Prediction and analysis of epitopes of hemagglutinin of measles virus / 中华流行病学杂志

ABSTRACT

Objective To discuss the antigenic change caused by the mutation of amino acid on the epitopes of the hemagglutinin of measles virus.Methods The B cell linear epitopes in the hemagglutinin were predicted with bioinformatics software.Peptide pairs,which located on the same region but originated from measles vaccine and wild-type virus respectively,were designed and synthesized.After detecting the immunogenicity of peptides with indirect ELISA assay,sera against each peptide was prepared.Antigenic specificity between the two peptides within each peptide pair were tested by using cross ELISA assay,and then antigen ratios were calculated.Results All the synthesized peptides could bind with immune sera against measles virus,of which the peptide pair CW23/CW22 designed on the epitope region (273-282 aa) possessed the highest binding ability,while the peptide pair CW150/CW151 designed on the non-epitope region (418-427 aa) showed the lowest binding ability.The difference in antigenic specificity between the two peptides from different sources was significant.The antigenic ratio was up to 16 between CW23 (vaccine-originated) and CW22 (wild-type originated),and 2.877 ± 0.583 between CW123 (vaccine-originated) and CW124 (wild-type originated) (236-246 aa).On the non-epitope regions,the antigenic ratios was only 1.631 ± 0.481 between peptide pair CW125 and CW126(356-364 aa),but reached to 10.367± 1.617 between CW150 and CW151.Conclusion Although there were several conservative epitopes,specific amino acid mutation on the predicted epitope or non-epitope regions might cause the antigenic change of wild-type measles virus.