title: The synergistic neutralization of Newcastle disease virus by two monoclonal antibodies to its haemagglutinin-neuraminidase protein.
abstract: Monoclonal antibodies (MAbs) to 2 epitopes on the haemagglutinin-neuraminidase (HN) protein of the Ulster strain of Newcastle disease virus neutralized synergistically: MAbs to HN-1 and HN-2 neutralized 1.2 and 1.7 log10 infectious units (i.u.) of virus when single as compared to 4.1 when combined. Although MAb to HN-1 but not to HN-2 inhibited haemagglutination they both neutralized more virus on desialyzed cells compared to normal cells and were considered to have interfered with viral attachments in a cooperative manner when combined. A third MAb to fusion (F) protein reduced infectivity by five log10 i.u. HN-1, HN-2 and F were not the only immunodominant epitopes because mutants, which simultaneously lacked all 3 epitopes, were indistinguishable from wild type when neutralized by polyclonal mouse, rabbit or chicken antiserum to whole virus.
mesh_terms: D000327:Adsorption; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology*; D002645:Chickens; D015707:HN Protein; D051379:Mice; D009500:Neutralization Tests; D009522:Newcastle disease virus / Q000276:immunology*; D011817:Rabbits; D014759:Viral Envelope Proteins / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D015707:HN Protein; D014759:Viral Envelope Proteins