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Biomedical subjects

P Trépanier

Publications and source records attributed to P Trépanier.

16 recordsLinked to original sources

A Phase I, randomized controlled clinical trial to study the reactogenicity and immunogenicity of a new split influenza vaccine derived from a non-tumorigenic cell line.

We have found that our MDCK-derived cell line (BV-5F1) is non-tumorigenic in tests conducted in accordance with FDA guidelines, and thus may be suitable for producing live, attenuated or inactivated vaccine. The cell line has been extensively tested for the presence of contaminating microorganisms. No infectious agents of viral or other microbial origin were present. Using the BV-5F1 cell line, we have now designed a process for the large-scale production of influenza virus for the manufacture of a vaccine. The production system involves expansion of cells anchored on a microcarrier using stirred fermenters, followed by virus infection. Viral particles are purified in a way similar to the licensed egg-derived vaccine Fluviral SF and mainly involves ultracentrifugation, ultrafiltration and formaldehyde inactivation. The final product is a split inactivated vaccine. A randomized, double-blind clinical study was made in healthy adults using the new split influenza vaccine derived from viruses grown in cell culture (bivalent formulation). The results of this Phase I study have demonstrated that the split influenza vaccine derived from cell culture is highly immunogenic and safe in adults.

Adolescent↗

Growth of poliovirus using alginate entrapped-anchorage dependent Vero cells.

Obligatory anchorage dependant Vero cells were successfully grown in gelatinous-like macrocarriers made of calcium alginate. Entrapped single cells were immobilized within the polymerized alginate matrix divide to form large spherical clumps of cells. A cell density of 17 x 10(6) cells/ml of alginate with over 95% viability was obtained after 14 days in spinner flasks. When subjected to poliovirus type I infection, spherical masses of Vero cells progressively showed extensive cytopathic effect but remained entrapped in the alginate matrix of the macrocarriers. Virus was released into a cellular debris free-like supernatant and reached a peak titer of 10(8.0) TCID50/ml after 72 hours.

Alginates↗

Growth of a murine coronavirus in a microcarrier cell culture system.

The growth of the murine coronavirus MHV-A59 on murine DBT cells adapted to dextran-made Cytodex 1 microcarriers was studied in comparison with cells grown on plastic dishes. With a microcarrier concentration of 5 g/l in spinner flasks, a density of 3 x 10(6) cells/ml was reached in 7 days. Under these conditions, cells supported virus growth to the same extent as when they were grown on the plastic substratum. This was shown by a similar development of virus-induced syncytia, the release of an equivalent number of infectious progeny virions per cell, similar recoveries observed after concentration and purification and an identical appearance of the purified virus under the electron microscope. On the other hand, the technical convenience of microcarriers and the ease of scale-up emphasize their potential for the growth of coronaviruses.

Animals↗

Further biological, serological and biochemical characterization of North American, European and Southeast Asian strains of bovine herpesvirus 1 compared with other alphaherpesvirinae members.

Hemagglutination activity, structural protein profiles and neutralization assays were used in a comparative study of bovine herpesvirus 1 strains from the U.S.A., Canada, Great Britain, Denmark and Malaysia with equine, feline and human herpesviruses in order to further characterize the bovine herpesvirus 1 hemagglutinin. Bovine herpesvirus 1 strains of different geographical origins all showed hemagglutinating activity for mouse erythrocytes; furthermore, feline herpesvirus 1 was also shown to hemagglutinate mouse erythrocytes. Analyses of partly purified viruses showed that a distinctive and specific polypeptides profile is associated with each species of herpesviruses used in our study; strains of bovine herpesvirus 1 from North America, Europe and Southeast Asia however, presented a remarkable similarity as to their electrophoretic protein patterns. A protein similar to the 97-kDa bovine viral hemagglutinin was not identified with the hemagglutinating feline herpesvirus. An important neutralization epitope on the bovine viral hemagglutinin was also not found on feline, equine and human herpesviruses but was identified on all bovine strains tested from North America, Europe and Southeast Asia stressing the importance of the bovine hemagglutinin for eventual prophylactic purposes.

Animals↗

Hemagglutination inhibition and virus neutralizing response of rabbits inoculated with bovine herpesvirus 1 subunit vaccine.

The immunogenicity of bovine herpesvirus type 1 (BHV-1) hemagglutinin has been investigated. Both live and nonionic detergent solubilized vaccines were prepared and 5000 hemagglutinating units (HAU) were injected subcutaneously into rabbits. Both types of vaccine induced a good antibody response but live virus was four times more efficient in inducing hemagglutination inhibiting and neutralizing antibodies than either Triton X-100- or octylglucoside-solubilized subunit vaccine. Blotting analysis revealed that five proteins, of 105,000, 90,000, 74,000, 64,000 and 54,000 mol. wt, were recognized by the serum of vaccinated animals. Triton X-100-solubilized vaccine did not induce antibodies against the 105,000 and 64,000 mol. wt proteins, indicating the important role of VP 90,000 and VP 74,000 in hemagglutination and neutralization. The order in which antibodies to the different viral proteins were induced was VP 90,000, (VP 105,000, VP 64,000, VP 54,000) and VP 74,000. Our data indicate that VP 90,000 is the hemagglutinin. Using convalescent serum from intranasally infected animals, we could identify nine structural proteins for BHV-1; VP 105,000, VP 90,000, VP 74,000, VP 64,000, VP 54,000, VP 50,000, VP 47,000, VP 40,000 and VP 31,000.

Animals↗

Bovine herpesvirus 1: strain comparison of polypeptides and identification of a neutralization epitope on the 90-kilodalton hemagglutinin.

The intracellular and structural polypeptides of the Los Angeles and Cooper 1 reference strains of bovine herpesvirus 1, together with 12 other Canadian field isolates, were analyzed by polyacrylamide gel electrophoresis. Although a few minor differences were noted among some isolates in regard to intracellular viral protein content, analysis of partly purified virus showed strikingly similar polypeptide profiles among 19 proteins with molecular masses of 14 to 145 kilodaltons (kDa). Moreover, a neutralizing monoclonal antibody produced against the Cooper 1 strain also neutralized all of the other 13 strains tested in this study and immunoprecipitated the major 90-kDa glycoprotein. A second monoclonal antibody with a high hemagglutination inhibition titer prevented hemagglutination of other strains tested and also reacted against the 90-kDa glycoprotein by immunoprecipitation, indicating that this glycoprotein is responsible for the hemagglutinating activity of the viral particle and carries an important neutralization epitope.

Antibodies, Monoclonal↗

Immunovirological studies on human respiratory syncytial virus structural proteins.

Immunovirological studies suggest that human respiratory syncytial virus may well be composed of five structural proteins as are other members of the Paramyxoviridae family: the two external membrane glycoproteins H (90 000) and Fo (F1, 49 000; F2, 20 000; disulfide linked), the internal membrane protein M (34 000), the nucleoprotein N (42 000), and a protein (78 000) designated P that could be the equivalent of the polymerase of the morbillivirus and paramyxovirus genus. Neutralizing monoclonal antibodies showed, by immunoprecipitation and immunoblotting, that the fusion protein carries neutralizing epitopes. One monoclonal antibody, which shows a high neutralizing titer, immunoblotted directly with the F1 fragment (49 000) of the fusion protein. Analysis in mice of the immunogenicity of the structural proteins separated on sodium dodecyl sulphate gels indicated that, under our conditions, only the fusion protein dimer Fo and its F1 fragment were capable of inducing neutralizing antibodies.

Animals↗

A semiquantitative probe for radiation-induced normal tissue damage at the molecular level.

Sheep antibodies to bovine type I collagen were employed in the immunohistochemical detection of type I collagen in lung tissue sections of irradiated LAF1 mice. A video image digitizing system was developed to estimate collagen levels, by assigning a numerical value (0-63) to each of approximately 53,800 picture elements (pixels) in the microscope field, according to the collagen-dependent fluorescence intensity at each locus. For lungs harvested 52 weeks subsequent to graded doses of 60Co gamma radiation between 0 and 10 Gy, a dose-dependent increase in type I collagen was observed in the alveolar walls. A reproducible increase was evident for doses as low as 5 Gy: doses of 7 to 10 Gy elicited type I collagen levels significantly elevated with respect to those of age-matched controls. These results are consistent with a role for type I collagen in the development of radiation-induced pulmonary fibrosis. The assay system developed here will be used to explore the role of connective tissue macromolecules in the development of radiation pneumonitis and fibrosis.

Animals↗

Hemagglutinating activity associated with bovine herpesvirus type 1.

Using C57BL/HPB mouse erythrocytes, hemagglutination has been observed with the Los Angeles and Colorado-1 strains of bovine herpesvirus type 1 and with 12 other Canadian field isolates as well. The specificity of the hemagglutination observed with the viral strains has been confirmed by a hemagglutination-inhibition assay.

Animals↗

Modified immunoprecipitation procedure for the identification of human respiratory syncytial virus polypeptides.

When analysed by polyacrylamide gel electrophoresis, human respiratory syncytial virus harvested after a one step growth cycle and purified through a continuous sucrose density gradient was shown to be composed of nine structural proteins of 90, 68, 49, 42, 34, 28, 25, 19 an 13 kd. The 90, 49 and 19 kd polypeptides were identified as glycopolypeptides by glucosamine incorporation. A modified immunoprecipitation procedure confirmed the viral specificity of the 49, 42, 28, 25 and 19 kd polypeptides.

Centrifugation, Density Gradient↗

Concentration of human respiratory syncytial virus using ammonium sulfate, polyethylene glycol or hollow fiber ultrafiltration.

Human respiratory syncytial virus was concentrated by polyethylene glycol or ammonium sulfate precipitation as well as by hollow ultrafiltration. Recoveries obtained were respectively 49.4%, 47.7%, and 75.2%; however, further analysis of these results by resuspension experiments showed that all the infectivity could be recovered from the different concentrates. The protein content of polyethylene glycol concentrates was much lower than those of ammonium sulfate or hollow fiber ultrafiltration. Electron microscopy revealed that the morphological integrity of virus particles was unaffected by the concentration methods used. Purified virus was obtained when polyethylene glycol concentrates were centrifuged through two successive density gradients.

Ammonium Sulfate↗

Comparison of three electron microscopy techniques for the detection of human rotaviruses.

Rotavirus detection by direct electron microscopy was compared with direct and indirect immune electron microscopy techniques. The latter two approaches permitted the enumeration of 25 and 103 times more rotaviruses respectively, than direct electron microscopy. Also, 70% and 90% of the virus particles were aggregated by direct and indirect immune electron microscopy techniques respectively, thus facilitating their detection.

Antibodies, Viral↗

A simple and rapid microassay for the titration of human respiratory syncytial virus.

A microassay, using tissue culture microplates for the titration of human respiratory syncytial virus by syncytium formation, is described. Virus titers obtained agreed well with those obtained in a larger assay system; the microassay, however, is more rapid and economical. Large numbers of virus samples are easily and rapidly processed as the assay necessitates an incubation period of only three days.

Animals↗

[Not Available].

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Canada↗