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PubMedDate not supplied

Anti-neuraminidase antibody response in hamsters experimentally infected with Sendai virus.

Investigations were performed to study the behaviour of neuraminidase-inhibiting (n.i.a.) and, by comparison, of neutralizing, hemagglutinin-inhibiting (h.i.a.) and anti-S and anti-V complement-fixing (c.f.a.) antibodies in hamsters inoculated intranasally with a Sendai virus strain of recent isolation. Moreover the distribution of the virus in the respiratory tract was followed. Preliminary experiences were done to assure a correct performance of the neuraminidase-inhibition test. First of all the optimal pH and then the influence of the normal hamster serum on the enzyme activity were evaluated. The n.i.a. as well as h.i.a. and anti-S and anti-V c.f.a. were demonstrable from day 6th after infection, neutralizing antibody from 8th day. The n.i.a. reached the peak of 24 days, that is later than the other types of antibodies, and started to decline after 1 month, together with the drop of the h.i.a and c.f.a. On the contrary the neutralizing antibody persisted at high titres till the end of the observation period (75 days). Detectable antibody response was coincidental with a marked drop in the titers of virus recovered from the respiratory tract. Because of the association of both hemagglutinating and neuraminidase activities with the same Sendai glycoprotein, it is stressed the possibility that hemagglutination-inhibition and neutraminidase-inibition tests titrate the same antibody.

Animals↗

PubMedDate not supplied

[Characteristics of various physico-chemical properties of vibrion neuraminidase].

Some physico-chemical properties of commercially available neuraminidase preparations from non-choleric vibrio were studied. The neuraminidase was shown to be weakly acid glycoprotein with molecular mass 90 +/- 5 kDa, sedimentation constant 5.37 S and pI 5.0 +/- 0.1. As shown by roentgen-diffractometric technique the neuraminidase preparations possessed a quasi-crystalline structure. All the preparations studied were highly purified, exhibited electrophoretic homogeneity, did not contain any protein and Me+ contaminations.

Chromatography, Gel↗

PubMedDate not supplied

[The role of myxovirus neuraminidase in the interferon induction system].

Interaction of myxovirus neuraminidases, in particular, that of influenza virus, with interferon (IFn) was established. When IFn is treated with viral neuraminidases, its antiviral activity tested in tissue culture does not change but it is eliminated from the body by the kidneys much more intensively and is more absorbed by the liver than native IFn. The degree of IFn elimination from the body is directly related to the level of enzymatic activity of viral neuraminidases affecting interferon. The homologous IFn treated with viruses, when inoculated into animals, is less capable than native IFn to protect mice from experimental influenza infection because of its more rapid elimination from the body. The presence of antineuraminidase antibodies in the blood of children slowed down endogenous IFn elimination which alleviates the course of influenza infection.

Animals↗

PubMed1990

Neuraminidase in juvenile calf thymus: determination and characterization by a continuous fluorometric assay procedure.

A continuous fluorometric neuraminidase assay has been developed. Within the pH range optimal for neuraminidases (from 3 to 6) the fluorescence intensity of 4-methylumbelliferone exceeds that of the glycoside 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid about 50 times (at lambda Ex = 335 nm and lambda Em = 445 nm), allowing the precise, simple and time-saving continuous fluorometric registration of enzymatically released 4-methylumbelliferone. In juvenile calf thymus a neuraminidase consisting of two components differing in pH optima and resistence to freezing and to detergents could be found. A beta-galactosidase activity in juvenile calf thymus could be proved by the same assay procedure using the synthetic substrate 4-methylumbelliferyl-beta-D-galactopyranoside.

Animals↗

PubMed1990

Role of membrane proteins in monosodium urate crystal-membrane interactions. I. Effect of pretreatment of erythrocyte membranes with glutaraldehyde and neuraminidase.

Intact human erythrocytes were pretreated with glutaraldehyde, neuraminidase or a combination of both treatments, incubated with monosodium urate monohydrate (MSUM) crystals and the percent hemolysis values determined by measuring hemoglobin release from the cells. The binding of MSUM crystals to pretreated erythrocyte membranes was also quantitated. Neuraminidase treated cells gave higher percent hemolysis values than untreated cells due primarily to the increased binding of MSUM to neuraminidase treated erythrocyte membranes. Pretreatment of red cells with glutaraldehyde up to a maximum concentration of 0.015% inhibited MSUM induced hemolysis but the binding of MSUM to glutaraldehyde treated and untreated cell membranes was the same. We propose a "pore" model for MSUM induced hemolysis.

Cross-Linking Reagents↗

PubMed1990

Lysosomal beta-galactosidase from rat liver: purification, molecular forms and association with neuraminidase.

A simple procedure for purification of lysosomal beta-galactosidase from rat liver was developed. The association state of the purified enzyme has been found to depend on pH and ionic strength. Under acidic conditions and at high ionic strength, the enzyme is aggregated into a high molecular weight complex having a molecular weight of about 700,000. Increasing pH and lowering the ionic strength favour the disaggregation of the complex to an enzyme species whose molecular weight is 160,000. These two enzyme forms differ markedly in their hydrophobicity, but no significant differences in kinetic properties have been found. Galactose and galactose-1-amine were competitive inhibitors of beta-galactosidase. Neuraminidase is associated with the multimeric form of beta-galactosidase, whereas the low molecular weight form did not show any neuraminidase activity. The stability of neuraminidase has been found increase in the presence of magnesium ions.

Animals↗

PubMed1975

Therapy in an intracerebral murine glioma model, using Bacillus Calmette-Guérin, neuraminidase-treated tumor cells, and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea.

The s.c.-propagated murine glioma, GL-26, was established in tissue culture. The tissue culture line, with a doubling time of 36 hr, was used as the common source for all tumor cells. Suspensions of the tumor cells were transplanted intracerebrally in mice to produce an anaplastic ependymoblastoma. In vitro 51-Cr cytotoxicity assays did not detect any cellular immunity against GL-26 tumor cells in animals bearing either s.c. or i.c. tumors, indicating that the tumor itself is not highly immunogenic. Howeveer,significant cellular cytotoxicity was elicited in non-tumor-bearing animals by immunization with Vibrio cholerae neuramini-animals by immunization with Vibrio cholerae neuraminidase and mitomycin C-treated tumor cells plus complete Freund's adjuvant. In vivo therapy studies revealed significant increases in survival of animals preimmunized with V. cholerae neuraminidase- and mitomycin C-treated cells plus complete Freund's adjuvant. 1(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea, when given i.p. on Day 3 or 12 after tumor challenge, also resulted in significant increases in survival. Furthermore, the effects of 1-(2-chloroethyl)- 3-cyclohexyl-1-nitrosourea and preimmunization were additive, with significanchloroethyl)-3-cyclohexyl-1-nitrosourea. In contrast to results reported for several extracranial tumor systems, immunotherapy, using either V.cholerae neuraminidase- and mitomycin-treated tumor cells, Bacillus Calmette-Guerin, or both, beginning 3 0r 4 days after tumor challenge, did not produce any significant increases in survival.

Animals↗

PubMedDate not supplied

[Antigenic specificity of the neuraminidases of epidemic strains of influenza A/H3N2 viruses circulating in the USSR 1983-1985].

The antigenic properties of neuraminidase of the epidemic strains of 1983-1985 were studied by means of lectin test and thiobarbituric method using polyclonal sera and monoclonal antibody. Populations of the viruses with respect to antigenic relationships of neuraminidase were shown to be heterogeneous. A considerable portion of the strains occurring in 1985 underwent antigenic drift from the reference A/Philippines/2/82 strain. The epidemic novelty of some strains was due to changes in only one supercapsid protein-neuraminidase.

Antibodies, Monoclonal↗

PubMed1978

Modifications of lectin binding on human leukemic cells after neuraminidase treatment.

Cell surface modifications after vibrio cholerae neuraminidase treatment were investigated using three different tritiated lectins: Concanavalin A, Ricinus sanguineus agglutinin (R.S.A.) and Robinia pseudoacacia lectin. Lectin binding measurements were performed on untreated and enzyme treated cells. The cells used were from chronic and acute leukemic donors. After neuraminidase treatment, a significant increase in the number of receptor sites, from 1 to 3 times, was found in all cases tested and for all three lectins utilized with only one exception. The affinity constant was generally decreased after neuraminidase treatment. The increase in number lectin binding sites, indicating extensive modification of the cell surface, is completely consistant with the known importance of sialic acid in determining immunogenicity.

Binding Sites↗

PubMed1989

[The composition of glycosphingolipids and the effect of neuraminidase on cultured glioma cell lines].

The composition of glycosphingolipid on human cultured glioma cell line U 251 and rat glioma cell line C6 was analysed by high performance thin layer chromatography. As a result, the major gangliosides were simple gangliosides such as GM3 (U 251: 7.7%, C6: 84.3%), GM2 (U 251: 32.6%) and SPG (U 251: 30.0%) on glioma cells whereas the major neutral glycosphingolipids were CDH, CTH and globoside. After treatment with neuraminidase 2.92 nmol/mg dry weight and 3.73 nmol/mg dry weight of sialic acid were freed from U 251 cells and C6 cell, but only 8.11% (U 251 cell) and 11.24% (C 6 cell) of these sialic acids originated from glycolipid, and thus the major part of sialic acid might be released from glycoprotein of the cells. The gangliosides that react to neuraminidase are SPG, GD1a and GD1b in U 251 cells and are GM1a and little GM3 in C 6 cells. The biolabelling study using N-acetyl-14C-mannosamine as a precursor of sialic acid demonstrated that the precursor was mainly incorporated into both or either of GM3 and SPG in the acidic glycolipid fraction. In addition, no significant change on proliferation and morphology of glioma cells after neuraminidase treatment was observed in this study.

Animals↗

PubMed1977

[The occurrence of neuraminidase and N-acetylneuraminate-pyruvate lyase in pathogenic haemophili of man (author's transl)].

We investigated the following six Haemophilus species from man for the both enzymes neuraminidase and N-acetylneuraminate pyruvate lyase: H. aegypticus, H. aphrophilus, H. influenzae. H. parahaemolyticus, H. parainfluenzae and H. vaginalis. It is shown that H. vaginalis does not produce either neuraminidase or N-acetylneuraminate pyruvate lyase. He differs, therefore, from all other investigated haemophili producing both enzymes, neuraminidase and N-acetylneuraminate pyruvate lyase. Colominic acid, Na-salt, is splitted better than N-acetylneuraminyllactose. It can be concluded, therefore, some substrate specificity of the neuramindase of Haemophili in the sense that the alpha, 2 leads to 8 linkage of neuraminic acid is cleaved quicker than the alpha, 2 leads to 3 linkage. The physiological and pathologenic role of the both enzymes is discussed.

Chromatography, Paper↗

PubMed1985

Murine TH response to influenza virus: recognition of hemagglutinin, neuraminidase, matrix, and nucleoproteins.

BALB/c mice were primed with type A influenza virus by footpad injection or by aerosol infection with PR8 [A/PR/8/34-(H1N1)]. Isolated T cells from draining lymph nodes were then tested for their proliferation in the presence of purified viral proteins hemagglutinin, neuraminidase, matrix, and nucleoprotein. Significant responses [( 3H]thymidine incorporation) were seen against each of the four proteins after either priming scheme. When helper T (TH) cell clones were isolated by hybridoma formation from two different strains of mice, responsiveness (interleukin 2 production) towards each protein was against apparent. Of 12 virus-specific T cell hybridomas isolated, four responded to matrix, three to nucleoprotein, one to neuraminidase, three to hemagglutinin, and one cell was of undefined specificity. Each hybridoma was also tested for recognition of the HK virus [A/Hong Kong/1/68-(H3N2)], which differs in subtype from the priming strain. All matrix-specific cells, two nucleoprotein-specific cells, and the cell of undefined specificity were cross-reactive with HK virus. H1-subtype specificity was seen for all hemagglutinin and neuraminidase-specific cells and one of the three nucleoprotein-specific cells. Because many virus-immune TH cells recognize antigenically variable determinants, a significant fraction of TH cell function may be lost after virus evolution. When selecting priming schemes for long-term immunization against influenza, the isolated enhancement of TH cells recognizing conserved determinants on matrix and nucleoprotein may therefore be considered.

Animals↗

PubMed1988

Crystallization and preliminary X-ray analyses of two neuraminidases from influenza B virus strains B/Hong Kong/8/73 and B/Lee/40.

Crystals of neuraminidase heads from two different influenza B virus strains have been grown. Neuraminidase crystals of influenza B/Hong Kong/8/73 were grown from solutions of potassium phosphate. The crystals are tetragonal prisms, space group I422; the axes are a = 123 A and c = 165 A. Influenza B/Lee/40 neuraminidase crystals were grown from solutions of polyethylene glycol 4000. The crystals are tetragonal pyramids, space group P4(1)2(1)2 or its enantiomorph P4(3)2(1)2; the axes are a = 125 A and c = 282 A.

Crystallization↗

PubMed1988

Tumor-associated antigen defined by a monoclonal antibody against neuraminidase-treated human cancer cells.

A monoclonal antibody, MH-A6, was produced by immunization with a human gastric cancer cell line, MKN 74, treated with neuraminidase. The antigen defined by the monoclonal antibody was detected on various tumor tissues and a limited number of normal tissues in immunoperoxidase assay, and the expression of MH-A6 antigen was not influenced by neuraminidase treatment except for some cases of tumor tissues. Interestingly, neuraminidase treatment enhanced binding of the antibody on some adenocarcinomas, but diminished binding of the antibody on squamous cell carcinomas. Both treatment of the immunizing tissues with trypsin and periodic acid diminished binding of the antibody. In isolation of MH-A6 antigen from MKN 74 cells by the monoclonal antibody coupled-affinity column, the epitope exists on molecules with molecular weights of 30,000 and 72,000, and with an acidic pH range in two-dimensional electrophoresis. CEA and CA 19-9 activities were not detected in purified MH-A6 antigen by solid-phase radioimmunoassay, and the reactivity of the MH-A6 antibody with CEA and CA 19-9 was not detected in enzyme-linked immunosorbent assay. Hemagglutination observed between erythrocytes (Lewisa, Lewisb, or NE-treated) and anti-Lewisa, anti-Lewisb sera, or anti-T-agglutinin (peanut lectin), respectively, was not inhibited by MH-A6 antigen. The results suggest that MH-A6 antigen is a tumor-associated antigen, probably glycoprotein, and different from CEA, CA 19-9, Lewisa, Lewisb, and Thomsen-Friedreich (T) antigen.

Antibodies, Monoclonal↗

PubMed1987

Abrogation of the capacity of delayed-type hypersensitivity responses to alloantigens by intravenous injection of neuraminidase-treated allogeneic cells.

BALB/c or C3H/He mice were inoculated i.v. with allogeneic spleen cells untreated or treated with neuraminidase. Appreciable or potent anti-allo-delayed-type hypersensitivity (DTH) responses were observed when mice were inoculated i.v. with untreated allogeneic cells or inoculated i.v. with those cells followed by s.c. immunization with untreated allogeneic cells. In contrast, i.v. inoculation of neuraminidase-treated allogeneic cells (presensitization) not only failed to induce any significant anti-allo-DTH responses but also abolished the capability of the animals to develop DTH responses after s.c. immunization, indicating the tolerance induction. This tolerance was alloantigen-specific, and rapidly inducible and long lasting. The induction of suppressor cell activity was demonstrated in tolerant mice. However, this activity was associated only with the tolerant state around 4 to 7 days after the i.v. presensitization, but was no longer detected in mice more than 14 days after the presensitization, although these mice exhibited complete tolerant state. When spleen cells from such tolerant mice were transferred i.v. into 600 R x-irradiated syngeneic recipient mice alone or together with normal syngeneic spleen cells, these tolerant spleen cells themselves failed to induce DTH responses but did not exhibit suppressive effect on the generation of DTH responses induced by normal spleen cells co-transferred. These results indicate that i.v. administration of neuraminidase-treated allogeneic cells results in the induction of alloantigen-specific tolerance which is not always associated with the induction of suppressor cell activity but rather with the elimination or functional impairment of alloantigen-specific clones.

Animals↗

PubMed1985

[Synthesis, cloning and determination of the primary structure of a full-size DNA copy of the neuraminidase gene from influenza virus type A subtype H1N1].

Complete nucleotide sequence of the cloned full-length DNA copy of the influenza virus A (H1N1) neuraminidase gene has been determined. The predicted amino acid sequence is compared with sequences of neuraminidases from other influenza virus strains. A section of the neuraminidase is found to be homologous to the chicken lysozyme catalytic centre.

Amino Acid Sequence↗

PubMed1977

[Use of the enzyme neuraminidase for immunotherapeutic treatment of chemically induced carcinogenesis].

The effect of vibrio cholerae neuraminidase (VCN) on the growth of dimethylbenzanthracene-induced sarcoma cells in the inbred CBA mice was investigated. The use of this preparation was started after the appearance of the tumour. Injection of 50 units of VCN twice a week for three months was effective at the early stages of carcinogenesis. An increase of the life-span of mice of comparison with control animals was also observed in the animals inoculated intraperitoneally with induced syngeneic sarcoma cells pretreated with VCN and simultaneously injected (into the developing tumour) with sensitized lymphocytes received from the syngeneic tumour-bearing mice. Lymphocytes were inoculated into the growing tumour. No positive effect ensued when the lymphocytes inoculated into the tumour region were pretreated with VCN. A simultaneous inoculation of neuraminidase into the growing tumour and of syngenous induced-sarcoma cells pretreated with this enzyme intraperitoneally was the most effective. Possibilities of application of neuraminidase under clinical conditions are discussed.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1972

Antigenic relationships between the neuraminidases of influenza B virus.

Antigenic relationships between neuraminidases of influenza B viruses isolated from 1940 to 1968 were studied by neuraminidase-inhibition tests using hyperimmune rabbit antisera. The cross-reactions between the enzymes of influenza B viruses showed that some antigenic drift had occurred but that they are all related. From these results it is concluded that the differences between the neuraminidases of influenza B viruses are not sufficiently clear-cut to allow the viruses to be separated into subgroups.

Animals↗