Construction Of Brucella Antigens Nano-particle

Brucellosis is a zoonotic infectious disease caused by Brucella that is widespread throughout the world.This disease not only sposes a huge threat to human health,but also eriously affects the development of the livestock industry.Especially in developing countries,it is difficult to eliminate them completely.Vaccination is always the important protocol for brucellosis control.At present,most veterinary vaccines are live attenuated vaccines,such as S19,Rev.1,M5,S2,etc.However,they have many problems in effectiveness and safety,such as susceptible to infect human,interference with serological diagnosis,susceptibility to abortion of female animals,and virulence maintaining.And,there is still no effective and safe commercial human brucellosis vaccine.Therefore,the development of a safe and effective new vaccine is the main research content for the control of brucellosis.P39 and Rs?are two protective antigenic proteins of Brucella melitensis and can be used as candidate vaccines for brucellosis.In recent years,a large number of studies have shown that nano-size can enhance antigens immunogenicity.In addition,nano-particles can carry multiple antigens,providing antigen stability and targeting.In this study,P39 and Rs?proteins were purified,and Fe₃O₄magnetic material nanoparticles were modified by phenolic resin with hydrothermal method.The purified P39 and Rs?proteins were adsorbed with phenolic resin magnetic composite microspheres Fe₃O₄@CFR nanoparticles.It was used to immunize experimental mice to compare and evaluate the effect of nanomaterials on the production of antibodies to two proteins.The experimental results showed,that the immunization of P39 protein with the Freund's adjuvant and nanoparticles increased the P39 antibody level with time,but the Freund's adjuvant induced higher levels of antibodies than the nanoparticles as vector.The Rs?protein nanoparticles were increased higher Ig G,Ig G1 and Ig G2a level than Freund's adjuvant.Among them,Ig G and Ig G1 significantly increased,but the levels of Ig G2b and Ig M did not change significantly.All these showed that the effects nanoparticles on the production of antibodies of different antigens were different,and it can not increase the antibody level of P39 protein,but induce much more antibody to Rs?protein.This study shows that nanoparticles can increase the production of antigen-induced antibodies,but there may be different in different antigens.It can promote the level of Ig G2a induction,and which might elicit Th1 immunity.All these showed that nano-particle vaccine can be used for the development of new vaccines against brucellosis in the future.