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H Van Heuverswyn

Publications and source records attributed to H Van Heuverswyn.

18 recordsLinked to original sources
PubMed1991

The development of specific rRNA-derived oligonucleotide probes for Haemophilus ducreyi, the causative agent of chancroid.

Part of a ribosomal ribonucleic acid (rRNA) cistron of Haemophilus ducreyi was enzymically amplified using conserved primers within the rRNA molecules, cloned in a plasmid vector, and sequenced. From the nucleotide sequence, eight oligonucleotides complementary to different regions in the 16S and 23S rRNA molecules were selected, chemically synthesized, and used as hybridization probes. Hybridization experiments with at least 41 H. ducreyi strains and 13 or 14 non-H. ducreyi strains revealed that all eight oligonucleotide probes were highly reliable and completely specific for H. ducreyi strains. Comparisons of 16S rRNA sequences confirm that H. ducreyi is a member of the Pasteurellaceae though not closely related to other species in this family.

Base Sequence↗
PubMed1991

Confirmation and differentiation of antibodies to human immunodeficiency virus 1 and 2 with a strip-based assay including recombinant antigens and synthetic peptides.

We evaluated the use of the INNO-LIA HIV-1/HIV-2 Ab test (LIA HIV; Innogenetics) for the confirmation of antibodies to human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2). The test includes three recombinant HIV-1 proteins: p24 (gag), p17 (gag), and endonuclease (p31; pol), in combination with two synthetic peptides derived from the env gene of HIV-1 and one synthetic peptide selected from the env gene of HIV-2. Analysis of 450 sera from blood donors, 220 sera from patients with non-HIV pathology, and 28 Western blot (WB) p24-only reactive sera revealed no false-positive results, and the rate of indeterminate results was substantially lower than that with WB. Testing of 334 WB-confirmed HIV antibody-positive sera (309 HIV-1; 25 HIV-2) revealed no false-negative results. In two of seven seroconversion panels tested, LIA HIV detected the presence of HIV antibodies before WB did. In the other five panels, LIA HIV and WB confirmed the presence of HIV antibodies in the same sample. The LIA HIV assay therefore appears well suited for routine confirmation of the presence of HIV-1 and HIV-2 antibodies.

Antibodies, Viral↗
PubMed1990

Evaluation of an rRNA-derived oligonucleotide probe for culture confirmation of Neisseria gonorrhoeae.

The reliability of an rRNA-derived oligonucleotide probe for Neisseria gonorrhoeae was tested with 187 N. gonorrhoeae isolates, 81 Neisseria meningitidis isolates, and several strains of other bacterial species. The probe proved to be 100% specific and 100% sensitive. N. gonorrhoeae cells could also be reliably identified in contaminated cultures with the oligonucleotide probe. The 2.6-megadalton cryptic plasmid used as a probe for N. gonorrhoeae was shown to be less sensitive, detecting 179 of 181 N. gonorrhoeae isolates.

DNA Probes↗
PubMed1990

Generation and characterization of a neutralizing rat anti-rmTNF-alpha monoclonal antibody.

A rat anti-recombinant mouse tumour necrosis factor-alpha (rmTNF-alpha) monoclonal IgM antibody (1F3F3) with high specific binding activity for rmTNF-alpha was generated. The 1F3F3 monoclonal antibody (mAb) neutralizes the cytotoxic activity in vitro of rmTNF-alpha on L929 cells and inhibits the binding of radiolabelled rmTNF-alpha to its putative receptor on L929 cells. The 1F3F3 mAb binds to monomeric, dimeric and trimeric rmTNF-alpha and does not bind to reduced rmTNF-alpha, indicating that the recognized epitope is sensitive to denaturation. Using the 1F3F3 mAb as a capturing antibody and a biotinylated anti-rTNF-alpha as a detecting antibody, we have developed a sandwich ELISA that can specifically detect biologically active mTNF-alpha with a detection limit of 10 pg mTNF-alpha/well. This assay correlates well with the classical L929 cristal violet assay for the detection of bioactive rmTNF-alpha in biological fluids. The 1F3F3 mAb inhibits various in vitro biological activities of the rmTNF-alpha, such as the TNF-alpha-mediated tumoricidal activity of activated macrophages, the rmTNF-alpha-dependent stimulation of neutrophil degranulation and the growth-promoting effect of rmTNF-alpha. In vivo the 1F3F3 mAb inhibits lipopolysaccharide (LPS)-induced endotoxic shock. In conclusion, the 1F3F3 mAb is a useful tool to probe rmTNF-alpha activity both in vitro and in vivo.

Animals↗
PubMed1985

Molecular cloning of mouse tumour necrosis factor cDNA and its eukaryotic expression.

Tumour necrosis factor (TNF), released by induced macrophages, causes tumour necrosis in animals and kills preferentially transformed cells in vitro. mRNA induced in the established mouse monocytic PU 5.1.8 cell line by lipopolysaccharide, was converted into double-stranded cDNA and cloned in the pAT153 vector. Recombinant plasmids were screened by plus-minus hybridization and TNF-specific oligonucleotide probes constructed on the basis of partial amino acid sequences of rabbit TNF. A series of TNF specific clones were identified and confirmed by hybrid selection of mouse TNF-specific mRNA. The sequence codes for a 235 amino acids long polypeptide, of which 156 amino acids presumably correspond to the mature product. It can be concluded that mature mouse TNF is a glycosylated dimer. Biologically active TNF was secreted by both Cos-I and CHO-cells transfected with the chimaeric expression vector pSV2d2-mTNF containing the coding region of the mouse TNF cDNA gene.

Amino Acid Sequence↗
PubMed1982

Molecular cloning of human immune interferon cDNA and its expression in eukaryotic cells.

Starting with mRNA derived from Staphylococcal enterotoxin A induced human splenocytes, dsDNA was synthesized and inserted into unique BamHI site of the eukaryotic expression vector pSV529 (1). A recombinant plasmid containing human immune interferon (IFN-gamma) cDNA was identified by hybridization of plasmid inserted DNA bound onto nitrocellulose filters with mRNA derived from SEA-induced splenocytes, translation of the eluted RNA in Xenopus laevis oocytes and assaying for IFN activity. Plasmids containing the entire human IFN-gamma cDNA sequence were identified by colony hybridization and were sequenced. A unique coding region was identified which predicted a protein of 166 amino acids, the 20 N-terminal amino acids of which presumably represent a signal peptide. After transfection of monkey cells with plasmid DNA isolated from one of the recombinant clones (pHIIF-SV-gamma 1), IFN was excreted into the culture medium. This IFN was not distinguishable from human IFN-gamma by serological criteria or by cell target species specificity.

Amino Acid Sequence↗
PubMed1980

Recognition sequence for the restriction endonuclease BglI from Bacillus globigii.

Restriction endonuclease BglI recognizes the DNA sequence (Formula: see text) and cleaves each strand at the site indicated, thus generating 3' protruding ends. The recognition sequence was deduced by correlating mapping data with nucleotide sequence information and the position of cleavage was unambiguously determined by 32P labeling of 5' termini produced by BglI digestion.

Bacillus↗
PubMed1980

Nucleotide sequence of simian virus 40 DNA: structure of the middle segment of the HindII + III restriction fragment B (sixth part of the T antigen gene) and codon usage.

We report here the nucleotide sequence of the simian virus 40 DNA region that lies between the EcoRII restriction endonuclease cleavage sites at map positions 0.214 and 0.281. The sequence was determined by partial chemical degradation of terminally labeled DNA fragments according to the procedure of Maxam and Gilbert. This region represents 6.7% of the SV40 genome and is located in the middle of HindII + III restriction fragment B. It is expressed as part of the early 19-S messenger RNA, which codes for the large-T antigen protein. Only one open reading frame for translation can be deduced from the message strand of the DNA and this reading frame connects in phase with the one of both neighboring fragments. This publication is the last in a series of papers about the T-antigen gene, and several properties of this gene and its product are discussed. The non-randomness of codon usage is similar to that previously discussed for the late part of the genome. Moreover, it appears that the choice of a third letter can be determined by the nature of the following codon; some codons which start with a pyrimidine are almost never preceded by an adenosine and some ANN-type codons are almost never preceded by a guanosine.

Amino Acid Sequence↗
PubMed1979

Nucleotide sequence of the Hind-C fragment of simian virus 40 DNA. Comparison of the 5'-untranslated region of wild-type virus and of some deletion Mutants.

We report here the nucleotide sequence of the wild-type simian virus 40 (strain 776) restriction fragment Hind-C-P1 DNA and of the homologous region of various mutant DNAs which lack part of this fragment. During this work, we detected between EcoRII fragments N and G an additional, 17-base-pair EcoRII fragment, fragment P, which had previously been overlooked. Also, an additional dTpdG dinucleotide at residues L 339--340 was observed by sequence analysis of the DNA minus (E) strand; the presence of this dinucleotide was masked on sequencing patterns of the plus strand due to the persistence (during gel electrophoresis) of some secondary structures in the strand's 5'-terminal region. These nucleotide additions raise the total length of SV40 DNA to 5243 base pairs. The longest tandemly repeated segment in SV40 DNA now extends over 72 base pairs. SV40 deletion mutants dl 893 and dl 894 and SV40 strains Rh 911 and 1801 all lack an identical 72-base-pair-long DNA segment in the Hind-C region. This deletion corresponds precisely to one of the two aforementioned large tandemly repeated sequences. Mutant dl 895 lacks 66 base pairs, 63 of which are part of the former repetition. All these mutants, except dl 895, very probably were generated by an intramolecular, homologous recombination event. The 40-base-pair deletion in mutant dl 1811 includes the major capping site of SV40 late RNA. dl 1812 lacks only three base pairs, which are part of the overlapping HhaI and HpaII restriction sites at position 0.725--0.726.

Base Sequence↗
PubMed1979

Nucleotide sequence analysis of two simian virus 40 mutants with deletions in the region coding for the carboxyl terminus of the T antigen.

Nucleotide sequence analysis of two simian virus 40 early mutants dl1263 and dl1265, which lack a DNA segment around map positions 0.21 and 0.18, respectively (C. Cole, T. Landers, S. Goff, S. MAnteuil-Brutlag, and P. Berg, J. Virol. 24:277--294, 1977), revealed in-phase deletions of 33 nucleotide pairs for dl1263 and 39 nucleotide paris for dl1265. The 33-base-pair deletion in dl1263 does not correspond to an apparent shortening by 6,000 daltons observed for the mutant T antigen. In dl1265 the normal termination signal as well as most of the proline-rich terminal tryptic peptide has been removed, and the carboxyl terminus of the mutant T antigen is a series of three cysteine residues.

Antigens, Viral↗
PubMed1978

Complete nucleotide sequence of SV40 DNA.

The determination of the total 5,224 base-pair DNA sequence of the virus SV40 has enabled us to locate precisely the known genes on the genome. At least 15.2% of the genome is presumably not translated into polypeptides. Particular points of interest revealed by the complete sequence are the initiation of the early t and T antigens at the same position and the fact that the T antigen is coded by two non-contiguous regions of the genome; the T antigen mRNA is spliced in the coding region. In the late region the gene for the major protein VP1 overlaps those for proteins VP2 and VP3 over 122 nucleotides but is read in a different frame. The almost complete amino acid sequences of the two early proteins as well as those of the late proteins have been deduced from the nucleotide sequence. The mRNAs for the latter three proteins are presumably spliced out of a common primary RNA transcript. The use of degenerate codons is decidedly non-random, but is similar for the early and late regions. Codons of the type NUC, NCG and CGN are absent or very rare.

Antigens, Neoplasm↗
PubMed1977

Nucleotide sequence of the SV40 DNA restriction fragment Hind C-Hap 2.

We here report the nucleotide sequence of the SV40 DNA fragment Hind C - Hap 2. The fragment was labeled at the 5'-ends by means of polynucleotide kinase and gamma-(32P) ATP and digested with a suitable restriction enzyme. The separated products were then partially degraded with the base-specific reagents dimethyl-sulphate or hydrazine followed by direct analysis on polyacrylamide gel. The Hind C - Hap 2 sequence is 126 base pairs long and one of the three possible reading frames for translation does not contain any termination codon. So, although no protein is known to be encoded by this region, the possibility cannot yet be completely ruled out. The sequence also contains several AT-rich blocks.

Adenosine Triphosphate↗