Development of PDA Nanoparticles for H9N2 Avian Influenza BPP-V/BP-IV Epitope Peptide Vaccines: Immunogenicity and Delivery Efficiency Improvement

Abstract

The protection of current influenza vaccines is limited due to the viral antigenic shifts and antigenic drifts. The universal influenza vaccine is a new hotspot in vaccine research that aims to overcome these problems. Polydopamine (PDA), a versatile biomaterial, has the advantages of an excellent biocompatibility, controllable particle size, and distinctive drug loading approach in drug delivery systems. To enhance the immunogenicities and delivery efficiencies of H9N2 avian influenza virus (AIV) epitope peptide vaccines, PDA nanoparticles conjugated with the BPP-V and BP-IV epitope peptides were used to prepare the nano BPP-V and BP-IV epitope peptide vaccines, respectively. The characteristics of the newly developed epitope peptide vaccines were then evaluated, revealing particle sizes ranging from approximately 240 to 290 nm (PDI<0.3), indicating that the synthesized nanoparticles were stable. Simultaneously, the immunoprotective effects of nano BPP-V and BP-IV epitope peptide vaccines were assessed. The nano BPP-V and BP-IV epitope vaccines, especially nano BP-IV epitope vaccine, quickly induced anti-hemagglutinin (HA) antibody production and a sustained immune response, significantly promoted humoral and cellular immune responses, reduced viral lung damage and provided effective protection against AIV viral infection. Together, these results reveal that PDA, as a delivery carrier, can improve the immunogenicities and delivery efficiencies of H9N2 AIV nano epitope vaccines, thereby providing a theoretical basis for the design and development of PDA as a carrier of new universal influenza vaccines.

An Intracellular Epitope of ASFV CD2v Protein Elicits Humoral and Cellular Immune Responses

“…A polytope DNA vaccine (pVAX1-rTEM) consisting of B cell and T cell epitopes from the Tembusu virus (TMUV) envelope € protein elicited both humoral and cellular immune responses in ducks against a TMUV challenge [ 43 ]. Polydopamine (PDA) nanoparticles conjugated with the BPP-V and BP-IV epitope peptides provided effective protection against avian influenza virus (AIV) viral infection [ 28 ]. ASFV T cell epitope peptides were identified by the ELISpot assay, providing the basis for the development of epitope vaccines [ 44 , 45 ].…”

“…Surprisingly, this epitope also induced high expression of IL-4 and IFN-γ ( Figure 7 C). IgG1 and IL-4 are related to humoral immune responses, whereas IgG2a and IFN-γ are associated with cellular immune responses [ 28 , 29 ]. Our results indicate that this epitope can efficiently elicit both humoral and cellular responses.…”

“…To perform the IgG, IgG1, and IgG2a antibody assay by ELISA, the serum was collected 7, 14, 28, and 35 days after immunization [ 28 , 29 ]. Briefly, 100 μL of the purified CD2v-IR domain was coated in 96-well plates (2 μg/mL) for 3 h at 37 °C.…”

“…To perform the IgG, IgG1, and IgG2a antibody assay by ELISA, the serum was collected 7, 14, 28, and 35 days after immunization [28,29]. Briefly, 100 µL of the purified CD2v-IR domain was coated in 96-well plates (2 µg/mL) for 3 h at 37 • C. After blocking, coated plates were incubated with mouse serum in a sequential dilution of 1:200, 1:400, 1:800, 1:1600, 1:3200, 1:6400, 1:12,800, 1:25,600, 1:51,200, 1:102,400, and 1:204,800 for 1.5 h at 37 • C. Then, 100 µL of a 1:100,000 dilution of HRP-conjugated goat anti-mouse IgG and a 1:5000 dilution of IgG1 and IgG2a (Proteintech, Wuhan, China) were incubated for 60 min at 37 • C. After extensive washing, tetramethyl benzidine (TMB, Solarbio, Beijing, China) substrate was added for 15 min at 37 • C, and the reaction was stopped with 2 M H 2 SO 4 .…”

Functionalization of and through Melanin: Strategies and Bio-Applications

“…Because melanin NPs have been shown to be highly advantageous nanocarriers, they have also been successfully employed for the delivery of peptides for therapy, diagnosis [152,153], and vaccination [154]. Indeed, knowing that peptides are short chains of amino acids, connected through amide bonds, that have different side groups depending on the sequence, they can modify the surface of synthesized MNPs through binding via the side amino group improving the active targeting ability of the NPs [155].…”