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S J Barteling

Publications and source records attributed to S J Barteling.

32 records · Page 2Linked to original sources
PubMed1983

Innocuity testing of foot-and-mouth disease vaccines. II. Aziridine-inactivated antigen produced in baby hamster kidney cells.

Methods for the testing of preparations of aziridine-inactivated foot-and-mouth disease virus for the absence of infective particles were studied. The system used for virus production, suspension cultures of baby hamster kidney cells, proved to be the most sensitive detection system for traces of infective virus as long as the 146S antigen concentration was below 1 microgram per 10(6) cells. Above this level interference may mask the presence of non-inactivated virus. Thus in a 1-1 suspension culture 1 mg of inactivated 146S antigen equivalent to at least 300 doses of vaccine could be tested. The kinetics of inactivation may be studied by the agar-cell suspension plaque assay which is nearly equal in sensitivity to the method described above. Antigen concentrations at which interference occurred were also estimated for this type of assay. Inactivation of polyethylene glycol-concentrated virus showed 'tailing-off' and such virus preparations should not be used in vaccine production. The data are discussed with reference to the recommendations for innocuity testing in the European Pharmacopoeia.

Animals↗
PubMed1982

The positively charged structural virus protein (VP1) of foot-and-mouth disease virus (type O1) contains a highly basic part which may be involved in early virus-cell interaction.

Polypeptides of 'trypsin-resistant' (TR) variants of foot-and-mouth disease virus type O1 (BFS 1860) were analysed by electrofocusing and two-dimensional gel electrophoresis. In contrast to parent O1 virus, trypsin treatment of these variants did not reduce their infectivity and their ability to attach to susceptible cells, although VP1 was cleaved as in the parent virus. In OTR1, one of the cloned isolates, an additional polypeptide (VPA) with a mol. wt. approx. 31 X 10(3) (31K), was found which resembled VP1 (28K) in being positively charged and cleaved by trypsinization of the virus into a neutral 18K polypeptide (P18) and a strongly basic fragment (pI greater than 10) with a mol. wt. of approx. 6K (P6). These findings substantiate the hypothesis that VPA is an elongated VP1. While P18 fragments of both trypsin-treated parent virus and OTR progeny viruses focused at identical (neutral) pH, P6 fragments of trypsinized OTR variants (including OTR1) were even more positively charged than P6 of parent virus. This difference in charge of the P6 polypeptide may be responsible for the retained cell attachment ability of trypsinized OTR viruses. The data are discussed with respect to the known amino acid sequence of VP1 of the closely related O1 Kaufbeuren.

Aphthovirus↗
PubMed1980

[Developments in foot-and-mouth disease (FMD) vaccine production (author's transl)].

Cattle in the Netherlands are annually vaccinated with MDV-vaccine which is prepared from FMD-virus grown in 'surviving' bovine lingual epithelium. This 'Frenkel production system' which was developed in the Central Veterinary Institute during the forties and early fifties is still fully operative under practically the same conditions as those by the late Dr. Frenkel. However, recent experiments show that the method can be made more productive among others by regulating the PH. Particulary in non-European countries FMD-vaccines are prepared from virus produced in suspension cultures of a Baby-Hamster kidney (BHK) cell line. In the present author's variant of the system, virus is produced in growing BHK cells. This is possible as antibodies were removed from the serum in the culture medium by pretreatment of the serum with PEG. Virus was partly purified and concentrated by a precipation-filtration-elution (PFE) process: virus is precipated with PEG, the precipated virus is collected (with 'filter-aid') on a filter and eluted by pumping a buffer solution through the filter cake. Adequate protection of cattle was obtained with Al(OH)3-vaccines, which were prepared from these AEI-inactivated antigens. For the vaccination of pigs, satisfactory results were obtained with double-oil emulsion (W/O/W) vaccines prepared from these antigens. For long-term storage below -70 degrees C, antigen was highly concentrated (200 x) by a second PFE cycle. Purified antigen was obtained, which, if incorporated in double oil emulsion vaccines, has so far induced satisfactory protection of pigs. By this method, a strategic stock of concentrated inactivated antigen may be built up in order to make it possible to produce large amounts of vaccine in a last.minute operation.

Aphthovirus↗
PubMed1979

Isolation and characterization of trypsin-resistant O1 variants of foot-and-mouth disease virus.

Strains of foot-and-mouth disease virus of types O1 and A10 were isolated which showed no significant loss of infectivity upon trypsinization. These 'trypsin-resistant' (TR) viruses were obtained by serial passage in BHK cells of virus that was trypsin-treated before inoculation of the cells. Three O1 isolates were cloned and studied further. Cell attachment of those TR O1 variants (OTR1) was not reduced by trypsinization, unlike that of parent virus. The polypeptide compositions of TR viruses as determined by SDS-polyacrylamide gel electrophoresis were identical with those of parent virus, with the exception of OTR1 which contained an additional polypeptide approx, 3000 daltons larger than VP1. After trypsinization, which normally cleaves VP1, the polypeptide composition of the three TR viruses (including OTR1) and of parent virus did not show any significant difference. In OTR1 both the additional virus protein and VP1 were cleaved into a P18 molecule and smaller fragments. The surface location of this additional polypeptide was confirmed by iodination experiments. It was shown by immunodiffusion experiments that only OTR1 differed from the parent virus. This antigenic change was present on the trypsin-sensitive part of the virus since trypsinized TR viruses (including OTR1) were antigenically identical to trypsinized parent virus. The electrophoretic mobilities of the three OTR viruses isolated, and of parent virus, differed somewhat before trypsinization. After trypsin-treatment, the mobilities of TR viruses were all increased to the same level; however, their rate of migration was lower than that of trypsin-treated parent virus. This lower mobility of trypsin-treated OTR viruses was the only difference which could be associated with retained infectivity.

Antigens, Viral↗
PubMed1979

Some aspects of FMDV-production in growing cells and a closed system for concentration of FMDV by polyethylene glycol.

Different commercially available peptone preparations, all derived by enzymatic digestion of meat, were tested for their ability to replace the individual amino acids and polyethylene glycol (PEG)-treated serum in BHK suspended cell culture growth medium. Cell growth was not impaired if the individual amino acids were replaced by 3 g/l of peptone in combination with 3 g/l LAH and 5% PEG-treated bovine serum. The concentration of the latter could be reduced to 1% by gradually lowering the concentration in successive cell passages. No significant differences in growth stimulating properties were observed between the peptone preparations. The virus produced was concentrated and partly purified by precipitation with PEG, collection of the precipitate by filter-aid filtration and direct elution from filter cake in the filter by pumping one tenth the original volume of buffer through the filter. The whole procedure was performed in a simple closed system, offering maximum guarantee of bacteriological sterility and preventing virus aerosol formation in the surroundings.

Animals↗
PubMed1976

Certain aspects of foot--and--mouth disease. Virus production in growing BHK suspended cell cultures.

Production of FMDV in growing BHK suspended cell cultures offers several technical advantages: no medium change and no sedimentation of cells prior to infection are needed, thus saving time and medium. However, the final product should be as free of serum proteins as possible. For this purpose polyethylene-glycol-(PEG)-treated serum can be used for the stimulation of cell growth in combination with precipitation of the virus with PEG. With this method virus preparations are obtained in which practically no serum proteins can be estimated. Recently the use of serum-free medium has been reported for a BHK line which had been adapted to this medium. This also offers possibilities of virus cultivation in growing cells. Two of our BHK lines also grow in a cheap serum-free medium in which amino acids are replaced by a combination of lactalbumin hydrolysate and peptic peptone. With BHK cells adapted to this medium high cell yields are obtained. The use of PEG-treated serum will be compared with the use of the low cost serum-free medium with respect to FMDV production.

Aphthovirus↗
PubMedDate not supplied

Use of polyethyleneglycol-treated serum for animal cell cultures.

Although many proteins will be removed from sera by precipitation with 10% polyethyleneglycol (PEG) the growth-promoting properties of such PEG-treated sera for many cell lines and cell strains are hardly reduced. Among the precipitated proteins are the macroglobulins which are difficult to remove from cell cultures and which may cause allergic reactions if incorporated into vaccines. The gammaglobulins are removed in this way as well. If the sera are contaminated with viruses or phages the titres will be reduced by approximately 4 logs and thus the incidence of virus contamination will be reduced by the PEG-treatment. For foot-and-mouth Disease (FMD) vaccine production PEG-treated sera from vaccinated cattle were applied for cell and virus cultivation. The virus obtained was subsequently precipitated with PEG and collected by filter-aid filtration. A concentrated virus product was obtained, which was practically devoid of serum proteins.

Animals↗