| virus-induced diabetes mellitus: mengovirus infects pancreatic beta cells in strains of mice resistant to the diabetogenic effect of encephalomyocarditis virus. | in mice, mengovirus produces a fatal encephalitis. plaque purification of the virus resulted in the isolation of a clone (mengo- 2t ), which in addition to encephalitis caused diabetes. microscopic examination of pancreases from infected mice revealed necrosis in the islets of langerhans and infiltration of inflammatory cells. by immunofluorescence viral antigens were found in the islets, and radioimmunoassays demonstrated a substantial decrease in pancreatic immunoreactive insulin. studies on s ... | 1984 | 6327999 |
| effects of interferon on drug metabolism. | the induction and passive transfer of interferons have been shown to depress the level of cytochrome p-450 drug metabolism system of liver microsomes. inducers of alpha or beta (type i) interferons, such as tilorone-hcl, statalon, mengovirus and others, suppressed the cytochrome p-450 system of rats or mice after administration. induction of gamma (type ii) interferon also resulted in depression of the cytochrome p-450 system of mice. the gamma interferon was induced by sensitization of mice wit ... | 1981 | 6817439 |
| comparison of surface properties of picornaviruses: strategies for hiding the receptor site from immune surveillance. | the surface topology and sequence conservation of different picornaviruses have been compared using molecular graphics and statistical analyses. the comparisons suggest that the canyons, surface depressions encircling the fivefold axes, are the sites of receptor attachment of enteroviruses as well as human rhinovirus (hrv). in hrv14, the receptor binding footprint extends beyond the canyon (olson et al. (1993), proc. natl. acad. sci. usa 90, 507-511), but these more exposed regions are not conse ... | 1993 | 8337843 |
| effect of canavanine on murine retrovirus polypeptide formation. | canavanine is an arginine analog which is widely used to inhibit proteolytic processing of viral polyproteins. certain results obtained with canavanine have suggested that it may have other effects. therefore, we examined the effects of canavanine on the cell-free synthesis of murine retrovirus proteins. it was found that the electrophoretic mobility of the major gag-related cell-free product of both rauscher murine leukemia virus (r-mulv) and moloney murine sarcoma virus 124 (mo-musv-124) rna w ... | 1980 | 7365878 |
| rna polymerase complexes from mengovirus infected cells. | | 1972 | 4341300 |
| capsid polypeptides of mouse elberfeld virus. i. amino acid compositions and molar ratios in the virion. | the four major polypeptide chains (alpha, beta, gamma, delta) constituting the capsid protein of mouse elberfeld (me) virus were isolated by preparative electrophoresis on polyacrylamide gels, and the amino acid composition of each chain was determined. in addition, the molecular weights of the smallest chains of me virus, mengovirus, and poliovirus, which had previously been determined by gel electrophoretic methods, were redetermined by gel filtration chromatography in 6 m guanidine hydrochlor ... | 1972 | 4342047 |
| mutational analysis of the mengovirus poly(c) tract and surrounding heteropolymeric sequences. | previously, we described three mengovirus mutants derived from cdna plasmids, containing shortened poly(c) tracts (c8, c12, and c13uc10), that exhibited strong attenuation for virulence in mice yet grew like wild-type virus in hela cells. thirteen additional mutants hav now been constructed and characterized. five of these differ only in poly(c) length, including one with a precise deletion of the tract. the other mutants bear deletions into the regions juxtaposing poly(c). studies with hela cel ... | 1996 | 8627731 |
| initiation of picornavirus protein synthesis in ascites cell extracts. | the current model of picornavirus protein formation implies that initiation of protein synthesis occurs at a single site on the viral rna, and that the large polypeptide formed is later cleaved. a direct test of this model was made in vitro by studying the incorporation of [(35)s]methionine from rabbit liver met-trna(m) (met) and fmet-trna(f) (met) into encephalomyocarditis virus rna-coded proteins in extracts of ehrlich ascites cells. the incorporation of n-formylmethionine was complete within ... | 1972 | 4345505 |
| transport as the rate-limiting step in the incorporation of uridine into mengovirus ribonucleic acid in novikoff rat hepatoma cells. | the incorporation of uridine into the nucleotide pool of actinomycin-treated, mengovirus-infected novikoff rat hepatoma cells in culture follows simple michaelis-menten kinetics, and the apparent v(max) and k(m) values are similar to those for uridine transport by uninfected cells. incorporation of uridine into mengovirus-specific ribonucleic acid (rna) also follows michaelis-menten kinetics, and the apparent k(m) (about 10 mum) is approximately the same as for uridine transport. inhibition of u ... | 1971 | 5543426 |
| protection of non-murine mammals against encephalomyocarditis virus using a genetically engineered mengo virus. | genetically engineered mengo viruses with artificial deletions in the 5' noncoding poly(c) tracts are highly attenuated for pathogenicity when introduced as live vaccines into the natural murine host. inoculation produces lifelong protective immunity without disease or viral persistence. this report extends the vaccination studies to non-murine hosts, including baboons, macaques and domestic pigs, all of which are susceptible to severe cardiovirus epizootics. all animals of these species that we ... | 1996 | 8852413 |
| effects of elevated temperatures on mengovirus ribonucleic acid synthesis and virus production in novikoff rat hepatoma cells. | the production of mengovirus in novikoff rat hepatoma cells is progressively reduced with an increase in incubation temperature of the cells from 34 to 40 c, in spite of the fact that about the same amounts of single-stranded and double-stranded viral ribonucleic acid (rna) are synthesized at 34, 37, and 40 c; the rate of overall protein synthesis is as high at 40 c as at 37 c. at 40 c, progeny viral rna accumulates in an undegraded form without being incorporated into virus particles. the resul ... | 1971 | 5543427 |
| ribosomes: effect of interferon on their interaction with rapidly labeled cellular and viral rna's. | rapidly labeled rna of mouse l cells and labeled rna of mengo virus, unlike cellular rna labeled under steady-state conditions, form detectable complexes with l-cell ribosomes. these ribosome-rna complexes formed in vitro appear analogous to those assembled during polysome formation in vivo. when ribosomes are prepared from l cells exposed to homologous interferon, their capacity to associate with cell messenger is preserved, while their ability to interact with viral rna is markedly reduced. th ... | 1967 | 6018644 |
| picornaviruses of two different genera have similar structures. | crystals of mengo virus were used to collect three-dimensional x-ray diffraction data to 7 a resolution. a self-rotation function showed the precise orientation of the mengo particles in the crystal unit cell. a cross-rotation function against similar data of cubic rhinovirus crystals showed a peak when the orientations of these two icosahedral viruses were superimposed. this demonstrates similarity of capsid construction between two picornaviruses of different taxonomic genera. | 1984 | 6098687 |
| epitope mapping of monoclonal antibodies raised to recombinant mengo 3d polymerase. | the cdna coding sequence of the rna-dependent rna polymerase (3dpol) of mengovirus was cloned and expressed in a bacterial system. eleven monoclonal antibodies were raised against the recombinant mengo 3dpol (rm3d). all of them recognized the recombinant and the viral-induced form of the protein. the panel of monoclonals belonged to the igg1 and igg2a isotypes and were mapped to four different epitopes in the 3d molecule by competition assays. all monoclonals recognized mengo 3dpol in western bl ... | 1996 | 8972569 |
| a multivalent minigene vaccine, containing b-cell, cytotoxic t-lymphocyte, and th epitopes from several microbes, induces appropriate responses in vivo and confers protection against more than one pathogen. | the development of safe and effective vaccines remains a major goal in the prevention, and perhaps treatment, of infectious diseases. ideally, a single vaccine would confer protection against several pathogens and would induce both cellular and humoral arms of the immune response. we originally demonstrated that two virus-specific cytotoxic t-lymphocyte (ctl) epitopes, from the same virus but presented by different major histocompatibility complex alleles, when linked in tandem as minigenes in a ... | 1997 | 9032365 |
| effect of interferon on transient shut-off of cellular rna and protein synthesis induced by mengo virus infection. | infection of mouse l929 cells with mengo virus resulted in a rapid shut-off of cellular rna synthesis followed within the first hours post infection by a gradual decrease in host protein synthesis. pretreatment of the cells with high doses of interferon, blocking viral multiplication, did not affect the virus-induced shut-off of host macromolecular synthesis. in these interferon-treated cells the 2',5'a-activated nuclease may account for the degradation of viral rna, soon after its replication. ... | 1981 | 6175273 |
| mechanism of antiviral action of quercetin against cardiovirus infection in mice. | oral treatment with quercetin protected abd2f1/jena mice significantly against intraperitoneal encephalomyocarditis, col, sk, mm, mengo m,l and mengom virus infections, but not against intracerebral challenge with mengom virus. enhanced resistance to mengom virus were induced in the genetically different dba 2/jena, c57bl/jena, c57bl/lati and abc2f1/jena mice, c57bl6/jena nu/nu mice were also protected, indicating that the thymus was non-essential to the protective effects of quercetin. in ab/je ... | 1981 | 6176184 |
| study of the immunogenicity of different recombinant mengo viruses expressing hiv1 and siv epitopes. | recombinant mengo viruses expressing heterologous genes have proven to be safe and immunogenic in both mice and primates, and to be able to induce both humoral and cellular immune responses (altmeyer et al., 1995, 1996). several recombinant mengo viruses expressing either a large region (aa 65-206) of the hiv1 nef gene product, or cytotoxic t lymphocyte (ctl) epitopic regions from the siv gag (aa 182-190), nef (aa 155-178) and pol (aa 587-601) gene products were engineered. the heterologous anti ... | 1998 | 9561560 |
| evolution of a common structural core in the internal ribosome entry sites of picornavirus. | the translational control involving internal ribosome binding occurs in poliovirus (pv), human rhinoviruses (hrv), encephalomyocarditis virus (emcv), foot-and-mouth disease virus (fmdv), and hepatitis a virus (hav). internal ribosome binding utilizes cis-acting genetic elements of approximately 450 nucleotides (nt) termed the internal ribosome entry sites (ires) found in these picornaviral 5'-untranslated region (5'utr). although these ires elements are quite different in their primary sequence, ... | 1998 | 9562889 |
| trans-encapsidation of a poliovirus replicon by different picornavirus capsid proteins. | a trans-encapsidation assay was established to study the specificity of picornavirus rna encapsidation. a poliovirus replicon with the luciferase gene replacing the capsid protein-coding region was coexpressed in transfected hela cells with capsid proteins from homologous or heterologous virus. successful trans-encapsidation resulted in assembly and production of virions whose replication, upon subsequent infection of hela cells, was accompanied by expression of luciferase activity. the amount o ... | 1998 | 9733835 |
| protection against lethal encephalomyocarditis virus infection in the absence of serum-neutralizing antibodies. | although the ability of serum-neutralizing antibodies to protect against picornavirus infection is well established, the contribution of cell-mediated immunity to protection is uncertain. using major histocompatibility complex class ii-deficient (rhabeta-/-) mice, which are unable to mediate cd4(+) t-lymphocyte-dependent humoral responses, we demonstrated antibody-independent protection against lethal encephalomyocarditis virus (emcv) infection in the natural host. the majority of rhabeta-/- mic ... | 1998 | 9733845 |
| genetically engineered mengo virus vaccination of multiple captive wildlife species. | encephalomyocarditis virus (emcv), has caused the deaths of many species of animals in zoological parks and research institutions. the audubon park zoo, (new orleans, louisiana, usa) attempted vaccination of several species with a killed emcv vaccine with mixed results. this paper reports an attempt at vaccination against emcv using a genetically engineered, live attenuated mengo virus (vmc0) at the audubon park zoo and miami metro zoo, (miami, florida, usa) from december 1996 to june 1997. seve ... | 1999 | 10231768 |
| selective irreversible inactivation of replicating mengovirus by nucleoside analogues: a new form of viral interference. | we describe the selective irreversible inhibition of mengovirus growth in cultured cells by a combination of two pyrrolopyrimidine nucleoside analogues, 5-bromotubercidin (brtu) and tubercidin (tu). at a concentration of 5 microgram/ml, brtu reversibly blocked the synthesis of cellular mrna and rrna but did not inhibit either mengovirus rna synthesis or multiplication. brtu is a potent inhibitor of adenosine kinase, and low concentrations of brtu (e.g., 0.5 microgram/ml), which did not by themse ... | 1999 | 10400738 |
| protein synthesis in extracts from interferon-treated mengo virus infected cells. | | 1982 | 6182881 |
| mengovirus and encephalomyocarditis virus poly(c) tract lengths can affect virus growth in murine cell culture. | many virulent aphthoviruses and cardioviruses have long homopolymeric poly(c) tracts in the 5' untranslated regions of their rna genomes. a panel of genetically engineered mengo-type cardioviruses has been described which contain a variety of different poly(c) tract lengths. studies of these viruses have shown the poly(c) tract to be dispensable for growth in hela cells, although the relative murine virulence of the viruses correlates directly and positively with tract length. compared with wild ... | 2000 | 10708422 |
| antiviral activity of a thymic factor in experimental viral infections. i. thymic hormonal effect on survival, interferon production and nk cell activity in mengo virus-infected mice. | a partially purified thymic factor, thymostimulin (ts), significantly increased the survival rate of adult, immune-intact mice infected with the neurotropic mengo virus. ts treatment was begun after virus inoculation by daily i.p. injections. in untreated c57bl/6 mice, ld50 was reached with 1 x 10(4) pfu, but 10-fold more virus (i.e., 1 x 10(5) pfu) was needed to reach ld50 in ts-treated animals. ts effect on survival, though, could be observed with several virus doses (1 x 10(3) to 1 x 10(6) pf ... | 1984 | 6202776 |
| evaluation of the antiviral activity of an aqueous extract from phyllanthus orbicularis. | the antiviral and cytotoxic activity of phyllanthus orbicularis, a member of the euphorbiaceae, was evaluated in tissue culture. an aqueous extract made from leaves and stems of this plant exhibited selective antiviral indexes of 12.3 and 26 against bovine herpesvirus type 1 and herpes simplex virus type 2, respectively, showing no selective antiviral activity against adenovirus type 5 and mengovirus. incubation with this plant extract during cell culture infection, impaired the productive repli ... | 2000 | 10967489 |
| broad antiviral activity in tissues of crustaceans. | innate antiviral substances occur in vertebrates and may function as host defenses. virus infections are common among invertebrates, but little is known about the ability of invertebrates to control viral infections. pre-existing antiviral substances may be particularly important, since invertebrates lack the antiviral defense conferred by specific immunity. in our study, we found that tissue extracts of blue crab (callinectes sapidus), shrimp (penaeus setiferus), and crayfish (procambarus clark ... | 2000 | 11080539 |
| attenuated mengo virus as a vector for immunogenic human immunodeficiency virus type 1 glycoprotein 120. | introduction of a sequence encoding 147 amino acids from human immunodeficiency virus type i (hiv-1) strain mn glycoprotein gp120 into the rna genome of the stably attenuated mengo virus strain vm16 yielded an infectious recombinant virus, vmln450, which expressed the heterologous hiv-1 sequence along with the normal mengo virus proteins. the hiv-1 gp120 sequence, fused to the amino terminus of the short, nonstructural mengo virus leader polypeptide was recognized by a gp120 v3 loop-specific mon ... | 1994 | 7937890 |
| translational control by messenger rna competition for eukaryotic initiation factor 2. | translation of globin mrna in a micrococcal nuclease-treated reticulocyte lysate was studied in the presence of increasing amounts of mengovirus rna, under conditions in which the number of translation initiation events remains constant as judged by the transfer of label from n-formyl[35s]methionyl-trnaf into protein. the translation of globin mrna is progressively inhibited by low concentrations of mengovirus rna, free of detectable traces of double-stranded rna, concomitant with the increasing ... | 1982 | 6274873 |
| a comparison of the translation of mengo virus rna and globin mrna in krebs ascites cell-free extracts. | | 1972 | 11946730 |
| social isolation modifies the response of mice to experimental mengo virus infection. | to investigate the effects of social isolation on host resistance male mice were housed either individually (ih) or in groups of four or five (gh). all animals were infected with mengom,l virus. incubation time (incub), duration of illness (ill), death rate (dr), histopathological changes, and serum corticosterone levels (cort) were recorded. first, the effect of ih starting 4 days prior to infection was studied in 5 different inbred strains. next, the effect of different ih length was examined, ... | 1994 | 8193172 |
| neuraminidase-sensitive erythrocyte receptor for enterovirus type 70. | enterovirus type 70 (ev70) agglutinated human 'o' erythrocytes at 4 degrees c as well as 22 degrees c, but visible agglutination was lost when warmed at 37 degrees c although the virus remained attached to the surface of the erythrocyte. the receptor sites for the virus were neuraminidase-sensitive. a direct involvement of sialic acid on the cell surface in virus-cell interaction was confirmed by the fact that the presence of fetuin or free n-acetylneuraminic acid inhibited the haemagglutinating ... | 1982 | 6294226 |
| a new look at viruses in type 1 diabetes. | type 1 diabetes (t1d) results from the destruction of pancreatic beta cells. genetic factors are believed to be a major component for the development of t1d, but the concordance rate for the development of diabetes in identical twins is only about 40%, suggesting that nongenetic factors play an important role in the expression of the disease. viruses are one environmental factor that is implicated in the pathogenesis of t1d. to date, 14 different viruses have been reported to be associated with ... | 2003 | 12592641 |
| the cellular u-particle, whose synthesis is induced by mengovirus infection, is homologous to apoferritin. | mengo virus infection of mouse l-cells results in induction of the synthesis of a cellular protein-containing particle, 12 nm in diameter, which was designated u (boege et al. (1987) virology 159, 358-367). we have purified the u-particle from virus-infected cells by a series of chromatographic steps and found it to be composed of two polypeptide species (mw 23,000 and 25,000), present in a ratio of approximately 7:3. neither of these polypeptides is measurably glycosylated or phosphorylated and ... | 1994 | 8259685 |
| a wild-type porcine encephalomyocarditis virus containing a short poly(c) tract is pathogenic to mice, pigs, and cynomolgus macaques. | previous studies using wild-type encephalomyocarditis virus (emcv) and mengo virus, which have long poly(c) tracts (61 to 146 c's) at the 5' nontranslated region of the genome, and variants of these viruses genetically engineered to truncate or substitute the poly(c) tracts have produced conflicting data on the role of the poly(c) tract in the virulence of these viruses. analysis of the nucleotide sequence of an emcv strain isolated from an aborted swine fetus (emcv 30/87) revealed that the viru ... | 2003 | 12915530 |
| characterization of mengo virus neutralization epitopes. ii. infection of mice with an attenuated virus. | a panel of five neutralizing monoclonal antibodies was generated from mice immunized with an attenuated strain of mengo virus. four of the antibodies were used to select mutants of mengo virus which were able to escape neutralization by the selecting antibody, but it was not possible to select mutants which could escape neutralization by the fifth antibody. the capsid coding region of the rna genome of each mutant was directly sequenced to identify the mutation(s) responsible for the neutralizat ... | 1995 | 8525606 |
| [induction of immune interferon by erythrogenic toxins a and b from streptococcus pyogenes]. | by interaction of streptococcal erythrogenic toxins a and b with chick embryo fibroblasts and human amnion (fl) cells an antiviral interferon-like factor was secreted. it inhibited the replication of vesicular stomatitis, vaccinia and mengo viruses. the streptococcal toxin type b was 50 times more cytotoxic for both cell cultures in comparison with streptococcal toxin a. the maximum tolerated doses of the two types of streptococcal toxins induced approximately the same antiviral protection effec ... | 1982 | 6817542 |
| characterization of interferon-alpha 13, a novel constitutive murine interferon-alpha subtype. | type-i interferons (ifns), also called ifns-alpha/beta, are a family of cytokines induced by viral infection and are primarily involved in antiviral defense of the cells. ifns-alpha/beta were also reported to be produced constitutively at low levels in mouse and human cells. these so-called endogenous or constitutive ifns are thought to exert important homeostatic functions in the uninfected host. by searching ifn genes that were not repressed by the leader protein of theiler's virus, we identif ... | 2003 | 12930842 |
| expression of a foreign gene by stable recombinant influenza viruses harboring a dicistronic genomic segment with an internal promoter. | based on the observation that an internally located 3' promoter sequence can be functional (r. flick and g. hobom, virology, 1999, 262(1), 93-103), we generated transfectant influenza a viruses harboring a dicistronic segment containing the cat gene (660 nt) or a fragment of the mengo virus vp0 capsid gene (306 nt) under the control of a duplicated 3' promoter sequence. despite slightly reduced na expression, the transfectant viruses replicated efficiently and proved to be stable upon both seria ... | 2003 | 12951036 |
| comparison of assays for mengovirus and reovirus-3. | | 1961 | 13701443 |
| the effect of cytotoxic lymphocytes on contraction, action potential and calcium handling in cultured myocardial cells. | cytotoxic t lymphocytes are important in the pathogenesis of several disease states, yet the pathophysiology of the lymphocyte-myocyte interaction is not well known. we have developed in vitro viral and autoimmune models to study the physiological phenomena associated with this interaction. to produce these models, lymphocytes were obtained from adult rats injected either with mengo virus or autologous cardiac myocytes. cardiac myocytes from neonatal rats were then exposed to these lymphocytes. ... | 1995 | 8540399 |
| induction of ferritin synthesis in cells infected with mengo virus. | we have recently identified ferritin as a cellular protein particle whose synthesis is stimulated in mouse or human cells infected by the picornavirus mengo. immunoprecipitation of the particle from infected murine l929 cells showed a 4- and 6-fold increase in the intracellular concentrations of h and l apoferritin subunits, respectively. this differential expression altered the h/l subunit ratio from 3.0 in uninfected cells to 2.2 in mengo virus-infected cells. the induction is not due to an in ... | 1996 | 8621669 |
| b cell epitopes of hiv type 1 p24 capsid protein: a reassessment. | the objective of the present study was to identify p24 antigenic domains recognized during natural human immunodeficiency virus type 1 (hiv-1) infection, the determination of the major epitopes of p24 having significant applications for both the improvement of diagnostic approaches and the development of vaccines. reactivity of 20 hiv-1-infected patients and 8 hiv-1-negative patients was analyzed using an enzyme-linked immunosorbent assay (elisa) developed with 45 overlapping synthetic pentadeca ... | 1996 | 8679307 |
| the isolation of three variants of mengo virus differing in plaque morphology and hemagglutinating characteristics. | | 1961 | 13889897 |
| mengovirus leader is involved in the inhibition of host cell protein synthesis. | the presence of a leader peptide in picornaviruses is restricted to the cardiovirus and aphthovirus genera. however, the leader peptides of these two genera are structurally and functionally unrelated. the aphthovirus leader is a protease involved in viral polyprotein processing and host cell translation shutoff. the function of the cardiovirus leader peptide is still unknown. to gain an insight into the function of the cardiovirus leader peptide, a mengovirus leader peptide deletion mutant was ... | 1996 | 8763999 |
| inhibition of 2-5a synthetase expression by antisense rna interferes with interferon-mediated antiviral and antiproliferative effects and induces anchorage-independent cell growth. | it has been shown previously that the ifn-induced enzyme 2-5a synthetase is sufficient to induce antiviral and antiproliferative effects in transfected cells expressing the protein. in this study, the possibility that this enzyme is also essential in generating these biological activities was investigated. for this purpose, a plasmid, pmsas-neo, was constructed. this plasmid carries an active neomycin-resistant gene. in addition, it contains a metallothionein promoter fused to an inverted 180-bp ... | 1996 | 8853892 |
| tandem mengovirus 5' pseudoknots are linked to viral rna synthesis, not poly(c)-mediated virulence. | the rna genomes from the cardioviruses, hepatoviruses, and aphthoviruses encode two to five tandem pseudoknots within their 5' untranslated regions. these pseudoknots lie adjacent to a pyrimidine-rich sequence, which in cardio- and aphthoviruses takes the form of a homopolymeric poly(c) tract. seven deletion mutations within mengovirus pseudoknots pk(b) and pk(c) were created and characterized. tested in tissue culture, mengovirus genomes with alterations in pk(c) were viable but had small plaqu ... | 1996 | 8892950 |
| molecular identification of cardioviruses by enzymatic amplification. | cardiovirus specific sequences located in the 5' ntr are used to amplify viral rna by pcr. general primers were selected for the amplification of cardioviruses, including encephalomyocarditis virus (emcv), mengovirus and theiler's murine encephalomyelitis virus (tmev. additionally, echo virus type 22, an atypical enterovirus, could also be detected with the general cardiovirus primers. an internal encephalomyocarditis virus specific probe and a general cardiovirus probe are used to discriminate ... | 1993 | 7511789 |
| mengo virus 3c proteinase: recombinant expression, intergenus substrate cleavage and localization in vivo. | mengo virus 3c proteinase was cloned and expressed to high levels in a bacterial vector system. the protein was solubilized from inclusion bodies then purified to homogeneity (> 95%) by ion exchange chromatography. the recombinant enzyme was proteolytically active in cell-free processing assays with a mengo capsid precursor substrate, l-p1-2a, correctly and proficiently cleaving it into l, 1ab, 1c, 1d and 2a protein products. further analyses with synthetic peptide substrates encompassing the me ... | 1996 | 8972564 |
| picornavirus-specific cd4+ t lymphocytes possessing cytolytic activity confer protection in the absence of prophylactic antibodies. | picornaviruses are a family of positive-strand rna viruses that are responsible for a variety of devastating human and animal diseases. an attenuated strain of mengovirus (vmc24) is serologically indistinguishable from the lethal murine wild-type mengovirus and encephalomyocarditis virus (emcv). immunogen-specific stimulation of vmc24-immune splenocytes in vitro demonstrates preferential activation of cd4+ lymphocytes. vmc24-immune splenocytes adoptively transferred to naive recipients conferred ... | 1995 | 7609060 |
| mengovirus-induced inhibition of host ribonucleic acid and protein synthesis. | | 1963 | 14097404 |
| effects of puromycin and p-fluorophenylalanine on mengovirus ribonucleic acid and protein synthesis. | | 1963 | 14097405 |
| the virion of mengovirus contains anti-interferon activity. | many viruses are resistant to the antiviral state induced by interferon (ifn) in certain cell lines because they produce factors having anti-ifn activity (aia). we show here that is+, a mengovirus strain resistant to low concentrations of ifn, also produces an aia, but that an ifn-sensitive mutant (is-1) does not. this activity was detected when is+ rescued is-1 from the antiviral state induced in mouse l cells by mouse ifn. the mengovirus aia was found in cell lysates prepared from cells infect ... | 1993 | 7681091 |
| encephalomyocarditis viruses with short poly(c) tracts are more virulent than their mengovirus counterparts. | we have constructed three cdna clones of encephalomyocarditis virus strain r (emcv-r) with poly(c) tracts of c4, c9, and c20. rna transcribed from these cdnas was infectious to hela cells, and the resultant viruses grew well in this system, albeit with plaque sizes that were proportional to the poly(c) length. when injected into mice, the progeny viruses were only slightly less pathogenic than emcv-r, and the observed degree of attenuation was not nearly as dramatic as for equivalent mengoviruse ... | 1995 | 7884926 |
| studies on the mechanism of interferon action. ii. the effect of interferon on some early events in mengo virus infection in l cells. | | 1964 | 14166118 |
| theiler's virus and mengo virus induce cross-reactive cytotoxic t lymphocytes restricted to the same immunodominant vp2 epitope in c57bl/6 mice. | c57bl/6 mice develop a virus-specific cytotoxic t-lymphocyte (ctl) response after intraperitoneal inoculation with either the da strain of theiler's virus or mengo virus, two members of the cardiovirus genus. these ctls contribute to viral clearance in the case of theiler's virus but do not protect the mice from the fatal encephalomyelitis caused by mengo virus. in this study we show that da and mengo virus-induced ctls are cross-reactive. the cross-reactivity is due to a conserved, h-2db-restri ... | 1997 | 9188606 |
| replication of mengovirus in chinese hamster ovary cells. la-3132-ms. | | 1964 | 14271615 |
| genetic analysis of mengovirus protein 2a: its function in polyprotein processing and virus reproduction. | to examine the functional requirements of mengovirus 2a for virus reproduction, a series of mutants with overlapping deletions within the 2a region of mengovirus, and two chimeric constructs in which 2a is replaced either by theiler's murine encephalomyelitis virus (tmev) 2a or by coxsackie b3 virus (cbv3) 2apro were generated. in vitro polyprotein synthesis showed that in both deletion mutants and the tmev 2a chimeric construct, viral 3c protease (3cpro)-mediated cleavage at the vp1-2a junction ... | 1998 | 9460917 |
| effects of some antiviral isatinisothiosemicarbazones on cellular and viral ribonucleic acid synthesis in mengovirus-infected fl cells. | three antiviral isatinisothiosemicarbazones strongly inhibited the incorporation of [(3)h]uridine into the ribonucleic acid (rna) of fl cells as a consequence of the inhibition of uridine transport. after prelabeling of cells at a low temperature (1 h at 16 c) with uptake of [(3)h]uridine into the acid-soluble nucleotide pool, the later addition of the test compounds revealed only a small or negligible influence on host-directed rna synthesis. the pulse-labeled soluble nucleotide pool of fl cell ... | 1974 | 15825394 |
| protein leakage from mengovirus-infected cells. | | 1967 | 15938266 |
| a coding rna sequence acts as a replication signal in cardioviruses. | theiler's virus and mengo virus are representatives of the cardiovirus genus within the picornavirus family. their genome is an 8-kilobase long positive strand rna molecule. this rna molecule plays three roles in infected cells: it serves as a messenger rna, acts as a template for genome replication, and is encapsidated to form progeny virions. we observed that a cis-acting signal required for replication of theiler's virus was contained within a 130-nt stretch of the region encoding the capsid ... | 1999 | 10500216 |
| interferon induction by viruses. vii. mengovirus: "interferon-sensitive" mutant phenotype attributed to interferon-inducing particle activity. | | 1981 | 6180093 |
| characterization of genetically engineered mengoviruses in mice. | we have shown that genetically engineered mengoviruses containing artificially shortened 5' noncoding poly(c) tracts (e.g., c0 or c13uc10) are dramatically attenuated in adult swiss/icr mice when compared to wild-type virus or to a genetically engineered virus containing a wild-type length poly(c) tract (c44uc10). to explore further the relationship between poly(c) tracts and virulence, we have conducted more extensive characterizations of several engineered viruses in the murine model. both sho ... | 2000 | 10733166 |
| development, evaluation, and standardization of a real-time taqman reverse transcription-pcr assay for quantification of hepatitis a virus in clinical and shellfish samples. | a standardized real-time reverse transcription-pcr (rt-pcr) assay has been developed for an accurate estimation of the number of genome copies of hepatitis a virus (hav) in clinical and shellfish samples. real-time procedures were based on the amplification of a fragment of the highly conserved 5' noncoding region and detection through an internal fluorescent probe, including taqman and beacon chemistries, in one- and two-step rt-pcr formats. the best performance in terms of sensitivity and repr ... | 2006 | 16751488 |
| genomic analysis of two porcine encephalomyocarditis virus strains isolated in china. | two strains of encephalomyocarditis virus (emcv), designated bjc3 and hb1, were isolated from an aborted fetus and the heart tissue of a dead piglet that had pericardial fluid, respectively. the complete genomic sequences of the two viruses were determined and analyzed. the size of the genomes of bjc3 and hb1 were 7746 and 7735 nucleotides, respectively, including poly(a) tails. comparative analysis with the genomic sequences of other emcv strains showed that bjc3 and hb1 shared higher identity ... | 2007 | 17294091 |
| pdtc inhibits picornavirus polyprotein processing and rna replication by transporting zinc ions into cells. | previously, it was shown that pyrrolidine dithiocarbamate (pdtc) inhibits proteolytic polyprotein processing and replication of human rhinovirus by transporting metal ions into cells. here, it is shown that pdtc also inhibits replication of two other picornaviruses: coxsackievirus b3 (cvb3), a closely related virus that belongs to the genus enterovirus, and mengovirus, an encephalomyocarditis virus strain that belongs to the genus cardiovirus, and that this inhibition is due to the dithiocarbama ... | 2007 | 17374764 |
| antiviral activities directed against wild-type and interferon-sensitive mengovirus. | two distinct antiviral activities can be detected in l cells treated with low levels of interferon and infected with a one-step interferon-sensitive mutant of mengovirus (is-1). the first antiviral activity (ava-1) primarily delayed virus rna and protein synthesis and thereby lengthened the virus replication cycle. it did not prevent cell death. the second antiviral activity (ava-2) allowed the virus-induced inhibition of host macromolecular synthesis but inhibited all other virus functions. by ... | 1983 | 6190989 |
| increased antiviral activity of microscale-purified huifn alpha 8 (human interferon alpha 8) over huifn alpha 2b in hep-2 cells challenged with mengo virus. | human proteins are not routinely expressed at high levels in escherichia coli for, among other reasons, different codon usage. several purification procedures have been applied to recover recombinant proteins for further biological characterization. however, the vast majority involve costly chromatography procedures. in the present study, both (hu)ifn(alpha 2b) (human interferon alpha 2b) and (hu)ifn(alpha 8) were expressed efficiently in e. coli bl21-codonplus-ril. subsequently, both recombinan ... | 2007 | 17523917 |
| phenotypic characterization of three phylogenetically conserved stem-loop motifs in the mengovirus 3' untranslated region. | an alignment of cardiovirus sequences led to the prediction of three conserved stem-loops in the 3' untranslated region (utr) of mengovirus. deletions of each stem were engineered in mengovirus cdnas and also in mengovirus replicons, in which part of the viral capsid sequences were replaced with the firefly luciferase gene. the effect of deletion on rna infectivity and plaque phenotype was evaluated after transfection of viral transcripts into hela cells or by luciferase assays of cellular extra ... | 2001 | 11238838 |
| encephalomyocarditis and mengo viruses productively infect murine t-lymphocyte cell lines but not fresh ex vivo derived t lymphocytes. | encephalomyocarditis virus (emcv) and mengo virus are highly virulent murine cardioviruses that are found in abundant quantities in the spleen and lymph nodes after infection. t lymphocytes are pivotal mediators of humoral and cellular immunity against cardioviral challenge, and are highly suspect candidates of emcv and mengo virus infection. we found t lymphocyte-like cell lines ctll-2, el-4, ly1+2/9, and lbrm33 were susceptible to productive viral infection and exhibited cytopathology after in ... | 2002 | 11952137 |
| the mengovirus leader protein suppresses alpha/beta interferon production by inhibition of the iron/ferritin-mediated activation of nf-kappa b. | in our studies on the biological function of the mengovirus leader protein, we identified a casein kinase ii (ck-2) phosphorylation site in the protein. here we report that the mengovirus leader protein can be phosphorylated by ck-2 in vitro. expression of a recombinant leader protein in which the consensus ck-2 sequence around threonine 47 was disturbed resulted in a mutant protein that could no longer be phosphorylated. the ck-2 consensus sequence was modified by site-directed mutagenesis and ... | 2002 | 12208945 |
| genetic analysis of a theiler-like virus isolated from rats. | although cardioviruses related to theiler's murine encephalomyelitis virus (tmev) appear to be common in mice and rats, few tmev isolates have been obtained from rat colonies. in 1991, a cardiovirus isolate designated ngs910 was obtained from sentinel rats exposed to cage bedding previously used by adult rats that were tmev seropositive, but had never manifested clinical signs of disease. to determine to which group and subgroup of cardiovirus this virus belongs, the sequence of the viral genome ... | 2003 | 12784854 |
| genetic stability of attenuated mengovirus vectors with duplicate primary cleavage sequences. | short poly(c)-tract mengoviruses have proven vaccine efficacy in many species of animals. a novel vector for the delivery of foreign proteins was created by insertion of a second autoproteolytic primary cleavage cassette linked to a multiple cloning site (mcs) into an attenuated variant of mengo. nineteen cdnas from foreign sequences that ranged from 39 to 1653 bases were cloned into the mcs. the viral reading frame was maintained and translation resulted in dual, autocatalytic excision of the f ... | 2003 | 12919752 |
| antiviral activity of the zinc ionophores pyrithione and hinokitiol against picornavirus infections. | we have discovered two metal ion binding compounds, pyrithione (pt) and hinokitiol (hk), that efficiently inhibit human rhinovirus, coxsackievirus, and mengovirus multiplication. early stages of virus infection are unaffected by these compounds. however, the cleavage of the cellular eukaryotic translation initiation factor eif4gi by the rhinoviral 2a protease was abolished in the presence of pt and hk. we further show that these compounds inhibit picornavirus replication by interfering with prop ... | 2009 | 18922875 |
| mengovirus-induced rearrangement of the nuclear pore complex: hijacking cellular phosphorylation machinery. | representatives of several picornavirus genera have been shown previously to significantly enhance non-controllable bidirectional exchange of proteins between nuclei and cytoplasm. in enteroviruses and rhinoviruses, enhanced permeabilization of the nuclear pores appears to be primarily due to proteolytic degradation of some nucleoporins (protein components of the pore), whereas this effect in cardiovirus-infected cells is triggered by the leader (l) protein, devoid of any enzymatic activities. h ... | 2009 | 19144712 |
| a rat model of picornavirus-induced airway infection and inflammation. | infection of the lower airways by rhinovirus, a member of the picornavirus family, is an important cause of wheezing illnesses in infants, and plays an important role in the pathogenesis of rhinovirus-induced asthma exacerbations. given the absence of natural rhinovirus infections in rodents, we investigated whether an attenuated form of mengovirus, a picornavirus whose wild-type form causes systemic rather than respiratory infections in its natural rodent hosts, could induce airway infections i ... | 2009 | 19671179 |
| differential ifn-alpha/beta production suppressing capacities of the leader proteins of mengovirus and foot-and-mouth disease virus. | picornaviruses encompass a large family of rna viruses. some picornaviruses possess a leader (l) protein at the n-terminus of their polyprotein. the l proteins of encephalomyocarditis virus, a cardiovirus, and foot-and-mouth disease virus (fmdv), an aphthovirus, are both dispensable for replication and their major function seems to be the suppression of antiviral host cell responses. previously, we showed that the l protein of mengovirus, a strain of encephalomyocarditis virus, inhibits antivira ... | 2010 | 19863558 |
| encephalomyocarditis viral protein 2a localizes to nucleoli and inhibits cap-dependent mrna translation. | panels of monoclonal antibodies were raised against viral non-structural proteins of encephalomyocarditis virus (emcv) and used to probe infected cells in laser confocal microscopy experiments and western analyses. surprisingly, all mengovirus and emcv-infected cells showed strong targeting of protein 2a, 3b(vpg), 3c(pro), and 3d(pol) signals to cellular nuclei, in particular to nucleoli, from the earliest times of infection. viral capsid proteins (1ab, 1c, and 1d) and other non-structural prote ... | 2003 | 12921995 |
| variability in inhibition of host rna synthesis by entero- and cardioviruses. | both entero- and cardioviruses have been shown to suppress host mrna synthesis. enteroviruses are also known to inhibit the activity of rrna genes, whereas this ability of cardioviruses is under debate. this study reported that mengovirus (a cardiovirus) suppressed rrna synthesis but less efficiently than poliovirus (an enterovirus). in contrast to poliovirus infection, the incorporation of brutp, fluorouridine and [14c]uridine in rrna precursors was observed even during the late stages of mengo ... | 2010 | 20089798 |
| evaluation of a rapid method for recovery of norovirus and hepatitis a virus from oysters and blue mussels. | foodborne outbreaks caused by noroviruses (novs) and hepatitis a virus (hav) are often linked to consumption of contaminated shellfish. the objective of this study was to identify an appropriate virus recovery method for real-time reverse transcriptase (rt)-pcr detection and subsequently to evaluate this method on shellfish bioaccumulated with virus in a collaborative study. five methods were compared for recovery of nov gii.7 and feline calicivirus from spiked digestive tissue of oysters and mu ... | 2010 | 20603152 |
| effect of actinomycin d on cellular nucleic acid synthesis and virus production. | actinomycin d inhibits the synthesis of ribonucleic acid in l cells and the yield of vaccinia virus containing deoxyribonucleic acid, but it does not inhibit cellular deoxyribonucleic acid synthesis or the multiplication of mengo virus containing ribonucleic acid. these observations serve to distinguish the replication of viral ribonucleic from ribonucleic acid synthesis which is controlled by viral or cellular deoxyribonucleic acid. | 1961 | 13740412 |
| the effect of mengovirus infection on the activity of the dna-dependent rna polymerase of l-cells. | | 1962 | 13864524 |
| translation of viral mrna without active eif2: the case of picornaviruses. | previous work by several laboratories has established that translation of picornavirus rna requires active eif2a for translation in cell free systems or after transfection in culture cells. strikingly, we have found that encephalomyocarditis virus protein synthesis at late infection times is resistant to inhibitors that induce the phosphorylation of eif2a whereas translation of encephalomyocarditis virus early during infection is blocked upon inactivation of eif2a by phosphorylation induced by a ... | 2011 | 21779397 |
| a comparison of the changes in fine structure of l cells during single cycles of viral multiplication, following their infection with the viruses of mengo and encephalomyocarditis. | the virus of encephalomyocarditis (emc), examined by the negative-contrast method, is indistinguishable from the serologically related mengovirus. the particles are 270 to 280 a in diameter. the surface of emc is composed of an undetermined number of subunits. frequent sampling of infected cells was carried out throughout one-step cycles of viral multiplication to observe cytopathic changes occurring in l cells infected by these two related rna viruses. emc and mengovirus, which multiply at equa ... | 1962 | 13883195 |
| localization of ribonucleic acid synthesis in mengovirus-infected l-cells. | | 1962 | 13894686 |
| a cytochemical description of the multiplication of mengovirus in l-929 cells. | a correlation of cytochemical changes with virus production has been studied in l cells infected with mengovirus. after a latent period of about 2 hours, virus was produced rapidly, reaching maximum titers of up to 12,000 particles per cell in 6 to 8 hours. the earliest cytological change was in the nucleus and consisted of a slight condensation of chromatin. there is no evidence, however, for the multiplication of either the viral rna or protein in the nucleus. rna, of high molecular weight, ac ... | 1962 | 13894687 |
| translation and replication of human rhinovirus type 14 and mengovirus in xenopus oocytes. | we have previously shown that xenopus oocytes require coinjection of both poliovirus rna and hela cell extracts to support a complete cycle of viral replication yielding high levels of infectious viral particles. this novel system provides a tool for identifying host factors and for biochemically dissect individual steps that lead to virus production. here we demonstrate that xenopus oocytes are able to support replication of other picornaviruses such as human rhinovirus 14 and mengovirus. unlik ... | 2000 | 11090201 |
| some factors influencing thermal stability of mengo virus. | | 1962 | 13915619 |
| ph and thermal stability of mengo virus. | | 1962 | 13915620 |
| synthesis of rna in l cells infected with mengo virus. | | 1963 | 14064126 |
| a new ribonucleic acid polymerase appearing after mengovirus infection of l-cells. | | 1963 | 14085393 |
| mengovirus replication. i. conservation of virus rna. | | 1964 | 14157500 |
| mengovirus replication. ii. isolation of polyribosomes containing the infecting viral genome. | | 1964 | 14157502 |
| intracellular fate of mengo virus ribonucleic acid. | homma, m. (the wistar institute, philadelphia, pa.), and a. f. graham. intracellular fate of mengo virus ribonucleic acid. j. bacteriol. 89:64-73. 1965.-p(32)-labeled, purified preparations of mengo virus adsorbed rapidly and irreversibly to l cells maintained in suspension cultures. at intervals after adsorption of labeled virus, the total ribonucleic acid (rna) of infected cells was extracted by a phenol technique. infectivity titrations on this rna showed that it retained its full biological ... | 1965 | 14255683 |
| an adenine-to-guanine nucleotide change in the ires sl-iv domain of picornavirus/hepatitis c chimeric viruses leads to a nonviable phenotype. | the inability for the internal ribosomal entry site (ires) of hepatitis c virus (hcv) to be readily studied in the context of viral replication has been circumvented by constructing chimeras such as with poliovirus (pv), in which translation of the genome polyprotein is under control of the hcv ires. during our attempts to configure the pv/hcv chimera for our drug discovery efforts, we discovered that an adenine- (a) to-guanine (g) change at nt 350 in domain iv of the hcv ires resulted in a nonv ... | 2003 | 14698672 |
| dipyridamole reversibly inhibits mengovirus rna replication. | dipyridamole is an effective inhibitor of cardiovirus growth in cell culture. the effects of dipyridamole on mengovirus replication in vivo and in vitro were examined in the hope the drug could be used as an experimental analog of the poliovirus inhibitor guanidine. guanidine selectively inhibits poliovirus rna synthesis but not rna translation, and as such, has been a valuable research tool. although guanidine does not inhibit cardiovirus infection, a compound with similar discriminatory charac ... | 2005 | 16103157 |
| cardiovirus leader proteins are functionally interchangeable and have evolved to adapt to virus replication fitness. | the leader (l) proteins encoded by picornaviruses of the genus cardiovirus [theiler's murine encephalomyelitis virus (tmev) and encephalomyocarditis virus (emcv)] are small proteins thought to exert important functions in virus-host interactions. the l protein of persistent tmev strains was shown to be dispensable for virus replication in vitro, but crucial for long-term persistence of the virus in the central nervous system of the mouse. the phenotype of chimeric viruses generated by exchanging ... | 2006 | 16603526 |
| synthesis of the allergen ovomucoid by a replicating mengo virus. | interferons induced by viral infections can have powerful immuno- modulatory effects, and several epidemiologic studies have found an association between certain viral infections and reduced prevalence of allergy. we hypothesized that allergenic proteins could be synthesized by a replicating virus, and this construct could be useful as an immunomodulator. to test this hypothesis, we cloned an allergenic protein (ovomucoid [ovm]) into a murine picornavirus (mengo virus) vector. this plasmid has a ... | 2006 | 16732496 |
| significance of the c-terminal amino acid residue in mengovirus rna-dependent rna polymerase. | replication of picornavirus genomes is accomplished by the virally encoded rna-dependent rna polymerase (rdrp). although the primary structure of this enzyme exhibits a high level of conservation, there are several significant differences among different picornavirus genera. in particular, a comparative alignment indicates that the c-terminal sequences of cardiovirus rdrp (known also as 3d(pol)), are 1-amino-acid residue (arginine or tryptophan) longer than that of the enterovirus or rhinovirus ... | 2007 | 17467026 |