Identification of conformational neutralization sites on the fusion protein of mumps virus. - GreenMedInfo Summary

In spite of the success of the mumps vaccination, recent mumps outbreaks were reported even among individuals with a history of mumps vaccination. For better understanding why the vaccination failed in cases of vaccinees which fell ill during recent mumps outbreaks, the immunological events during infection and/or vaccination should be better defined. In the work presented here we sought for new neutralization sites on the mumps virus surface glycoproteins. By using anti-mumps monoclonal antibodies (mAbs), three amino acid positions at residues 221, 323 and 373 in the F protein of mumps virus were shown to be located in at least two conformational neutralization epitopes. MAbs which specifically target these sites effectively neutralized mumps virus in vitro. The newly acquired glycosylation site at position 373 or loss of the existing one at position 323 were identified as the mechanism behind the escape from the specific mAbs. Based on the findings of this study we suggest that the influence of the antigenic structure of the F protein should not be ignored in a thorough investigation of the underlying mechanism of the mumps vaccine failure or when making a strategy for development of a new vaccine.