Expression of pres2/s antigen of Hepatitis B virus isolated from Pakistan in yeast cells

Recombinant vaccines are an indispensable component of disease management of hepatitis b infection. genetic evolution of hepatitis b virus (hbv) necessitates the production of new types of antigens for next generation vaccine. this study aimed the expression of hbv middle surface (pres2/s) protein in pichia pastoris for production of an antigen for improved hbv vaccine formulation. a pres2/s antigen-gene was cloned into a vector (ppiczaα) for secretory expression in p. pastoris. expression of recombinant p. pastoris was optimized under control of aox1 promoter to produce pres2/s recombinant protein,which was purified through column chromatography. specificity of the protein was confirmed through sds-page,western blot and elisa. for immunization study,recombinant pres2/s antigen and commercially available hbv vaccine comprising hbsag alone were injected to immunize four groups of rabbits. the results of analysis of immunization showed that recombinant pres2/s protein produced double antibody-titer than that of commercially available hbsag indicating that pres2/s antigen could be an ideal candidate for new generation hbv vaccines. this is the first report of secretory expression of biologically active pres2/s antigen in p. pastoris from pakistan and it will help to produce more effective vaccine to immunize 180 million people of pakistan against hbv.