Biomedical subjects

J Mankertz

Publications and source records attributed to J Mankertz.

23 records · Page 2Linked to original sources

PubMed1995

Cell specific uptake of antiretroviral drugs: AZT coupled to LDL inhibits HIV replication in human macrophages.

Macrophages, besides helper T-lymphocytes, are target cells for the human immunodeficiency virus (HIV). We report on a mechanism to deliver selectively antiretroviral drugs to cells of the monocyte/macrophage lineage. These cells and cells of the endothelium express scavenger receptors which mediate the transport of modified low density lipoprotein (LDL). LDL modified by covalently bound azidothymidine (AZT), a potent inhibitor of HIV replication, is internalized via this pathway into human macrophages. Treatment of HIV-1 infected human macrophages with AZT-LDL showed in vitro efficient inhibition of viral replication. In contrast, HIV replication in T-lymphocytes (Molt 4/8), which do not express scavenger receptors, is not inhibited by AZT-LDL but by free AZT.

Antiviral Agents↗

PubMed1993

cis-acting elements in the lytic origin of DNA replication of Epstein-Barr virus.

oriLyt, the cis-acting element of Epstein-Barr virus, mediates viral DNA replication in the lytic phase of the virus's life cycle. Oligonucleotide-directed in vitro mutagenesis of oriLyt plasmids allowed the identification of two noncontiguous components within the complex structure of oriLyt. Both components were indispensable for DNA replication of this origin. The upstream component colocalized with the promoter of the viral BHLF1-encoding gene, and mutants affecting DNA replication affected RNA transcription, too. The second component crucial for oriLyt function was determined to be 40 bp long and positioned approximately 530 bp downstream. It was dispensable for transcriptional transactivation but it was absolutely required for replication. Thus, the overall design of oriLyt has striking similarity to multipartite regulatory elements of transcription, consisting of proximal promoters and distal enhancers, but special elements are exclusively dedicated to DNA replication.

Base Sequence↗

PubMed1991

Conserved domains of glycoprotein B (gB) of the monkey virus, simian agent 8, identified by comparison with herpesvirus gBs.

The herpesvirus simian agent 8 (SA8) gene which corresponds to the herpes simplex virus (HSV) gene encoding glycoprotein B (gB) was localized, cloned and sequenced. Comparison of its deduced amino acid sequence with those of its counterparts in 12 other distinct herpesvirus was used to evaluate their homology and phylogenetic relationship. The results emphasized that SA8 gB is more closely related to those of HSV-1 and -2, and bovine herpesvirus 2 than to the homologous proteins of other herpesviruses. Furthermore, the alignment showed several regions of domains conserved in the closely related sequences, including four conserved in all the herpesvirus gB sequences examined. The conservation of 10 cysteine residues and most of the proline residues, as well as several potential N-glycosylation sites, suggested that the secondary and tertiary structures of these gBs were similar.

Amino Acid Sequence↗

PubMed1988

Conservation of a gene cluster including glycoprotein B in bovine herpesvirus type 2 (BHV-2) and herpes simplex virus type 1 (HSV-1).

A library of subgenomic fragments of bovine herpesvirus type 2 (BHV-2) DNA was constructed in the expression cloning vector lambda gt11 and screened with monoclonal antibodies to the glycoprotein gb BHV-2, which is homologous to glycoprotein gB (gB-1) of herpes simplex virus type 1 (HSV-1). Lambda gt11 clones containing gB BHV-2-specific sequences were used to identify lambda EMBL3 vectors with DNA inserts which contained the complete gB BHV-2 gene. Nucleotide sequencing revealed that the gB BHV-2 gene is highly conserved compared to gB-1. The amino acid sequences and the predicted secondary structures of both glycoproteins are very similar. Two further open reading frames (ORF) in close vicinity to the gene encoding gB BHV-2 showed considerable homology to HSV-1 genes. They code for the major DNA-binding protein (dbp) of BHV-2 and a putative 72-kDa polypeptide. The gene of the latter protein corresponding to ICP18.5 of HSV-1 is interspersed between the ORFs of gB BHV-2 and the dbp of BHV-2. All three genes map in the unique long region of the genome. Their homology and the colinear arrangement compared to HSV-1 indicate a close relationship between the two viruses.

Amino Acid Sequence↗

PubMed1988

Common epitopes of glycoprotein B map within the major DNA-binding proteins of bovine herpesvirus type 2 (BHV-2) and herpes simplex virus type 1 (HSV-1).

Bovine herpesvirus 2 (BHV-2) specifies a glycoprotein of 130 kDa (gB BHV-2) which shows extensive homology to glycoprotein B (gB-1) of herpes simplex virus 1 (HSV-1). The BHV-2-specific 130-kDa glycoprotein is able to induce cross-reacting antibodies, some of which even cross-neutralize HSV-1. In order to determine the genome localization of gB BHV-2 and in order to identify conserved antigenic domains in both glycoproteins, we established libraries of subgenic fragments of BHV-2 and HSV-1 DNA in the prokaryotic expression vector lambda gt11 and screened them with cross-reacting monoclonal antibodies which allowed us to identify recombinant lambda gt11 clones expressing gB fusion protein. Nucleotide sequencing of inserted DNA fragments within these recombinant lambda gt11 clones revealed that they originated from the carboxy-terminal part of the major DNA-binding proteins (dbp) of BHV-2 (dbp BHV-2) and its counterpart ICP8 in HSV-1. Antisera raised against the beta-galactosidase fusion protein of recombinant phage lambda-113/2 coding for an 84 amino acid (aa) polypeptide originating from dbp BHV-2 neutralized infectivity of BHV-2 and HSV-1 in the presence of complement and precipitated [3H] glucosamine-labeled gB BHV-2 and gB-1. This antiserum also reacts with ICP8 and presumably with dbp BHV-2. Two hypotheses are discussed to explain this unexpected result: (i) epitopes in the carboxy-terminal part of gB BHV-2 and gB-1 are similar to antigenic determinants in the amino-terminal region of the gBs, thus providing cross-reacting antibody-binding sites; (iii) during gene expression a carboxy-terminal part of dbp BHV-2 and ICP8 genes might be spliced to the amino-terminal region of the glycoproteins gB BHV-2 and gB-1.

Amino Acid Sequence↗