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Biomedical subjects

H L Bachrach

Publications and source records attributed to H L Bachrach.

At least 19 recordsLinked to original sources
PubMed1985

Foot-and-mouth disease and its antigens.

Many factors combine to make foot-and-mouth disease (FMD) one of the most damaging and intractable disease of animals. These include its extreme contagion, wide geographic distribution, great multiplicity of both susceptible animal hosts and viral serotypes, a relatively short duration of immunity to a given serotype and a post-recovery carrier state of the virus in many animal species (e.g., cattle, sheep and goats). Nevertheless, import restrictions and other actions of the U.S. Government have kept the United States free of FMD since 1929, even during outbreaks of the disease in Mexico and Canada in the early 1950's. Beginning in the late 1940's, the systematic vaccination of cattle has been practiced in several areas of the world with varying degrees of success. While this procedure has succeeded in Western Europe in greatly reducing the incidence of FMD, the presence of live virus in some batches of vaccine and the escape of virus from vaccine from manufacturing facilities are now responsible for a large proportion of the outbreaks that still occur there. A vaccine is needed that has no possibility of producing the disease. During the last few years, it has been demonstrated that capsid protein VP1, isolated from type A and C virions or biosynthesized in E. coli transformed with the gene for VP1, can be used to immunize livestock against FMD. Immunization of livestock has also been achieved with a 13 kd fragment (amino acid residues 55 through 179) cleaved with CNBr from the 213 amino acid long VP1 chain of type A virions. Immunogenic sites on intact virions, 12 S subunit particles and isolated VP1 chains have been studied by a combination of methods, including: assessment of the immunogenicity of VP1-specific fragments and synthetic peptides and mapping monoclonal antibodies (Mabs) generated with virus, VP1 and the 13 kd fragment to virus, 12 S subunits, VP1, VP1-specific fragments and a biosynthetic 32mer. Correlation of these results with sites having variant and serotype sequence variability indicates that the 136-179 region of type A12 VP1 possesses four putative neutralization-specific epitopes (ca. 137-143, 146-151, 152-157 and 170-175). Of three neutralization-specific epitopes on type A12 virus, two are also present on 12 S subunits and isolated VP1 chains. Mabs to the three epitopes appear to neutralize virus by different mechanisms: by viral aggregation, by blocking the site on viral VP1 that binds to cell receptors or by interfering with a postreceptor attachment step, possibly penetration or uncoating.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1982

Recombinant DNA technology for the preparation of subunit vaccines.

Recombinant DNA technology appears to be on the verge of producing safe and effective protein vaccines for animal and human diseases. The procedure is applicable to most viruses because their isolated surface proteins generally possess immunogenic activity. Strategies used for the preparation and cloning of the appropriate genes depend on the characteristics of the viral genomes: whether DNA or RNA; their size, strandedness, and segmentation; and whether messenger RNA are monocistronic or polycistronic. Cloned surface proteins of foot-and-mouth disease and hepatitis B viruses are being tested for possible use as practical vaccines. Two doses of the cloned foot-and-mouth disease viral protein have elicited large amounts of neutralizing antibody and have protected cattle and swine against challenge exposure with the virus. Surface proteins have also been cloned for the viruses of fowl plague, influenza, vesicular stomatitis, rabies, and herpes simplex. Cloning is in progress for surface proteins of viruses causing canine parvovirus gastroenteritis, human papillomas, infectious bovine rhinotracheitis, Rift Valley fever, and paramyxovirus diseases. In addition, advances in recombinant DNA and other facilitating technologies have rekindled interest in the chemical synthesis of polypeptide vaccines for viral diseases. The bioengineering of bacterial vaccines is also under way. Proteinaceous pili of enterotoxigenic Escherichia coli are being produced in E coli K-12 strains for use as vaccines against neonatal diarrheal diseases of livestock.

Animals↗
PubMed1982

Foot-and-mouth disease virus: immunogenicity and structure of fragments derived from capsid protein VP and of virus containing cleaved VP.

Peptide fragments were obtained from the immunogenic capsid protein VP3, ca. 24 kilodaltons (kd), of foot-and-mouth disease virus type A12 119ab by three procedures: (1) spontaneous proteolysis of in virion VP3 in tissue cultures to produce a 15 kd peptide, designated S fragment; (2) trypsin treatment of purified virus to produce a 16 kg peptide, designated T fragment; and (3) cyanogen bromide cleavage of purified VP3 to produce a 13 kd fragment. Following isolation and purification by gel electrophoresis, VP3 and each of the three fragments were immunogenic for livestock. Lyophilization appeared to impair the immunogenicity of VP3. In addition, viruses containing VP3 fragments produced either by the spontaneous- or trypsin-induced proteolysis were as immunogenic as virus with its VP3 intact. Amino acid sequencing of N-terminal regions revealed that the S fragment was homologous with the N-terminus of VP3, whereas the 13 kd fragment possessed a unique N-terminus. Thus, putative common immunogenic amino acid sequences would appear to reside within an overlap region of the 15 kd S and 13 kd fragments. Sequencing of cDNA prepared to viral genome RNA provided three kinds of information: it (1) placed the above overlap region in the second and third quarters of VP3; (2) demonstrated that the codons for the C-terminus of VP1 and N-terminus of VP3 are contiguous; and (3) supported earlier evidence that these same codons program a chain reversal where VP1 and VP3 are joined in the precursor polyprotein.

Amino Acid Sequence↗
PubMed1981

Cloned viral protein vaccine for foot-and-mouth disease: responses in cattle and swine.

A DNA sequence coding for the immunogenic capsid protein VP3 of foot-and-mouth disease virus A12, prepared from the virion RNA, was ligated to a plasmid designed to express a chimeric protein from the Escherichia coli tryptophan promoter-operator system. When Escherichia coli transformed with this plasmid was grown in tryptophan-depleted media, approximately 17 percent of the total cellular protein was found to be an insoluble and stable chimeric protein. The purified chimeric protein competed equally on a molar basis with VP3 for specific antibodies to foot-and-mouth disease virus. When inoculated into six cattle and two swine, this protein elicited high levels of neutralizing antibody and protection against challenge with foot-and-mouth disease virus.

Amino Acid Sequence↗
PubMed1981

Identification of a protein kinase activity in purified foot- and-mouth disease virus.

Purified preparations of foot-and-mouth disease virus types A, O, and C contain a protein kinase activity which can transfer the gamma phosphate of [32P]ATP to virion structural proteins VP2 and VP3 and exogenous acceptor proteins. Utilizing protamine sulfate as an acceptor, the kinase activity can be demonstrated in disrupted virus but not in intact virus. The enzyme is heat labile with optimal activity at pH 7 or greater. Serine residues of protamine sulfate were identified as the amino acid phosphorylated by the protein kinase. Treatment of purified virus with trypsin, which cleaves VP3, did not affect the protein kinase activity. The results indicate that the protein kinase activity found in FMDV is present in an internally located protein of viral or host origin.

Adenosine Triphosphate↗
PubMed1980

The structural polypeptides of aphthovirus are phosphoproteins.

Analysis of aphthovirus A12, strain 119ab, grown in the presence of inorganic 32P revealed that two of the major viral polypeptides, VP4 and trypsin-sensitive protein VP3, were highly phosphorylated. The other major polypeptides, VP1 and VP2, were also phosphorylated but to a much lesser extent. Polypeptides VP0 and P56, of which there are approximately one of two copies per aphthovirion, were also labeled with 32P. Phosphoserine and phosphothreonine appeared to be the amino acids labeled with 32P.

Aphthovirus↗
PubMed1980

Caliciviridae.

The caliciviruses, as a proposed family Caliciviridae, have a distinct virion morphology with cup-shaped depressions on a spherical capsid surface. The viruses have single-stranded RNA, which has a molecular weight about 2.6 x 10(6) and is infectious. The RNA is covalently linked to a small protein. A single major polypeptide is found in the capsid. A subgenomic RNA, molecular weight about 1 x 10(6), coding for the capsid polypeptide is found in infected cells. Caliciviruses infecting swine, pinnipeds and cats have been characterized. Viruses which are morphologically identical to the known caliciviruses have been identified in human feces; these viruses have been shown to be associated with gastroenteritis, but they have not yet been propagated in the laboratory.

Animals↗
PubMed1979

Foot-and-mouth disease virus immunogenic capsid protein VPT: N-terminal sequences and immunogenic peptides obtained by CNBr and tryptic cleavages.

The immunogenic capsid protein (VPT), circa 30 kiladaltons (kd), of foot-and-mouth disease virus was examined for (i) its ability to induce neutralizing antibody in guinea pigs after chemical modifications and CNBr or tryptic cleavages and (ii) N-terminal amino sequence homology across three virus types. The immunogenicity of VPT was inactivated by glutaraldehyde treatment, carboxymethylation and maleylation or citraconylation. However, de-citraconylation restored part of the lost activity. Cleavage of type A12 VPT with CNBr produced an immunogenic peptide of circa 13 kd. A slightly larger (ca. 16 kd) immunogenic doublet, VPTab, was obtained by tyrptic cleavage of VPT in the virion. Sequence homologies of circa 85% were found between the first 26 amino acids at the N-terminus of VP chains from virus types A12 strain 119 (A12), C3 Resende (C3R) and O1 Brugge (O1B).

Amino Acid Sequence↗
PubMed1978

Effect of zinc and other chemical agents on foot-and-mouth-disease virus replication.

Chemical agents reported to inhibit the growth of various ribonucleic acid and deoxyribonucleic acid viruses were tested against foot-and-mouth disease virus in cell culture. These included Zn(2+), aurintricarboxylic acid, polyribocytidylic acid, polyriboinosinic acid, phosphonoacetic acid, and the viral contact inactivator N-methyl isatin beta-thiosemicarbazone alone and with CuSO(4). The most effective agent, Zn(2+), inhibited foot-and-mouth disease virus production in primary calf kidney cells by 1 log unit at 0.05 mM Zn(2+) and completely at 0.50 mM. Zinc was inhibitory even when added late in infection and was nontoxic to uninfected cells as measured by protein and nucleic acid syntheses. Polyacrylamide gel patterns of [(35)S]methionine-labeled, virus-specific proteins showed increasing amounts of higher-molecular-weight material, in accord with reports that Zn(2+) inhibits post-translational cleavages of other picornavirus precursor polypeptides.

Antiviral Agents↗