scholarly journals The Block in Assembly of Modified Vaccinia Virus Ankara in HeLa Cells Reveals New Insights into Vaccinia Virus Morphogenesis

2002 ◽  
Vol 76 (16) ◽  
pp. 8318-8334 ◽  
Author(s):  
M. Carmen Sancho ◽  
Sibylle Schleich ◽  
Gareth Griffiths ◽  
Jacomine Krijnse-Locker
Keyword(s):  
Vaccinia Virus ◽  
Hela Cells ◽  
Immunofluorescence Microscopy ◽  
Close Association ◽  
Viral Dna ◽  
Virus Morphogenesis ◽  
Modified Vaccinia Virus Ankara ◽  
Replication Sites ◽  
Mature Virus ◽  
H 30

ABSTRACT It has previously been shown that upon infection of HeLa cells with modified vaccinia virus Ankara (MVA), assembly is blocked at a late stage of infection and immature virions (IVs) accumulate (G. Sutter and B. Moss, Proc. Natl. Acad. Sci. USA 89:10847-10851, 1992). In the present study the morphogenesis of MVA in HeLa cells was studied in more detail and compared to that under two conditions that permit the production of infectious particles: infection of HeLa cells with the WR strain of vaccinia virus (VV) and infection of BHK cells with MVA. Using several quantitative and qualitative assays, we show that early in infection, MVA in HeLa cells behaves in a manner identical to that under the permissive conditions. By immunofluorescence microscopy (IF) at late times of infection, the labelings for an abundant membrane protein of the intracellular mature virus, p16/A14L, and the viral DNA colocalize under permissive conditions, whereas in HeLa cells infected with MVA these two structures do not colocalize to the same extent. In both permissive and nonpermissive infection, p16-labeled IVs first appear at 5 h postinfection. In HeLa cells infected with MVA, IVs accumulated predominantly outside the DNA regions, whereas under permissive conditions they were associated with the viral DNA. At 4 h 30 min, the earliest time at which p16 is detected, the p16 labeling was found predominantly in a small number of distinct puncta by IF, which were distinct from the sites of DNA in both permissive and nonpermissive infection. By electron microscopy, no crescents or IVs were found at this time, and the p16-labeled structures were found to consist of membrane-rich vesicles that were in continuity with the cellular endoplasmic reticulum. Over the next 30 min of infection, a large number of p16-labeled crescents and IVs appeared abruptly under both permissive and nonpermissive conditions. Under permissive conditions, these IVs were in close association with the sites of DNA, and a significant amount of these IVs engulfed the viral DNA. In contrast, under nonpermissive conditions, the IVs and DNA were mostly in separate locations and relatively few IVs acquired DNA. Our data show that in HeLa cells MVA forms normal DNA replication sites and normal viral precursor membranes but the transport between these two structures is inhibited.

scholarly journals Entry of the Two Infectious Forms of Vaccinia Virus at the Plasma Membane Is Signaling-Dependent for the IMV but Not the EEV

2000 ◽  
Vol 11 (7) ◽  
pp. 2497-2511 ◽  
Author(s):  
Jacomine Krijnse Locker ◽  
Annett Kuehn ◽  
Sibylle Schleich ◽  
Gaby Rutter ◽  
Heinrich Hohenberg ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Surface ◽  
Vaccinia Virus ◽  
Hela Cells ◽  
Signaling Cascade ◽  
Enveloped Virus ◽  
Kinase C ◽  
Mature Virus

The simpler of the two infectious forms of vaccinia virus, the intracellular mature virus (IMV) is known to infect cells less efficiently than the extracellular enveloped virus (EEV), which is surrounded by an additional, TGN-derived membrane. We show here that when the IMV binds HeLa cells, it activates a signaling cascade that is regulated by the GTPase rac1 and rhoA, ezrin, and both tyrosine and protein kinase C phosphorylation. These cascades are linked to the formation of actin and ezrin containing protrusions at the plasma membrane that seem to be essential for the entry of IMV cores. The identical cores of the EEV also appear to enter at the cell surface, but surprisingly, without the need for signaling and actin/membrane rearrangements. Thus, in addition to its known role in wrapping the IMV and the formation of intracellular actin comets, the membrane of the EEV seems to have evolved the capacity to enter cells silently, without a need for signaling.

scholarly journals The vaccinia virus F12L protein is associated with intracellular enveloped virus particles and is required for their egress to the cell surface

2002 ◽  
Vol 83 (1) ◽  
pp. 195-207 ◽  
Author(s):  
Henriette van Eijl ◽  
Michael Hollinshead ◽  
Gaener Rodger ◽  
Wei-Hong Zhang ◽  
Geoffrey L. Smith
Keyword(s):  
Cell Surface ◽  
Vaccinia Virus ◽  
Virus Particles ◽  
Enveloped Virus ◽  
Virus Morphogenesis ◽  
C Terminus ◽  
Specific Proteins ◽  
Infected Cells ◽  
Mature Virus ◽  
Confocal And Electron Microscopy

The vaccinia virus (VV) F12L gene encodes a 65 kDa protein that is expressed late during infection and is important for plaque formation, EEV production and virulence. Here we have used a recombinant virus (vF12LHA) in which the F12L protein is tagged at the C terminus with an epitope recognized by a monoclonal antibody to determine the location of F12L in infected cells and whether it associates with virions. Using confocal and electron microscopy we show that the F12L protein is located on intracellular enveloped virus (IEV) particles, but is absent from immature virions (IV), intracellular mature virus (IMV) and cell-associated enveloped virus (CEV). In addition, F12L shows co-localization with endosomal compartments and microtubules. F12L did not co-localize with virions attached to actin tails, providing further evidence that actin tails are associated with CEV but not IEV particles. In vΔF12L-infected cells, virus morphogenesis was arrested after the formation of IEV particles, so that the movement of these virions to the cell surface was inhibited and CEV particles were not found. Previously, virus mutants lacking IEV- or EEV-specific proteins were either unable to make IEV particles (vΔF13L and vΔB5R), or were unable to form actin tails after formation of CEV particles (vΔA36R, vΔA33R, vΔA34R). The F12L deletion mutant therefore defines a new stage in the morphogenic pathway and the F12L protein is implicated as necessary for microtubule-mediated egress of IEV particles to the cell surface.

scholarly journals The Vaccinia Virus E8R Gene Product: a Viral Membrane Protein That Is Made Early in Infection and Packaged into the Virions' Core

2002 ◽  
Vol 76 (19) ◽  
pp. 9773-9786 ◽  
Author(s):  
Laura Doglio ◽  
Ario De Marco ◽  
Sibylle Schleich ◽  
Norbert Roos ◽  
Jacomine Krijnse Locker
Keyword(s):  
Life Cycle ◽  
Membrane Protein ◽  
Vaccinia Virus ◽  
Gene Product ◽  
Viral Entry ◽  
Hela Cells ◽  
Two Dimensional Gel Electrophoresis ◽  
Dna Viruses ◽  
Replication Sites

ABSTRACT Vaccinia virus (VV), a member of the poxvirus family, is unique among most other DNA viruses in that both transcription and DNA replication occur in the cytoplasm of the host cell. It was recently shown by electron microscopy (EM) that soon after viral DNA synthesis is initiated in HeLa cells, the replication sites become enwrapped by the membrane of the endoplasmic reticulum (ER). In the same study, a novel VV membrane protein, the E8R gene product, that may play a role in the ER wrapping process was identified (N. Tolonen, L. Doglio, S. Schleich, and J. Krijnse Locker, Mol. Biol. Cell 12:2031-2046, 2001). In the present study, the gene product of E8R was characterized both biochemically and morphologically. We show that E8R is made predominantly early in infection but is packaged into the virion. On two-dimensional gel electrophoresis, the protein appeared as a single spot throughout the VV life cycle; however, in the assembled virion, the protein underwent several modifications which resulted in a change in its molecular weight and its isoelectric point. EM of labeled cryosections of infected HeLa cells showed that the protein localized to the ER and to membranes located on one side of the Golgi complex as early as 1 h postinfection. Late in infection, E8R was additionally associated with membranes of immature virions and with intracellular mature viruses. Although E8R is predominantly associated with membranes, we show that the protein is associated with viral cores; the protein is present in cores made with NP-40-dithiothreitol as well as in incoming cores, the result of the viral entry process, early in infection. Finally, we show that E8R can be phosphorylated in vitro by the viral kinase F10L. It is able to bind DNA in vitro, and this binding may be modulated by phosphorylation by F10L. A putative role of the E8R gene product throughout the VV life cycle is discussed.

Biochemical and electron microscopic observations of vaccinia virus morphogenesis in HeLa cells after hydroxyurea reversal

Virology ◽  
1974 ◽  
Vol 61 (2) ◽  
pp. 376-396 ◽  
Author(s):  
William Fil ◽  
John A. Holowczak ◽  
Lizabeth Flores ◽  
Virginia Thomas
Keyword(s):  
Vaccinia Virus ◽  
Hela Cells ◽  
Electron Microscopic ◽  
Virus Morphogenesis

scholarly journals Role of Viral Factor E3L in Modified Vaccinia Virus Ankara Infection of Human HeLa Cells: Regulation of the Virus Life Cycle and Identification of Differentially Expressed Host Genes

2005 ◽  
Vol 79 (4) ◽  
pp. 2584-2596 ◽  
Author(s):  
Holger Ludwig ◽  
Jörg Mages ◽  
Caroline Staib ◽  
Michael H. Lehmann ◽  
Roland Lang ◽  
...  
Keyword(s):  
Life Cycle ◽  
Vaccinia Virus ◽  
Hela Cells ◽  
Immune Defense ◽  
Oligoadenylate Synthetase ◽  
Molecular Monitoring ◽  
Late Gene Expression ◽  
Modified Vaccinia Virus Ankara ◽  
Inducible Protein

ABSTRACT Modified vaccinia virus Ankara (MVA) is a highly attenuated virus strain being developed as a vaccine for delivery of viral and recombinant antigens. The MVA genome lacks functional copies of numerous genes interfering with host response to infection. The interferon resistance gene E3L encodes one important viral immune defense factor still made by MVA. Here we demonstrate an essential role of E3L to allow for completion of the MVA molecular life cycle upon infection of human HeLa cells. A deletion mutant virus, MVA-ΔE3L, was found defective in late protein synthesis, viral late transcription, and viral DNA replication in infected HeLa cells. Moreover, we detected viral early and continuing intermediate transcription associated with degradation of rRNA, indicating rapid activation of 2′-5′-oligoadenylate synthetase/RNase L in the absence of E3L. Further molecular monitoring of E3L function by microarray analysis of host cell transcription in MVA- or MVA-ΔE3L-infected HeLa cells revealed an overall significant down regulation of more than 50% of cellular transcripts expressed under mock conditions already at 5 h after infection, with a more prominent shutoff following MVA-ΔE3L infection. Interestingly, a cluster of genes up regulated exclusively in MVA-ΔE3L-infected cells could be identified, including transcripts for interleukin 6, growth arrest and DNA damage-inducible protein β, and dual-specificity protein phosphatases. Our data indicate that lack of E3L inhibits MVA antigen production in human HeLa cells at the level of viral late gene expression and suggest that E3L can prevent activation of additional host factors possibly affecting the MVA molecular life cycle.

scholarly journals The Vaccinia Virus I3L Gene Product Is Localized to a Complex Endoplasmic Reticulum-Associated Structure That Contains the Viral Parental DNA

2003 ◽  
Vol 77 (10) ◽  
pp. 6014-6028 ◽  
Author(s):  
Sonja Welsch ◽  
Laura Doglio ◽  
Sibylle Schleich ◽  
Jacomine Krijnse Locker
Keyword(s):  
Endoplasmic Reticulum ◽  
Dna Replication ◽  
Vaccinia Virus ◽  
Gene Product ◽  
Close Association ◽  
Viral Dna ◽  
Mrna Accumulation ◽  
Double Labeling ◽  
Viral Dna Replication ◽  
Early Protein

ABSTRACT The vaccinia virus (VV) I3L gene product is a single-stranded DNA-binding protein made early in infection that localizes to the cytoplasmic sites of viral DNA replication (S. C. Rochester and P. Traktman, J. Virol. 72:2917-2926, 1998). Surprisingly, when replication was blocked, the protein localized to distinct cytoplasmic spots (A. Domi and G. Beaud, J. Gen. Virol. 81:1231-1235, 2000). Here these I3L-positive spots were characterized in more detail. By using an anti-I3L peptide antibody we confirmed that the protein localized to the cytoplasmic sites of viral DNA replication by both immunofluorescence and electron microscopy (EM). Before replication had started or when replication was inhibited with hydroxyurea or cytosine arabinoside, I3L localized to distinct cytoplasmic punctate structures of homogenous size. We show that these structures are not incoming cores or cytoplasmic sites of VV early mRNA accumulation. Instead, morphological and quantitative data indicate that they are specialized sites where the parental DNA accumulates after its release from incoming viral cores. By EM, these sites appeared as complex, electron-dense structures that were intimately associated with the cellular endoplasmic reticulum (ER). By double labeling of cryosections we show that they contain DNA and a viral early protein, the gene product of E8R. Since E8R is a membrane protein that is able to bind to DNA, the localization of this protein to the I3L puncta suggests that they are composed of membranes. The results are discussed in relation to our previous data showing that the process of viral DNA replication also occurs in close association with the ER.

scholarly journals Plasma Membrane Budding as an Alternative Release Mechanism of the Extracellular Enveloped Form of Vaccinia Virus from HeLa Cells

2003 ◽  
Vol 77 (18) ◽  
pp. 9931-9942 ◽  
Author(s):  
Andrea Meiser ◽  
Carmen Sancho ◽  
Jacomine Krijnse Locker
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Vaccinia Virus ◽  
Hela Cells ◽  
International Health ◽  
Health Department ◽  
Release Mechanism ◽  
Enveloped Virus ◽  
Modified Vaccinia Virus Ankara ◽  
Membrane Budding

ABSTRACT In HeLa cells the assembly of modified vaccinia virus Ankara (MVA), an attenuated vaccinia virus (VV) strain, is blocked. No intracellular mature viruses (IMVs) are made and instead, immature viruses accumulate, some of which undergo condensation and are released from the cell. The condensed particles may undergo wrapping by membranes of the trans-Golgi network and fusion with the plasma membrane prior to their release (M. W. Carroll and B. Moss, Virology 238:198-211, 1997). The present study shows by electron microscopy (EM), however, that the dense particles made in HeLa cells are also released by a budding process at the plasma membrane. By labeling the plasma membrane with antibodies to B5R, a membrane protein of the extracellular enveloped virus, we show that budding occurs at sites that concentrate this protein. EM quantitation revealed that the cell surface around a budding profile was as strongly labeled with anti-B5R antibody as were the extracellular particles, whereas the remainder of the plasma membrane was significantly less labeled. To test whether budding was a characteristic of MVA infection, HeLa cells were infected with the replication competent VV strains Western Reserve strain (WR) and International Health Department strain-J (IHD-J) and also prepared for EM. EM analyses, surprisingly, revealed for both virus strains IMVs that evidently budded at the cell surface at sites that were significantly labeled with anti-B5R. EM also indicated that budding of MVA dense particles was more efficient than budding of IMVs from WR- or IHD-J-infected cells. This was confirmed by semipurifying [35S]methionine-labeled dense particles or extracellular enveloped virus (EEVs) from the culture supernatant of MVA- or IHD-J-infected HeLa cells, respectively, showing that threefold more labeled dense particles were secreted than EEVs. Finally, although the released MVA dense particles contain some DNA, they are not infectious, as assessed by plaque assays.

scholarly journals Intracellular Transport of Vaccinia Virus in HeLa Cells Requires WASH-VPEF/FAM21-Retromer Complexes and Recycling Molecules Rab11 and Rab22

2015 ◽  
Vol 89 (16) ◽  
pp. 8365-8382 ◽  
Author(s):  
Jye-Chian Hsiao ◽  
Li-Wei Chu ◽  
Yung-Tsun Lo ◽  
Sue-Ping Lee ◽  
Tzu-Jung Chen ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Membrane Fusion ◽  
Hela Cells ◽  
Fluid Phase ◽  
Content Type ◽  
Virus Core ◽  
Early Endosomes ◽  
Fluid Phase Endocytosis ◽  
Mature Virus ◽  
In Cells

ABSTRACTVaccinia virus, the prototype of theOrthopoxvirusgenus in the familyPoxviridae, infects a wide range of cell lines and animals. Vaccinia mature virus particles of the WR strain reportedly enter HeLa cells through fluid-phase endocytosis. However, the intracellular trafficking process of the vaccinia mature virus between cellular uptake and membrane fusion remains unknown. We used live imaging of single virus particles with a combination of various cellular vesicle markers, to track fluorescent vaccinia mature virus particle movement in cells. Furthermore, we performed functional interference assays to perturb distinct vesicle trafficking processes in order to delineate the specific route undertaken by vaccinia mature virus prior to membrane fusion and virus core uncoating in cells. Our results showed that vaccinia virus traffics to early endosomes, where recycling endosome markers Rab11 and Rab22 are recruited to participate in subsequent virus trafficking prior to virus core uncoating in the cytoplasm. Furthermore, we identified WASH-VPEF/FAM21-retromer complexes that mediate endosome fission and sorting of virus-containing vesicles prior to virus core uncoating in the cytoplasm.IMPORTANCEVaccinia mature virions of the WR strain enter HeLa cells through fluid phase endocytosis. We previously demonstrated that virus-containing vesicles are internalized into phosphatidylinositol 3-phosphate positive macropinosomes, which are then fused with Rab5-positive early endosomes. However, the subsequent process of sorting the virion-containing vesicles prior to membrane fusion remains unclear. We dissected the intracellular trafficking pathway of vaccinia mature virions in cells up to virus core uncoating in cytoplasm. We show that vaccinia mature virions first travel to early endosomes. Subsequent trafficking events require the important endosome-tethered protein VPEF/FAM21, which recruits WASH and retromer protein complexes to the endosome. There, the complex executes endosomal membrane fission and cargo sorting to the Rab11-positive and Rab22-positive recycling pathway, resulting in membrane fusion and virus core uncoating in the cytoplasm.

An association between replicating adenovirus DNA and the nuclear matrix of infected HeLa cells

1985 ◽  
Vol 63 (6) ◽  
pp. 654-660 ◽  
Author(s):  
H. B. Younghusband
Keyword(s):  
Hela Cells ◽  
Nuclear Matrix ◽  
Close Association ◽  
Human Adenovirus ◽  
Adenovirus Type ◽  
Viral Dna ◽  
Chase Period ◽  
Nuclease Digestion ◽  
Mature Virus Particle ◽  
Cellular Dna

An association between newly synthesized human adenovirus type 5 DNA and the nuclear matrix of infected HeLa cells is described. Adenovirus-infected cells were pulsed labeled with [3H]thymidine late in infection and the nuclear matrix was prepared. After a 1-min pulse more than 95% of the labeled viral DNA was matrix associated and, when compared with total cell DNA, was resistant to DNase I digestion. When the pulse is longer or is followed by a chase period, the viral DNA remains nuclear matrix associated and less nuclease sensitive than bulk cellular DNA. The resistance to nuclease digestion may result from the close association of viral DNA with the nuclear matrix or could be due to a number of viral-specific proteins which are nuclear matrix associated. It is concluded that viral DNA synthesis occurs in association with the nuclear matrix and the newly synthesized DNA remains matrix associated until it is incorporated into a mature virus particle.

scholarly journals Slowly Declining Levels of Viral RNA and DNA in DNA/Recombinant Modified Vaccinia Virus Ankara-Vaccinated Macaques with Controlled Simian-Human Immunodeficiency Virus SHIV-89.6P Challenges

2002 ◽  
Vol 76 (20) ◽  
pp. 10147-10154 ◽  
Author(s):  
Yuyang Tang ◽  
Francois Villinger ◽  
Silvija I. Staprans ◽  
Rama Rao Amara ◽  
James M. Smith ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Vaccinia Virus ◽  
Infectious Virus ◽  
Vaccine Trial ◽  
Decay Rates ◽  
Viral Rna ◽  
Viral Dna ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus ◽  
Rna And Dna

ABSTRACT In a recent vaccine trial, we showed efficient control of a virulent simian-human immunodeficiency virus SHIV-89.6P challenge by priming with a Gag-Pol-Env-expressing DNA and boosting with a Gag-Pol-Env- expressing recombinant-modified vaccinia virus Ankara. Here we show that long-term control has been associated with slowly declining levels of viral RNA and DNA. In the vaccinated animals both viral DNA and RNA underwent an initial rapid decay, which was followed by a lower decay rate. Between 12 and 70 weeks postchallenge, the low decay rates have had half-lives of about 20 weeks for viral RNA in plasma and viral DNA in peripheral blood mononuclear cells and lymph nodes. In vaccinated animals the viral DNA has been mostly unintegrated and has appeared to be largely nonfunctional as evidenced by a poor ability to recover infectious virus in cocultivation assays, even after CD8 depletion. In contrast, in control animals, which have died, viral DNA was mostly integrated and a larger proportion appeared to be functional as evidenced by the recovery of infectious virus. Thus, to date, control of the challenge infection has appeared to improve with time, with the decay rates for viral DNA being at the lower end of values reported for patients on highly active antiretroviral therapy.

Sign in / Sign up

Export Citation Format

Share Document