Antigen Optimiztion Of Human Immunodeficiency Virus-1 Envelope Glycoprotein Gp140 Trimer And Screening Of Neutralizing Monoclonal Antibodies

Acquired Immune Deficiency Syndrome(AIDS)is a Acquired Immune Deficiency Syndrome caused by Human Immunodeficiency Virus C(HIV)infection.As of June 2017,China still had 718,270 people infected with HIV,including 221,628 deaths.Althop.gh the Highly Active Antiretro Viral Therapy(HAART)can effectively inhibit the replication of virus in the host body to make the partients have a same life as normal people,the needing for AntiretroViral Therapy(ART)is lifelong,so it may be difficwLt to sustain economically.Therefore,the development of an HIV vaccine is crucial for the whole world.The envelope glycoprotein(Env)on the surface of HIV-1 virion can bind to the receptor,mediate the virus to fuse with the host cell membrane,and it is the only target for antibodies recognition,thus becoming an important target for the development of HIV vaccine.In addition,the reports about natural-like Env trimer design,such as SOSIP and NFL2P,make it possible to express the natural-like Env trimer in vitro.And the natural-like Env trimer co?Ld stim?Late a high serum neutralizing titer in Bab/c mice.These studies provide guidance and new hope for HIV vaccine research and development.In this study,the gp 140 trimer of BG505,JR-FL and NL4-3 were obtained by using the Expi293F suspension system,expanding the antigen library and laid a foundation for antibodies screening and antigen design.Moreover,the His-tag was introduced and extended appropriately to simplify the conditions for protein purification and improve the purificational efficiency and purity of the protein.At present,the protein yield remained around l0mg/L.Indirect ELISA confirmed the afifinity between the protein and the antibody,and the structure of the protein co?Ld be seen under electron microscope.Using trimer protein as immunogen for animal immunization can arouse high serum neutralization titer in animals,indicating that the antigen has good biological activity and immunogenicity.By using sequential immune and mixed immune with low doses to immune the mice,screening three antibodies that had cross-netralizing ability,comforming that low dose immxnization can induce broadly neutralizing antibodies,which provided certain guiding significance for HIV vaccine development and antibody screening.