Studies on the antigenic determinants of paramyxoviruses

Abstract

Monoclonal antibodies (MAbs) were produced to study the antigenic relationships between SV5, PIV-2 and other paramyxoviruses, these MAbs had specificities for the HN, F, M, NP and P-proteins of SV5 and for the HN, NP and P-proteins of PIV-2. A minority of these MAbs reacted with Western blotted virus polypeptides. All anti-HN and anti-F MAbs neutralized virus infectivity. At least 4 and 3 antigenic sites were demonstrated on the HN-proteins of SV5 and PIV-2 respectively. Immunofluorescence revealed different patterns and distributions of virus proteins between SV5 and PIV-2. The majority (55 out of 60) of MAbs were specific for the virus against which they were raised, the minority that did cross-react between SV5 and PIV-2 had specificities for the M, NP and P-proteins and one of these MAbs, with specificity for the P-protein, also showed cross reaction with mumps virus. In contrast only minor differences were detected between canine, human and simian isolates of SV5. None of the MAbs showed cross-reactivity between the HN-proteins of SV5 and PIV-2 but, polyclonal sera raised against purified preparations of these proteins did show limited cross-reactivity. Anti-SV5 and anti-PIV-2 antibodies, in the same human sera, were shown to be a mixture of specific and cross-reacting species of antibody.