Delivery of a MalE CD4(+)-T-cell epitope into the major histocompatibility complex class II antigen presentation pathway by Bordetella pertussis adenylate cyclase.

Recombinant adenylate cyclase toxoids are shown to deliver inserted foreign CD4(+)-T-cell epitopes into the major histocompatibility complex class II presentation pathway, inducing a specific CD4(+)-T-cell response in vivo and yielding in vitro stimulation of specific CD4(+) T cells at a 100-times-higher molar efficiency than the free peptide containing the epitope.