Deconstructing the antigenic profile of a protective epitope from measles virus fusion protein using overlapping peptides

Three different approaches of using overlapping peptides have been compared to analyse the fine specificity of the antibody response to a protective e pitope from measles virus (MV) fusion protein, spanning residues 397-420, A nti-peptide antibodies raised in BALB/c, CBA and C57BL/6 mice were shown to react with the homologous peptide and the MV by ELISA. Results from indire ct ELISA using 15mer peptides (overlapping by one residue) as solid phase a ntigens have shown that anti-peptide antibodies from CBA and C57BL/6 mice r ecognised the same B-cell epitope(s) located within the 398-414 region, whe reas BALB/c mice predominantly recognised epitopes located within the 400-4 17 region. When the 15mer peptides were used as fluid phase antigens in an inhibition ELISA, peptide 405-419 was shown to be the most effective inhibi tor in all three strains of mice. Analysis of serum samples by SPOTs ELISA has shown that the region 407-417 was predominantly recognised by BALB/c mi ce, whereas antibodies from C57BL/6 mice recognised the 408-420 region. No reactivity was observed with serum samples from CBA mice. Although the majority of the identified B-cell epitopes were shown to overl ap by the three methods, the identified boundaries of these epitopes differ ed, suggesting that the size and the mode of peptide presentation affects t heir antigenicity. (C) 1999 Elsevier Science Ltd. All rights reserved.