A large-tumor-antigen-specific monoclonal antibody inhibits DNA replication of simian virus 40 minichromosomes in an in vitro elongation system.
In productively infected cells, a fraction of large-tumor antigen (T antigen) is tightly bound to replicating simian virus 40 (SV40) minichromosomes and does not dissociate at salt concentrations of greater than 1 M NaCl. We present electronmicrograms demonstrating the presence of T antigen on the replicated sections of replicating SV40 minichromosomes. We also show that the fraction of tightly bound T antigen is recognized by antibodies from mouse tumor serum and, more specifically, by a particular T-antigen-specific monoclonal antibody, PAb 1630. A second T-antigen-specific monoclonal antibody, PAb 101, does not react with the T-antigen fraction remaining on replicating SV40 chromatin at high salt concentrations. We used an in vitro replication system which allows, via semiconservative DNA replication, the completion of in vivo-initiated replicative intermediate DNA molecules. We show that monoclonal antibody PAb 1630, but not monoclonal antibody PAb 101, inhibits viral DNA replication. We discuss the possibility that SV40 T antigen may play a role in chain elongation during SV40 chromatin replication.
Stahl
H
H
Dröge
P
P
Zentgraf
H
H
Knippers
R
R
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000952:Antigens, Polyomavirus Transforming; D000957:Antigens, Viral, Tumor / Q000276:immunology / Q000502:physiology*; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D009691:Nucleic Acid Denaturation; D010441:Peptide Chain Elongation, Translational; D013539:Simian virus 40 / Q000235:genetics*; D014764:Viral Proteins / Q000276:immunology / Q000502:physiology*; D014779:Virus Replication
D000911:Antibodies, Monoclonal; D000952:Antigens, Polyomavirus Transforming; D000957:Antigens, Viral, Tumor; D004279:DNA, Viral; D014764:Viral Proteins