Related Experiment Video
Updated: Aug 19, 2026
Peptide Scanning-assisted Identification of a Monoclonal Antibody-recognized Linear B-cell Epitope
Published on: March 24, 2017
Characterization of genotype-specific epitopes of the HN protein of mumps virus
C Orvell1, A R Alsheikhly, M Kalantari
1Huddinge University Hospital, Department of Clinical Virology, Karolinska Institute, Sweden. clor@vird01.hs.sll.se
Abstract:
The SBL-1 strain of mumps virus, grouping with genotype A on the basis of the small hydrophobic protein gene sequence, was grown in the presence of three different monoclonal antibodies. The monoclonal antibodies were directed against the haemagglutinin-neuraminidase (HN) protein and they inhibited haemagglutinating activity and infectivity of the virus. The HN genes of the nine neutralization-escape virus mutants were sequenced and the predicted amino acid sequences were compared with that of the parental virus. Amino acid substitutions were found at positions 269, 352 and 354, respectively, of the 582 amino acid long protein. The three monoclonal antibodies did not react with 35 virus strains isolated in Stockholm during the years 1970 to 1985. Thirteen and four of the strains were found to belong to the D and C genotypes, respectively. A type-specific neutralization antibody response was also found in sera of rabbits hyperimmunized with purified virions of genotype A and D. The genotype-specific difference in neutralizing activity in mice and rabbits was not corroborated by an overall difference in the amino acid sequence of the HN protein of the different genotypes. Further studies are needed to explore the efficacy of mumps virus vaccines for protection against homologous and heterologous genotypes of mumps virus.
Insights
Mumps virus genotype A was studied using monoclonal antibodies targeting the HN protein. Escape mutants showed amino acid changes, but these changes did not explain genotype-specific neutralization differences.
Area of Science:
- Virology
- Immunology
- Molecular Biology
Background:
- Mumps virus exhibits genetic diversity with multiple genotypes.
- The haemagglutinin-neuraminidase (HN) protein is crucial for mumps virus infectivity and is a target for neutralizing antibodies.
Purpose of the Study:
- To investigate the antigenic properties of the mumps virus HN protein.
- To analyze mutations in the HN gene of neutralization-escape mutants.
- To explore genotype-specific neutralization responses.
Main Methods:
- Culturing mumps virus (SBL-1 strain, genotype A) with monoclonal antibodies against the HN protein.
- Sequencing the HN genes of neutralization-escape mutants.
- Comparing amino acid sequences of parental and mutant viruses.
- Testing monoclonal antibody reactivity against various mumps virus strains (genotypes C and D).
- Assessing type-specific neutralization antibody responses in rabbits.
Main Results:
- Monoclonal antibodies targeting the HN protein inhibited viral activity.
- Amino acid substitutions at positions 269, 352, and 354 were identified in escape mutants.
- These specific monoclonal antibodies did not react with genotype C or D strains.
- Type-specific neutralization responses were observed for genotypes A and D, but not consistently reflected in HN protein sequence differences.
Conclusions:
- The study identified specific amino acid changes in the HN protein associated with escape from monoclonal antibody neutralization.
- Significant antigenic differences exist between mumps virus genotypes, impacting neutralization.
- Further research is required to assess the effectiveness of mumps virus vaccines against different genotypes.
Related Concept Videos
00:42Cross-reactivity
02:28Leaky Scanning
01:26Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.