Study On Immunization And Neutralization Of Epitope Membrane-Proximal External Region Epitope Of Human Immunodeficiency Virus Type 1 Glycoprotein Gp41

The HIV has resulted in 40 million death since it has been found in 1981 and there are 36.7 billion people living with it.HIV is a retrovirus that can attack the human immune system and can lurk in the patient for decades without disease,and can escape the immune system's attacks in a variety of ways.There is no effective vaccine to control the infection and spread of HIV,therefore,for the HIV vaccine research and exploration of great significance.In this study,the MPER epitope was choosed to study for has obviously attractive features:highly conserved,tryptophan-rich and linear epitope recognized by bNAbs including 2F5,4E10,and 10E8.We fused the 2F5(ELLELDKWA)and 4E10(LWNWFDITNWL)epitope in the CRM197-Ato enhance the epitope immunogenicity.The purified fusion proteins were used to immune Babl/C mice,and all the immune sera were evaluated by enzyme-linked immunosorbent assay(ELISA),virus neutralization test and flow cytometry.Mice with good immune effect were prepared hybridoma cells and the MPER epitope specific monoclonal antibody were screened.The anbodies were characterized by ELISA,alanine mutation scanning,virus neutralization test and homologous modeling.This study also explored the effect of DNA priming and protein-boosting immunization strategies on MPER epitope-specific antibody induction.Immunization was assessed by ELISA,virus neutralization and immunization regimens.The study had shown thad the fusion proteins had good immunogenicity,and it could stimulate mice Thl and Th2 immune response.The immunization produced specific antibodies against the MPER epitope and the immune sera could neutralized different HIV-1 virus.10 MPER specific monoclonal antibodies were screened after spleen hybridoma.These antibodies had good binding ability to MPER epitope on gp41,and 18C8-2 and 21A1-1 had cros-neutralization ability.Alanine scans showed that the two antibodies recognized the same amino acid as 4E10.The results of homologous modeling showed that the binding of 18C8-2 to MPER antigen was mainly through the heavy chain of the antibody.After DNA prime and 2F5 epitope fused VLP protein enhanced immunizing,partial groups induced a higher titer against gp41,but no neutralizing ability were observed in all groups.All these indicated that the anchored MPER epitope scheme need be improved.This study,while,for the first time,has showed that antibodies that recognize the similar epitope as 4E10 coult be induced in mice,which provide strong support for vaccine research and exploration.In addition,this study also proved that CRM197-A as a carrier protein has good immunogenicity,and can stimulate the mouse T cell immune response.So it can be applied to other vaccine development and research.