Recombinant antibodies against Iranian cobra venom as a new emerging therapy by phage display technology

The production of antivenom from immunized animals is an established treatment for snakebites; however, antibody phage display technology may have the capacity to delivery results more quickly and with a better match to local need. Naja oxiana, the Iranian cobra, is a medically important species, responsible for a significant number of deaths annually. This study was designed as proof of principle to determine whether recombinant antibodies with the capacity to neutralize cobra venom could be isolated by phage display. Methods: Toxic fractions from cobra venom were prepared by chromatography and used as targets in phage display to isolate recombinant antibodies from a human scFv library. Candidate antibodies were expressed in E. coli HB2151 and purified by IMAC chromatography. The selected clones were analyzed in in vivo and in vitro experiments. Results: Venom toxicity was contained in two fractions. Around a hundred phage clones were isolated against each fraction, those showing the best promise were G12F3 and G1F4. While all chosen clones showed low but detectable neutralizing effect against Naja oxiana venom, clone G12F3 could inhibit PLA2 activity. Conclusion: Therefore, phage display is believed to have a good potential as an approach to the development of snake antivenom.(AU)

Production of Human Fab Monoclonal Antibody to Surface Protein, preS1, of Hepatitis B Virus using Antibody Phage Display Library / 대한면역학회지

Human monoclonal antibodies have considerable potential in the prophylaxis and treatment of viral disease. By cloning human Ig gene segments from the B cells of volunteer into pComb3 phagemid vector, antibody library was created of filamentous phage particles displaying Fab fragments on their surface after being rescued with M13KO7 helper phages. The size of library was 7x10' pfu. Phage antibodies (phabs) were panned against biotinylated preS1 using streptavidine coated Dynabead. The soluble Fab antibodies were prepared from phagemid colonies and assayed directly for the ability to bind preS1 by ELISA. And then 3DW and SGW specific to preS1 which have both heavy and light chain to form Fab fragment, were selected. The soluble Fab antibody from 3DW was expressed highly at the concentration of 0.1 - 1.0 mM of IPTG, and 5 hours postinduction. The soluble antibodies from 3DW and SGW showed their relative affinities of 2x10' M ', and Sx10 M ', respectively, and the specificities to preS1 on ELISA. Our results suggest that antibody phage display library is very useful method to generate the human monoclonal antibody and that the human Fab monoclonal antibodies specific to preS1 selected in this study open the way to treat hepatitis B as a component of passive irnmunotherapeutics.