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C Orvell

Publications and source records attributed to C Orvell.

At least 91 records · Page 5Linked to original sources
PubMed1988

Mapping of monoclonal antibodies to the Sendai virus P protein and the location of its phosphates.

The epitopes of a panel of five monoclonal antibodies to the Sendai virus P protein were mapped by generating modified forms of the P mRNA via SP6 expression followed by in vitro translation. The epitopes were found to be clustered in the C-terminal region of the protein. Two epitopes were within the last 30 residues, two were within the next 65, and one was between residues 308 and 451 of this 568-residue-long protein. By a combination of partial proteolysis and Western immunoblotting with one of these antibodies, the sites at which phosphates are added in vitro by the virion-associated kinase were mapped to the second quarter of the molecule from the N terminus.

Antibodies, Monoclonal↗
PubMed1987

F1 polypeptides of two canine distemper virus strains: variation in the conserved N-terminal hydrophobic region.

The fusion protein of canine distemper virus was isolated by immunoadsorption from two virus strains, the rapidly growing Onderstepoort strain (forming large plaques) and the Convac vaccine strain (forming microplaques). The F1 subunits of the two fusion proteins were purified by preparative polyacrylamide gel electrophoresis. Direct amino acid sequence analysis revealed that 36-residue N-terminal regions of the proteins from the two strains are identical except at position 9, where Ala in the Convac strain is substituted by Val in the Onderstepoort strain. The two sequences show high homology with the previously determined N-terminal sequence of the F1 polypeptide of measles virus, and moderate homology with corresponding sequences of five paramyxoviruses, emphasizing the occurrence of an extensive conservation of these structures.

Amino Acid Sequence↗
PubMed1987

Preparation and characterization of monoclonal antibodies directed against five structural components of human respiratory syncytial virus subgroup B.

Mouse hybridomas producing antibodies against the structural proteins of strain WV4843, a subgroup B strain of respiratory syncytial (RS) virus, were produced by fusion of Sp2/0 myeloma cells with spleen cells from BALB/c mice immunized with purified preparations of the virus. After immunoprecipitation test with [35S]methionine-labelled extracellular virions, 35 clones found to produce antibodies against the fusion (F) protein, six against the member (M) protein, 21 against the nucleocapsid (NP) and eight against the phospho- (P) protein were further characterized. Immunoprecipitation with [3H]glucosamine-labelled intracellular virus polypeptides detected nine hybridoma cell lines producing antibodies against the large glyco- (G) protein of the virus. By competitive binding ELISA tests with monoclonal antibodies against each of the structural components, a minimum of two, 24, four, 15 and three epitopes were detected on the G, F, M, NP and P proteins, respectively. Eleven monoclonal antibodies directed against nine epitopes of the F protein could neutralize the infectivity of the virus. In contrast, none of the nine monoclonal antibodies against G could neutralize the infectivity of the virus. In order to find out more about the antigenic relationship between human and bovine RS virus strains all monoclonal antibodies were reacted with subgroup A RS virus and also with three different strains of bovine RS virus and one strain of caprine RS virus in immunofluorescence, ELISA and immunoprecipitation tests. In addition, 31 previously developed monoclonal antibodies against subgroup A virus were reacted with the bovine and caprine strains. The numbers of monoclonal antibodies of subgroup B specific for the B type of the two human subgroups were 9/9, 3/35, 0/6, 0/21, 0/8, for the G, F, M, NP and P proteins, respectively. No antigenic variations were found between the three bovine strains and the caprine strain. They did not react with the nine monoclonal antibodies against the G protein of subgroup B, nor did they react with nine monoclonal antibodies against subgroup A. Most but not all of the monoclonal antibodies against the other structural proteins of the two human RS virus subgroups reacted with the four strains. All 11 monoclonal antibodies against the F protein of subgroup B that could neutralize the infectivity of subgroup B also reacted with the bovine strains and neutralized their infectivity. It is concluded that although the bovine strains share many epitopes with the two human subgroups, they are antigenically distinct from the human viruses.

Antibodies, Monoclonal↗
PubMed1987

Antigenic analysis of human and bovine parainfluenza virus type 3 strains with monoclonal antibodies.

The antigenic characteristics of eight human strains and two bovine strains, one of which is represented by two plaque variants, of parainfluenza virus type 3 were analysed. The strains and variants were compared using 52 monoclonal antibodies against five, two, six and six epitopes of the haemagglutinin-neuraminidase (HN), fusion, nucleocapsid and matrix viral proteins respectively, employing radioimmuno-precipitation and immunofluorescence assays. The human strains, seven of which were isolated over 6 years at different geographical locations and the eighth one representing an older prototype strain, showed very little antigenic variation. Extensive differences were detected in all four proteins examined between the human strains and the two strains of bovine origin. Two bovine variants were less effectively neutralized than the prototype human strain with a series of monoclonal antibodies against the HN protein.

Animals↗
PubMed1987

Subgroup characteristics of respiratory syncytial virus strains recovered from children with two consecutive infections.

Respiratory syncytial virus strains from 13 children who had repeat infections at least 1 year apart were identified as either subgroup A or subgroup B according to reaction patterns with several monoclonal antibodies directed against the large surface glycoprotein (G), fusion protein (F), nucleoprotein (NP), and matrix protein (M). The virus strains were characterized by enzyme immunoassay, polyacrylamide gel electrophoresis, and immunofluorescence procedures. During the first infection, 10 children had subgroup A strains and 3 had subgroup B strains. Of the 10 children with subgroup A strains during their first infection, 6 had subgroup B and 4 had subgroup A strains during the second infection. Of the three children with subgroup B strains during their first infection, one had subgroup A and two had subgroup B strains during their second infection. No child experienced unusually severe respiratory tract illnesses during second infections with respiratory syncytial virus. Fourfold or greater rises in serum antibody as determined by enzyme immunoassay were as common after the first infection as after the second infection among the seven children tested. Thus, second infections with strains of either subgroup of respiratory syncytial virus did not potentiate respiratory illness, and infection with subgroup A strains of respiratory syncytial virus provided some protection from a second infection with the homologous, but not the heterologous, subgroup of the virus.

Acute Disease↗
PubMed1987

Immunoglobulin class and immunoglobulin G subclass enzyme-linked immunosorbent assays compared with microneutralization assay for serodiagnosis of mumps infection and determination of immunity.

Total immunoglobulin G (IgG) and IgG subclass reactivities with purified mumps glycoproteins (GP) and nucleoprotein (NP), measured in enzyme-linked immunosorbent assays (ELISAs), were compared with titers in a mumps microneutralization assay (NT). For determination of mumps immunity, the sensitivity of both ELISAs was 100% in comparison with the NT and the specificity was 90%. IgG1 was the dominant subclass against the two antigens found in seropositive healthy individuals. In samples from patients with clinical mumps infections and positive mumps IgM, titer rises of total IgG against NP were invariably seen before GP titer rises. Significant but often late titers rises in NT were found in all patients. Changes of IgG1 levels against both antigens followed the changes of total specific IgG. High levels of IgG3 against NP were diagnostic for mumps infection. In parainfluenza infections, titer rises in the mumps ELISAs and NT were found, but mumps IgM, NP IgG3, and the high ratio between the NP and GP titers found in early samples from patients with mumps infection were not observed.

Adolescent↗
PubMed1986

Antigenic variation of envelope and internal proteins of mumps virus strains detected with monoclonal antibodies.

Antigenic characteristics of nine mumps virus strains were determined by immunofluorescence and radioimmunoprecipitation assay (RIPA) using a collection of 44 monoclonal antibodies. These antibodies were directed against five different structural components of mumps virus, the haemagglutinin-neuraminidase (HN), fusion (F), matrix (M), phospho- (P) and nucleocapsid (NP) proteins. The nine mumps virus strains could be divided into two groups according to their antigenic characteristics. One group included two strains isolated more than a decade ago and the Jeryl Lynn vaccine strain. These three strains reacted with a wider range of monoclonal antibodies than the second group of six recently isolated strains of different geographical origin. In the F, M and P proteins variations were only found in single antigenic determinants. In the HN and NP components, RIPA revealed variations in three and seven determinants respectively. The Jeryl Lynn vaccine strain showed a unique lack of reaction with one anti-HN antibody clone in the RIPA.

Antibodies, Monoclonal↗
PubMed1986

The antigenic relationship between measles, canine distemper and rinderpest viruses studied with monoclonal antibodies.

Monoclonal antibodies (MAbs) were used to delineate the antigenic relationship between the three morbillivirus types: measles virus (MV), canine distemper virus (CDV) and rinderpest virus (RPV). Panels of six to 31 MAbs against the haemagglutinin (H), fusion (F), nucleocapsid protein (NP), phosphoprotein (P) and matrix (M) proteins of MV and the H, F, NP and P proteins of CDV were employed. Nine strains of MV, three strains of CDV and four strains of RPV were examined by radioimmunoprecipitation assay and immune fluorescence for reactivity with the heterologous MAbs. Overall, the NP and in particular the F proteins of the morbilliviruses showed a high degree of epitopic homology; the P and M proteins showed a partial epitopic homology, with the greatest variation between the M proteins of CDV and MV; the H proteins showed a low degree of epitopic homology and then only between MV and RPV. These data indicate that the major cross-protecting antigen in heterotypic vaccination amongst morbilliviruses is the F antigen. The epitopic relationships found between morbilliviruses as identified by the MAbs were classified as follows. (i) Group-specific epitopes were present on all strains of the three morbillivirus types. (ii) Group-cross-reactive epitopes were present on only some of the strains from each morbillivirus type (these epitopes identified the presence of intratypic strain variation in all proteins of all three virus types). (iii) Type-specific epitopes, i.e. MV unique or CDV unique, were found only on the homologous morbillivirus type. (iv) CDV-RPV intertypic and MV-RPV intertypic epitopes were, respectively, epitopes shared by CDV and RPV but not with any MV strain, and epitopes shared by MV and RPV but not with any CDV strain. These cross-reactivities and type-specific reactions were obtained with the internal viral proteins (M, P and NP). The epitopes of the F proteins were mainly group-specific and no CDV-RPV or MV-RPV intertypic epitopes were found. The epitopes of the H protein were either type-specific or MV-RPV intertypic. These data support the proposed evolutionary relationship between the morbilliviruses.

Antibodies, Monoclonal↗
PubMed1986

Characterization of four parainfluenza virus type 3 proteins by use of monoclonal antibodies.

Monoclonal antibodies directed against four structural components of the ATCC strain C243 of parainfluenza virus type 3 were produced. The specific reaction of the antibodies with individual structural components was determined by radioimmune precipitation assay. In the collection of monoclonal antibodies, 21 reacted with the haemagglutinin-neuraminidase (HN) glycoprotein (mol. wt. 72,000), eight with the fusion (F) glycoprotein (mol. wt. 64,000), 27 with the nucleocapsid (NP) protein (mol. wt. 69,000) and 24 with the matrix (M) protein (mol. wt. 40,000). The F-specific monoclonal antibodies precipitated two proteins which were interpreted to represent intact F protein and the large cleavage product F1 (mol. wt. 52,000). The numbers of epitopes were determined in a competition ELISA with the monoclonal antibodies. The epitopes found were six for the HN, two for the F, six for the NP and six for the M protein. The six groups of antibodies reacting with different epitopes on the HN molecule showed varying capacities to inhibit biological activities. Two exhibited high neutralization (NT), haemagglutination inhibition (HI) and haemolysis inhibition (HLI) activity. Three groups had somewhat lower NT, lower HI and no detectable HLI activity. One group showed no activity in these tests. Of the eight monoclonal antibodies directed to the F protein two had demonstrable HLI activity.

Antibodies, Monoclonal↗
PubMed1986

Immunological relationships between mumps virus and parainfluenza viruses studied with monoclonal antibodies.

The immunological relationships between mumps virus and parainfluenza viruses were investigated with 74, 78 and 80 previously developed monoclonal antibodies directed against five major structural proteins of mumps virus, Sendai virus (a murine parainfluenza type 1 virus) and parainfluenza type 3 virus. These monoclonal antibodies were reacted with the three viruses, with parainfluenza type 2 virus and with Newcastle disease virus (NDV) in ELISA and immunofluorescence (IF) tests. In addition, immunoprecipitation tests with [35S]methionine-labelled extracellular virions were carried out with cross-reacting monoclonal antibodies. None of all 232 monoclonal antibodies against the three viruses cross-reacted with either parainfluenza type 2 virus or NDV in ELISA and IF tests. In the collection of 74 mumps virus monoclonal antibodies, three directed against the nucleocapsid (NP) protein, polymerase protein, and fusion protein cross-reacted with Sendai virus. Two Sendai virus monoclonal antibodies directed against two different epitopes of the haemagglutinin-neuraminidase (HN) protein cross-reacted with parainfluenza type 3 virus. Six other Sendai virus monoclonal antibodies directed against four different epitopes of the HN protein and one directed against the NP protein cross-reacted with mumps virus. Eight out of 80 monoclonal antibodies directed against parainfluenza type 3 virus cross-reacted with Sendai virus. One was directed against the HN protein, four were directed against a minimum of two epitopes of the matrix protein and three were directed against three different epitopes of the NP protein. The different cross-reactions found show that Sendai virus is antigenically related to both mumps virus and parainfluenza type 3 virus. In contrast, no antigenic relationship could be demonstrated between mumps virus and parainfluenza type 3 virus.

Antibodies, Monoclonal↗
PubMed1986

Viral IgM and IgG antibody synthesis within the central nervous system in mumps meningitis.

With the use of enzyme-linked immunosorbent assay (ELISA) for demonstration of specific viral antibodies in 21 patients with mumps meningitis (MM), 19 (91%) displayed evidence for synthesis within the central nervous system (CNS) of IgG antibodies and 11 (52%) of IgM antibodies. Only one MM patient did not show local antibody production, but he had high mumps IgM titers in serum. Elevated IgG and IgM indices reflecting local IgG and IgM production, were found in 4 (19%) and 17 (81%) of the patients, respectively, and frequently did not coincide with local synthesis of specific antibodies. None of 21 control patients with acute aseptic meningitis of other etiology showed evidence for a local antibody response against mumps. In one of the MM patients, local production of measles IgM antibodies was demonstrated, reflecting an IgM response within the CNS against an antigen unrelated to the disease. This study concludes that in less serious CNS infections, such as MM, highly sensitive methods as ELISA are needed to demonstrate intrathecal specific viral immune response.

Adolescent↗
PubMed1986

Protection against canine distemper virus in dogs after immunization with isolated fusion protein.

Canine distemper virus attachment (hemagglutinin [H] equivalent) and fusion (F) antigens were purified by affinity chromatography with monoclonal antibodies. The purified antigens were used to immunize groups of three dogs. Radioimmune precipitation assays with sera from these animals showed that the F antigen preparation was pure and induced only an F polypeptide-specific antibody response but that the H antigen preparation had a slight contamination by the F antigen. Immunized animals were challenged with virulent canine distemper virus. Two animals in each group developed pronounced humoral and cellular immune responses after challenge. Among these infected animals, only the dogs immunized with H antigen developed symptoms, albeit mild. In contrast, three nonimmunized control animals developed severe disease, with a fatal outcome in two cases. The complete resistance against challenge in two dogs was interpreted to reflect in one case anti-F immunity and in the other case most likely a high level of anti-H immunity. It is suggested that the F antigen may be of particular interest for the development of morbillivirus and possibly other paramyxovirus subunit or synthetic vaccines, because it can induce immunity capable of blocking virus infection and in situations of virus replication prevent the emergence of symptoms.

Animals↗
PubMed1986

Affinity of human carcinoma cell nuclei for polyinosinic acid demonstrated by monoclonal antibodies.

The anti-nuclear cross reactivity of the monoclonal anti-actin antibodies M 372/809 was studied in some detail. The reactivity against a number of nuclear constituents was examined in the ELISA test and the capacities of these constituents to block the M 372/809 anti-nuclear and anti-actin reactions were evaluated in indirect immunofluorescence tests against tissue sections and monolayer cultures of fibroblasts and Vero cells. The repetitive polynucleotides polyinosinic and polyguanylic acid and their deoxyanalogues, actin and vimentin, were found to have the antigenic epitope. The epitope was covered or otherwise inactivated in the presence of polycytidylic acid. Using the M 372/809 antibodies as a reagent, carcinoma cell nuclei were found commonly to have an affinity for polyinosinic and polyguanylic acid. This was seldom noted with non-neoplastic cells.

Actins↗
PubMed1985

The effects of monoclonal antibodies against the hemagglutinin-neuraminidase and fusion protein on the release of Sendai virus from infected cells.

Vero cell cultures in Leighton tubes were infected with egg-grown Sendai virus at high multiplicity of infection. Four hours after infection, the cultures were labelled with 35S-methionine, after which various concentrations of fourteen and five mouse monoclonal antibodies directed against different antigenic determinants of the hemagglutinin-neuraminidase (HN) and fusion (F) protein, respectively, were added to the medium. Fourty-eight hours after infection radiolabelled virions released into the medium were collected and purified by discontinuous sucrose gradient centrifugations. The amount of virus-bound radioactivity obtained in the various extracellular materials allowed an estimation of the capacity of the different monoclonal antibodies to inhibit the release of Sendai virus. In addition, the release of virions from infected cells was studied ultrastructurally. Based on their serological reactivity the fourteen anti-HN monoclonal antibodies could be divided into four groups. The first group of clones could not inhibit any biological activity of the virus. These clones were binding proximally, near the base of the HN glycoprotein and could not inhibit the release of the virus. The second group blocked hemolysis, but did not block hemagglutination (HA) or neuraminidase (NA) activity. The third group of clones blocked all biological activities of the HN glycoprotein. The fourth group could only block NA activity. With the exception of one of five monoclonal antibodies belonging to the second group, antibodies of the second, third and fourth group were found to bind more distally on the HN glycoprotein. Except for two monoclonal antibodies of the second group they could all effectively inhibit release of the virus from infected cells. Ultrastructurally, these antibodies caused aggregation of virions in contact with the plasma membrane. The five monoclonal antibodies directed against the F protein reacted with four different antigenic sites. These antibodies could not prevent the release of Sendai virus.

Animals↗
PubMed1985

Two distinct subtypes of human respiratory syncytial virus.

Antigenic variation of human respiratory syncytial (RS) virus strains was analysed using a collection of nine, six, six, nine and one monoclonal antibodies respectively directed against the large glycoprotein (G), fusion protein (F), matrix protein (M), nucleoprotein (NP) and phosphoprotein (P) components of the Long strain of RS virus. A comparison was made with seven other strains isolated during different years in radioimmune precipitation analyses and immune fluorescence tests. Two different subtypes of the virus were demonstrable. Subtype A included the prototype strains Long and A2 and virus isolates from 1973, 1983 and 1984; subtype B included four virus strains isolated in successive years from 1979 to 1982. Subtype A viruses reacted with all the antibodies, whereas subtype B viruses showed different epitope characteristics in four structural components. The number of altered epitopes were 5/6, 1/2, 2/6 and 1/6 in the G, F, M and NP components, respectively. It is concluded that the two subtypes have evolved separately. The finding of two subtypes may explain previously observed strain variations in neutralization tests, and gives a new perspective on the immunobiology of RS virus.

Antibodies, Monoclonal↗
PubMed1985

Preparation and characterization of monoclonal antibodies directed against four structural components of canine distemper virus.

Mouse hybridomas producing antibodies against structural proteins of canine distemper virus (CDV) were produced by fusion of Sp2/0 myeloma cells with spleen cells from BALB/c mice immunized with purified preparations of Vero cell-grown CDV. Ascites fluids collected after intraperitoneal inoculation with 149 CDV antibody-producing hybridoma cell lines were characterized by different serological tests. By immune precipitation tests with [35S]methionine-labelled extracellular virions and intracellular virus polypeptides, 57 clones were found to produce antibodies against the nucleocapsid protein (NP), 22 against the polymerase (P) protein, 10 against the fusion (F) protein and nine against the large uncleaved glycoprotein (named H in analogy with measles virus). By competitive binding enzyme-linked immunosorbent assay (ELISA) tests with monoclonal antibodies against each structural component, a minimum of 18, six, three and seven separate antigenic determinants were identified on the NP, P, F and H proteins, respectively. The reactions of clones directed against F and H surface components of the virus were tested for their ability to inhibit the infectivity of both CDV and measles virus in the absence and presence of anti-gamma-globulin. In addition, the inhibitory activity of the clones on measles haemagglutinating (HA) and haemolysis (HL) activity were examined. Monoclonal antibodies against six of the seven antigenic determinants of the H protein could neutralize the infectivity of the virus. After addition of anti-gamma-globulin to the test, increases of titres varying from twofold to several hundredfold were observed with the different clones. None of all the clones against H could block measles virus infectivity, HA or HL activity. The 10 clones directed against the F protein could not neutralize the infectivity of CDV even in the presence of anti-gamma-globulin. Further, the antibodies could not inhibit measles HA and HL activity in the absence of anti-gamma-globulin. However, after the addition of anti-gamma-globulin, antibodies against two of the three sites were found to block measles virus HL activity. The reactions of all clones were tested in immune fluorescence, ELISA and immune precipitation tests with three strains of CDV. Each strain had a few unique antigenic sites. Variation was found in four, one and three different antigenic sites of the NP, P and H proteins, respectively.

Antibodies, Monoclonal↗
PubMed1985

The role of serologically defined epitopes on mumps virus HN-glycoprotein in the induction of virus-dependent cell-mediated cytotoxicity. Analysis with monoclonal antibodies.

The importance of virus structural proteins for the induction of virus-dependent cellular cytotoxicity (VDCC) was studied by means of monoclonal antibodies raised in mice against mumps virions. Antibodies against the viral glycoprotein bearing the haemagglutination and neuraminidase activities (HN) inhibited VDCC but not the natural cytotoxicity (NK) displayed by the lymphocytes in the absence of virus. Antibodies to the fusion factor, the membrane protein or the nucleoprotein were inactive. These results confirmed our previous conclusion, that the only viral component required for VDCC induction is the HN protein. To clarify the role of this protein in VDCC further, the inhibitory activity of 13 HN-specific monoclonals, all of IgG isotype and directed against 9 distinct determinants, was studied in detail. Seven antibodies reacting with 3 different determinants of the peptide moiety of the HN protein were strongly inhibitory. The remaining antibodies, specific for 5 additional peptide epitopes, had intermediate or weak inhibitory effects. One carbohydrate specific anti-HN antibody was inactive although its antigen-binding capacity was of the same magnitude as that of a good inhibitory antibody. The anti-HN antibodies inhibited VDCC regardless of their IgG subclass. Moreover, VDCC inhibition was not correlated with the capacity of the antibodies to inhibit haemagglutination, haemolysis, neuraminidase activity, or the infectivity of the virus. These results suggest that full expression of VDCC requires the interaction of more than one of the serologically defined structures of the HN polypeptide with virus receptors on the lymphocytes and probably also on the target cells. These structures may be different at least in part from those involved in other known biological activities of the virus. Treatment of lymphocytes with virus increases both the number of target-binding cells (TBC) and the number of cytotoxic effector cells. However, when treated under conditions which gave optimal VDCC inhibition, none of the inhibitory antibodies reduced the virus-mediated increase in TBC. This indicates either that the anti-HN antibodies decreased the efficiency of effector-target cell interaction necessary for VDCC induction, or that they blocked a post-binding step required for triggering of cytotoxicity.

Animals↗