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O Closs

Publications and source records attributed to O Closs.

At least 19 recordsLinked to original sources
PubMed1991

Human antibody responses after vaccination with the Norwegian group B meningococcal outer membrane vesicle vaccine: results from ELISA studies.

Antibody responses after vaccination with three different formulations of a new meningococcal group B outer membrane vesicle (OMV) vaccine have been studied with the ELISA technique using four different antigens. Sera from about 1200 vaccinees participating in steps 1, 2, 3 and 6 of the phase II clinical trials in Norway were analysed. The effects of non-covalently complexing the OMV antigen to group C polysaccharide (C-PS) and of adsorbing OMV (with and without C-PS) to aluminium hydroxide (AH) were studied. All three vaccine formulations were highly immunogenic in humans. Adsorption of the vaccine to AH had a relatively small effect on the immune response, but the results indicated that the booster response was stronger with the adsorbed than with the unadsorbed vaccines. Some increase in the immune response against OMV was also observed by non-covalent complexing OMV with C-PS, particularly after the second dose. In most of the vaccinees the antibody levels were significantly reduced 6 to 12 months after vaccination. Adsorption of the vaccine to AH had no effect on the antibody response against C-PS. Comparison with bactericidal activity of the same sera was done. A highly significant correlation was observed between the bactericidal titres and the levels of IgG antibodies against OMV and class 5C protein, whereas the correlation between antibody levels against lipopolysaccharide and the bactericidal activity was poor.

Adolescent↗
PubMed1991

Results of an efficacy trial with an outer membrane vesicle vaccine against systemic serogroup B meningococcal disease in Norway.

A placebo controlled, double blind efficacy trial with a new outer membrane vesicle vaccine against systemic meningococcal disease of serogroup B, has been conducted in Norwegian secondary schools. The study was randomized at school level (1335 schools) and 171,800 students volunteered. The study started in October 1988 and the code was opened in June 1991. Out of the thirty-six proven cases of acute, severe, systemic disease caused by serogroup B meningococci among the participants, twelve occurred in eleven schools given vaccine, twenty-four in twenty-four schools given placebo. twenty-four cases were recorded among secondary school students who did not participate in the study. The protection rate was calculated to 57.4% with a p-value of 1.2% and lower limit of confidence (95%) to 27.7%. The results have initiated research towards an improved outer membrane vesicle vaccine against this disease.

Adolescent↗
PubMed1991

Design of clinical trials with an outer membrane vesicle vaccine against systemic serogroup B meningococcal disease in Norway.

An outer membrane vesicle vaccine against acute, systemic disease caused by meningococci of serogroup B has been developed. The vaccine has been tested consecutively in phase I and phase II clinical trials including more than 5000 volunteers. These trials provided data on safety, immunogenicity and reactogenicity and possible effect on carriage of meningococci in the throat, and consequently formed the basis for two major protection trials; one in secondary school students and one among military recruits. The aims, design and major results of phase I and phase II studies are described as well as the design and organization of the protection trials.

Adolescent↗
PubMed1989

Local reactivity, local resistance and systemic dissemination in Mycobacterium lepraemurium (MLM) infection.

Local reactivity measured as swelling of the infected footpad, local resistance to bacterial multiplication, and capacity to limit systemic dissemination were studied in C57BL, C3H/Bom, C3H/HeJ, and A/Sn mice inoculated with Mycobacterium lepraemurium. C57BL mice developed a strong local reaction with a sudden onset, and effectively limited local multiplication as well as systemic dissemination of bacteria to the liver and spleen as determined 19 weeks after the inoculation. C3H/Bom mice showed no local reaction, had high numbers of bacteria locally, and had extensive systemic dissemination of the infection. C3H/HeJ mice, on the other hand, developed a small local reaction and had less systemic dissemination of bacteria than C3H/Bom mice. In C57BL mice and in the two C3H substrains local reactivity, local resistance to infection, and resistance to systemic spread of the infection paralleled each other. In contrast, A/Sn mice showed a small local reaction, had the most extensive bacterial multiplication at the site of inoculation of the four mouse strains tested, and at the same time were the mice that most effectively restricted systemic dissemination of the infection. Thus, the mechanisms restricting local bacterial multiplication may be different from the mechanisms limiting bacterial dissemination. Neither bacterial growth locally at the site of subcutaneous inoculation in the footpad, nor systemic dissemination of the infection, followed a mouse strain pattern consistent with the Ity/Lsh/Bcg gene model. In experimental mycobacterial infection both local bacterial growth at the site of inoculation and systemic dissemination should be determined.

Animals↗
PubMed1988

The antigens of Mycobacterium tuberculosis, H37Rv, studied by crossed immunoelectrophoresis. Comparison with a reference system for Mycobacterium bovis, BCG.

On the basis of a previously developed reference system for Mycobacterium bovis, BCG, in crossed immunoelectrophoresis (CIE), antigens of Mycobacterium tuberculosis were identified in an analogous system. A majority of the numbered lines in the BCG system were also present and identified in the M. tuberculosis system. The corresponding antigens in the two systems were identified by dual dilution in CIE, and using monospecific antisera and monoclonal antibodies. Some of the antigens were specifically identified by the demonstration of enzyme activity and by means of hydroxyapatite, concanavalin A (Con A), EDTA, and blue-Sepharose. Three antigens (nos 10, 78, and 81), which were found in high concentrations in M. tuberculosis culture fluid, were not identified or were present in low concentrations in BCG culture fluid. The high percentage of corresponding antigens confirms that there is a very close taxonomic relationship between BCG and M. tuberculosis. Corresponding antigens in BCG and M. tuberculosis did not differ in electrophoretic mobility in the antigenic preparations studied.

Antigens, Bacterial↗
PubMed1987

Characterization of antibody-reactive epitopes on the 65-kilodalton protein of Mycobacterium leprae.

Twenty-three monoclonal antibodies (MAbs) prepared in seven different laboratories were studied, all of which recognized the 65-kilodalton (kDa) protein of Mycobacterium leprae as determined by Western blotting or gel radioimmunoassay or both. Fourteen of the MAbs recognized different epitopes, as evaluated by cross-competition studies using radiolabeled MAb and unlabeled inhibitors; the species specificity of these epitopes was defined by nitrocellulose dot blot immunoassays with bacterial sonic extract antigen preparations from 23 species of mycobacteria. Each of the 14 distinct MAbs recognized a 65-kDa protein produced by a lysogenized Escherichia coli Y1089 host containing cloned rDNA which included the gene for the M. leprae 65-kDa protein. Of the 14 distinct MAbs, 1 recognized an epitope found only on M. leprae, and the others recognized epitopes present on as few as 8 or as many as all 23 of the mycobacterial species studied. Identification of these distinct 65-kDa protein epitopes and use of the MAbs which recognize them should assist future structural studies of this protein and characterization of the T-cell reactive and serodiagnostically useful portions of the molecule.

Antibodies, Monoclonal↗
PubMed1986

Catalases, peroxidases, and superoxide dismutases in Mycobacterium leprae and other mycobacteria studied by crossed immunoelectrophoresis and polyacrylamide gel electrophoresis.

The five mycobacteria Mycobacterium lepraemurium, M. leprae, M. bovis BCG, M. smegmatis, and M. intracellulare were studied. Catalase and peroxidase activities were demonstrated in polyacrylamide and crossed immunoelectrophoresis gels for M. lepraemurium, M. intracellulare, and BCG, but not for M. leprae. Peroxidase and catalase activities were associated with the same precipitate line in crossed immunoelectrophoresis for M. lepraemurium, M. intracellulare, and BCG, showing that in these mycobacteria the two enzyme activities resided in the same molecule. M. smegmatis peroxidase and catalase activities were closely associated on polyacrylamide gel electrophoresis, but on the crossed immunoelectrophoresis catalase and peroxidase activities were associated with two different precipitate lines. Catalases without peroxidase activity were demonstrated in crossed immunoelectrophoresis and polyacrylamide gel electrophoresis in M. intracellulare and M. smegmatis. The catalase without peroxidase activity in M. intracellulare was heat resistant and therefore classified as an m-catalase. In M. smegmatis the catalase without peroxidase activity was only partially heat resistant. All of the catalases with peroxidase activity were heat-sensitive t-catalases. Superoxide dismutase activity in the crossed immunoelectrophoresis was associated with the M. leprae antigen no. 4 and with cross-reacting antigens in the other mycobacteria studied. Several superoxide dismutases were demonstrated in Mycobacterium duvalii. They were antigenically different from the other superoxide dismutases in this study, as shown by lack of reactivity with a monospecific antibody to M. lepraemurium superoxide dismutase. Molecular weights were estimated for all the enzymes in this study by sodium dodecyl sulfate-polyacrylamide gels.

Catalase↗
PubMed1985

Characterization of the immune response to an epitope on Mycobacterium leprae antigen 7 defined by a monoclonal antibody.

A mouse monoclonal antibody (038D-C6) was shown by crossed immunoelectrophoresis and radioimmunoassay to react with an epitope on the Mycobacterium leprae antigen 7. This epitope was highly crossreactive with BCG/M. tuberculosis and of a non-arabinogalactan-arabinomannan nature. A solid-phase radioimmunoassay (SPRIA) was applied, based on competitive inhibition by human sera of antigen binding by this anti-M. leprae monoclonal antibody. Inhibitory activity determined by this assay decreased markedly upon treatment in both lepromatous and tuberculoid leprosy patients. A correlation was found between the bacterial load of the patient and the inhibitory activity measured in the SPRIA assay. Serum-inhibitory activity could therefore perhaps be used as a follow-up test for patients on treatment or as a screening method to detect infective cases. A dot enzyme-linked immunosorbent assay based, like the SPRIA assay, on competitive inhibition by human sera, was explored as an inexpensive and technically simple alternative also applicable under field conditions.

Animals↗
PubMed1985

Further characterization including preliminary chemical analysis of antigen MLW1 from Mycobacterium leprae.

MLW1, an antigen preparation from Mycobacterium leprae previously shown to have a high content of M. leprae antigen No. 7 (ML7), was found to contain the typical cell wall constituents arabinose, galactose and mannose. The fatty acid composition of MLW1 was largely comparable to that of undisrupted cells. The capacity of MLW1 to stimulate lymphocytes was further studied. Good correlation was obtained between the in vitro lymphocyte responses to MLW1 and human-derived M. leprae, indicating similar specificity of the two antigen preparations in this test. The stimulatory activity of MLW1 was not significantly influenced by batch to batch variations, was well-preserved during storage and most of it was heat-stable. Attempts to remove the ML7 antigen indicate that this component plays a dominant role in inducing in vitro lymphocyte stimulation.

Antigens, Bacterial↗
PubMed1979

The humoral immune response to alpha, beta and gamma crystallins of the human lens.

By radioimmunoassay the occurrence of antibodies against alpha, beta and gamma crystallins was examined in sera from groups of patients with clear lenses, cataracts or lens injuries. In about half of the sera from each group low anti alpha crystallin activity was found. No significant difference in antibody activity was found between the groups. Antibody activity against beta or gamma crystallins was not detected in any of the sera. Four patients with lens damage were followed for 2 years; two of them developed uveitis and showed increasing anti alpha crystallin activity. It is suggested that in man immunological tolerance to lens crystallins is normally present.

Adolescent↗
PubMed1979

Cross-reactions between mycobacteria. II. Crossed immunoelectrophoretic analysis of soluble antigens of BCG and comparison with other mycobacteria.

Cross-reactions between Mycobacterium bovis BCG and various other mycobacteria, Nocardia asteroides, Corynebacterium pyogenes and Listeria monocytogenes were studied by incorporating antibodies against these bacteria in the intermediate gel of a crossed immunoelectrophoretic system with BCG antigen and anti-BCG antibodies. In the BCG reference system forty-four distinct antigenic components were recorded, of which thiryt-three cross-reacted with Mycobacterium tuberculosis, twenty-five with M. avium, twenty-one with M. suvalii, eighteen with M. smegmatis, Fifteen with M. nonchromogenicum, twelve with M. phlei, eight with N. anteroides and two with C. pyogenes, whereas no cross-reaction was detected with L. monocytogenes. The value of the method for characterization of mycobacterial antigens is discussed. A taxonomic system based on this method appears particularly valuable for studies of non-cultivativable mycobacteria such as M. leprae. A majority of twenty-one patients with lepromatous leprosy had anti-BCG antibodies of restricted specificity, affecting only four or five BCG antigens, although one patient had twelve anti-BCG specificities. Most of these antibodies reacted with those BCG antigens that cross-react extensively with other mycobacteria.

Antibodies, Bacterial↗
PubMed1979

Antibody response in rabbits to Mycobacterium bovis BCG.

The specificity of the immune response after immunization with Mycobacterium bovis BCG was studied by crossed immunoelectrophoresis with intermediate gel in a BCG/anti-BCG system, in which the reaction against thirty distinct components of BCG was recorded. After a single injection of total sonicate of 3 mg (dry weight) bacilli, the antibody response was markedly similar in eight rabbits. Th earliest and strongest response was directed against nine components of BCG; all but one of these belonged to the group of thirteen components that cross-react extensively with other mycobacteria. After repeated immunization with sonicate from about 0.8 microgram of BCG bacilli, five components still induced a marked antibody response. All but one of these components are among the most widely cross-reacting BCG components, and the observations made after subsequent challenge with the higher dose of BCG indicate that low-zone tolerance was induced against other components of the bacilli. The implication of these findings concerning formation of anti-mycobacterial antibodies in normal individuals and during mycobacterial infection is discussed.

Animals↗
PubMed1979

Antigenic analysis of Mycobacterium leprae.

About twenty distinct antigenic components have been demonstrated in Mycobacterium leprae (M. leprae) by crossed immunoelectrophoresis against a rabbit antiserum produced by immunization with concentrated M. leprae antigen. This system allows a more detailed analysis of the antigenic relationship between M. leprae and other mycobacteria and a better characterization of the antigenic content of various M leprae preparations than with previously available anstisera of the antigenic content of various M. leprae preparations than with previously available antisera which reacted with far fewer components. The antibody activity in sera of patients with lepromatous leprosy was studied by incorporating the sera into the intermediate gel of the M. leprae reference system. Antibodies were found against only seven of the components. Since those compared are all known to be cross-reacting widely with antigens of other mycobacteria, it is speculated that cross-immunization may influence the antibody response in lepromatous leprosy.

Animals↗
PubMed1979

Cross-reactions between serum proteins and water soluble liver tissue antigens of the nine-banded armadillo (Dasypus novemcinctus Linn.) and man.

Cross-reactions between serum proteins and water soluble liver antigens of the nine-banded armadillo (Dasypus novemcinctus Linn.) and man were studied by crossed immunoelectrophoresis (CIE). Armadillo serum tested with rabbit antiserum against human serum proteins gave twelve components in CIE. Nine of these cross-reacting proteins were identified and showed partial identity with the corresponding human proteins. The electrophoretic mobility of alpha 2-macroglobulin and Gc-globulin differed in the two species. An ultrasonicate of normal armadillo liver gave twenty-eight anodic and eight cathodic components in CIE. By absorption experiments with armadillo serum, twenty of the former and seven of the latter were shown to be liver tissue components. A combination of CIE and crossed-line immunoelectrophoresis (CLIE) revealed the presence of twelve anodic and six cathodic liver tissue components cross-reacting with man. A cathodic armadillo liver antigen called (CALA-17) showed partial identity with that of man both in tandem and fused rocket immunoelectrophoresis. The implications of the findings are discussed in relation to the use of armadillo-grown M. leprae for skin testing and other purposes in man.

Animals↗