Background. Layered double
hydroxide (LDH) has been demonstrated as a highly efficient
antigen platform to induce effective and durable immune response. However, whether LDH nanoparticles could act as an adjuvant for
pertussis vaccines is still unknown. Here we evaluated the potential of Mg/Al-LDH as a nano-adjuvant to improve immune response against
pertussis and compared it with commercial
aluminum hydroxide (AH) adjuvant.Method. The Mg/Al-LDH nanoparticles were synthesized by a hydrothermal reaction. The morphology, structure and size of Mg/Al-LDH were characterized by transmission electron microscope, x-ray diffraction and MALVERN particle analysis. The
ovalbumin and
Pertussis toxin (PTd) was adsorbed to Mg/Al-LDH. The immune response of
antigen-LDH complex was evaluated in mice, compared with commercial adjuvant
alum.
Hematoxylin-
eosin staining was used to evaluate the inflammatory response at injection site.Results. The synthetic Mg/Al-LDH nanoparticles showed a typical hexagonal lamellar structure. The average size of synthetic nanoparticles was 102.9 nm with PDI of 0.13 and zeta potential was 44.4 mV. Mg/Al-LDH nanoparticles effectively adsorbed
protein antigen and mediated
antigen uptake by DC cells. Animal experiments showed that Mg/Al-LDH gave enhancement in anti-
pertussis toxin (PTd) humoral immune response, which was considerable to commercial AH adjuvant. Finally, Mg/Al-LDH produced a slighter inflammatory response than AH at injection site and this injury was quickly recovered.Conclusion. Our study demonstrated the potential of Mg/Al-LDH as an effective adjuvant for
pertussis vaccine, which induced comparable antibody response and had a better safety compared with commercial AH adjuvant.