Synergistic effect of immunization with a peptide cocktail inducing antibody, helper and cytotoxic T-cell responses on protection against respiratorysyncytial virus

Respiratory syncytial virus (RSV)-specific cytotoxic T lymphocytes (CTL) or neutralizing antibodies can protect against RSV infection when induced sep arately by immunization with synthetic peptides. In the work described here , RSV-specific neutralizing antibodies and CTLs were induced after immuniza tion with a cocktail of peptides consisting of a B-cell mimotope (S1S-MAP), a T-helper epitope (SH:45-60) and a CTL epitope linked to a fusion (F) pep tide (F/M2:81-95) that were comparable to those induced by the peptides alo ne. Following challenge, a 190-fold reduction in RSV titre was observed in the lungs of peptide cocktail-immunized mice. The combination of RSV-specif ic humoral and cellular immunity induced by the peptide cocktail was thus m ore effective at clearing RSV than peptide-induced humoral or cellular immu nity alone.