Prokaryotic Expression of a Novel Therapeutic recombinant transbody H2L2 Targeting Hepatitis B Virus core protein

Background and Purpose Chronic Hepatitis B virus (CHB) infection is a global burden for public health. Treatment methods such as interferon and nucleoside analogues may effectively control viral infection but cannot eliminate the virus due to their inability to remove viral covalently closed circular DNA (cccDNA) inside host nuclear. The persistence of cccDNA in the infected hepatocytes is a crucial obstacle to antiviral therapies. For years, efforts had been undertaken to understand the formation and regulation of HBV cccDNA. Natural core antibodies were modified to target intracellular core proteins across the membrane to achieve antiviral effect in several studies. However, modified natural antibody had limits: 1) it was unstable inside cells; 2) it had strong immunogenicity; 3) lack of targeting. Experimental approach and Key Results Therefore, we altered natural antibody into a micro-transbody which has correct intracellular folding, stronger affinity, and weaker immunogenicity to establish a new recombinant transbody for the specific and efficient immune clearance of viruses in hepatocytes. Immunofluorescence and immunohistochemistry were used to verify the transmembrane and antigen-binding ability of our recombinant transbody. Conclusions & Implications Taken together, we demonstrate a recombinant transbody H2L2 with transmembrane and antigen-binding activity expressed by E.coli in this study, which may be an encouraging exploration of therapeutic strategies against hepatitis B infection inside hepatocellular.