Versatile Functionalization of Ferritin Nanoparticles by Intein-Mediated Trans-Splicing for Antigen/Adjuvant Co-delivery

Abstract

Self-assembling protein nanoparticles are extensively and increasingly engineered to integrate adjuvants with antigens to elicit potent and long-term immunity due to uniform architecture, inherent biocompatibility, and excellent plasticity. However, functionalization of nanoparticles by surface tailoring has two common problems: (1) disassembly caused by loaded cargoes; and (2) an adjuvant that is inconvenient to co-deliver with an antigen by genetic fusion. Here, we report an intein-mediated trans-splicing approach that overcomes the detrimental effects of loaded proteins on ferritin nanoparticle stability and allows concurrent display of antigen and adjuvant in a facile, efficient, and site-specific manner. An immunization study with an epitope-based model antigen reveals that antigen and adjuvant co-delivery nanoparticles induce a more potent protective immunity than other formulations do. Our results demonstrate that protein engineering represents an intriguing approach for antigen/adjuvant co-delivery to potentiate antigen-associated immune responses.

Designing spatial and temporal control of vaccine responses

“…Moreover, improved trafficking by activated dendritic cells increases activation of T H 1-type CD4 + and CD8 + T cell responses and leads to higher antibody titres and improved antibody affinity maturation compared with immunization with soluble TLR7/8a ligands. Similarly, presenting CpG on the surface of peptide-based ferritin particles increases the valency of this adjuvant and improves the potency of adjuvant responses 118 .…”

“…Co-delivery of antigen and PAMP molecules, such as TLR agonists (for example, by encapsulation or surface presentation), improves recognition by PRRs and promotes APC maturation and antigen processing 15 , 97 , 128 . Precise co-delivery of adjuvant and antigen can be achieved using nanoparticles based on self-assembled virus-like particles, such as ferritin 118 , 129 and hepatitis B core antigen (HBcAg) proteins 130 , 131 , or synthetic nanoparticles, such as liposomes 125 or degradable PLGA nanoparticles 109 , 128 . A diverse array of antigens has been co-delivered by nanoparticles, including ovalbumin 128 , HIV BG505 SOSIP (ref.…”

Nanobody‐Ferritin Conjugate for Targeted Photodynamic Therapy

“…Instead of chemical conjugation, enzyme‐mediated ligation is highly desired for protein modification, which can avoid protein aggregation caused by chemical modification. Recently, SpyTag/SpyCatcher‐enabled click techniques were used to construct vaccine‐modified ferritin for tumor immunotherapy, and intein‐mediated protein trans‐splicing was applied to fabricate antigen/adjuvant co‐displayed on the surface of ferritin . However, Nbs cannot tolerate the harsh pH conditions required for drug loading in ferritin.…”

“…Recently,S pyTag/SpyCatcherenabledc lick techniques were used to construct vaccine-modified ferritin for tumor immunotherapy, [34] and intein-mediated protein trans-splicingw as appliedt of abricate antigen/adjuvant co-displayedo nt he surfaceo ff erritin. [35] However,N bs cannott olerate the harsh pH conditions required for drug loading in ferritin. Therefore, ap ost protein conjugation strategy was conducted by ligation of Nb to the drug-loaded Ftn.…”

Nanocage‐Based Capture‐Detection System for the Clinical Diagnosis of Autoimmune Disease

“…Nanocage-based systems have been utilized as platforms for a wide range of applications, including nanovaccines, nanoadjuvants, antigen, and immunostimulatory delivery nanoparticles. [10] Current protein nanocages used for peptides displaying include ferritin (12 nm), DNA-binding proteins from starved cells (Dps, 8 nm), virus-like particle (VLP, 28 nm), and encapsulin (24-32 nm) etc. [11] Ferritin is an iron storage protein that exists in organisms.…”