Pcs) , recently shown to have guanine-nucleotide-exchange (GEF) activity toward Rab11, co-localizes with Rab11 on the trans-side of Golgi units and post-Golgi vesicles at the base of the rhabdomeres in pupal photoreceptors. (sdbonline.org)
  • Deciphering the intra- and intermolecular steps via which prepare secretory vesicles for fusion is key to understanding neuronal and hormonal communication. (edu.au)
  • Virus-mediated gene therapy has the potential to deliver exogenous genetic material into specific cell types to promote survival and counteract disease. (frontiersin.org)
  • Gene therapy viruses are non-replicating, but still hijack host cell machinery to express transgenes of interest in the nucleus. (frontiersin.org)
  • Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. (plos.org)
  • CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). (lookformedical.com)
  • The family is composed of nonenveloped viruses with a segmented double-stranded RNA (dsRNA) genome. (bvsalud.org)
  • How USMB regulates endocytic processes remains incompletely understood. (plos.org)
  • Furthermore, we show that microbat IFITM3 is S-palmitoylated on cysteine residues C71, C72, and C105, mutation of each cysteine individually impairs virus restriction, and a triple C71A-C72A-C105A mutant loses all restriction activity, concomitant with subcellular re-localization of microbat IFITM3 to Golgi-associated sites. (life-science-alliance.org)
  • method to introduce genetic material into select neuronal populations is by virus administration into muscle, which is the focus of this review. (frontiersin.org)
  • The foot-and-mouth disease virus (FMDV) capsid is highly acid labile and tends to dissociate into pentameric subunits at acidic condition to release viral RNA for initiating virus replication. (biomedcentral.com)
  • Even though the replicative lifecycle of viruses differs greatly between species and categories, there are common stages that are essential for viral replication: attachment, entry and uncoating, replication, assembly, and release. (thermofisher.cn)
  • Meaning, that a human infected with Mammalian orthoreovirus, regardless of the serotype, is nearly or completely asymptomatic, and therefore, don't exhibit signs or symptoms of the virus. (wikipedia.org)
  • The human Decay( NMD) download Drawing Dynamic Hands dissociates the decarboxylation of vesicles being viral complex physics( PTCs)( composed in Isken and Maquat 2007, Chang et al. (erik-mill.de)
  • When injected into a muscle, viruses are close to nerve endings for longer periods and at higher concentrations than when systemically injected. (frontiersin.org)
  • EM demonstrated that cytochalasin D leads to an increase in the number of coated pits in the apical surface where it suppresses the pinching off of coated vesicles. (rupress.org)
  • In the absence of both HVEM and nectin-1, illness was severely delayed resulting in greatly reduced viral spreading and virus production [4]. (bioskinrevive.com)
  • Gumboro illness is caused by the highly contagious immunosuppressive infectious bursal disease virus (IBDV), which affects the poultry industry globally. (bvsalud.org)
  • SARS-CoV-2, the virus responsible for COVID-19, is an enveloped, non-segmented, single-stranded positive-sense RNA (+ssRNA) virus and a newly identified β-coronavirus. (thermofisher.cn)
  • However, the acid stability of virus capsid is greatly required for the maintenance of intact virion during the process of virus culture and vaccine production. (biomedcentral.com)