The Truncated HBc149 Interferes with Replication of Hepatitis B Virus J.C. Han 1,2 , X.B. Pan 1,2 , L. Wei 1,2 , K. Deng 1,2 1 Institute of Hepatology, 2 Peking University People's Hospital, China Hepatitis B virus (HBV) capsids play an important role in production of progeny virus and other elements of the virus life cycle. Misdirection of capsid assembly and formation of aberrant particles may be an effective approach to interfere with virus replication. HBV capsids can be assembled in vivo and vitro from the dimeric HBV core protein (HBcAg). The interaction of single and dimeric HBcAg with some truncated HBcAg is verified in vitro. The truncated HBcAg consists of the first 149 amino acids and lacks the C-terminal, 34-residue RNA-binding domain. Method: we transiently transfected hepG2.2.15 with pcDNA3.1HBc149 by Fugene6.after 48 and 96h, HBVDNA, HBeAg and HBsAg in culture supernatant were detected and cell subjected to Southern blot and Immunofluorescence analysis. Result: The level of HBsAg and HBeAg had gentle change, we found that HBVDNA decreased at 96h after transfection( 10 3 10 4 copies/ml P<0.01) ,but replication intermediates obviously decreased from 48h. Some positive signal of HBcAg located around the nuclear and conglomerated in cytoplasm compared to the control. Conclusion: The truncated HBc149 can inhibit replication of hepatitis B virus. Misdirection of capsid assembly and formation of aberrant particles could be an important cause.