Preparation And Immunological Effects Of N - 2 - HACC / CMC Nano - Live Live Vaccine Against Newcastle Disease And Infectious Bronchitis

Newcastle disease (ND) and avian infectious bronchitis (IB) are highly contagious viral disease of poultry caused by pathogenic strains of the Newcastle disease virus (NDV) and and infectious bronchitis virus (IBV). Live NDV and IBV bivalent vaccines are administered by drinking water, eyedrops or coarse aerosol spray.ND and IB spread through respiration and feed, and the NDV and IBV have tropism for the respiratory and gastrointestinal mucosa. So, the way of immunization by oral or intranasal immunization can not only simulate two virus natural route of infection, but also can improve the body’s overall level of mucosal immunity, which can effectively prevent the adsorption of NDV and IBV and intrusive, to achieve better prevention ND and IB purposes.To further enhance mucosal immune responses, N-2-hydroxypropyl trimethyl ammonium chloride chitosan/carboxymethyl chitosan nanoparticles (N-2-HACC/CMC-NPs) were developed for the mucosal delivery of a live NDV and IBV bivalent vaccine. In this article, lentogenic live-virus vaccine (strain LaSota+H120) against NDV and IBV encapsulated in N-2-HACC/CMC-NPs were developed using polyelectrolyte complex method. N-2-HACC/CMC-NPs containing the lentogenic livevirus vaccine against NDV and IBV were produced with good morphology, high stability, a mean diameter of 251.8nm and 122.4nm, a zeta potential of 46.6mVand 53.2mV, an entrapment efficiency of (96.10±1.13)% and (95.56±0:28)%, and a loading capacity of (53.21±0.97)% and(52.13±1.52). The virus release assay results of NDV-N-2-HACC/CMC-NPs and IBV-N-2-HACC/CMC-NPs. indicated that NDV and IBV were slowly released from NDV-N-2-HACC/CMC-NPs and IBV-N-2-HACC/CMC-NPs. Storage stability tests showed that no significant changes in the appearance of nanoparticles storage at 20℃,4℃,-20℃ for 3 weeks, and have good stability.NDV-IBV-N-2-HACC/CMC-NPs and NDV/IBV-N-2-HACC/CMC-NPs were prepared on the basis of these researches. The results of cytotoxicity and safety showed that the two nano-vaccines have very low toxicity and higher security of mucosal delivery. The storage stability tests show that the prepared two kinds of nano-vaccine also have good stability at room temperature, refrigerated, and under low temperature conditions. Live virus detected in two nano-vaccine virus indicated that the NDV and IBV volume in accordance with the People’s Republic of China Veterinary Biological Products requirements. SPF chickens immunized intranasally experimental results showed that the two nano-vaccines induced more long-lasting IgG antibodies, and slgA antibody levels and IFN-γ, IL-2 and IL-4 secretion than the commercially bivalent vaccine, and immune chicken spleen lymphocyte transformation rate have increased significantly. These results indicated that the Newcastle disease and infectious bronchitis N-2-HACC/CMC nanoparticles bivalent vaccine can induce efficient immune effect.This preparation of NDV/IBV-N-2-HACC/CMC-NPs and NDV-IBV-N-2-HACC/CMC-NPs which have characteristic of stability, sustained-release, protective effect, long-term protection and higher immune effects, have important theoretical and practical value.