Application potential of bacterial flagellin in treatment of autoimmune rheumatic diseases with Treg epitope peptides

Abstract

Immunization with regulatory T cell (Treg) epitope peptides to activate and induce Tregs, by which to suppress pathological autoimmune responses and reconstitute a new homeostasis, is a promising therapeutic regimen for autoimmune rheumatic diseases. However, it is usually hard to induce potent peptide-specific immune responses in vivo with small molecular peptides. Bacterial flagellin is one of the agonists triggering innate immune responses. When used as carrier, it shows strong adjuvant activity to its conjugated antigens. In some particular situations, bacterial flagellin can also activate and induce Tregs. Thus if Treg epitope peptides are covalently conjugated to a bacterial flagellin, the conjugates should be able to effectively enhance the Treg-based immune responses via flagellin itself and the adjuvanticity of flagellin to Treg epitope peptides, and thereby enhance the immunotherapeutic effects on autoimmune rheumatic diseases. Key words: Bacterial flagellin; Treg epitope; Autoimmune rheumatic disease; Conjugate; Vaccine efficacy