| absence of neuraminidase from influenza c virus. | influenza c viruses did not possess neuraminidase activity when examined using either fetuin or sialyllactose as substrate. purified preparations of influenza c virus inhibited hemagglutination by nws hemagglutinin. the hemagglutination inhibiting activity was abolished by treatment of influenza c virus with neuraminidase. these findings indicated the absence of neuraminidase activity on influenza c virus particles. | 1976 | 56930 |
| properties of influenza c virus grown in cell culture. | influenza c virus was propagated successfully in primary chicken embryo lung (cel) and fibroblast cells and in madin-darby canine kidney (mdck) cells. in other cell lines, either no virus or only noninfectious hemagglutinin (ha) was produced. in productively infected cells (cel), ha and infectious virus appeared by 24 h and reached a maximum by 36 to 48 h, cell-associated virus remaining at a constant low level. infected vero cells produced noninfective ha by 24 h which also remained predominant ... | 1977 | 73602 |
| antigenic relationship between influenza c viruses. | the object of this study was to determine whether antigenic groupings exist among influenza c viruses. altogether seven influenza type c strains were examined by reciprocal haemagglutination-inhibition and serum neutralization tests with sera produced in ferrets. some biological properties were also compared and differences were found in their ability to agglutinate erythrocytes from various species, in their ability to adsorb onto rat and fowl erythrocytes, and in their rates of elution from th ... | 1978 | 104696 |
| established cell line sensitive to influenza c virus. | various strains of influenza c virus grew productively in an established line of monkey kidney cells (llcmk2) without prior adaptation. when trypsin was added to the medium, higher virus yields were obtained than in other cell cultures. all influenza c virus strains tested formed well defined plaques under the agar overlay medium containing trypsin. infectivity determined by plaque assay in llcmk2 cells was higher than that determined by amniotic inoculation of fertile hens' eggs. | 1979 | 113496 |
| properties of the erythrocyte receptors for influenza c virus. | properties of the receptor for influenza c virus were studied. although the receptor for influenza c virus on chicken erythrocytes was destroyed by the homologous virion, neuraminidase activity could not be detected in any of the influenza c virus strains tested. the receptor activity of chicken erythrocytes for influenza c virus was diminished by formaldehyde treatment but not by periodate oxidation. there was a considerable variation in the pattern and the titer of hemagglutination of influenz ... | 1978 | 211399 |
| carbohydrate components of influenza c virions. | the carbohydrate components of influenza c virions grown in chicken kidney (ck) cells were analyzed by gel filtration following exhaustive digestion with pronase. the [(3)h]glucosamine-labeled glycopeptides were larger and more heterogeneous than those of influenza a/wsn virions; three major size classes (g(1), g(2), and g(3)) were resolved. treatment with vibrio cholerae neuraminidase caused a decrease in size of g(1) and g(2), along with release of about 16% of the (3)h label. the released sug ... | 1979 | 448803 |
| a precursor glycoprotein in influenza c virus. | | 1979 | 494495 |
| rna's of influenza c virus strains. | up to 9 rna segments with molecular weights (mw) 2.3--9.4 x 10(5) were found in an influenza c virus by polyacrylamide gel electrophoresis at 50 degrees c and three different strains. all contained rna of the same mobility. possible coding assignments of the rna segments is discussed. | 1979 | 496645 |
| isolation of influenza c virus recombinants. | recombinants between two different influenza c viruses were isolated. in mdck (canine kidney) cells, one strain, c/jj/50, caused lytic plaques, whereas c/jhg/66 virus did not produce clear plaques. from a mixed infection of mdck cells with c/jhg/66 virus and uv-inactivated c/jj/50 virus, clones were isolated which possessed the clear-plaque phenotype. fingerprint analyses indicated that the rnas of parent viruses had different oligonucleotide patterns and that one of the clones derived from the ... | 1979 | 513198 |
| inhibition of influenza c virus replication by actinomycin d, alpha-amanitin, and uv irradiation. | actinomycin d and alpha-amanitin caused similar reductions in the yields of influenza a/wsn and influenza c/jbh/1/66 viruses in a chicken kidney cell culture system. irradiation of host cells with uv light before virus infection also produced a similar reduction in yields of the two viruses. the results indicate a close similarity between the replication processes of influenza c and other orthomyxoviruses. | 1979 | 513199 |
| the incidence of antibodies to influenza c virus in egyptian sera. | | 1977 | 556274 |
| the multiplication of an influenza c virus in an established line of canine kidney (mdck) cells. | jj/50 and four other strains of influenza c virus grew in an established line of canine kidney (mdck) cells. multicycle virus growth was markedly enhanced by the addition of trypsin to the culture medium and these viruses could be passaged serially in this system. the addition of appropriate concentrations of trypsin to the agar overlay medium enabled plaquing of influenza c/jj/50 virus. titration by plaque assay on mdck cells was more sensitive than that by intra-amniotic inoculation of fertile ... | 1978 | 641530 |
| growth characteristics of influenza virus type c in avian hosts. brief report. | influenza virus type c could be propagated to high yield in primary chick embryo kidney cell culture (pcek) provided that trypsin (2 microgram/ml) was used as a medium supplement. the virus could also be titrated by plaque assay using pcek host cells and influenza c virus that had been plaque-purified in pcek cells could then be serially passaged to high titer using the allantoic route of 10--11-day-old embryonated eggs. | 1978 | 736797 |
| study on the growth of influenza virus type c in hen's embryo (other than amniotic and allantoic) and in tissue culture. | | 1976 | 829119 |
| structural components of influenza c virions. | the genome rna species of influenza type c virions were analyzed by polyacrylamide gel electrophoresis. the pattern obtained was found to resemble those of other influenza viruses. six rna species were resolved, with estimated sizes ranging from 0.37 x 10(6) to 1.25 x 10(6) daltons. the internal ribonucleoproteins of influenza c virions were found to sediment heterogeneously in glycerol velocity gradients as demonstrated previously with influenza a/wsn virus. the ribonucleoproteins possessed dia ... | 1977 | 833941 |
| lack of characteristic hexagonal surface structure on a newly isolated influenza c virus. | the hexagonal surface structure believed to be characteristic for influenza c virus was not initially observed for a newly isolated virus of this type. after a few additional egg passages of the virus, however, the hexagonal structure could be readily seen on many virions. | 1977 | 886010 |
| increase in titer of the naturally occurring human antibody to neuraminidase-treated lymphocytes after influenza. | nine of 25 (36%) humans suffering from naturally acquired influenza a infection developed significant increases in the titer of a "naturally" occurring antibody to neuraminidase-treated human lymphocytes. only two of 43 normal and noninfluenza respiratory infection controls showed titer changes of this antibody, p less than 0.001. the antibody was not directed at influenza virus c fixation, hemagglutination inhibition, or neuraminidase antigens. three of 10 normals given a highly immunogenic, fo ... | 1977 | 915272 |
| rnas of influenza a, b, and c viruses. | the nucleic acids of influenza a, b, and c viruses were compared. susceptibility to nucleases demonstrates that influenza c virus, just as influenza a and b viruses, possesses single-stranded rna as its genome. the base compositions of the rnas of influenza a, b, and influenza c virus are almost identical and comparative analysis on polyacrylamide gels shows that the genome of influenza c/gl/1167/54 virus, like that of the rnas of influenza a and b viruses, is segmented. eight distinct rna bands ... | 1976 | 944790 |
| presence of a segmented single-stranded rna genome in influenza c virus. | | 1976 | 982819 |
| [is there evidence for antigenic drift of influenza c viruses? (author's transl)]. | antigenic differences between the influenza c strains c/1233/47 (taylor), c/paris/1/67 and strains isolated in johannesburg 1967 have been reported (pereira, 1969). our experiments performed with chicken immune sera did not differentiate clearly between the strains c/paris/1/67 and c/jhb/4/67, however, antigenic differences between the strains c/1233/47 and the strains isolated in 1967 could be confirmed. these antigenic differences were found to be of approximately the same degree as those obse ... | 1975 | 1154916 |
| influenza virus type c (taylor's 1233) in egg allantois. | | 1975 | 1205551 |
| antigenic variation amongst influenza virus type c. | | 1975 | 1213825 |
| growth properties of influenza virus type c. | | 1975 | 1240093 |
| seroepidemiological study of the circulation of influenza c virus in man. | the seroepidemiological study of the circulation of influenza c virus was achieved by testing hi antibodies in human sera collected from healthy subjects in bucharest belonging to various age groups. the investigations were carried out over a two years period (october 1988--september 1990), using 3 influenza c virus strains: c/taylor/1233/47, c/ussr/0303/77 and c/moscow/1/84, the last two being antigenically similar. the analysis of the distribution of hi antibody values against the three influe ... | 1992 | 1304830 |
| influenza c virus infection in france. | little is known of the epidemiology of influenza c virus infections in western europe and of the exact role of this agent in acute viral respiratory infections. several tests may be used for detecting antibodies against this agent but the significance of their respective results is not clear. a total of 301 samples of serum was collected from persons aged from 4 months to 88 years living in france in 1988. the samples were tested for the presence of antibodies to influenza c virus by haemaggluti ... | 1992 | 1312564 |
| natural infection of dogs by influenza c virus. | to date, only one seroepidemiological survey, carried out in japan, gave a strong indication that dogs may be naturally infected by the influenza c virus, long considered to be exclusively human. in the present work, 134 serum samples were collected during the winter of 1988/89 from dogs aged 6 months to 16 years in northern france. samples were tested for the presence of antibodies to influenza c virus by both haemagglutination inhibition (hi) and elisa. using antibody absorption by staphylococ ... | 1992 | 1325663 |
| antigenic and genetic analyses of eight influenza c strains isolated in various areas of japan during 1985-9. | eight strains of influenza c virus isolated in various areas of japan between january 1985 and january 1989 were compared using monoclonal antibodies to the haemagglutinin-esterase (he) glycoproteins and by oligonucleotide mapping of total vrna. five of six strains isolated during 1986-9 were closely related to one another and also resembled the virus, c/aichi/1/81, isolated in 1981 in aichi prefecture. this suggests that the c/aichi/1/81-related viruses had an epidemiological advantage over any ... | 1992 | 1374720 |
| location of neutralizing epitopes on the hemagglutinin-esterase protein of influenza c virus. | neutralization-resistant variants of influenza c/ann arbor/1/50 virus were selected with monoclonal antibodies against four different antigenic sites on the hemagglutinin-esterase (he) glycoprotein, and their he genes were sequenced to identify amino acid residues important for the integrity of each site. twelve different amino acid substitutions in a total of 18 antigenic variants were all located on the he1 subunit. although variants for antigenic site a-2 had a change at position 367, all sub ... | 1992 | 1376542 |
| increased influenza a virus sialidase activity with n-acetyl-9-o-acetylneuraminic acid-containing substrates resulting from influenza c virus o-acetylesterase action. | influenza virus type c (johannesburg/1/66) was used as a source for the enzyme o-acetylesterase (ec 3.1.1.53) with several natural sialoglycoconjugates as substrates. the resulting products were immediately employed as substrates using influenza virus type a [(singapore/6/86) (h1n1) or shanghai/11/87 (h3n2)] as a source for sialidase (neuraminidase, ec 3.2.1.18). a significant increase in the percentage of sialic acid released was found when the o-acetyl group was cleaved by o-acetylesterase act ... | 1992 | 1413991 |
| binding of plasmodium falciparum 175-kilodalton erythrocyte binding antigen and invasion of murine erythrocytes requires n-acetylneuraminic acid but not its o-acetylated form. | sialic acid on human erythrocytes is involved in invasion by the human malaria parasite, plasmodium falciparum. mouse erythrocytes were used as a reagent to explore the question of whether erythrocyte sialic acid functions as a nonspecific negative charge or whether the sialic acid is a necessary structural part of the receptor for merozoites. human erythrocytes contain n-acetylneuraminic acid (neu5ac), whereas mouse erythrocytes, which are also invaded by p. falciparum merozoites, contain 9-o-a ... | 1992 | 1565137 |
| a single point mutation of the influenza c virus glycoprotein (hef) changes the viral receptor-binding activity. | from strain jhb/1/66 of influenza c virus a mutant was derived with a change in the cell tropism. the mutant was able to grow in a subline of madin-darby canine kidney cells (mdck ii) which is resistant to infection by the parent virus due to a lack of receptors. inactivation of cellular receptors by either neuraminidase or acetylesterase and generation of receptors by resialylation of cells with n-acetyl-9-o-acetylneuraminic acid (neu5,9ac2) indicated that 9-o-acetylated sialic acid is a recept ... | 1992 | 1566586 |
| a synthetic sialic acid analogue is recognized by influenza c virus as a receptor determinant but is resistant to the receptor-destroying enzyme. | synthetic sialic acid analogues varying in the substitutents at position c-9 were analyzed for their ability to replace the natural receptor determinant for influenza c virus, n-acetyl-9-o-acetylneuraminic acid (neu5,9ac2). by incubation of erythrocytes with sialyltransferase and the cmp-activated analogues, the cell surface was modified to contain sialic acid with one of the following c-9 substituents: an azido, an amino, an acetamido, or a hexanoylamido group. among these, only 9-acetamido-n-a ... | 1992 | 1618756 |
| selection of antigenically distinct variants of influenza c viruses by the host cell. | five strains of influenza c virus were isolated and passaged in the amniotic sacs of embryonated hens' eggs, or in the hmv-ii line of human malignant melanoma cells, and were tested for reactivity with a panel of monoclonal antibodies to the hemagglutinin-esterase (he) glycoprotein. it was observed with two strains (c/yamagata/4/88, c/yamagata/7/88) that the he of virus passaged in hmv-ii cells was antigenically distinguishable from that of virus cultivated in eggs. virus clones obtained after r ... | 1992 | 1641987 |
| [studies on sialidase and esterase in influenza viruses]. | the main contributions of the author and collaborators about sialidase (ec 3.2.1.18) of influenza virus types a and b and o-acetylesterase (ec 3.1.1.53) of type c are summarized. after a short introduction on the topic, the negative results obtained by the author on inhibitors are commented. then, the peculiarities of the three procedures assayed, based on the nadh determination as a measurement for the sialidase activity, are discussed. the spectrofluorimetric measurement of nadh concentration ... | 1991 | 1656837 |
| flow cytometric analysis of virus-infected cells and its potential use for screening antiviral agents. | virus-infected cells were analyzed using multiparameter flow cytometry. two virus-cell systems were investigated: hsv-1-infected vf cells and influenza c virus jhb/1/66-infected mdck cells. analysis included the measurement of the appearance of virus specific antigens. on individual cells, with polyclonal antibodies, antigens were first detected at 12 h p.i., and the numbers of labeled cells were followed up to 96 h p.i. the efficacy of four antiviral agents was tested with this system. the resu ... | 1990 | 1691199 |
| analytical detection of 9(4)-o-acetylated sialoglycoproteins and gangliosides using influenza c virus. | the unique glycoprotein of influenza c virus, designated hemagglutinin (hef), exhibits three functions: hemagglutination, esterase activity, and fusion factor. as the virus uses 9-o-acetylated sialic acid as a high-affinity receptor determinant for attachment to cells, its binding activity was used to reveal o-acetylated sialic acid residues after polyacrylamide gel electrophoresis and transfer onto nitrocellulose sheets of proteins and thin-layer chromatography of lipids. the specificity of the ... | 1991 | 1713751 |
| the hemagglutinin/esterase gene of human coronavirus strain oc43: phylogenetic relationships to bovine and murine coronaviruses and influenza c virus. | the complete nucleotide sequences of the hemagglutinin/esterase (he) genes of human coronavirus (hcv) strain oc43 and bovine respiratory coronavirus (brcv) strain g95 were determined from single-stranded cdna fragments generated by reverse transcription of virus-specific mrnas and amplified by polymerase chain reaction. an open reading frame of 1272 nucleotides was identified as the putative he gene by homology to the bovine coronavirus he gene. this open reading frame encodes a protein of 424 a ... | 1992 | 1727608 |
| protective effect of serum antibody on respiratory infection of influenza c virus in rats. | the effects of serum antibody on the replication of influenza c virus in the nose and lung were evaluated in rats challenged with the virus by the intranasal and endotracheal routes, respectively. convalescent rat serum administered intraperitoneally prior to infection suppressed virus replication significantly in both the nasal and pulmonary tissues. resistance achieved was however much greater in the lung than in the nose. rats with a serum neutralizing antibody titer of 1:800 showed almost co ... | 1992 | 1729984 |
| use of influenza c virus for detection of 9-o-acetylated sialic acids on immobilized glycoconjugates by esterase activity. | an overlay and a solid-phase assay are presented which allow the specific detection of 9-o-acetylated sialic acids on sialoglycoconjugates immobilized on microtiter plates, nitrocellulose or separated on thin-layer chromatograms. the assay takes advantage of two different biological properties of influenza c virus, its high-affinity binding to 9-o-acetylated sialic acids and its sialate 9-o-acetylesterase that is used for detection of bound virus with fluorogenic or chromogenic substrates. thoug ... | 1992 | 1740131 |
| prevalence of antibody to influenza c virus among pigs in hyogo prefecture, japan. | the prevalence of influenza c virus among pigs in hyogo prefecture, japan, was investigated by serological techniques. out of 240 sera tested, 45 (19%) showed haemagglutination inhibition (hi) to influenza c virus. pig sera with high hi titres also scored high in neutralization tests and elisas. when fractionated by sucrose density gradient ultracentrifugation, the hi/elisa reactivities corresponded to antibodies of the igm and igg classes. radioimmunoprecipitation tests revealed that some, but ... | 1991 | 1848603 |
| 9-o-acetylated sialic acid, a receptor determinant for influenza c virus and coronaviruses. | influenza c virus and a group of coronaviruses, a typical representative of which is bovine coronavirus, use the same strategy for binding to cells. surface components containing 9-o-acetylated sialic acid are recognized as cellular receptors by these viruses. in addition to the receptor determinant both virus groups have a receptor-destroying enzyme in common, which has been identified as a sialate 9-o-acetylesterase. differences are, however, found in the distribution of these activities on th ... | 1991 | 1930096 |
| new data on influenza virus type c confirm its peculiarities as a new genus. | | 1991 | 1938304 |
| structure and function of the hef glycoprotein of influenza c virus. | | 1991 | 1957719 |
| use of a sialic acid analogue to analyze the importance of the receptor-destroying enzyme for the interaction of influenza c virus with cells. | influenza c virus uses 9-o-acetyl-n-acetylaneuraminic acid (9-o-acetyl-neu5ac) as a receptor determinant for attachment to cells. the virus contains an acetylesterase which releases acetyl residues from position c-9 of sialic acid thereby inactivating the receptors. a synthetic sialic acid analogue, 9-n-acetyl-neu5ac, was attached to cell surface glycoconjugates by purified sialyltransferase and analyzed for its ability to substitute the 9-o-acetylated sialic acid. erythrocytes which have been m ... | 1990 | 1965334 |
| isolated he-protein from hemagglutinating encephalomyelitis virus and bovine coronavirus has receptor-destroying and receptor-binding activity. | bovine coronavirus (bcv) and hemagglutinating encephalomyelitis virus (hev) from swine were found to grow to high titers in mdck i cells, a subline of madin darby canine kidney cells. virus grown in these cells was used to isolate and purify the he-protein. this protein has been shown recently to have acetylesterase activity and to function as the receptor-destroying enzyme of bcv. here we show that hev contains this enzyme, too. the glycoproteins were solubilized by treatment of virions with oc ... | 1991 | 1984649 |
| comparison of the genome organization of toro- and coronaviruses: evidence for two nonhomologous rna recombination events during berne virus evolution. | recently, toroviruses and coronaviruses have been found to be ancestrally related by divergence of their polymerase and envelope proteins from common ancestors. in addition, their genome organization and expression strategy, which involves the synthesis of a 3'-coterminal nested set of mrnas, are comparable. nucleotide sequence analysis of the genome of the torovirus prototype, berne virus (bev), has now revealed the results of two independent nonhomologous rna recombinations during torovirus ev ... | 1991 | 1984666 |
| antigenic characterization of the nucleoprotein and matrix protein of influenza c virus with monoclonal antibodies. | monoclonal antibodies against the nucleoprotein (np) and matrix (m) protein of influenza c virus were prepared and characterized. at least two non-overlapping or partially overlapping antigenic sites were delineated on each of the proteins by competitive binding assays. western blot analysis showed that two antigenic sites on the m protein were highly resistant to conformational changes whereas two sites on np were sensitive. no antigenic variation was seen in either the np or the m protein when ... | 1991 | 1990058 |
| activity of influenza c virus o-acetylesterase with o-acetyl-containing compounds. | influenza c virus (strain c/johannesburg/1/66) was grown, harvested, purified and used as source for the enzyme o-acetylesterase (n-acyl-o-acetylneuraminate o-acetylhydrolase; ec 3.1.1.53). this activity was studied and characterized with regard to some new substrates. the ph optimum of the enzyme is around 7.6, its stability at different ph values shows a result similar to that of the ph optimum, and its activity is well maintained in the ph range from 7.0 to 8.5 (all these tests were performed ... | 1991 | 1991039 |
| community-acquired influenza c virus infection in children. | to clarify the epidemiologic and clinical features of community-acquired influenza c infection in children, we took specimens throughout the year from a larger number of patients with acute respiratory illnesses in a pediatric clinic in yamagata, japan. during a 2-year survey, 20 strains of influenza c virus were isolated from 13,426 specimens. these isolates were recovered throughout the year. the ages of patients with influenza c virus isolates ranged from 2 months to 11 years and peaked at th ... | 1991 | 1993950 |
| differential reactivity of bovine coronavirus (bcv) and influenza c virus with n-acetyl-9-o-acetylneuraminic acid (neu5,9ac2)-containing receptors. | | 1990 | 2103097 |
| influenza c virus infection in rats. | four-week-old rats (wka/hkm strain) were infected intranasally with the ann arbor/1/50 strain of influenza c virus and examined for clinical symptoms, virus replication, and serum antibody response. although the animals showed no definite signs of illness, the virus replicated in the nose, and the hemagglutination-inhibiting (hi) and neutralizing antibodies were produced in their sera. when the inoculum sizes of 10(6.2) and 10(3.2) pfu were used, virus was recovered from nasal homogenates betwee ... | 1990 | 2157944 |
| human malignant melanoma cell line (hmv-ii) for isolation of influenza c and parainfluenza viruses. | hmv-ii, a human malignant melanoma cell line, was compared with other cell lines (mdck, vero, and llc-mk2) and primary cultures of monkey kidney (pmk) cells for the isolation and quantification of influenza and parainfluenza viruses. hmv-ii cells were superior to mdck and llc-mk2 cells in quantification of the influenza c virus and were used successfully in the isolation of the virus from clinical specimens. the hmv-ii cell line was also more sensitive for isolating parainfluenza viruses from cl ... | 1990 | 2166075 |
| characterization of the cord-like structures emerging from the surface of influenza c virus-infected cells. | when hmv-ii cells (a human malignant melanoma cell line) infected with a newly isolated influenza c strain (yamagata/1/88) were examined by simple light microscopy, it was found that a large number of cord-like structures which had lengths up to about 500 microns or greater were emerging from the cell surface. the existence of viral glycoproteins (hemagglutinin-esterase, he) on the surface of these huge structures was confirmed by hemadsorption experiments with erythrocytes from a variety of spe ... | 1990 | 2219719 |
| monoclonal antibody a2b5, which detects cell surface antigens, binds to ganglioside gt3 (ii3 (neuac)3laccer) and to its 9-o-acetylated derivative. | the monoclonal antibody a2b5 recognizes antigens at the surface of neuronal and glial cells but also at the surface of thymus epithelia and pancreatic islet cells. although these antigens have been characterized as polysialogangliosides, a2b5 also reacts with other unidentified gangliosides. in order to characterize further the epitope of a2b5, two new ganglioside antigens isolated from chicken brain are identified in this study. one is the ganglioside neuac alpha 2-8neuac alpha 2-8neuac alpha 2 ... | 1990 | 2303428 |
| inhibition of influenza virus replication by phosphorothioate oligodeoxynucleotides. | oligodeoxynucleotides (odns) were synthesized and tested for their antiviral activity against influenza viruses. odns corresponded to the polymerase pb1 gene of either influenza a/wsn/33 virus or influenza c/jj/50 virus. all compounds were 20 nucleotides long, including control odns containing mismatches. the phosphodiester odns (o-odns) failed to inhibit replication of influenza a and influenza c viruses at concentrations up to 80 microm, possibly due to intracellular nuclease digestion of the ... | 1990 | 2333292 |
| fusion characteristics of influenza c viruses. | a number of different influenza c virus strains were tested for their fusion properties using a resonance energy assay which allows direct monitoring of fusion between virus membranes and artificial lipid vesicles. the fusion ph of various strains was found to range between 5.6 and 6.1. haemolytic activity of the different strains with chicken erythrocytes was observed at slightly lower ph values and varied between 5.1 and 5.7. studies of the kinetics of influenza c virus fusion showed distinct ... | 1990 | 2345368 |
| [diagnosis of influenza virus type c infection]. | | 1990 | 2355544 |
| the hemagglutinating glycoproteins of influenza b and c viruses are acylated with different fatty acids. | we present evidence that the hemagglutinin (ha) of influenza b virus and the glycoprotein of influenza c virus (hef) are acylated. the fatty acid linkage is sensitive to treatment with hydroxylamine and mercaptoethanol, which points to a labile thioester-type linkage. the ha of influenza b virus contains mainly palmitic acid, whereas the hef glycoprotein of influenza c virus is acylated with stearic acid which has not been observed before as the prevailing fatty acid in viral or cellular acyl pr ... | 1990 | 2371783 |
| hemagglutinating encephalomyelitis virus attaches to n-acetyl-9-o-acetylneuraminic acid-containing receptors on erythrocytes: comparison with bovine coronavirus and influenza c virus. | the receptors for the hemagglutinating encephalomyelitis virus (hev, a porcine coronavirus) on chicken erythrocytes were analyzed and compared to the receptors for bovine coronavirus (bcv) and influenza c virus. evidence was obtained that hev requires the presence of n-acetyl-9-o-acetylneuraminic acid (neu5,9ac2) on the cell surface for agglutination of erythrocytes as has been previously shown for bcv and influenza c virus: (i) incubation of red blood cells with sialate 9-o-acetylesterase, the ... | 1990 | 2385959 |
| the receptor-destroying enzyme of influenza c virus is neuraminate-o-acetylesterase. | the nature of the receptor-destroying enzyme (rde) of influenza c virus has been elucidated by analyzing its effect on the haemagglutination inhibitors rat alpha 1-macroglobulin (rmg) and bovine submandibulary mucin (bsm), respectively. the inhibitory activity of both compounds is abolished by incubation with influenza c virus. after inactivation, rmg and bsm were found to contain reduced amounts of n-acetyl-9-o-acetylneuraminic acid (neu5,9ac2) and increased amounts of n-acetylneuraminic acid ( ... | 1985 | 2411539 |
| isolation and characterization of influenza c virus inhibitor in rat serum. | two hemagglutination inhibitors for influenza c virus were isolated from pooled sera of normal rats by sequential chromatography on blue sepharose cl 6b, ultrogel aca 22, and deae-cellulose. the two inhibitors were identified as alpha 1-macroglobulin and murinoglobulin by comparison with the authentic samples. these inhibitors abolished the hemagglutination by influenza c virus strains but did not affect the hemagglutination by influenza a and b virus strains. hemagglutination inhibition activit ... | 1985 | 2416143 |
| effects of alpha-macroglobulins and murinoglobulins on the hemagglutination by influenza c virus. | rat alpha-1- and alpha-2-macroglobulins as well as rat murinoglobulins i and ii were shown to inhibit hemagglutination by influenza c virus. in marked contrast, neither alpha-macroglobulins nor murinoglobulins from mouse or guinea pig plasma had the inhibitory activity. these results suggest that the hemagglutination-inhibiting activity of rat alpha-macroglobulins or murinoglobulins is not related to their protease-binding capacity. | 1986 | 2425807 |
| [the nature of the influenza c virus receptor and the specificity of the receptor-destroying enzyme]. | bacterial neuraminidases destroy influenza c virus receptors of chick erythrocytes and inactivate hemagglutination inhibitors: rat alpha 1-macroglobulin (rmg) and bovine submaxillary mucin (bsm). these data indicate that neuraminic acid may be a component of influenza c virus receptor. the inhibiting activity of rmg and bsm is also eliminated by the receptor-destroying enzyme (rde) of influenza c virus. after inactivation, the inhibitors (rmg and bsm) contain a reduced amount of n-acetyl-9-0-ace ... | 1987 | 2445106 |
| operational and topological analyses of antigenic sites on influenza c virus glycoprotein and their dependence on glycosylation. | in our previous study, seven monoclonal antibodies specific for influenza c virus glycoprotein (gp88) were prepared and tentatively classified into two groups: group a (j14, j9, q5, k16) has neutralization activity whereas group b (s16, j6, j15) does not. these antibodies were used to analyse the antigenic structure of gp88 and to examine the effect of glycosylation on the antigenicity of the glycoprotein. operational analysis with a panel of antigenic variants selected with each of the group a ... | 1988 | 2450965 |
| effect of anti-haemagglutinin-esterase glycoprotein monoclonal antibodies on the receptor-destroying activity of influenza c virus. | five monoclonal antibodies (j14, j9, q5, k16, s16), directed to three distinct antigenic sites (a-1, a-2, b-1) on the haemagglutinin-esterase glycoprotein of influenza c virus, were analysed for their ability to inhibit the receptor-destroying enzyme (rde) activity of the virus, utilizing various assay systems. the ability of influenza c virus to destroy the receptors on chicken erythrocytes was inhibited efficiently by the antibodies to site a-1 (j14, j9, q5) but not by those to site a-2 (k16) ... | 1989 | 2471808 |
| persistent infection of mdck cells by influenza c virus: initiation and characterization. | persistent influenza c virus infection was readily initiated in madin-darby canine kidney (mdck) cells at low m.o.i. and has been maintained for over 1 year. the persistently infected (p.i.) cultures were characterized by the following properties: virus infection was limited to a minority of cells, small amounts of infectious virus were produced together with low levels of interferon (ifn) and the cultures were resistant to superinfection by homologous virus and vesicular stomatitis virus, but n ... | 1989 | 2481713 |
| influenza c virus esterase: analysis of catalytic site, inhibition, and possible function. | the active site serine of the acetylesterase of influenza c virus was localized to amino acid 71 of the hemagglutinin-esterase protein by affinity labeling with 3h-labeled diisopropylfluorophosphate. this serine and the adjacent amino acids (phe-gly-asp-ser) are part of a consensus sequence motif found in serine hydrolases. since comparative analysis failed to reveal esterase sequence similarities with other serine hydrolases, we suggest that this viral enzyme is a serine hydrolase constituting ... | 1989 | 2495370 |
| o-acetylation and de-o-acetylation of sialic acids. sialic acid esterases of diverse evolutionary origins have serine active sites and essential arginine residues. | we and others have recently described 9-o-acetyl-sialic acid esterase (9-o-ac-sa esterase) activities that appear to be specific for removal of o-acetyl esters from the 9-position of naturally occurring sialic acids. we have now examined a variety of species for such enzymes and found them in vertebrates and higher invertebrates, but not in plants or in lower invertebrates. this evolutionary distribution correlates well with that of the sialic acids themselves. all of the 9-o-ac-sa esterase acti ... | 1989 | 2509478 |
| transfer of synthetic sialic acid analogues to n- and o-linked glycoprotein glycans using four different mammalian sialyltransferases. | this paper presents kinetic properties of the transfer of several synthetic 9-substituted sialic acid analogues onto n- or o-linked glycoprotein glycans by four purified mammalian sialyltransferases: gal beta 1,4glcnac alpha 2,6sialyltransferase, gal beta-1,4(3)glcnac alpha 2,3-sialyltransferase, gal beta 1,3galnac alpha 2,3sialyltransferase, and galnac alpha 2,6sialyltransferase. the substituents at c-9 of the sialic acid analogues introduce special biochemical characteristics: 9-amino-neuac re ... | 1989 | 2510824 |
| [comparative study of the hemolytic activity of ortho- and paramyxoviruses]. | a comparative study of hemolytic activity of influenza type a, b, and c viruses, human parainfluenza type 3, and sendai virus showed the pattern of ph-dependence and the nature of the curve to differ not only for different viruses under study but also for different erythrocyte species. studies of virus-induced hemolysis of influenza c virus demonstrated that, depending on the erythrocyte species used, it had common properties both with influenza types a and b viruses and with paramyxoviruses. | 1989 | 2548343 |
| rat alpha 1 macroglobulin inhibits hemagglutination by influenza c virus. | purified alpha 1-macroglobulin (rmg) isolated from rat plasma was found to be a potent inhibitor of hemagglutination by influenza c virus. neuraminidase treatment of purified rmg reduced its inhibitory activity by more than 80% indicating that sialic acid is required for maximal hi-activity. the inhibitory activity of rmg was shown to be sensitive to the receptor-destroying activity (rda) of influenza c virus. methylation analysis of the glycopeptides of rmg indicated the presence of only one ma ... | 1985 | 2581392 |
| developmentally expressed o-acetyl ganglioside gt3 in fetal rat cerebral cortex. | monoclonal antibody m6704, established against the chick neural tube, was shown to recognize a trisialosyl residue, neuac alpha 2-8neuac alpha 2-8neuac alpha 2-3-r of c-series gangliosides. using this antibody, the developmental changes of c-series gangliosides in fetal rat cerebral cortex have been examined. two dimensional thin layer chromatography (tlc) enzyme-immunostaining analysis revealed that alkali treatment resulted in a great increase in gt3 that amounted to more than 85% of the total ... | 1989 | 2586826 |
| [influenza c: the immunological aspects of the problem]. | the use of the complex of methods for the characterization of cell-mediated and humoral immunity to influenza c virus has made it possible to establish that with the increase of the age of children and, simultaneously, with the increase of the number of persons found to be seropositive to influenza c the asymptomatic forms of this infection occur more frequently. practically all examined adults selected by random choice have proved to be immune to this infective agent. the results of this invest ... | 1989 | 2609814 |
| a human melanoma cell line highly susceptible to influenza c virus. | the relative amounts of influenza c virus-specific receptors of 25 established lines of mammalian cells including four lines of human malignant melanoma origin were compared by virus binding experiments. all the human melanoma cell cultures studied possessed two to four times more receptors than were found on mdck cells, a cell line known to be highly susceptible to influenza c virus. it may therefore be a feature common to human melanoma cells that o-acetylsialic acid, a determinant for the att ... | 1989 | 2738578 |
| detection of influenza c virus by using an in situ esterase assay. | a variety of chemically defined compounds were tested to characterize the substrate specificity of the influenza c virus esterase and to determine whether a substrate could be found that would be useful in an assay to detect the virus. two new substrates, alpha-naphthyl acetate and alpha-naphthyl propionate, were identified; alpha-naphthyl acetate was employed to develop an assay specific for influenza type c virus in mdck cells. the assay was sufficiently sensitive to detect esterase activity i ... | 1989 | 2745694 |
| comparison of the three large polymerase proteins of influenza a, b, and c viruses. | the three large rna segments of influenza c virus c/jj/50 were cloned and sequenced, and the deduced amino acid sequences were compared with those of the polymerase (p) proteins of influenza a and b viruses. the coding strategy of the c virus rna segments is the same as that for the large a and b virus segments as one long open reading frame is present in each segment. rna segment 1 of influenza c virus encodes the equivalent of the pb2 protein; it has an approximate 25% sequence identity with t ... | 1989 | 2763462 |
| antigenic and genetic characterization of three influenza c strains isolated in the kinki district of japan in 1982-1983. | three strains of influenza c virus (c/kyoto/41/82, c/nara/82, c/hyogo/1/83) have been isolated from humans in the kinki district of japan between february 1982 and december 1983. oligonucleotide mapping of total vrna and antigenic analysis with anti-he monoclonal antibodies have shown previously that they are closely similar to one another but dissimilar to any of the strains isolated in japan before 1982. in the present study, the nucleotide sequences of the hemagglutinin-esterase (he) genes of ... | 1989 | 2773313 |
| distribution of the antibody to influenza c virus in dogs and pigs in yamagata prefecture, japan. | the distribution of the antibody to influenza c virus in the dogs and pigs in yamagata prefecture, japan was investigated by using three different serological methods: hemagglutination-inhibition (hi), radioimmunoprecipitation (rip), and immunoblotting. the antibody against influenza c virus glycoprotein (gp88) was detected in 5 out of 112 sera collected from mongrel dogs, three by rip test and two by any of the three methods, suggesting that the virus can cause natural infection in dogs. signif ... | 1987 | 2836710 |
| sequence of mouse hepatitis virus a59 mrna 2: indications for rna recombination between coronaviruses and influenza c virus. | the nucleotide sequence of the unique region of coronavirus mhv-a59 mrna 2 has been determined. two open reading frames (orf) are predicted: orf1 potentially encodes a protein of 261 amino acids; its amino acid sequence contains elements which indicate nucleotide binding properties. orf2 predicts a 413 amino acids protein; it lacks a translation initiation codon and is therefore probably a pseudogene. the amino acid sequence of orf2 shares 30% homology with the ha1 hemagglutinin sequence of infl ... | 1988 | 2845655 |
| epidemiology of influenza c virus in man: multiple evolutionary lineages and low rate of change. | the nucleotide sequences of nonstructural protein (ns) genes of human influenza c viruses isolated between 1947 and 1983 were determined and compared. assuming constant evolutionary rates, the extent of nucleotide differences among ns genes does not correspond to the isolation years of the strains. this suggests that more than one gene lineage is present in the population. furthermore, examination of the eight c virus ns gene sequences by the maximum parsimony method (w. m. fitch, 1971, syst. zo ... | 1986 | 2943076 |
| the influenza c virus ns gene: evidence for a spliced mrna and a second ns gene product (ns2 protein). | it has previously been shown that the shortest rna (rna 7) of influenza c viruses codes for a nonstructural (nsi) protein (nakada et al. (1985) j. virol. 56, 221-226). experiments reported here indicate that rna 7 also directs the synthesis of a second nonstructural protein via a spliced mrna. the amino terminal 62 codons of this ns2 protein appear to be shared with the ns1 protein and the carboxyl terminal 59 amino acids are unique (derived from a +1 open reading frame in the mrna). although th ... | 1986 | 2943090 |
| influenza c virus in the united kingdom. | | 1985 | 2984296 |
| [influenza virus c and its characteristics]. | | 1987 | 3037794 |
| attachment of influenza c virus to human erythrocytes. | binding experiments with radioactively labelled influenza c virions were carried out to investigate the interaction of the virus with human erythrocytes. the erythrocytes from any of 35 different individuals were found to contain influenza c virus-binding sites though their number was variable among the individuals and was much less than that on mouse, rat and chicken erythrocytes. attachment of influenza c virus to human erythrocytes was inhibited completely by prior treatment of the virus with ... | 1988 | 3049938 |
| [serodiagnosis of the infection caused by the influenza c virus using immunoenzyme analysis]. | serological studies employing enzyme immunoassay and hi tests suggest that influenza c viruses not only play an etiological role in respiratory diseases but can also take part in exacerbation of a number of chronic diseases predominantly affecting children. | 1988 | 3057743 |
| serine 71 of the glycoprotein hef is located at the active site of the acetylesterase of influenza c virus. | the acetylesterase of influenza c virus has been reported recently to be inhibited by diisopropylfluorophosphate (dfp) [muchmore ea, varki a (1987) science 236: 1293-1295]. as this inhibitor is known to bind covalently to the serine in the active site of serine esterases, we attempted to determine the serine in the active site of the influenza c acetylesterase. incubation of purified influenza c virus with 3h-dfp resulted in the selective labelling of the influenza c glycoprotein hef. the labell ... | 1988 | 3144264 |
| sialate o-acetylesterases: key enzymes in sialic acid catabolism. | sialate 9(4)-o-acetylesterases (ec 3.1.1.53) have been isolated from equine liver, bovine brain and influenza c virus. in this latter case, the esterase represents the receptor-destroying enzyme of the virus. the kinetic properties of these enzymes were determined with neu5,9ac2 and in part with 4-methylumbelliferyl acetate and neu5,9ac2-lactose. the km values vary between 0.13 and 24 mm and the vmax values from 0.55 to 11 u/mg of protein. the ph optima are in the range of 7.4-8.5, the molecular ... | 1988 | 3149520 |
| acetylated galactosamine is a receptor for the influenza c virus glycoprotein. | we have investigated the specificity of influenza c virus receptor destroying enzyme (rde) by treatment of erythrocytes of various species with influenza c virus followed by examination of the agglutination patterns of the erythrocytes with a panel of 13 lectins and four anti-human blood group sera of known receptor specificity. human and animal erythrocytes were agglutinated by lectins sba, dba, wfa, vaa ii, rca ii, and wga which have a specificity for the n-acetyl group of galactosamine (nac-d ... | 1988 | 3178492 |
| characteristics of a persistent infection in madin-darby canine kidney cells with influenza c virus. | influenza c/ann arbor/1/50 was used to establish a persistent infection in madin-darby canine kidney cells. the persistent state has been stable for more than 4 years (over 66 passages), with infected cells differing from controls in morphology and growth characteristics. in addition, virus recovered from the media of persistent cultures (passage 58) differed from parental wild-type virus c/ann arbor/1/50 in (i) antigenicity by the hemagglutination-inhibition test; (ii) its ability to produce pl ... | 1988 | 3182232 |
| isolation and characterization of sialate 9(4)-o-acetylesterase from influenza c virus. | an esterase was isolated from influenza c virus with a specific activity from 1.7-5 u/mg protein, and its substrate specificity was tested with various naturally occurring o-acylated sialic acids, synthetic carbohydrate acetates, and other esters. the enzyme hydrolyses only acetic acid esters at significant rates. the non-natural substrates 4-methyl-umbelliferyl acetate, 4-nitrophenyl acetate, and alpha-naphthyl acetate are cleaved at highest hydrolysis rates, followed by the natural substrate n ... | 1988 | 3242542 |
| influenza b virus evolution: co-circulating lineages and comparison of evolutionary pattern with those of influenza a and c viruses. | sequence analyses and comparison of the genes coding for the nonstructural (ns) and hemagglutinin (ha) proteins of different influenza b viruses isolated between 1940 and 1987 reveal that the number of substitutions is not always proportional to the time between isolates. examination of 14 influenza b virus ns gene and 10 ha gene sequences by the maximum parsimony method suggested that--as with influenza c viruses--there are multiple evolutionary lineages which can coexist for considerable perio ... | 1988 | 3267218 |
| the glycoprotein of influenza c virus is the haemagglutinin, esterase and fusion factor. | of the biological activities of influenza c virus, haemagglutination, receptor inactivation and fusion, only the latter has been conclusively correlated with its surface glycoprotein (gp). we have purified the gp by octylglucoside treatment of influenza c virions followed by centrifugation into a sucrose gradient. evidence was obtained that gp also represents the receptor-destroying enzyme of influenza c virus, which has been characterized as a neuraminate 9-o-acetylesterase: (i) it inactivated ... | 1988 | 3356980 |
| human and bovine coronaviruses recognize sialic acid-containing receptors similar to those of influenza c viruses. | human coronavirus oc43 and bovine coronavirus elute from agglutinated chicken erythrocytes when incubated at 37 degrees c, suggesting the presence of a receptor-destroying enzyme. moreover, bovine coronavirus exhibits an acetylesterase activity in vitro using bovine submaxillary mucin as substrate similar to the enzymatic activity found in influenza c viruses. furthermore, pretreatment of erythrocytes with either influenza c virus or bovine coronavirus eliminates subsequent binding and agglutina ... | 1988 | 3380803 |
| evidence that the matrix protein of influenza c virus is coded for by a spliced mrna. | in contrast to influenza a and b viruses, which encode their matrix (m) proteins via an unspliced mrna, the influenza c virus m protein appears to be coded for by a spliced mrna from rna segment 6. although an open reading frame in rna segment 6 of influenza c/jj/50 virus could potentially code for a protein of 374 amino acids, a splicing event results in an mrna coding for a 242-amino-acid m protein. the message for this protein represents the major m gene-specific mrna species in c virus-infec ... | 1988 | 3404579 |
| isolation of the influenza c virus glycoprotein in a soluble form by bromelain digestion. | the spike glycoprotein of influenza c/johannesburg/1/66 was isolated in a soluble form by digestion of mdck cell-grown virions with bromelain. the whole ectodomain of the glycoprotein could be recovered with an apparent molecular weight of 75,000 daltons determined in sds-page. comparison to triton x-100-isolated glycoprotein revealed that a c-terminal peptide of 3000-4500 daltons must have remained in the viral membrane. when purified by sucrose density gradient centrifugation the glycoprotein ... | 1988 | 3414182 |
| n-acetyl-9-o-acetylneuraminic acid, the receptor determinant for influenza c virus, is a differentiation marker on chicken erythrocytes. | erythrocytes from chicken of different age were analysed for their agglutinability by influenza c virus, which has been shown recently to use n-acetyl-9-o-acetylneuraminic acid as a high-affinity receptor determinant for the attachment to cells. only with birds not younger than six days complete agglutination of the erythrocytes was observed. the hemagglutination titer which was initially low reached its maximum value at the age of about 20 days. sialic acid was isolated from erythrocytes, purif ... | 1987 | 3497642 |
| prevalence of the antibody to influenza c virus in a northern luzon highland village, philippines. | a total of 101 serum samples were collected from the persons (1 to 85 years of age) living in a philippine mountain village where the contact with other communities has largely been restricted. these sera were tested for the presence of antibody to influenza c virus with hemagglutination-inhibition and radioimmuno-precipitation tests. the results showed that all the subjects, including the persons who had never been outside the village, contained the antibody to the surface glycoprotein of the v ... | 1987 | 3502168 |
| selective inactivation of influenza c esterase: a probe for detecting 9-o-acetylated sialic acids. | the influenza c virus (inf-c) hemagglutinin recognizes 9-o-acetyl-n-acetylneuraminic acid. the same protein contains the receptor-destroying enzyme (rde), which is a 9-o-acetyl-esterase. the rde was inactivated by the serine esterase inhibitor di-isopropyl fluorophosphate (dfp). [3h]dfp-labeling localized the active site to the heavy chain of the glycoprotein. dfp did not alter the hemagglutination or fusion properties of the protein, but markedly decreased infectivity of the virus, demonstratin ... | 1987 | 3589663 |
| the surface receptor is a major determinant of the cell tropism of influenza c virus. | n-acetyl-9-o-acetylneuraminic acid (neu5,9ac2) has been shown to be a high-affinity receptor determinant for attachment of influenza c virus to erythrocytes (g. n. rogers, g. herrler, j. c. paulson, and h-d. klenk, 1986, j. biol. chem. 261, 5947-5951). in this report the nature of the cell surface receptor for influenza c virus on tissue culture cells was analyzed. pretreatment with either neuraminidase or neuraminate 9-o-acetylesterase was found to render llc-mk2 cells resistant to infection by ... | 1987 | 3604057 |
| the influenza c virus glycoprotein (he) exhibits receptor-binding (hemagglutinin) and receptor-destroying (esterase) activities. | a cdna copy of rna segment 4 of influenza c/cal/78 virus was cloned into an sv40 vector and expressed in cv-1 cells. the gene product expressed from the sv40 recombinant virus was immunoprecipitated by monoclonal antibodies directed against the influenza c virus glycoprotein. cells infected with the recombinant virus also exhibited c virus-specific hemagglutinin and o-acetylesterase activity. this suggests that the same c virus protein is associated with receptor-binding as well as receptor-dest ... | 1987 | 3660588 |