Synergistic Effect of M Cell Targeting Peptide and Mucoadhesive Vehicle on Induction of Immune Responses in Oral Vaccine Delivery

Orally ingested pathogens or antigens are taken up by microfold cells (M cells) in the follicle-associated epithelium of Peyer's patches in intestine to initiate protective immunity against infections. Here, we developed a new model of M cell–specific recombinant vaccine which when delivered through oral route using mucoadhesive vehicle induced both mucosal and systemic immunity. Initially, M cell-targeting peptide, selected by phage display technique, was fused to a model lipoprotein antigen (BmpB) by recombinant DNA technology. The recombinant protein (M-BmpB) was loaded into a mucoadhesive vehicle made from thiolated Eudragit (TE) polymer. TE also has ability to protect protein from harsh gastric condition and enzymes in gastrointestinal tract. As a consequence, oral delivery of M-BmpB vaccine through TE vehicle in mouse succeeded to generate both mucosal and systemic immune response against the antigen.