Generation Of Genetic Antibody Against Epitope PreS1 Of HBV: Construction Of Na?ve And Immune Human Single Chain Antibody Library

As known to all, therapy of Hepatitis B is something of difficulties. Until now only immune enhancers such as interferon and thymus peptide are clinically utilized. But their actions are not certain. Today, study of antibody medicine against HBV is newly in this field. Accompanied the development of phage display technology, the construction of antibody library is becoming matured. And the research of completely humanized antibody against HBV is focused on.Antibodies play a crucial role in protective immune, among which only that against epitope can satisfy prevention or therapy. PreS 1 is one of the important epitope of HBsAg, which has been pointed out to have relationship with infection of HBV. Humanized antibody against PreSl with high affinity is a new way for blocking or cleaning HBV.This study interested in the most advanced field: completely humanized genetic antibody. Based on diversity of antibody and aimed at clinical therapy, it studied genetic antibody against PreSl according to recent advance of protective immunity. This study was taken as a basic research for antibody therapy.Two scFv libraries were constructed paralleled via phage display technique. PBLs were from healthy donors and divided into two parts. One was in vitro immunized by PreSl peptide, the other was natural. Then the two were used to amplify antibody genes for the naive and immune library respectively.High affinity scFvs against PreSl were obtained from both two libraries after panning against PreSl peptide, so were the genes encoding them. Comparison of the two libraries showed, monoclonal ELISA and polyclonal ELISA of immune library were better than that of naive one. The size of immune library during every round of panning was 4-50 folds bigger than that of the naive one. It is reasonableto consider that genes of lymphocytes were rearranged to the antigen during in vitro immunization. Competed ELISA confirmed further that the higher affinity scFv was from immune lib. All of above testify it is the expeditious way to get higher affinity scFv from in vitro immunized antibody library.This study obtained the high affinity human scFv against PreS 1 for the first time. It is the foundation of therapy of Hepatitis B. The patent of the gene encoding this scFv is processing, number of which is 01127973.7.