title: Monoclonal antibodies against simian virus 40 nuclear large T tumour antigen: epitope mapping, papova virus cross-reaction and cell surface staining.
abstract: Thirty six cloned hybridomas have been isolated which produce monoclonal antibodies directed against simian virus 40 (SV40) large T tumour antigen. They have been shown to recognize at least six different epitopes along the T antigen polypeptide according to their reaction with the various truncated forms of T antigen expressed by adenovirus-SV 40 hybrid viruses. Sixteen antibodies cross-react with cells infected by the closely related human BK virus. Only two antibodies, PAb1604 and PAb1614, directed against different epitopes of the SV40 T antigen, cross-react with polyoma large T tumour antigen which has a more limited amino acid sequence homology. This cross-reaction is rarely seen with polyclonal antibodies. Monoclonal antibody PAb1620 gave nuclear immunofluorescence only with murine cells transformed by SV40 and was found to react with a complex of T-antigen and 53 000-dalton host-coded protein. All the monoclonal antibodies react with nuclear T antigen and all but four antibodies stained the surface of SV40-transformed cells. These were four of the five antibodies directed against the central third of the T antigen. Thus the monoclonal antibodies show that cell surface T antigen differs from nuclear T antigen, either in accessibility or structure.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D000952:Antigens, Polyomavirus Transforming; D000957:Antigens, Viral, Tumor / Q000276:immunology*; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D002472:Cell Transformation, Viral; D003429:Cross Reactions; D000939:Epitopes; D051379:Mice; D008970:Molecular Weight; D027383:Papillomaviridae / Q000276:immunology*; D027382:Polyomaviridae; D013539:Simian virus 40 / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000952:Antigens, Polyomavirus Transforming; D000957:Antigens, Viral, Tumor; D000939:Epitopes; D014764:Viral Proteins